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Model 340 - Lake Shore Cryotronics, Inc.

1. sssssssssssssesseseeeeee eene 10 5 Model 340 Mounting Holes and Analog Option Plug eeee 10 6 Mounting Holes amp Analog Plug sese eene 10 6 Model 340 Rear Panel with Model 3462 Option Card Installed 10 7 Model 340 Rear Panel with Model 3464 Option Card Installed 10 8 Sensor Input Connechor ooooocccccccccoconoccnnccccnncnnnnnonnncnnnnnnnnnnne nn ncnn cnn nen nnnn men n ens n netter EEEn 10 15 Line Input Assembly 5 td ida Be Rn ER 11 2 Fuse Data Legends Agedro A Ee EE MEE 11 3 Serial I O RJ 11 Rear Panel Connector Details 11 4 Digital I O DA 15 Rear Panel Connector Details 11 5 Relays LO 8 HI Rear Panel Connector Details 11 5 Analog OUT 1 amp 2 BNC Rear Panel Connector Details 11 6 Sensor Input A amp B Rear Panel Connector Details 11 6 Heater Output Rear Panel Connector Details sse 11 6 IEEE 488 Rear Panel Connector Details ssessse e 11 7 Model 2001 RJ 11 Cable Assembly Wiring Details 11 8 Model 2002 RJ 11 to DB 25 Adapter Wiring Details 11 8 Optional Model 2003 RJ 11 to DE 9 Adapter Wiring Details 11 8 Location Of Internal Components nennen nennen 11 10 Table No Table 1 1 Table 1 2 Table 1 3 Table 1 4 Table 1 5 Table 1 6 Table 3 1 Table 3 2 Table 3 3 Table 5 1 Table 5 2 Table 5 3 Table 6 1 Table 6 2 Tabl
2. 4 5 CHANGING DISPLAY FORMAT The Model 340 lets the user decide which information is shown on the display This section discusses the display fields that can be configured using the Display Format key 4 5 1 Number of Readings Displayed The Model 340 can display between one and eight input readings at a time If one to four readings are chosen they will be shown with the large characters If five to eight readings are chosen they will be shown with small characters To change the number of display readings press the Display Format key You will see the Reading Display Format screen with the current number of Input Displays highlighted Use a number key or the A or V key to select the desired number of reading displays then press the Enter key The lower portion of the setting display will now show the available display fields ready for the operator to enter a sensor input and reading source The default setting is 2 4 5 2 Sensor Input The Model 340 has two sensor inputs A and B More sensor input can be added with Model 340 options Input A can be used to monitor more than one sensor with the use of an external scanner Scanner support is covered in Paragraph 5 4 To select a sensor input for a display field press the Display Format key You will see the Display Format screen with the current number of Input Displays highlighted Use the Enter or Next Setting key to select the display number then use the A or W key to select the d
3. Lake Shore Model 340 Temperature Controller User s Manual Table 1 2 Typical Sensor Performance 340 3462 Example Temp Nominal Typical Measurement Electronic Temperature Electronic Lake Shore Resistance Sensor Resolution Accuracy Accuracy including Control Stability Sensor Voltage Sensitivity Temperature Temperature Electronic Accuracy Temperature Equivalents Equivalents CalCurve and Equivalents Calibrated Sensor Silicon Diode DT 670 1 4K 1 664 V 12 49 mV K 0 8 mK 13 mK 25 mK 1 6 mK CO 13 with 77K 1 028 V 1 73mV K 5 8 mK 76 mK 98 mK 11 6 mK ae 300 K 0 5597 V 2 3 mV K 4 4 mK 47 mK 79 mK 8 8 mK calibration 500 K 0 0907 V 2 12 mV K 4 8 mK 40 mK 90 mK 9 6 mK Silicon Diode DT 470 SD 1 4K 1 6981 V 13 1 mV K 0 8 mK 13 mK 25 mK 1 6 mK 13 with 77K 1 0203 V 1 92 mV K 5 2 mK 69 mK 91 mK 10 4 mK 1 4H 300 K 0 5189 V 2 4 mV K 4 2 mK 45 mK 77 mK 8 4 mK calibration 475 K 0 0906 V 2 22 mV K 4 5 mK 38 mK 88 mK 9 mK GaAlAs Diode TG 120 SD 1 4K 5 391 V 97 5 mV K 0 1 mK 7 mK 19 mK 0 2 mK with 1 4H 77K 1 422 V 1 24 mV K 8 1 mK 180 mK 202 mK 16 2 mK calibration 300 K 0 8978 V 2 85 mV K 3 6 mK 60 mK 92 mK 7 2 mK 475 K 0 3778 V 3 15 mV K 3 2 mK 38 mK 88 mK 16 4 mK 1000 PT 103 with 30K 3 660 Q 0 191 Q K 5 3 mK 13 mK 23
4. 9 1 4 IEEE Interface Example Programs Two BASIC programs are included to illustrate the IEEE 488 communication functions of the instrument The first program was written in Visual Basic Refer to Paragraph 9 1 4 1 for instructions on how to setup the program The Visual Basic code is provided in Table 9 2 The second program is written in Quick Basic Refer to Paragraph 9 1 4 3 for instructions on how to setup the program The Quick Basic code is provided in Table 9 3 Finally a description of operation common to both programs is provided in Paragraph 9 1 4 5 While the hardware and software required to produce and implement these programs not included with the instrument the concepts illustrated apply to almost any application where these tools are available 9 1 4 1 IEEE 488 Interface Board Installation for Visual Basic Program This procedure works for Plug and Play GPIB Hardware and Software for Windows 98 95 This example uses the AT GPIB TNT GPIB card 1 Install the GPIB Plug and Play Software and Hardware using National Instruments instructions 2 Verify that the following files have been installed to the Windows System folder a gpib 32 dll b gpib dll c gpib32ft dll Files b and c support any 16 bit Windows GPIB applications being used 3 Locate the following files and make note of their location These files will be used during the development process of a Visual Basic program a Niglobal bas b Vbib 32 bas NOTE If the
5. lt minutes gt lt seconds gt lt rate gt 8 Ramp SP Abs lt SP value gt lt hours gt lt minutes gt lt seconds gt lt rate gt 9 Ramp SP Rel lt deviation value lt hours gt lt minutes gt lt seconds gt lt rate gt 10 Parameters lt control channel gt lt control mode gt lt P value gt lt I value gt lt D value gt lt heater range gt 11 Digital Output lt bit weighting gt 12 Relays lt high enable gt lt low enable gt 13 Settle lt hours gt lt minutes gt lt seconds gt lt band gt PGM 1 5 2 term Appends a Call command that calls program 2 to the end of program 1 Query A Program Line PGM lt program gt lt line gt Variable Format variable Returns the command and parameters for the specified program and line number See the PGM command and Paragraph 8 3 Querying past the end of a program returns an End command Erase A Program PGMDEL lt program gt Nothing Erases a program lt program gt specifies the program to erase Valid entries 1 10 PGMDEL 2 term Erases program 2 Query Number of Program Lines Remaining PGMMEM lt lines gt Format nnn term Returns the number of programs lines remaining in program memory Run a Program PGMRUN lt program gt Nothing Runs or terminates a program lt program gt Specifies the program to run Valid entries 0 terminate current progra
6. Numeric plus special function Front panel curve entry display brightness control and keypad lock out SH1 AH1 T5 L4 SR1 RL1 PPO DC1 DTO CO El To 20 readings per s National Instruments LabVIEW driver RS 232C 19 200 baud RJ 11 To 20 readings per s Two high and low for each installed input Temperature Sensor Units and Linear Equation Source High and Low Setpoint Latching or Non Latching and Audible On Off Display annunciator beeper and relays 2 Normally open NO normally closed NC and common 30 VDC at 2A Activate relays on high or low alarms for any input or manual off on Detachable terminal block when not used as control loop 2 output 2 1 9 Scale Update rate Data source Settings Range Resolution Accuracy Max output power Min load resistance Source impedance Digital I O Data card 1 7 5 General Ambient temp range Power requirements Size Weight Approval Lake Shore Model 340 Temperature Controller User s Manual User selected 20 readings per s Temperature Sensor Units and Linear Equation Input Source Top of Scale Bottom of Scale or Manual 10 V 1 25 mV 2 5 mV 1W 100 O short circuit protected 0 01 0 5 inputs and 5 outputs TTL voltage level compatible PC card Type II slot used for curve transfer setup storage and data logging 20 C to 30 C 68 F to 86 F for specified accuracy 15 C to 35 C 59 F to 95 F for reduced accuracy
7. Reads the programs from the data card and Programs reset the Model 340 The programs may then be accessed by pressing the Program key Reads the user curves from the data card and User Curves saves the curves to memory Press Curve Entry to access the curves Reads the selected CalCurve from the data CalCurves card Select the CalCurve from the data card and the curve location in the Model 340 E Reads the Model 340 Main Code from the M340 Main Code data card and resets the Model 340 Used to receive factory software updates 8 4 3 Writing To A Data Card To write to a data card place the card into the slot then press the DataCard Key The Identifying Card message is displayed followed by the DATACARD screen Press the Next Setting key until Write DataCard is highlighted Press the Enter key Use the Next Setting or Previous Setting key to select which type of information is to be written to the data card d P Writes the configuration programs and curves Configuration to dala dara Writes the selected CalCurve to the data card CalCurves Write as many individual curves to the data card as there is room in card memory P A data card required to copy the Model 340 8 4 4 Erasing A Data Card To erase a data card place the card into the slot then press the DataCard Key The Identifying Card message is displayed followed by the DATACARD screen Press the Next Setting key until Erase DataCard is highlighted Pr
8. SETP SETP 9 22 SETTLE SETTLE TUNEST ZONE ZONE Process Last Query Received Clear Interface Set Std Event Status Enable Query Std Event Status Enable Query Std Event Status Register Query Identification Set Operation Complete Query Operation Complete Reset Instrument Set Service Request Enable Query Service Request Enable Query Status Byte Query Self Test Wait To Continue ALMRST ANALOG AOUT BEEP BEEP BEEPST BUSY COMM Set Alarm COMM Query Alarm Query Alarm Status Query Celsius Reading Set Filter Query Filter Set Input Curve Query Input Curve Set Input Mode Query Input Mode Set Input Type Query Input Type Query Kelvin Reading Query Linear Data Query Linear Data Status Set Linear Equation Query Linear Equation Query Max Min Data Query Max Min Data Status Set Max Min Query Max Min Query Reading Status Query Sensor Units Reading DFLT DIOST DISPFLD DISPLAY DOUT DOUT IEEE IEEE KEYST LOCK LOCK MODE MODE RELAY RELAY REV XSCAN Set Control Portion of Display XSCAN Query Control Portion of Display Set Control Portion of Display Query Control Portion of Display Set Max Current Loop 1 Query Control Max Current Loop 1 Set Control Limits Query Control Limits Set Control Mode Query Control Mode Set Control Loop Query Control Loop Query Heater Output Query Heater Status Set Manual Output Query Manual Output CRVDEL CRVHDR CRVPT CRV
9. Some systems require that a control output remains off if power is lost The power up enable feature enables the user to choose whether or not they want the control output to be disabled each time the instrument power is turned off then on Setting the power up parameter to off disables the control output on power up Setting the power up parameter to on enables the control output on power up To change the power up setting press the Control Setup key The CONTROL SETUP screen is displayed The control loop indicator is highlighted in the upper left hand corner Use the A or W key to select Loop 1 or 2 Press the Enter or Next Setting key The control setup parameters for that loop appear on the screen Press the Next Setting key until the Power Up field is highlighted Use the A or V key to select on or off Press the Enter or Next Setting key to continue with more settings or press the Save Screen key to store the changes in the Model 340 The default setting is Off 6 3 CONTROL LOOP FILTER The control loop filter quiets feedback sensor noise that causes instability in the control loop The control filter works best on electrical noise from the environment or noise in temperature measurement The control filter can worsen control stability when unwanted disturbances exist in the load temperature because filtering reduces the control loop bandwidth The control loop filter uses the same filter window and number of filter points as the input chosen
10. There are situations where AutoTune is not the answer The algorithm can be fooled when cooling systems are either very fast very slow have a large thermal lag or have a nonlinear relationship between heater power and load temperature If a load can reach a new setpoint in just under 10 seconds with an appropriate setting of gt 500 the cooling system is too fast for AutoTuning Systems with a very small thermal mass can be this fast Adding mass is a solution but it is unappealing to users who need the speed for fast cycle times Manual tuning is nat difficult on these systems since new settings can be tested very quickly Some systems are too slow for the AutoTune algorithm Any system that takes more than 15 minutes to stabilize with an appropriate setting of lt 5 is too slow Thermal lag can be improved by using the sensor and heater installation techniques discussed in this chapter Lag times of a few seconds should be expected much larger lags can be a problem System non linearity is a problem for both AutoTune and manual tuning It is most commonly noticed when controlling near the maximum or minimum temperature of a temperature control system It is not uncommon however for a user to buy a cryogenic cooling system specifically to operate near its minimum temperature If this is the case try to tune the system at 5 degrees above the minimum temperature and gradually reduce the setpoint manually adjusting the control settings with
11. User s Manual Model 340 Temperature Controller 340 Temperature Controller LakeShore Lake Shore Cryotronics Inc 575 McCorkle Blvd Westerville Ohio 43082 8888 USA Internet Addresses sales lakeshore com service lakeshore com Visit Our Website www lakeshore com Fax 614 891 1392 Telephone 614 891 2243 Methods and apparatus disclosed and described herein have been developed solely on company funds of Lake Shore Cryotronics Inc No government or other contractual support or relationship whatsoever has existed which in any way affects or mitigates proprietary rights of Lake Shore Cryotronics Inc in these developments Methods and apparatus disclosed herein may be subject to U S Patents existing or applied for Lake Shore Cryotronics Inc reserves the right to add improve modify or withdraw functions design modifications or products at any time without notice Lake Shore shall not be liable for errors contained herein or for incidental or consequential damages in connection with furnishing performance or use of this material Rev 3 3 P N 119 011 14 May 2009 Lake Shore Model 340 Temperature Controller User s Manual LIMITED WARRANTY STATEMENT WARRANTY PERIOD ONE 1 YEAR 1 Lake Shore warrants that this Lake Shore product the Product will be free from defects in materials and workmanship for the Warranty Period spec
12. 0 Rate Ramp rate in kelvin per minute K m from 0 to 100 Rate 0 0K m with 0 1 resolution NOTE Ramp time or ramp rate can be set but not both If ramp time and rate are both zero then the ramp is a step change 8 3 1 2 Ramp Setpoint Relative Ramp the control setpoint a specified difference relative from its present setting value The setpoint units must be in temperature for this instruction to operate The ramp can be done at a specified ramp rate or in a specified length of time This instruction is used with a closed loop temperature control mode If the instrument is configured for in Zone control mode the control parameters including heater range are updated as the setpoint temperature changes through new zones Setpoint ramps in an internal program override the stand alone setpoint ramp parameter Dev Deviation in Loop 1 control setpoint temperature units Ramp SP Rel gt Dev 0 000K bipolar Hours 0 Hours Hours to make setpoint deviation 0 to 23 Minutes 0 Minutes Minutes to make setpoint deviation 0 to 59 Seconds 0 Seconds Seconds to make setpoint deviation 0 to 59 Rate 0 0K m Rate Ramp rate in kelvin per minute K m from 0 to 100 with 0 1 resolution NOTE Ramp time ramp rate and deviation are related The instrument calculates a ramp rate based on deviation and ramp time If ramp time and rate are both zero then the ramp is a step change 8 3 1 3 Ramp Manual Output MOut Absolute Ra
13. 4 Bit Name Ramp SRQ ESB Error Alarm Ses M NEM Done OPT A amp B If the Service Request is enabled any of these bits being set causes the Model 340 to pull the SRQ management low to signal the BUS CONTROLLER These bits are reset to zero upon a serial poll of the Status Byte Register These reports can be inhibited by turning their corresponding bits in the Service Request Enable Register to off The Service Request Enable Register allows the user to inhibit or enable any of the status reports in the Status Byte Register The SRE command is used to set the bits If a bit in the Service Request Enable Register is set 1 then that function is enabled Also refer to the SRE command Ramp Done Bit 7 This bit is set when the ramp is completed Service Request SRQ Bit 6 Determines whether the Model 340 is to report via the SRQ line and four bits determine which status reports to make If bits O 1 2 4 or 5 are set then the corresponding bit in the Status Byte Register is set The Model 340 produces a service request only if bit 6 of the Service Request Enable Register is set If disabled the Status Byte Register can still be read by the BUS CONTROLLER by means of a serial poll SPE to examine the status reports but the BUS CONTROLLER will not be interrupted by the Service Request The STB common command reads the Status Byte Register but will not clear the bits It must be understood that certain bits in the Status Byte Re
14. CONTROL DISPLAY FORMAT screen Press the Next Setting key until the Heat Display line is highlighted then use the A or V key to select Current or Power Press the Enter or Next Setting key to continue with other settings Press the Save Screen key to store the changes The default setting is Current 4 5 7 Display Contrast The Model 340 has a high contrast LCD display with a bright backlight The factory contrast setting is good for most applications but it will need to be changed for arrangements of equipment that put the Model 340 well above or below eye level Display contrast can be set to a value between 0 an 100 Please note that changing contrast has no effect on the display backlight To change display contrast press the Display Format key then press the More key until the Misc Display Format screen is displayed Press the Next Setting key until the Contrast line is highlighted then use the A or Y key to adjust contrast The contrast will change as the parameter is being set so adjustments should be made with the operator and instrument in their normal positions Press the Enter or Next Setting key to continue with other settings Press the Save Screen key to store the changes in the Model 340 The default setting is 50 4 5 8 Display Backlight On Off The Model 340 display used a florescent tube as a backlight The backlight is powered with a high voltage supply operating at 30 kHz Some experiments are sensitive to noise in the freq
15. GaAlAS Diode TG 120 1 4 475 K Positive Temperature Coefficient RTDs 100 Q Platinum PT 100 250 Q Full Scale 30 675 K 100 Q Platinum PT 100 500 Q Full Scale 30 800 K Rhodium lron RF 800 4 4 400 K Negative Temperature Coefficient RTDs GR 200A 1000 GR 200A 250 CGR 1 500 CX 1050 AA or SD CX 1030 AA or SD SOEN RX 202A 3 300 K TX 104 GB 110 325 K Sensors sold separately 10 16 Options and Accessories Lake Shore Model 340 Temperature Controller User s Manual Table 10 3 Model 3468 Sensor Input Performance Chart m 100 Platinum RTD 1000 Q TM Sensor Type Silicon Diode GaAlAs Diode 500 Q Full scale Platinum RTD Cernox RTD Sensor Units Volts V Volts V Ohms Q Ohms Q Ohms Q Input Range 0 2 5V 0 7 5V 0 500 Q 0 5000 Q 0 7500 Q Sensor Excitation Constant Current 10 pA 0 01 10 pA 0 01 1 mA 20 3 1 mA 0 3 10 pA 0 01 Display Resolution Sensor Units 100 uV 100 pV 100 ma 100 ma Example Lake Shore Sensor DT 470 CO 13 with TG 120SD with 1 4H PT 103 with 14J PT 1001 with 1 4G CX 1050 SD with 4L 1 4H calibration calibration calibration calibration calibration Temperature Range 14 475K 14 475K 30 800 K 30 800 K 3 55 400 K Standard Sensor Curve Lake Shore Curve 10 30 mV K at 4 2 K 1 9 mV K at 77 K 2 4 mV K at 300 K 2 2 mV K at 475 K Typical Sensor Sensitivity Measurement Resolution Sensor Units 20 uV Temperature Equivalence 1 mK at 4 2 K 11 mK at 77 K 10 mK at 300 K 10 mK at 475
16. Introduction Lake Shore Model 340 Temperature Controller User s Manual Rox RX 202 0 1 K to 40 K T gt 2K amp BS10T Thermocouples Type K 9006 006 3 2 K to 1505 K Not Recommended 3464 Type E 9006 004 3 2 K to 934 K Not Recommended Chromel AuFe 0 07 9006 002 1 2K to 610K Not Recommended Capacitance CS 501 1 4 K to 290 K Not Recommended 3465 Diodes Silicon Diode DT 670 SD 1 4 K to 500 K TOG0K amp Bs3T 3468 Silicon Diode DT 670E BR 30 K to 500 K TO60K amp Bs3T Silicon Diode DT 414 1 4 K to 375 K TO60K amp Bs3T Silicon Diode DT 421 1 4K to 325 K TO60K amp Bs3T Silicon Diode DT 470 SD 1 4 K to 500 K TO60K amp Bs3T Silicon Diode DT 471 SD 10 K to 500 K TO60K amp Bs3T GaAlAs Diode TG 120 P 1 4 K to 325 K T gt 42K amp BS5T GaAlAs Diode TG 120 PL 1 4 K to 325 K T gt 42K amp BS5T GaAlAs Diode TG 120 SD 1 4 K to 500 K T gt 42K amp BS5T Positive Temperature 100 Q Platinum PT 102 3 14 K to 800 K T gt 40K amp BS25T Coefficient RTDs 100 O Platinum PT 111 14 K to 673 K T gt 40K8B lt 25T 3468 Rhodium Iron RF 800 4 1 4 K to 500 K T gt 77K amp BS8T Rhodium lron RF 100T U 1 4 K to 325 K T gt 77K amp BS8T Negative Cernox CX 1010 2 K to 325 K T gt 2K amp BS19T Temperature Cernox CX 1030 HT 3 5 K to 420 K gt T gt 2K8B lt 19T Coefficient RTDs Cernox CX 1050 HT 4 K to 420 KP T gt 2K amp BS19T 3468 Cernox CX 1070 HT 15Kto420K T
17. It is E E unlikely that wire that large will be required to carry the rated 2 amp Figure SM RELAIS ES and n current of the relay Rear Panel Connector Details 3 12 Installation Lake Shore Model 340 Temperature Controller User s Manual CHAPTER 4 FRONT PANEL OPERATION 4 0 GENERAL This chapter covers turning power on in Paragraph 4 1 display formats in Paragraph 4 2 keyboard description in Paragraph 4 3 keypad navigation in Paragraph 4 4 and changing display format in Paragraph 4 5 Be sure to read Paragraph 3 3 on line voltage verification before proceeding 4 1 TURNING POWER ON Once the line voltage setting has been verified Paragraph 3 3 plug the instrument end of the line cord included in the connector kit into the back of the instrument Then plug the opposite end of the cord into a properly grounded three prong receptacle Place the power switch located next to the line cord connector to the On position The display backlight will brighten the display area and a Lake Shore graphic logo will appear on the display The alarm beeper will sound once and the instrument will show a display of sensor readings and control settings There are several types of feedback that may be present at this time Some indicate a problem with the instrument and others indicate the need for the user to setup the sensor inputs or control loops Problems are indicated by the following The display backlight does not turn on backlight is dim in
18. Lake Shore Model 340 Temperature Controller User s Manual Accessories Continued Model Description Of Model 340 Accessories 268 301 DA 15 D Style Shell Used for Digital UO connector 268 303 DA 15 D Style Plug Used for Digital I O connector 2001 RJ 11 Cable Assembly Four Wire Cable Assembly with RJ 11 plugs on each end Used with RS 232C Interface Cable is 14 feet 4 6 meters long See Figure 10 1 2002 RJ 11 to DB 25 Adapter Adapts RJ 11 receptacle to female DB 25 connector Connects Model 340 to Customer computer rear RS 232C Serial Port See Figure 10 3 2003 RJ 11 to DE 9 Adapter Adapts RJ 11 receptacle to female DE 9 connector Connects Model 340 to Customer computer rear RS 232C Serial Port See Figure 10 2 Heater Output Conditioner The heater output conditioner is a passive filter which further reduces the already low Model 340 heater output noise The typical insertion loss for the Model 3003 is 20 dB at line frequency and gt 40 dB from double the line frequency up A 144 mm x 72 mm x 165 mm 5 67 x 2 84 x 6 5 inches panel mount enclosure houses this option weight is 3003 1 6 kilograms 3 5 pounds See Figure 3 3 The Model 3003 requires no external power Take care not to reverse the polarity of incoming heater signal A protection diode on the Model 3003 input acts as a short in case of reversed polarity It is not necessary to use the ground terminals provided but in certain circumstances it
19. Valid entries 0 No 1 Yes lt start mode gt Specifies start mode Valid entries 0 clear 1 continue LOGSET Query data logging parameters Input LOGSET Returned lt log type gt lt interval gt lt overwrite gt lt start mode gt Format n n n n term Remarks Returns the data logging parameters If there is no valid SRAM Data card mounted the Model 340 returns 0 0 0 0 See LOGSET command for parameter descriptions LOGVIEW Query record of logged data Input LOGVIEW lt record gt lt point gt Returned lt timestamp gt lt point data gt The format of lt point data gt varies depending on the point type specified by point See DATETIME command for the lt timestamp gt parameters format 1 point type Input lt reading gt lt status gt lt reading gt Input reading in K C or sensor units lt status gt Shows status of the input in decimal Possible maximum value is 255 Each bit has its own meaning if set to 1 Bit7 DISABLED Bit6 NOCURVE Bit5 S OVER Bit4 S ZERO Bit3 T OVER Bit2 T UNDER Bit1 Old reading Bit 0 Invalid reading 2 point type SP1 2 lt value gt lt value gt SP1 2 value in K C or sensor units 3 point type Out2 lt value gt lt value gt Out2 value in 4 point type Out lt value gt lt pow cur gt lt heater range gt lt value gt Out1 value in 96 lt pow cur gt 1 current 2 power lt heater range gt Heater range in W 0 0 when
20. but are sent in response to a query A leading is not required but a leading is required 9 2 8 Troubleshooting New Installation 1 Check instrument Baud rate 2 Make sure transmit TD signal line from the instrument is routed to receive RD on the computer and vice versa Use a null modem adapter if not Always send terminators Send entire message string at one time including terminators many terminal emulation programs do not Send only one simple command at a time until communication is established Be sure to spell commands correctly and use proper syntax on kw Old Installation No Longer Working 7 Power instrument off then on again to see if it is a soft failure 8 Power computer off then on again to see if communication port is locked up 9 Verify that Baud rate has not been changed on the instrument during a memory reset 10 Check all cable connections Intermittent Lockups 11 Check cable connections and length 12 Increase delay between all commands to 100 ms to make sure instrument is not being over loaded 9 20 Remote Operation Lake Shore Model 340 Temperature Controller User s Manual 9 3 IEEE 488 SERIAL INTERFACE COMMANDS The IEEE 488 Serial Interface command list that follows is grouped by function with the most often used commands listed first The actual list of commands is presented in alphabetical order Parameter conventions used in the command list are as follows en
21. improve accuracy to room temperature and above 8 4 Instrument Programming Lake Shore Model 340 Temperature Controller User s Manual Point 3 Calibration data point near room temperature 305 K Temperatures outside the range of 200 K to 350 K are not allowed 8 2 2 SoftCal Accuracy with Silicon Diode Sensors SoftCal allows an abbreviated calibration based on 1 2 or 3 points to generate a voltage versus temperature curve over the useful range of a Lake Shore DT 400 Series silicon diode sensor A SoftCal calibration is only as good as the accuracy of the calibration points The accuracies listed for SoftCal assume 0 05 K for 77 35 K liquid nitrogen and 305 K room temperature points and 0 01 K for 4 2 K liquid helium Users performing the SoftCal with silicon diodes and Lake Shore instruments should note that liquefied nitrogen and ice point temperatures can vary as much as 0 5 K Use calibrated standard sensors if possible The boiling point of liquid helium though accurate is affected by atmospheric pressure Perform one point SoftCal calibrations for applications under 30 K at liquid helium 4 2 K Accuracy for the DT 470 SD 13 diode is 0 5 K from 2 K to lt 30 K with no accuracy change above 30 K Perform two point SoftCal calibrations for applications above 30 K at liquid nitrogen 77 35 K and room temperature 305 K Accuracy for the DT 470 SD 13 diode sensor is as follows 1 0 K from 2 Kto lt 30 K no change be
22. lt value gt specifies value for manual output MOUT 1 22 45 term Control Loop 1 manual output is 22 45 Remote Operation MOUT Input Returned Remarks PGM Input Returned Remarks Example PGM Input Returned Remarks PGMDEL Input Returned Remarks Example PGMMEM Input Returned Remarks PGMRUN Input Returned Remarks Lake Shore Model 340 Temperature Controller User s Manual Query Control Loop Manual Output Values MOUT lt loop gt manual output value Format tnnn nn term Returns the control loop manual output value loop specifies which loop to query Add A Program Line PGM program lt command gt lt param1 gt lt param2 gt Nothing Adds a command to a program The command appends to the end of the specified program Each command has a different number of parameters and parameter formats The parameters are detailed under each command Paragraph 8 3 lt command gt specifies the command End commands are ignored Valid entries are 0 End no parameters 1 NOP no parameters 2 Repeat lt iterations gt infinite loop enable gt 3 End Repeat no parameters 4 Wait lt hours gt lt minutes gt lt seconds gt 5 Call lt program gt 6 Ramp MOut Abs lt MOut value gt lt hours gt lt minutes gt lt seconds gt lt rate value gt 7 Ramp MOut Rel deviation value gt lt hours gt
23. off on gt points lt window gt Format a nn nn term Returns input filter configuration See the FILTER command for parameter descriptions lt input gt specifies which input to query Query Heater Output HTR lt heater value gt Format nnn n term Returns the heater output in percent Query Heater Status HTRST lt error code gt Format nn term Returns the heater error code Paragraph 11 8 Configure IEEE 488 Interface Parameters IEEE lt terminator gt lt EOI enable gt lt address gt Nothing Configures parameters of the IEEE interface terminator Specifies the terminator Valid entries 0 no terminator 1 lt CR gt lt LF gt 2 lt LF gt lt CR gt 3 CR 4 lt LF gt EOl enable Disables enables the EOI mode lt address gt Specifies the IEEE address IEEE 1 1 4 term After receipt of the current terminator the instrument responds to address 4 uses lt CR gt lt LF gt as the new terminator and uses EOI mode Query IEEE 488 Interface Parameters IEEE lt terminator gt EOI enable address Format n n nn term Returns the IEEE interface parameters See the IEEE command for parameter descriptions Configure Input Curve Number INCRV lt input gt lt curve number gt Nothing Specifies the curve an input uses for temperature conversion lt input gt Specifies which input to configure lt curve number gt Specifies which curve the input uses I
24. ssssssssseeeeemme Paragraph 11 1 10 Loop 1 HEATER OUTPUT Banana Jacks Paragraph 3 5 11 Loop 1 HEATER FUSE sesseeeees Paragraph 3 5 4 Figure 3 2 Model 340 Rear Panel 3 4 Installation Lake Shore Model 340 Temperature Controller User s Manual 3 3 Line Input Assembly This section describes how to properly connect the Model 340 to line power Please follow these instructions carefully to ensure proper operation of the instrument and the safety of operators Power On Off Screwdriver Fuse Switch Slot Drawer Figure 3 3 Line Input Assembly Depending upon the date of manufacture the unit will have either of two fuse data legends printed under the Line Input Assembly Za LINE 10 5 FUSE 100 120 220 240 50 60 Hz DATA 2 0A 10A 190 VA MAX 25x1 25in T 5x20mm T 50 60 Hz DATA 20A 1 0A 190 VA MAX 5x20mm T 5x20mm T Figure 3 4 Fuse Data Legends Only the dimensions of the 2 A fuse change the rating does not Line voltage is discussed in Paragraph 3 3 1 Fuse verification is discussed in Paragraph 3 3 2 The power cord is discussed in Paragraph 3 3 3 The power switch is identified in Paragraph 3 3 4 3 3 1 Line Voltage The line input assembly contains the line voltage selector line fuse holder and power cord connector It is important to verify that the Model 340 is set to the appropriate line voltage and has the correct line fuse before itis powered on for the first time R
25. 100 120 220 240 VAC 5 10 50 or 60 Hz 190 VA 432 mm W x 89 mm H x 368 mm D 17 in x 3 5 in x 14 5 in full rack 8 kg 17 6 Ib approx CE mark 1 7 6 Product Configuration Part Number Description Input configuration cannot be changed in the field Standard Temperature Controller all features included 340 Two Diode Resistor Inputs Refer to Chapter 10 of this manual for a complete description of Model 340 options and accessories Specifications subject to change without notice Introduction Lake Shore Model 340 Temperature Controller User s Manual CHAPTER 2 COOLING SYSTEM DESIGN 2 0 GENERAL Selecting the proper cryostat or cooling source is probably the most important decision in designing a temperature control system The cooling source defines minimum temperature cool down time and cooling power This chapter provides information on how to get the best temperature measurement and control from cooling sources with proper setup including sensor and heater installation Chapter 2 contains the following major topics Temperature sensor selection is covered in Paragraph 2 1 Calibrated sensors are covered in Paragraph 2 2 Sensor installation is covered in Paragraph 2 3 Heater selection and installation is covered in Paragraph 2 4 Considerations for good control are covered in Paragraph 2 5 PID Control is covered in Paragraph 2 6 Manual Tuning is covered in Paragraph 2 7 AutoTuning is covered in Paragraph 2 8 F
26. 16 1432 9 602020 5 153520 16 9403 9 581740 4 970330 17 7798 9 560710 4 784590 18 6624 9 537440 4 596330 19 5881 9 513290 4 405600 20 5573 9 486720 4 212440 21 5702 9 457560 A 3 992330 22 627 9 427340 3 769140 23 7279 9 396080 3 543070 S 24 873 9 363810 3 314120 i 26 0623 9 330540 3 082340 27 3356 9 296270 2 847790 28 6935 9 257090 2 610520 30 1761 9 216690 2 343820 31 8242 9 175140 2 073770 i 33 7187 9 132450 1 800570 36 1028 9 088620 1 524210 d 41 8502 9 043710 1 244740 44 2747 8 997710 0 962207 46 2907 8 950650 0 676647 48 1007 8 902530 0 359204 49 8256 8 840980 0 009079 51 5056 8 777760 i 0 344505 A 4 Curve Tables Curve Tables Lake Shore Model 340 Temperature Controller User s Manual Table A 6 Type T Copper vs Copper Nickel Thermocouple Curve Break Break Break E Temp K IET rompo UC MV Tempe 6 257510 6 257060 6 256520 6 255810 6 254950 6 253920 6 252780 6 251380 6 249730 6 247810 6 245590 6 243040 6 240300 6 237210 6 233710 6 229800 6 225630 6 221000 6 215860 6 210430 6 204430 6 198680 6 191780 6 184530 6 176930 6 168310 6 159280 6 149830 6 139220 6 128130 6 116580 6 103700 6 090300 6 075460 6 060040 6 044070 6 025470 6 006200 5 986280 5 965730 5 942210 5 917930 5 892970 5 864730 5 835680 5 805860 5 776
27. 2 Measurement Operation 5 7 Lake Shore Model 340 Temperature Controller User s Manual 5 4 4 Auto Scanning Once the individual input channels are enabled and have a designated curve the Auto Scan feature can sequence through the enabled channels A scan interval can be set by the user to tell the instrument how long to read a channel before moving to the next The interval is set in seconds and has a range of 2 to 200 The Model 340 can set its digital outputs to the corresponding Auto Scan channel If the external scanner has digital control inputs the Model 340 can be used to select a channel This is a convenient way to synchronize the scanned readings or automate the scan operation using only Model 340 To change the reading interval for the Auto Scan mode start with the scan mode set to Auto Scan Press the Scan Setup key and the scan setup screen will appear Press the Next Setting or Previous Setting key until the interval field is highlighted Use the A or V key to select the appropriate scan interval in seconds Press the Save Screen key to store the setting in the Model 340 Please note that only input channels that have been enabled on the input setup screen will be read in sequence The default setting is 2 The digital outputs must be set to scan mode to report the scan channel refer to Paragraph 7 2 for digital output mode setting When the digital outputs are set to work with the scanner and Auto Scan mode selected d
28. 2 127070 2 324710 2 523070 2 643480 2 708890 2 764030 2 797580 2 950200 3 008310 3 031200 3 218040 3 300110 4 000810 4 246390 4 701810 4 947390 5 636410 5 870300 6 547630 6 711600 6 781410 6 931500 7 001360 7 166710 7 260420 7 412010 7 529070 7 657460 7 704410 A 7 Lake Shore Model 340 Temperature Controller User s Manual Table A 9 Standard DT 670 Diode Curve Breakpoint ov Temp K Breakpoint ov Temp K Breakpoint vw Temp K oo JO Om PS Ga MM A 0 090570 0 110239 0 136555 0 179181 0 265393 0 349522 0 452797 0 513393 0 563128 0 607845 0 648723 0 686936 0 722511 0 755487 0 786992 0 817025 0 844538 0 869583 0 893230 0 914469 0 934356 0 952903 0 970134 0 986073 0 998925 1 01064 1 02125 1 03167 1 04189 1 05192 1 06277 1 07472 1 09110 1 09602 1 10014 10393 10702 10974 11204 11414 11628 11853 12090 12340 12589 12913 13494 14495 16297 17651 1 19475 1 24208 1 26122 1 27811 1 29430 1 31070 1 32727 1 34506 1 36423 1 38361 1 40454 1 42732 1 45206 1 48578 1 53523 1 56684 1 58358 1 59690 1 60756 1 62125 1 62945 1 63516 1 63943 1 64261 1 64430 Curve Tables
29. 2 and Serial nierrace interface parameters Al Set Displays the ALARM SETTINGS screen which enables or disables alarms and sets arm Setup various alarm parameters Displays the MATH COMPUTATIONS screen which sets Max Min and Filter parameters Press the More key to see the LINEAR EQUATION screen Analog Output Displays the ANALOG OUTPUTS screen which specifies Mode Bipolar Status and Nalog v Hrpurs other parameters for Analog Output A and B Alarm Reset Immediately resets all latched alarms Math Reset Immediately resets all Max and Min values Displays four screens 1 The DIGITAL I O screen manually sets the digital inputs and outputs The RELAY amp BEEPER SETUP screen allows the user to choose alarm or manual control for relays and to turn the beeper on or off The DATE amp TIME screen is used to set real time clock The REVISION INFORMATION screen displays the controller serial number and revision history Use the More key to toggle between the screens Front Panel Operation Lake Shore Model 340 Temperature Controller User s Manual Key Definitions Continued Kay Displays the DATACARD screen Allows the user to select Data Logging Read DataCard Write DataCard and Erase DataCard Datacards are useful for transferring temperature response curves storing and restoring instrument parameters and internal programs and updating main processor software Displays a help screen for the highlighted parameter Data Card
30. 340 Temperature Controller User s Manual 10 6 5 Computer Interface Commands Most of the computer interface commands used by the Model 340 are independent of installed options or sensor type The following commands or formats change when the 3468 is installed 1 In most command strings the input field accepts A B or C1 C4 D1 D4 instead of only A and B 2 The INTYPE command changes to the following format for 3468 inputs INTYPE lt input gt lt type gt input Specifies input to configure C or D type Specifies input sensor type Valid entries 1 7 Silicon Diode 4 Platinum 100 5000 7 NTC RTD 2 GaAlAs Diode 5 Platinum 1000 3 Platinum 100 25002 6 Rhodium Iron Example INTYPE C 1 Sets sensor type to silicon diode for all C channels 3 The INTYPE query changes to the following format INTYPE input input Specifies input to query C or D Returned type units coefficient lt excitation gt lt range gt type See the INTYPE command units Sensor units 1 volts 2 ohms coefficient Temperature coefficient 1 negative 2 positive excitation Input excitation 6 10 uA 10 1mA range Input range 8 250mV 11 2 5V 13 7 5V 9 500mV 12 5V 14 75mV 10 6 6 Specifications The 3468 Option Card input specifications are listed in Table 10 3 Supported Lake Shore Sensors Type Mode Temp Range Diodes Silicon Diode DT 670 1 4 500 K
31. 5 1 3 special sensor type configuration in Paragraph 5 1 4 and turning an input off in Paragraph 5 1 5 5 1 1 Sensor Type The first step in sensor input configuration is setting the sensor type parameter The Model 340 works with a variety of different sensors each with special requirements for excitation and input range Selections for several different types of sensors are pre programmed into the Model 340 If using one of these sensor types select that type to automatically change the associated parameters listed in Table 5 1 Table 5 1 Sensor Types Recognized by the Model 340 Type Units Y Excitation Range Temp Coefficient Update Refer to Paragraph 5 1 2 for voltage excitation for these sensors Approximate temperature ranges are given with specifications Other sensor types are available with input option cards To select a pre programmed sensor type press Input Setup The input setup setting screen appears with the input letter in the top left hand corner Use the A or V key to select an input Press Enter or Next Setting to display the input parameters Press Next Setting until the type field highlights and then use the A or V key to select one of the sensor types in the table above Press Enter or Next Setting to show the input parameters for that sensor type To proceed to temperature response curve selection Paragraph 5 2 press Previous Setting or press Save Screen to store the changes in the Model 340 The de
32. 6 17142 2 95792 23 1752 53 3945 6 15103 E 2 82629 24 5166 53 8074 6 12998 2 6762 25 6001 54 2182 6 10828 2 52392 26 5536 54 6439 6 08343 2 36961 27 4199 54 8813 6 05645 2 21329 28 2413 OO JO Om P 0 bh Curve Tables A 3 Lake Shore Model 340 Temperature Controller User s Manual Table A 5 Type E Nickel Chromium vs Copper Nickel Thermocouple Curve Break Break Break EA Temp K coin rompo Some mV Temp 9 834960 8 713010 0 701295 9 834220 8 646710 1 061410 9 833370 8 578890 1 424820 9 832260 8 509590 a 1 791560 9 830920 8 438800 2 161610 9 829330 8 366570 2 534960 9 827470 j 8 292900 2 943070 9 825370 8 217810 i 3 355100 9 822890 8 141330 z 3 770870 9 820010 8 047780 4 190420 9 816880 7 952190 4 613650 9 813290 7 854690 5 040520 9 809180 7 755260 5 470960 9 804510 7 653960 5 938380 9 799510 i 7 550790 i 6 409870 9 793900 7 445790 6 885210 9 787610 7 338970 7 364360 9 780590 7 230370 7 881760 9 773150 7 120010 a 8 403380 9 764910 6 989110 8 928940 9 755820 6 855790 9 493760 9 746230 6 720200 10 0629 9 735700 6 582330 10 6361 9 724650 6 442220 11 2494 9 713080 6 299900 11 867 9 699960 6 155400 a 12 5253 9 686220 6 008740 13 188 9 671890 3 5 859960 d 13 892 9 655790 5 687430 S 14 6005 9 638980 5 512090 15 3507 9 621500 5 334130
33. CFILT lt loop gt lt off on gt Nothing Configure the control filter lt loop gt Specifies which loop to configure lt offlon gt Specifies whether the control filter is off or on CFILT 1 10 term The control filter on Loop 1 is turned on The control loop filter uses the same filter window and number of filter points as the input chosen as the control channel Query Control Filter CFILT lt loop gt off on Format n term Returns the control filter configuration See the CFILT command for parameter descriptions lt loop gt specifies which loop to query 9 27 CLIMI Input Returned Remarks CLIMI Input Lake Shore Model 340 Temperature Controller User s Manual Configure Control Loop 1 Maximum Current Setting CLIMI lt max I gt Nothing Sets the maximum output current for loop 1 when the Max Current Limit setting is set to User See CLIMIT command for Max Current Limit Setting This setting is used to limit the maximum power to be delivered into a heater load This setting is only available in main firmware version 01 03 08 and later lt max gt Specifies the maximum current output for loop 1 when operating in the User setting for the Max Current Limit Valid entries are from 0 1 to 2 0 Query Control Loop 1 Maximum Current Setting CLIMI Returned lt max I gt Format n nnn term Remarks CLIMIT Input Returned Remarks Example CLIMIT Input Returned
34. Chr 10 ZeroCount 0 strReturn strHold If frmSerial MSComml PortOpen True Then frmSerial MSComml PortOpen False End If frmSerial MSComml CommPort 1 frmSerial MSComml Settings 9600 0 7 1 frmSerial MSComml InputLen 1 frmSerial MSComml PortOpen True Do Do DoEvents Loop Until gSend True gSend False strCommand frmSerial txtCommand Text strReturn strCommand UCase strCommand If strCommand EXIT Then End End If frmSerial MSComml Output strCommand amp Term If InStr strCommand lt gt 0 Then While ZeroCount lt 20 And strHold lt gt Chr 10 If frmSerial MSComml InBufferCount frmSerial Timerl Enabled True Do DoEvents Loop Until frmSerial Timerl Enabled ZeroCount ZeroCount 1 Else ZeroCount 0 strHold frmSerial MSComml Input strReturn strReturn strHold End If Wend If strReturn lt gt Then strReturn Mid strReturn 1 InStr strReturn Else strReturn No Response End If frmSerial txtResponse Text strReturn strHold ZeroCount 0 End If Loop End Sub Main code section Used to return response Temporary character space Terminators Counter used for Timing out Data string sent to instrument Show main window Terminators are lt CR gt lt LF gt Initialize counter Clear return string Clear holding string Close serial port to change settings Example of Comm 1 Example of 9600 Baud Parity
35. DATETIME 2 3 1996 15 30 0 O term Sets date to February 3 1996 time to 3 30pm DATETIME Query Date and Time Input Returned Remarks DFLT Input Returned Remarks DIOST Input Returned Remarks Remote Operation DATETIME lt MM gt lt DD gt lt YYYY gt lt HH gt lt mm gt lt SS gt lt sss gt Format nn nn nnnn nn nn nn nnn term Returns date and time See the DATETIME command for parameter descriptions Set To Factory Defaults DFLT 99 Nothing Sets all configuration values to factory defaults and resets the instrument The 99 is required to prevent accidentally setting the unit to defaults May take some time use the BUSY command to determine completion Query Digital Input Output Status DIOST lt input bit weighting gt lt output bit weighting gt Format nnn nnn term Returns the status of the digital input and output in bit weighting format 9 31 DISPFLD Input Returned Remarks Example DISPFLD Input Returned Remarks DISPLAY Input Returned Remarks Example DISPLAY Input Returned Remarks DOUT Input Returned Remarks Example DOUT Input Returned Remarks 9 32 Lake Shore Model 340 Temperature Controller User s Manual Configure Displayed Field DSPFLD lt field gt lt input gt lt source gt Nothing Configures the displayed field lt field gt Specifies field to configure Valid entries 1
36. GENERAL Standard curve tables included in the Model 340 Temperature Controller are as follows Curve 1 DT 470 Silicon Diode esssssssss Table A 1 Curve 2 amp 3 DT 500 D E1 Silicon Diode Table A 2 Curve 4 amp 5 PT 100 1000 Platinum RTD Table A 3 Curve 6 Type K Thermocouple ssssssssssssssesrerrrereserrrrrn renn Table A 4 Curve 7 Type E Thermocouple sss Table A 5 Curve 8 Type T Thermocouple s nssssesseeeeeerreneseeerrer ren Table A 6 Curve 9 Chromel AuFe 0 03 Thermocouple Table A 7 Curve 10 Chromel AuFe 0 07 Thermocouple Table A 8 Curve 11 DT 670 Silicon Diode ooooooconinnocococccnnnnncccccnanonoos Table A 9 Table A 1 Lake Shore DT 470 Standard Curve 10 Curve 1 in the Model 340 Break Break Break Temp amp Temp K Temp K 0 09062 0 82405 10476 0 10191 0 84651 10702 0 11356 i 0 86874 10945 0 12547 0 87976 11212 0 13759 0 89072 i 11517 0 14985 0 90161 11896 0 16221 0 91243 12463 0 17464 0 92317 i 13598 0 18710 0 93383 15558 0 19961 0 94440 17705 0 22463 0 95487 19645 0 24964 0 96524 1 22321 0 27456 a 0 97550 1 26685 0 28701 0 98564 S 1 30404 0 32417 i 0 99565 i 1 33438 0 36111 1 00552 i 1 35642 0 41005 1 01525 A 1 38012 0 44647 1 02482 1 40605 0 45860 1 03425 1 43474 0 50691 1 04353 1 46684 0 51892 1 05630 i 1 5
37. IEEE 488 devices Cable is 1 meter 3 3 feet in length Accessories included with a new Model 340 10 2 Options and Accessories Lake Shore Model 340 Temperature Controller User s Manual Accessories Continued Model Description Of Model 340 Accessory HTR 25 25 Q 25 Watt Cartridge Heater The heater features precision wound nickel chromium resistance wire magnesium oxide insulation two solid pins non magnetic package and has UL and CSA component recognition The heater is 25 watt 6 35 mm 0 25 inch diameter by 25 4 mm 1 inch long The 25 watt rating is in dead air In cryogenic applications the cartridge heater can handle many times this dead air power rating HTR 25 100 25 O 100 Watt Cartridge Heater The heater is 100 watt 6 35 mm 0 25 inch diameter by 25 4 mm 1 inch long HTR 50 50 Q 50 Watt Cartridge Heater The heater features precision wound nickel chromium resistance wire magnesium oxide insulation two solid pins non magnetic package and has UL and CSA component recognition The heater is 50 watt 6 35 mm 0 25 inch diameter by 25 4 mm 1 inch long The 50 watt rating is in dead air In cryogenic applications the cartridge heater can handle many times this dead air power rating RM 1 Rack Mounting Kit Mounting brackets ears and handles to attach one Model 340 to a 482 6 mm 19 inch rack mount cabinet See Figure 10 4 Wire Lake Shore Cryogenic Wi
38. Instruments CalCurve Carbon Glass Cernox DriftTrak Duo Twist Quad Lead Quad Twist Rox SoftCal and Thermox are trademarks of Lake Shore Cryotronics Inc Chromel and Alumel are trademarks of Hoskins Manufacturing Company Formvar is a trademark of Monsanto Chemical Company MS DOS and Windows are trademarks of Microsoft Corporation NI 488 2 is a trademark of National Instruments PC XT AT and PS 2 are trademarks of IBM Stycast is a trademark of Emerson amp Cuming Teflon is a trademark of DuPont De Nemours Copyright 1996 2001 and 2003 2009 by Lake Shore Cryotronics Inc All rights reserved No portion of this manual may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording or otherwise without the express written permission of Lake Shore Lake Shore Model 340 Temperature Controller User s Manual CE Declaration of Conformity Lake Shore Cryotronics Inc 575 McCorkle Blvd Westerville OH 43082 8888 USA hereby declare that the equipment specified conforms to the following Directives and Standards Application of Council directives 73 23 EEC 89 336 EEC EN 61010 1 2001 Overvoltage II Pollution Degree 2 EN 61326 A2 2001 Class A Annex B El Mate Signature Ed Maloof Printed Name Vice President of Engineering Position Lak
39. K Electronic Accuracy Sensor Units 160 uV 0 01 of reading 11 mK at 4 2 K 138 mK at 77 K 88 mK at 300 K 77 mK at 475 K Temperature Equivalence 31 mK at 4 2 K 193 mK at 77 K 138 mK at 300 K 177 mK at 475 K Temperature Accuracy including electronic accuracy CalCurve and calibrated sensor Requires calibrated sensor 180 mV K at 10 K 1 25 mV K at 77 K 2 75 mV K at 300 K 2 75 mV K at 475 K 20 uV 1 mK at 10K 16 mK at 77 K 10 mK at 300 K 10 mK at 475 K 160 uV 0 02 of reading 6 mK at 10 K 300 mK at 77 K 150 mK at 300 K 110 mK at 475 K 21 mK at 10 K 390 mK at 77 K 140 mK at 300 K 210 mK at 475 K 0 19 Q K at 30 K 0 42 Q K at 77 K 0 39 Q K at 300 K 0 35 Q K at 675 K 0 33 Q K at 800 K 2mQ 10 6 mK at 30 K 10 mK at 77 K 10 mK at 300 K 10 mK at 675 K 10 mK at 800 K 0 004 2 0 02 of reading 25 mK at 30 K 18 mK at 77 K 70 mK at 300 K 162 mK at 675 K 187 mK at 800 K 45 mK at 30 K 38 mK at 77 K 105 mK at 300 K 262 mK at 675 K 287 mK at 800 K 1 9 Q K at 30 K 4 2 Q K at 77 K 3 9 Q K at 300 K 34 Q K at 675 K 20 MQ 10 6 mK at 30 K 10 mK at 77 K 10 mK at 300 K 10 mK at 800 K X 0 03 Q 0 02 of reading 40 mK at 30K 33 mK at 77 K 135 mK at 300 K 370 mK at 800 K 60 mK at 30 K 53 mK at 77 K 170 mK at 300 K 470 mK at 800 K DIN 43760 Scaled from Requires calibrated DIN 43760 sensor 770 QIK at 4 2 K 1 5 Q K at 77 K 0 1 Q K
40. K at 100 output 10 0 V and 0 0 K at 0 output 0 0 V high value low value Query Analog Output Parameters ANALOG output bipolar enable mode input source high value low value manual value Format n n ann n nnn nnnE n nnn nnnE n tnnn n term Returns the parameters of an analog output See the ANALOG command for parameter descriptions lt output gt specifies which analog output to query Query Analog Output Data AOUT lt output gt analog output gt Format tnnn n term Returns the percentage of output of an analog output lt output gt specifies which analog output data to query Configure System Beeper Parameters BEEP lt off on gt Nothing Enables or disables system beeper sound when an alarm condition is met lt off on gt disables enables the beeper Query System Beeper Parameters BEEP off on Format n term Returns system beeper parameters See the BEEP command for parameter descriptions Query System Beeper Status BEEPST lt beeper status gt Format n term Returns the current condition of the system beeper Remote Operation BUSY Input Returned Remarks CDISP Input Returned Remarks Example CDISP Input Returned Remarks CFILT Input Returned Remarks Example CFILT Input Returned Remarks Remote Operation Lake Shore Model 340 Temperature Controller User s Manual Query Instr
41. Once collected and isolated the gases liquefy when properly cooled A quick comparison between LHe and LN is provided in Table 3 1 Table 3 1 Comparison of Liquid Helium to Liquid Nitrogen PROPERTY LIQUID HELIUM LIQUID NITROGEN Boiling Point 1 atm in K Thermal Conductivity Gas w lcm K Latent Heat of Vaporization Btu liter Liquid Density pounds liter 3 1 5 2 Handling Cryogenic Storage Dewars All cryogenic containers dewars must be operated in accordance with instructions from the manufacturer Safety instructions are normally posted on the side of each dewar Cryogenic dewars must be kept in a well ventilated O place where they are protected from the weather and away from any sources of heat A typical cryogenic dewar is shown in Figure 3 1 3 1 5 3 Liquid Helium and Nitrogen Safety Precautions Zeeche Transferring LHe and LN and operation of the storage dewar controls should be in accordance with instructions from the manufacturer supplier During this e EEN HELIUM transfer it is important that all safety precautions written on the storage dewar and recommended by the manufacturer be followed KEEP UPRIGHT WARNING e Liquid helium and liquid nitrogen are potential asphyxiants and can cause rapid suffocation without warning Store and use in area with adequate ventilation DO NOT vent container in confined spaces DO NOT enter confined spaces where gas may be present unless
42. There should not be any breakpoint locations left blank in the middle of a curve The search routine in the Model 340 interprets a blank breakpoint as the end of the curve NOTE If the curve you wish to enter has similar parameters to an existing curve first copy the similar curve as described in Paragraph 8 1 5 to a new location then edit the curve to the desired parameters To enter a curve press the Curve Entry key Press the Next Setting key until Edit curve is selected then press the Enter key Use the A or V key to select the desired curve number to edit then press the Enter key You may now enter the serial number SN Limit Format and Sensor Temp K breakpoint pairs Use the Previous Setting and Next Setting keys to move from one edit field to the next Use the I and D keys to Insert or Delete lines from the breakpoint field When the edit is complete press the Save Screen key The Saving user curves message appears for a few seconds If you do not wish to save the new curve press the Cancel Screen key 8 1 4 Front Panel Curve Copy Curves can be copied from one location inside the Model 340 to another This is a good way to make small changes to an existing curve Curve copy may also be necessary if the user needs the same curve with two different temperature limits or needs to extend the range of a standard curve The curve that is copied is always preserved NOTE Copying an internal curve from one location to ano
43. above the cooling systems lowest temperature Enter a low proportional setting of approximately 5 or 10 and then enter the appropriate heater range as described above The heater display should show a value greater than zero and less than 100 The load temperature should stabilize at a temperature below the setpoint If the load temperature and heater meter swing rapidly the heater range may be set too high and should be reduced Very slow changes in load temperature that could be described as drifting are an indication of a proportional setting that is too low which is addressed in the next step Cooling System Design 2 11 Lake Shore Model 340 Temperature Controller User s Manual Tuning Proportional Continued Gradually increase the proportional setting by doubling it each time At each new setting allow time for the temperature of the load to stabilize As the proportional setting is increased there should be a setting in which the load temperature begins a sustained and predictable oscillation rising and falling in a consistent period of time See Figure 2 3a The goal is to find the proportional value in which the oscillation begins do not turn the setting so high that temperature and heater output changes become violent Record the proportional setting and the amount of time it takes for the load change from one temperature peak to the next The time is called the oscillation period of the load and it helps describe the dominant time co
44. additional mating connectors can be purchased from local electronics suppliers They can also be ordered from Lake Shore P N G 106 233 Table 3 3 Sensor INPUT A and B Connector Definition Pin Symbol LL Minus Current Femina INPUT A INPUT B 3 snen omen mer er cuam Ej prueva venal V V V e Nocomecion v 3 4 2 Sensor Lead Cable The sensor lead cable used outside the cooling system can be much different form what is used inside Between the instrument and vacuum shroud error and noise pick up need to be minimized not heat leak Larger conductor 22 to 28 AWG stranded copper wire is recommended because it has low resistance yet remains flexible when several wires are bundled in a cable The arrangement of wires in a cable is also important For best results voltage leads V and V should be twisted together and current leads I and I should be twisted together The twisted pairs of voltage and current leads should then be covered with a braided or foil shield which is connected to the driven shield pin of the instrument This type of cable is 3 6 Installation Lake Shore Model 340 Temperature Controller User s Manual available through local electronics suppliers Instrument specifications are given assuming 10 feet of sensor cable Longer cables 100 feet or more can be used but environmental conditions may degrade accuracy and noise specifications 3 4 3 Grounding and Shielding Sensor Leads The sensor
45. an outer shield The connectors at each end are 24 way Amphenol 57 Series or equivalent with piggyback receptacles to allow daisy chaining in multiple device systems The connectors are secured in the receptacles by a pair of captive locking screws with metric threads The total length of cable allowed in a system is 2 meters for each device on the bus or 20 meters maximum This instrument can drive a bus with up to 10 devices Figure 11 9 shows the IEEE 488 Interface connector pin location and signal names as views from the rear panel of the controller IEEE 488 INTERFACE SH1 AH1 T5 L4 SR1 RL1 PPO DCH DTO CO E1 12 11 10 9 8 7 6 5 4 3 2 1 24 23 22 21 20 19 18 17 16 15 14 13 C 340 11 7 eps PIN SYMBOL DESCRIPTION Data Input Output Line 1 Data Input Output Line 2 Data Input Output Line 3 Data Input Output Line 4 End Or Identify Data Valid Not Ready For Data Not Data Accepted Interface Clear Service Request Attention Cable Shield Data Input Output Line 5 Data Input Output Line 6 Data Input Output Line 7 Data Input Output Line 8 Remote Enable Ground Wire Twisted pair with DAV Ground Wire Twisted pair with NRFD Ground Wire Twisted pair with NDAC Ground Wire Twisted pair with IFC Ground Wire Twisted pair with SRQ Ground Wire Twisted pair with ATN Logic Ground OONDOOAARWDND Figure 11 9 IEEE 488 Rear Panel Connector Details Service 11 7 Lake Shore Model 340 Temper
46. as the control channel It can be turned on or off independently from the input filter To turn the control loop filter on or off press Control Setup to display the CONTROL SETUP screen with the control loop indicator highlighted in the upper left hand corner Use the A or W key to select Loop 1 or 2 Press Enter or Next Setting to display control setup parameters for that loop Press Next Setting until the Filtered field highlights Use the A or W key to select ON or OFF Press Enter or Next Setting to continue with more settings or press Save Screen to store changes in the Model 340 The default setting is Off 6 2 Temperature Control Operation Lake Shore Model 340 Temperature Controller User s Manual 6 4 CONTROL CHANNEL A control loop gets feedback from a control sensor located with or near the load Either standard input can be used for control optional inputs appear on the setting list if useable Configure the sensor input used for control to match the sensor type or as a special type with the correct temperature coefficient No temperature response curve is needed if the user controls in sensor units Inputs using a scanner are not recommended for control use If the user changes the control channel without selecting a temperature response curve for both the old and new Channel the Model 340 sets control units to sensor units and picks the sensor units reading from the new control channel as the new Setpoint The user can choose wh
47. can help to reduce the noise Shorting out the filter input or output with the controller driving it turned on is not recommended as the Model 3003 may have a large stored charge 3401 Connector Kit MAN 340 Model 340 Temperature Controller User s Manual 3405 DCARD Data Card Flash For Model 340 update setup and curve storage 3405 SRAM Data Card Blank SRAM For data logging 3507 1S Cable Assembly for 1 Sensor 10 feet long 3507 2SH Cable Assembly for 2 Sensors and 1 Heater 10 feet long CalCurve Floppy Disk Consists of breakpoint pairs from a Sensor Precision Calibration loaded on a floppy disk in ASCII format for Customer downloading 8000 CalCurve Factory Installed The Model 8001 provides custom factory programming of specific sensor calibration curves The Precision Option improves combined sensor and 8001 340 instrument accuracy to within 0 1 K or better over the calibrated temperature range of the sensor The Precision Option data is stored in non volatile memory Requires a calibrated sensor CalCurve Field Installation Precision option field installation for Model 340 owners 8002 05 340 Consists of the break point table from a calibrated sensor stored in the instrument When ordering specify your instrument serial number and calibrated sensor model and serial number IEEE 488 GPIB Computer Interface Interconnect Cable Assembly This cable assembly is 8072 used to connect two
48. changing systems but it is often turned off during steady state control because it reacts too strongly to small disturbances The derivative setting D is related to the dominant time constant of the load similar to the setting The derivative term is set in seconds Cooling System Design 2 9 Lake Shore Model 340 Temperature Controller User s Manual change in setpoint temperature P Only too high actual temperature response a time P Only b P Only too low c Dr d P I D e 340 2 3 bmp Figure 2 3 Examples of PID Control 2 10 Cooling System Design Lake Shore Model 340 Temperature Controller User s Manual 2 6 4 Manual Heater Output MHP The Model 340 has a control setting that is not a normal part of a PID control loop Manual heater output can be used for open loop control meaning feedback is ignored and the heater output stays at the users manual setting This is a good way to put constant heating power into a load when needed The manual output term can also be added to the PID output Some users prefer to set a power near that necessary to control at a setpoint and let the closed loop make up the small difference Manual output is set in percent of full scale current or power for a given heater range 2 7 MANUAL TUNING There has been a lot written about tuning closed loop control systems and specifically PID control loops This section does not attempt to compete with con
49. configuration See the XSCAN command for parameter descriptions Configure Control Loop Zone Table Parameters ZONE lt loop gt zone lt top value gt lt P value gt lt I value gt lt D value gt lt mout value gt lt range gt Nothing Configures the control loop limit band parameters used in conjunction with the Status Byte Register refer to Paragraph 9 1 3 lt loop gt Specifies which loop to configure lt zone gt Specifies which zone in the table to configure Valid entries are 1 10 top value Specifies the top temperature of this zone lt P value Specifies the P for this zone value Specifies the for this zone D value Specifies the D for this zone mout value Specifies the manual output for this zone range Specifies the heater range for this zone if loop 1 Valid entries 0 5 ZONE 1 1 25 0 10 20 0 2 term Control Loop 1 zone 1 is valid to 25 0 K with a P of 10 an of 20 no D and a heater range of 2 Query Control Loop Zone Table Parameters ZONE lt loop gt zone top value P value lt I value D value mout value range Format nnn nnn nnnn n nnnn n nnnn nnn nn n term Returns control loop zone table parameters See the ZONE command for parameter descriptions loop Specifies which loop to query zone Specifies which zone in the table to query Valid entries 1 10 Remote Operation 9 43 Lake Sho
50. enter both numbers and letters enter curves over computer interface The default is blank A setpoint temperature limit can be included with every curve If the control sensor is an input using a curve and operating in temperature units then the setpoint cannot exceed the limit entered with the curve The default is 375 K The instrument must know the data format of the curve breakpoints Different sensor types use different data formats The standard sensor inputs require one of the formats below The range and resolution specified are not always available at the same time Practical range and resolution depend on the sensor type Sensor Units Sensor Units Format Description Full Scale Range Maximum Resolution VIK Volts vs Kelvin 10 V 0 00001 V Q K Resistance vs Kelvin 10 k 9 0 00001 Q log R K log Resistance vs Kelvin 4 log R 0 00001 log R log R log K log Resistance vs log Kelvin 4 log R 0 00001 log R mV K mV vs Kelvin 100 mV 0 00001 mV Enter an appropriate temperature for proper temperature control A positive coefficient indicates the sensor signal increases with increasing temperature A negative coefficient indicates the sensor signal decreases with increasing temperature The instrument derives the temperature coefficient from the first two breakpoints If it is set improperly check the first two breakpoints Table 8 1 Recommended Curve Parameters Lake Shore Ao T Recommended mes tiation y Unie F
51. gt 1 for current 2 for power heater range indicates the heater range in W 4 Out2 value value is in 96 5 None 0 0 This bit is typically set if the input is configured as one of Negative Voltage Coefficient Resistance Temperature Device with constant voltage excitation and when its thermal compensation is ON In this situation this bit is set in every other reading which indicates 10 readings update per second term Currently specified Serial Terminator 8 4 1 6 Line Power Loss When line power is lost while the Model 340 is logging data it resumes the data log sequence when power is restored if the battery in the SRAM Data Card has enough voltage to keep the logged data 8 16 Instrument Programming Lake Shore Model 340 Temperature Controller User s Manual 8 4 2 Reading From A Data Card To read a data card place the card into the slot then press the DataCard Key The Identifying Card message is displayed followed by the DATACARD screen Press the Next Setting key until Read DataCard is highlighted Once Read DataCard is highlighted press the Enter key Use the Next Setting or Previous Setting key to select which type of information is to be read from the data card 1 S Reads configuration programs and curves Configuration from the data card saves user curves then resets the Model 340 to the new configuration Reads the settings from the data card and resets the Model 340
52. gt 4 lt LF gt lt bps gt Specifies the bits per second bps rate Valid entries 1 300 2 1200 3 2400 4 4800 5 9600 6 19200 lt parity gt Specifies communication parity Valid entries 1 7 data bits 1 stop bit odd parity 2 7 data bits 1 stop bit even parity 3 8 data bits 1 stop bit no parity COMM 1 6 3 term After receiving the current terminator the instrument responds at 19 200 bps using 8 data bits 1 stop bit no parity and lt CR gt lt LF gt as a terminator Query Serial Interface Parameters COMM lt terminator gt lt bps gt lt parity gt Format n n n term Returns the serial interface parameter See COMM command for parameter descriptions Query Input Celsius Reading CRDG lt input gt Celsius value Format xnnn nnnE n term Returns the Celsius reading for an input input specifies which input to query Delete User Curve CRVDEL curve Nothing Deletes a user curve see Paragraph 8 1 2 NOTE Curves are not permanently updated in the curve Flash until a CRVSAV command is issued curve specifies which curve to delete Valid entries 21 60 CRVDEL 21 term Deletes User Curve 21 Use CRVSAV for permanent deletion 9 29 CRVHDR Input Returned Remarks Example CRVHDR Input Returned Remarks CRVPT Input Returned Remarks Example CRVPT Input Returned Remarks CRVSAV Input Returned Remarks 9 30 Lake
53. gt lt master rev number gt lt master serial number gt lt switch setting SW1 gt lt input rev date gt lt input rev number gt option ID option rev date gt lt option rev number Format nnnnnn nn nn nn nnnnnn nnn nnnnnn nn nn nn nnnn nnnnnn nn nn nn term Returns instrument revision information 9 41 SCAL Input Returned Remarks Example SETP Input Returned Remarks Example SETP Input Returned Remarks SETTLE Input Returned Remarks Example SETTLE Input Returned Remarks 9 42 Lake Shore Model 340 Temperature Controller User s Manual Generate SoftCal Curve SCAL lt std gt lt dest gt lt SN gt lt T1 value gt lt U1 value gt lt T2 value gt lt U2 value gt lt T3 value gt lt U3 value gt Nothing Generates a SoftCal curve Paragraph 8 2 NOTE Curves are not permanently updated in the curve Flash until a CRVSAV command is issued May take some time use the BUSY command to determine completion lt std gt Specifies the standard curve to generate a SoftCal from Valid entries 1 20 lt dest gt Specifies the user curve to store the SoftCal curve Valid entries 21 60 lt SN gt Specifies the curve serial number Limited to 10 characters lt T1 value Specifies first temperature point U1 value Specifies first sensor units point T2 value Specifies second temperature point U2 value Specifies second sensor units point
54. gt 2K8B lt 19T Cernox CX 1080 HT 50 K to 420 K T 2K amp Bs19T Germanium GR 200A B 1000 2 2 K to 100 K Not Recommended Germanium GR 200A B 1500 2 6 K to 100 K Not Recommended Germanium GR 200A B 2500 3 1 K to 100 K Not Recommended Carbon Glass CGR 1 500 4 K to 325 K T gt 2K amp B lt 19T Carbon Glass CGR 1 1000 5 K to 325 K T gt 2K amp BS19T Carbon Glass CGR 1 2000 6 K to 325 K T gt 2K amp BS19T Rox RX 102A 1 4 K to 40 K T gt 2K8B lt 10T Single excitation current may limit the low temperature range of NTC resistors 3 Non HT version maximum temperature 325 K Low temperature limited by input resistance range Low temperature specified with self heating error lt 5 mK Low temperature specified with self heating error x 12 mK Silicon diodes are the best choice for general cryogenic use from 1 4 K to above room temperature Diodes are economical to use because they follow a standard curve and are interchangeable in many applications They are not suitable for use in ionizing radiation or magnetic fields Cernox thin film RTDs offer high sensitivity and low magnetic field induced errors over the 0 3 K to 420 K temperature range Cernox sensors require calibration Platinum RTDs offer high uniform sensitivity from 30 K to over 800 K With excellent reproducibility they are useful as thermometry standards They follow a standard curve above 70 K and are interchangeable in many applications Introduction
55. industry For you convenience Lake Shore offers a Model 2001 RJ 11 Cable When combined with either the Model 2002 DB 25 Adapter or Model 2003 DE 9 Adapter this cable assembly can be used to connect the instrument to a computer with the corresponding connector type See Figure 9 4 These adapters are described in Paragraph 10 2 and are schematically diagramed in Figures 11 8 through 11 10 Equipment with Data Communications Equipment DCE wiring can be connected to the instrument with a straight through cable However if the interface is for Data Terminal Equipment DTE a Null Modem Adapter is required to exchange the transmit TxD and receive RxD lines The instrument uses drivers to generate the transmission voltage levels required by the RS 232C standard These voltages are considered safe under normal operating conditions because of their relatively low voltage and current limits The drivers are designed to work with cables up to 50 feet in length LSCI Model 2002 RJ 11 To customer supplied to DB 25 SERIAL UO computer with DB 25 Adapter Serial Interface Output on rear of Model 340 Serial Interface Connector configured as DCE If the interface is DTE a Null Modem Adapter is required to exchange Transmit and Receive lines The Model 2001 and 2003 are included with the Model 340 The Model 2002 is an option available from Lake Shore To customer supplied LSCI Model 2003 RJ 11 y compute
56. input gt lt units gt lt off on gt lt powerup enable gt Nothing Configures a control loop lt loop gt Specifies which loop to configure lt input gt Specifies which input to control from Valid entries A and B lt units gt Specifies setpoint units Valid entries 1 kelvin 2 Celsius 3 sensor units lt offlon gt Specifies whether the control loop is on or off lt powerup enable gt Specifies whether the control loop is on or off after power up CSET 1 A 1 1 term Control Loop 1 controls off of Input A with setpoint in kelvin Query Control Loop Parameters CSET lt loop gt lt input gt lt units gt lt off on gt lt powerup enable gt Format a n n n term Returns the parameters for a control loop See the CSET command for parameter descriptions lt loop gt specifies which loop to query Configure Date and Time DATETIME lt MM3 lt DD gt lt YYYY gt lt HH gt lt mm gt lt SS gt lt sss gt Nothing Configures date and time using 24 hour format MM Specifies month Valid entries are 1 12 lt DD gt Specifies day Valid entries are 1 31 lt YYYY gt Specifies year Valid entries are 1996 lt HH gt Specifies hour Valid entries are 0 23 mm Specifies minutes Valid entries are 0 59 lt SS gt Specifies seconds Valid entries are 0 59 lt sss gt Specifies milliseconds only updated in 10 ms increments Valid entries 0 999
57. input gt lt on pause gt lt source gt Nothing Configures the minimum and maximum input functions lt input gt Specifies input to configure lt on pause gt Turns on or Pauses the max min function Valid entries 1 on 2 paused lt source gt Specifies input data to process through max min Valid entries 1 kelvin 2 Celsius 3 sensor units 4 linear data MNMX B 1 3 term Input B min max function is on and processes data from the input sensor units reading Query Minimum and Maximum Input Function Parameters MNMX lt input gt lt on pause gt lt source gt Format n n term Returns a min max input configuration See the MNMX command for parameter descriptions lt input gt specifies which input to query Resets Min Max Function for All Inputs MNMXRST Nothing Resets the minimum and maximum data for all inputs Configure Remote Interface Mode MODE lt mode gt Nothing Configures the remote interface mode mode specifies which mode to operate Valid entries 1 local 2 remote 3 remote with local lockout MODE 2 term Places the Model 340 into remote mode Query Remote Interface Mode MODE lt mode gt Format n term Returns the remote interface mode See the MODE command for parameter descriptions Configure Control Loop Manual Output Value MOUT lt loop gt lt value gt Nothing Configures the control loop manual output values lt loop gt specifies loop to configure
58. is discussed in Paragraph 3 5 7 Loop 2 output resistance is discussed in Paragraph 3 5 8 The Loop 2 output connector is discussed in Paragraph 3 5 9 Loop 2 heater protection is discussed in Paragraph 3 5 10 Finally boosting the output power is discussed in Paragraph 3 5 11 3 5 4 Loop 1 Output The Model 340 has two control loops Loop 1 can be considered a primary loop because it is capable of driving 100 W of heater power The heater output for Loop 1 is a traditional control output for a cryogenic temperature controller It is a variable DC current source with several software settable ranges and limits The maximum heater output current is 2 A and maximum compliance voltage is 50 V 3 5 2 Heater Output Connector for Loop 1 A dual banana jack on the rear panel of the instrument is used for connecting wires to the Loop 1 heater A standard dual banana plug mating connector is included in the connector kit shipped with the instrument This is a common jack and additional mating connectors can be purchased from local electronic suppliers They can also be purchased from Lake Shore P N 106 009 3 5 3 Heater Output Wiring for Loop 1 Heater output current is what determines the size gauge of wire needed to connect the heater The maximum current that can be sourced from the Loop 1 heater output is 2 A When less current is needed to power a cooling system it can be limited in software with range settings The load can be protected against c
59. left hand corner Use the A or V key to select an input Press the Enter key or the Next Setting key to display the input parameters for that input Press the Next Setting key until the curve field is highlighted and then use A or Y key to select a curve from the list Press the Enter key or the Next Setting key and to advance to the next parameter If curve selection was not successful press the Next Setting key and verify the appropriate type selection Press the Save Screen key to store the changes in the Model 340 Table 5 3 Standard Curve Table Curve Setting No Sensor Type Model Number Curve Name Temp Range Table DT 470 1 Silicon Diode DT 470 Curve 10 14 475K A 1 DT 500 D 2 Silicon Diode DT 500 DRC D Curve D 1 4 365 K A2 DT 500 E1 3 Silicon Diode DT 500 DRC E1 Curve E1 14 330K PT 100 4 Platinum RTD 100 PT 100 DIN 43760 30 800K A3 PT 1000 5 Platinum RTD 1000 PT 1000 DIN 43760 30 800K Type K 6 Thermocouple Type K Type K 3 15 864 K 1500 K A 4 Type E 7 Thermocouple Type E Type E 3 15 622 K 930 K A 5 Type T 8 Thermocouple Type T Type T 3 15 670K A 6 AuFe 03 9 Thermocouple Chromel AuFe 0 03 Chromel AuFe 0 03 3 50 500 K A 7 AuFe 07 10 Thermocouple Chromel AuFe 0 07 Chromel AuFe 0 07 3 15 610K A 8 DT 670 11 Silicon Diode DT 670 DT 670 14 500 K A 9 Curves supported but sensors no longer available through Lake Shore Temperature range extend
60. located at U26 e 28 pin IC M340SV EEPROM Memory chip located at U146 Required tools Small Standard flat head screwdriver or pry tool for chip extraction e Small Phillips head screwdriver e 5 64 inch Allen wrench Before Starting 1 Record the instrument settings This update requires chip replacement 2 Stop your application while updating the software The update process may take as long as ten minutes Disable the instrument from controlling digital UC and analog outputs 3 Press the Options key then press the More key until the REVISION INFORMATION SCREEN displays the current firmware revision information for both Master and Input processors If the instrument displays no version numbers please contact Lake Shore Instrumentation Service Department Replacing the Firmware WARNING To avoid potentially lethal shocks turn off controller and disconnect it from AC power before performing these procedures 1 Turn the Model 340 power switch OFF Unplug the power cord from the wall outlet then from the instrument 2 Stand unit on its face Use the Allen wrench to remove the 4 screws on each side of the covers 3 Use the small Phillips screwdriver to remove the top cover screws Your Model 340 may have 1 or 2 screws on the top cover 4 Remove the rear plastic bezel The covers are tracked Slide the top cover to the rear on the tracks to remove it 5 Remove four screws attaching the Transformer Assembly to the c
61. m deh cd wad denne Geddes 4 3 Direct Settings tr apa 4 3 Using Setting WE EE 4 4 Data Re 4 4 The Help Key A is 4 4 Keypad Rue 4 4 Key Definitions iaa it 4 5 Changing Display Format tica ia 4 6 Number of Readings Displayed A 4 6 SENSO Input 5 5 E ond t tti EE 4 6 Reading Source and Display Units sese emm ens 4 7 Control Loop Display eti fere tete teo a da b e e 4 7 Large Heater Display usina n te p rt eT de ede ec da 4 7 Heater Output Display Units 1 2 ai a ree teil edens 4 8 Display ue 4 8 Display Backlight On Off 2 teet tr eret ee ro a Podere ere 4 8 Locking the Keypad x n ttai tei eet des dile t e dene dua 4 8 Default Val s 2x A E ent e tct Ie Perdu edere ts aed 4 8 Sensor Input and Temperature Measurement Operation ee 5 1 c r EE 5 1 Sensor Input Setup detecte ene A a e 5 1 DENOTA ege 5 1 Voltage Excitation Current Autorange ssssseseeeee eene 5 2 Thermal EMF Compensation with Voltage Excitation seene 5 2 Special Sensor Type Configuration sss eene 5 2 Turning an Input Off tice Diete Hiec e uisu pai desde cedrus 5 3 Selecting a Temperature Response Curve ssssssssseeeee eene 5 3 Filter and Maltly ecd ete tat enean dauid 5 4 guae TER 5 4 EV er DEEP 5 5 Linear Equation cutn cet rect e eti ottenere ci demie 5 6 Scanner Suppott oso etd et theol edt rated tede degit cda Edere dieit edes 5 6 Scan Modes EE 5 6
62. n tnnn nnn n n tnnn nnn term Returns input linear equation configuration See the LINEAR command for parameter descriptions lt input gt specifies which input to query 9 35 LOCK Input Returned Remarks Example LOCK Input Returned Remarks LOG Input Returned Remarks LOG Input Returned Remarks LOGCNT Input Returned Remarks LOGPNT Input Returned Remarks LOGPNT Input Returned Remarks 9 36 Lake Shore Model 340 Temperature Controller User s Manual Configure Lock out and Lock out Code LOCK lt off on gt lt code gt Nothing Configures keypad lock out and lock out code lt offlon gt Disables enables the keypad lock out lt code gt Specifies lock out code Valid entries 000 999 LOCK 1 123 term Enables keypad lock out and sets the code to 123 Query Lock out and Lock out Code LOCK off on lt code gt Format n nnn term Returns lock out status and lock out code See the LOCK command for parameter descriptions Data Logging On Off LOG lt stop start gt Nothing Turns data logging on and off lt stop start gt 0 stop 1 start Query Data Logging Status LOG lt offlon gt Format n term Returns data logging status 0 stopped 1 logging in progress Query Total Number of Logged Records LOGCNT lt of logged records gt Format n term Returns total number of logged records Configure a data point for data logg
63. negative slope value gt lt max current gt lt max range Format tnnn nnnE n nnn n nnn n n n term Returns parameters for control loop limits See the CLIMIT command for parameter descriptions lt loop gt specifies which loop to query Remote Operation CMODE Input Returned Remarks Example CMODE Input Returned Remarks COMM Input Returned Remarks Example COMM Input Returned Remarks CRDG Input Returned Remarks CRVDEL Input Returned Remarks Example Remote Operation Lake Shore Model 340 Temperature Controller User s Manual Configure Control Loop Mode CMODE lt loop gt lt mode gt Nothing Configures the control mode for a control loop lt loop gt Specifies which loop to configure lt mode gt Specifies the control mode Valid entries 1 Manual PID 2 Zone 3 Open Loop 4 AutoTune PID 5 AutoTune PI 6 AutoTune P CMODE 1 4 term Control Loop 1 uses PID AutoTuning Query Control Loop Mode CMODE lt loop gt lt mode gt Format n term Returns the control mode for a control loop See the CMODE command for parameter descriptions lt loop gt specifies which loop to query Configure Serial Interface Parameters COMM lt terminator gt lt bps gt lt parity gt Nothing Configures the serial interface parameters terminator Specifies the terminator 1 lt CR gt lt LF gt 2 lt LF gt lt CR gt 3 lt CR
64. of nitrogen 77 35 K Temperatures outside 50 K to 100 K are not allowed Point 2 Calibration data point near room temperature 305 K Temperatures outside 200 K to 350 K are not allowed Point 3 Calibration data point at a higher temperature 480 K Temperatures outside 400 K to 600 K are not allowed 8 2 4 SoftCal Accuracy with Platinum Sensors The SoftCal procedure makes small adjustments to the DIN curve so that the resulting curve matches the resistance versus temperature characteristic of the individual sensor more closely Instrument Programming 8 5 Lake Shore Model 340 Temperature Controller User s Manual A SoftCal calibration is only as good as the accuracy of the calibration points The accuracies listed for SoftCal assume 0 05 K for 77 35 liquid nitrogen K and 305 K room temperature points If you are performing the SoftCal yourself with Lake Shore instrumentation be aware that liquefied nitrogen and ice point temperatures can vary as much as 0 5 K Use a calibrated standard sensor if possible One point SoftCal calibrations with platinum sensors have no specified accuracy Perform two point SoftCal calibrations for applications above 70 K at liquid nitrogen 77 35 K and room temperature 305 K Accuracy for the PT 102 PT 103 or PT 111 platinum sensor is as follows 250 mK from 70 K to 325 K 500 mK from 325 K to 1400 mK at 480 K DIN Class A or Class B tolerance Perform three point SoftCal calibrations a
65. on or off for that relay Use the Next Setting or Enter key to make more changes or press the Save Screen key to store the changes The default setting is Off 7 6 Analog Digital Alarm amp Relay Operation Lake Shore Model 340 Temperature Controller User s Manual CHAPTER 8 INSTRUMENT PROGRAMMING 8 0 GENERAL The Model 340 has a powerful processor user interface and special programming features Internal programming is not intended to replace computer interface operation and in most cases the two complement each other Programming features include entering a temperature response curve saving and restoring instrument parameters and internal programming that allows the instrument to run temperature profiles This chapter covers front panel curve entry in Paragraph 8 1 SoftCal in Paragraph 8 2 internal programming in Paragraph 8 3 and data card operations in Paragraph 8 4 8 1 CURVE ENTRY FROM THE FRONT PANEL Enter a temperature response curve into the Model 340 in several ways Field install a CalCurve with a Data Card or order it factory installed enter a user generated curve from the front panel create a SoftCal curve with the SoftCal feature Paragraph 8 2 or load a curve with a computer interface refer to Chapter 9 8 1 1 Curve Numbers and Storage The Model 340 has 20 standard curve locations numbered 1 through 20 At present only curve locations 1 through 10 are occupied by curves the others are reserved for fu
66. prevent leads from heating the sample e Attaching lead wires and passing through vacuum tight connectors are often necessary in cryogenic systems Remember the thermocouple wire is the sensor any time it joins or contacts other metal there is potential for error Temperature verification and calibration of room temperature compensation is difficult after the sensor is installed When possible keep a piece of the same wire installed in a system for future use 10 4 3 3 Grounding and Shielding For lowest measurement noise do not ground thermocouple sensors The instrument usually operates with more noise if one of the thermocouples is grounded Grounding both thermocouples is not recommended The instrument does not offer a shield connection on the terminal block Twisting the thermocouple wires helps reject noise If shielding is necessary extend the shield from the oven or cryostat to cover the thermocouple wire but do not attach the shield to the instrument 10 4 4 Operation 10 4 4 1 Default Settings Following the installation the 3464 option adds 2 new inputs to the standard front panel operations This allows configuration of inputs C and D assigned as thermocouple inputs When the instrument is first powered on the default settings for channels C and D are range is 50 mV range temperature compensation is turned ON and curve 0 NO CURVE is selected If the option card is replacing another option card all configuration pa
67. problem but greases and varnishes must be checked Another source of problems is the wide extremes in temperature most sensors are exposed to The linear expansion coefficient of a material becomes important when temperature changes are so large Never try to permanently bond materials with linear expansion coefficients that differ by more than three A flexible mounting scheme should be used or the parts will break apart potentially damaging them The thermal expansion or contraction of rigid clamps or holders could crush fragile samples or sensors that do not have the same coefficient Thermal conductivity is a property of materials that can change with temperature Do not assume that a heat sink grease that works well at room temperature and above will do the same job at low temperatures 2 3 2 Sensor Location Finding a good place to mount a sensor in an already crowded cryostat is never easy There are fewer problems if the entire load and sample holder are at the same temperature Unfortunately this not the case in many systems Temperature gradients differences in temperature exist because there is seldom perfect balance between the cooling source and heat sources Even in a well controlled system unwanted heat sources like thermal radiation and heat conducting through mounting structures can cause gradients For best accuracy sensors should be positioned near the sample so that little or no heat flows between the sample and sensor This may n
68. selected instructions Paste copies an instruction and its parameters to another line in a program To insert a NOP to make room for a new instruction highlight the instruction field on the left side of the display Use Next Setting or Previous Setting to select the line to receive the inserted instruction Press the key located in the control section of the keypad to enter a NOP in the highlighted line To change a NOP to a desired instruction highlight the instruction field on the left side of the display Use Next Setting or Previous Setting to select the desired line of the program location Use the A or Y key to select the desired instruction Press Next Setting to advance to the next instruction line To set instruction parameters highlight the desired instruction on the left half of the display to display the parameters for that instruction on the right half of the display Press Enter to highlight the parameters Use Next Setting or Previous Setting to move up and down the list of parameters Set them like parameters on a normal setting screen Press Save Screen key to return to the left half of the display 8 3 4 Saving a Program When a program is entered it is automatically saved The Save Screen key must be pressed when changing from the right side of the display to the left or instruction parameter settings will be lost 8 3 5 Summary of Key Operation in Program Mode Previous Setting parameters on the right side of the set
69. table of breakpoints each containing a temperature value and its sensor units equivalent for the sensor The section on sensor selection discusses different ways of obtaining temperature response curves Curves can also be created by the user and entered into the instrument as described in the curve entry section It is assumed that an appropriate curve is present in the Model 340 before proceeding with this section Some types of sensors behave in a predictable manner and a standard temperature response curve can be created for them The Model 340 has standard curves included in firmware Refer to Table 5 3 Details on standard curves are provided in Appendix B Curves entered by the user or loaded as CalCurves will appear during curve selection list They will have curve number 21 to 60 The sensor serial number will appear on the setting screen and can be used to identify a unique curve if the serial number was included with the curve table NOTE During curve selection the instrument may only show the curves that are appropriate for an input type It is necessary to select an appropriate input type before selecting a curve Refer to Paragraph 5 4 for a description of how to select multiple curves for a scanned input Measurement Operation 5 3 Lake Shore Model 340 Temperature Controller User s Manual To select a temperature response curve press the Input Setup key The input setup setting screen will appear with the input letter in the top
70. temperature zone Paragraph 6 8 OPEN LOOP Open loop control allows the user to directly set control output This is not a PID control mode but it is available for absolute setting of output Use the Manual Output parameter for open loop settings NOTE Internal programming is not a selection for control mode but a separate feature that can change PID control parameters and several other parameters Internal programming overrides Manual PID but it can be used with Zone control refer to Paragraph 8 3 To select a control mode press the Control Setup key and the CONTROL SETUP screen appears The control loop indicator is highlighted in the upper left hand corner Use the A or W key to select Loop 1 or 2 Press the Enter or Next Setting key The control setup parameters for that loop are displayed Press the Next Setting key until the Ctrl Mode field is highlighted Use the A or Y key to select the control mode Press the Enter or Next Setting key to continue with more settings or press the Save Screen key to store the changes in the Model 340 The default setting is Manual Temperature Control Operation 6 3 Lake Shore Model 340 Temperature Controller User s Manual 6 6 MANUAL SETTING OF PID CONTROL PARAMETERS This section describes entry of PID control parameters into the Model 340 To select Manual PID control mode refer to Paragraph 6 5 6 6 1 Proportional P The proportional parameter also called gain is the P part of th
71. the Alarm Setup key The ALARM SETTINGS screen appears with the input letter in the top left hand corner Use the A or W key to select an input Press the Enter or Next Setting key to show the alarm parameters for that input Press the Next Setting key until the source field is highlighted Use the A or V key to select a source from that input Use the Next Setting key to make more changes or press the Save Screen key to store the changes The default setting is Temp K 7 3 3 Input Alarm High and Low Settings High alarm and low alarm setting values for an input alarm are set with a 6 digit value and an additional scale factor The scale factor can be selected as n u m k M and G Blank indicates a scale factory of x1 If the source is changed the settings return to their default values The instrument does not restrict the range or resolution of the alarm setting To select an input alarm high or low setting press the Alarm Setup key The ALARM SETTINGS screen appears with the input letter in the top left hand corner Use the A or V key to select an input Press the Enter or Next Setting key to show the alarm parameters for that input Press the Next Setting key until the High or Low setting field is highlighted Use the number keys to enter a value for the setting and press the Enter key Press the Enter key Use the A or W key to select a scale factor n u m k M and G Blank indicates a scale factory of x1 Press the Next Setting key t
72. the display returns to normal 6 1 3 Loop Indication on Setting Screens The loop indicator appears in the top left hand corner of setting screens change it like a parameter for that screen Press Enter after selecting a loop to display parameters for that loop on the setting screen Temperature Control Operation 6 1 Lake Shore Model 340 Temperature Controller User s Manual 6 1 4 Control Output Display The Model 340 shows the control output value on the display so the operator can monitor the control loop performance during an experiment or while tuning The output value is shown on the display whenever loop parameters for that loop are shown Control output can also be shown on the display using large characters Refer to Paragraph 4 5 for display format If the message Disabled appears in the control output field of the display the control loop must be enabled from the CONTROL SETUP screen before it is operational refer to Paragraph 6 2 There is an enable setting for each control loop and it is independent of heater range Hardware included in the heater output circuit allows more features in monitoring and displaying control output for Loop 1 If the correct value of heater resistance is entered the heater output can be shown on the display in power To change heater output units refer to Paragraph 4 5 6 The heater output is reported in percent of full scale current or power for a given heater range Full scale for the range
73. the rear panel of a controller and a resistive heater See Figure 3 5 Specifications are as follows Max Current 2A Max Voltage 60 V Attenuation 50 or 60 Hz line frequency 20 dB 100 Hz and above line frequency harmonics 40 dB Size 144 mm wide x 72 mm long x 165 mm deep 5 7 x 2 8 x 6 5 inches Weight 1 6 kilograms 3 5 pounds The Model 3003 is a passive filter and requires no external power supply The High and Low EROM GONTROLI R terminals on the controller must be connected to the High and Low terminals marked From CAUTION THIS HI TERMINAL IST BE Controller on the Model 3003 The binding posts or a dual banana plug can be used to connect to Ho the model 3003 Precautions must be taken to Lo 8 e ensure the High and Low terminals are not reversed A diode in the Model 3003 shorts the heater output if the polarity of the terminals is Ell akeShore 3003 Heater Output Conditioner reversed Figure 3 5 Model 3003 Heater Output Conditioner The High and Low terminals marked To Heater Installation 3 9 Lake Shore Model 340 Temperature Controller User s Manual on the Model 3003 should be attached to a resistive heater used for temperature control The binding posts or a dual banana plug can be used to connect to the Model 3003 The ground terminals on the Model 3003 continue the shield if the heater cable is shielded 3 5 7 Loop 2 Output The Model 340 has a second control loop called Loop 2 Loop 2 is an aux
74. the rear panel of the instrument is there to provide one more level of protection for delicate cooling systems A fuse is a current limiting device it burns out if too much current is passed through it Some systems require little heater power which requires only a small amount of current Even though the Model 340 has software current limits the user may wish to put a smaller fuse into the heater fuse holder to protect against inadvertent changes in instrument settings The heater fuse is shipped from the factory with a 2 5 A 74 x 174 inch fuse This fuse can be replaced with a value less than 2 5 A but should never be replaced with a higher value 3 5 5 Loop 1 Heater Noise The heater output circuitry in the Model 340 must be capable of sourcing 100 W of power This type of circuitry can generate some excess electrical noise The Model 340 was designed to generate as little noise as possible but even noise that is a small percentage of the output voltage or current can be too much when sensitive measurements are being made near by If the Model 340 heater leads are too noisy and the above wiring techniques do not help Lake Shore offers the Model 3003 Heater Output Conditioner that may help 3 5 6 Model 3003 Heater Output Conditioner The Lake Shore Model 3003 heater output conditioner is a passive filter that reduces the already low noise present in the heater output of the Model 340 The Model 3003 connects between the heater output terminals on
75. thermocouple types Select the range that matches the operating temperature The thermocouple temperature response curve can help when choosing an input range Room temperature compensation can limit the useable range The voltage range for inputs C and D is set independently To select an input range press Input Type 10 4 4 7 Room Temperature Compensation Room temperature compensation must be used to correct for the voltage difference between temperature response curves normalized to 273 15K and instrument operating temperature room temperature An external ice bath is the most accurate form of compensation but is often inconvenient The 3464 has built in room temperature compensation that is adequate for most applications The built in compensation can be turned on or off by the user It will operate with any thermocouple type that has an appropriate temperature response curve loaded Calibration of the built in compensation is recommended when a thermocouple is first installed or any time a thermocouple is changed 10 10 Options and Accessories Lake Shore Model 340 Temperature Controller User s Manual To turn room temperature compensation on or off press Input Setup The input setup setting screen appears with the input letter in the top left hand corner Use the A or W key to select an input Press Enter to display parameters for that input Press Next Setting until the room compensation Room Comp field highlights then use the A or
76. to their best advantage Use four lead measurement whenever possible Do not connect sensor leads to chassis or earth ground If sensor leads must be grounded ground leads on only one sensor Use twisted shielded cable outside the cooling system Attach the shield pin on the sensor connector to the cable shield Donotattach the cable shield at the other end of the cable not even to ground Run different inputs and outputs in their own shielded cable e Use twisted wire inside the cooling system Use similar technique for heater leads Use a grounded receptacle for the instrument power cord Consider ground strapping the instrument chassis to other instruments or computers 3 5 HEATER OUTPUT SETUP The following paragraphs cover the heater wiring from the vacuum shroud to the instrument for both control loop outputs Software settings and limit configuration of the heater output are detailed in Paragraph 6 12 1 For information on choosing and installing an appropriate resistive heater refer to the Paragraph 2 4 Loop 1 output is discussed in Paragraph 3 5 1 Heater output connector for Loop 1 is discussed in Paragraph 3 5 2 Heater output wiring for Loop 1 is discussed in Paragraph 3 5 3 Heater protection and fuse for loop is discussed in Paragraph 3 5 4 Noise on Loop 1 heater leads is discussed in Paragraph 3 5 5 The Lake Shore Model 3003 Heater Output Conditioner is discussed in Paragraph 3 5 6 The Loop 2 output
77. values for both P and parameters D is set to zero This mode is recommended for stable control at a constant temperature It may take slightly longer to stabilize after setpoint change than Auto PID Expect some overshoot or undershoot of the setpoint and stable temperature control at the setpoint value Auto PID Sets values for P and D parameters D is always set to the integral time in seconds and cannot be changed by the operator This mode is recommended when setpoint changes are frequent but temperature is allowed to stabilize between changes Stability at setpoint may be worse than Auto Pl in noisy systems Expect slightly less overshoot or undershoot than the other modes and control at the setpoint value Once AutoTune mode is selected the Tune annunciator will turn on when AutoTune is active No AutoTuning will occur until the setpoint is changed at least 0 5 K At that time the Tune annunciator changes to Tuning indicating the instrument is gathering data This process may take from 1 to 17 minutes depending on the system reaction time The Tuning annunciator returns to Tune when calculations are complete and new parameter values are stored The annunciator will also return to Tune if the algorithm was unable to complete Some possible reasons are setpoint change too small manual control parameter changed during tuning heater not turned on or control sensor curve not selected If the controller is not tuned satisfactorily on the
78. will reduce the update rate of these inputs from 20 readings per second to 10 readings per second 5 1 3 Thermal EMF Compensation with Voltage Excitation Sensors that require voltage excitation must be operated with little power dissipated in the sensor To keep power low the voltage across the sensor is kept low There are two major problems that occur when measuring small DC voltages The first is external noise entering the measurement through the sensor leads which is discussed with sensor setup The second problem is the presence of thermal EMF voltages sometimes called thermocouple voltages in the lead wiring Thermal EMF voltages appear whenever there is a temperature gradient across a piece of voltage lead They can be canceled in the measurement with a similar temperature gradient in the other voltage lead Thermal EMF voltages must exist because the sensor is almost never the same temperature as the instrument They can be minimized by careful wiring making sure the voltage leads are symmetrical in the type of metal used and how they are joined and by keeping unnecessary heat sources away from the leads Even in a well designed system thermal EMF voltages can be an appreciable part of a low voltage sensor measurement The Model 340 can help with a thermal correction algorithm The instrument will automatically reverse the polarity of the current source every other reading The average of the positive and negative sensor readings will canc
79. 0 9 3 IEEE 488 Serial Interface Commands sse enne 9 21 9 4 IEEE 488 Serial Interface Commands Alphabetical Listing esee 9 23 10 OPTIONS AND ACCESSORIES 5 erre tert tor tuo fo marea eae iex RE ERR Hiro nnmnnn nnna 10 1 10 0 O Li M LE 10 1 10 1 OPINAS ais 10 1 10 2 ACCES ices toe te LEE ebe 10 1 10 3 Model 3462 Dual Standard Input Option Card ssssssssssssssseee ees 10 5 10 3 1 Field Installatiom c n c ee rat ea EE 10 5 10 3 2 OperatiOh cutis A ee des ee keen Haee 10 7 10 3 3 elle ee EE 10 7 10 4 Model 3464 Dual Thermocouple Input Option Card coooooocccoccccconincoccnccnnonocnnnnnonononnnnnnonannnnnnnnos 10 7 10 4 1 Generalii arron odi A A A A enter o 10 7 10 4 2 Option Installation issii 2 eite ad race 10 8 10 4 3 Sensor Installation eege eee aie bed e Ede et A ken nes 10 8 10 4 3 1 Sensor Input Terminals iieis eiia ea ii a a a 10 8 10 4 3 2 Measurement Point Connection sss enne 10 9 10 4 3 3 Grounding and Shielding TE 10 9 10 4 4 Operation EP ELT 10 9 10 4 4 1 Default SOMOS iin Ld AAA di 10 9 10 4 4 2 Inp t Selection cuca a aid es eee ented 10 9 10 4 4 3 Displaying Option Readings ssssssssesee eene nennen 10 9 10 4 4 4 Curve Selection eee eee AA ee ce gebe ust ve ee 10 10 10 4 4 5 Curve Data Format eene etched ehe eed eine eese neve bed 10 10 10 4 4 6 Range Selection con corte tette eed e c eei tecti em tie 10 10 1
80. 0 000K 0 4 0 0 0K m Instrument Programming Lake Shore Model 340 Temperature Controller User s Manual Programmed Actual kelvin minutes Program Instructions e 1 2 3 Hbe678 567 8 5 67 sp 10 340 8 3 CVS Figure 8 3 Sample Program 1 8 3 7 Example of Using Subprograms Example 2 This is an example of a short subprogram that could easily be called from the program in example 1 It opens then closes the high relay before returning to the calling program The subprogram should be stored in program location 2 To use this subprogram insert a Call instruction with Program parameter set to 2 in the first example program Run the first example again and listen for the relays to click at the appropriate time Edit Program 402 1 Relays gt High ON Low OFF 2 Wait gt Hours 0 Minutes 0 Seconds 30 3 Relays gt High OFF Low OFF 4 End gt 8 3 8 Run an Internal Program To run a program already entered into memory press the Program key Use the Next Setting key to highlight Run program Press the Enter key Use the A or Y key or the numerical keypad to enter the program number Press the Enter key The display returns to normal and the program begins to execute If you wish to monitor where the program is press the Program key The Status line displays Running and the Line number the program is cur
81. 0 4 4 7 Room Temperature Compensation eee eene 10 10 10 4 5 Computer Interface Commands sss eene ener 10 11 10 4 6 Thermocouple Temperature Curves ssssssssseeseeeeeme emere 10 12 10 4 7 Specifications ele etn edt teet t nerit eit eau tetas e eso 10 12 10 5 Model 3465 Single Capacitance Input Option Card oooooonococccccccccccocononononnnnnnnonannoncnncnnnnnannnnns 10 12 10 5 1 Option Installation 35 her irte tite edt Pe eat ad i 10 12 10 5 2 sensor Installation iia 10 12 10 5 2 1 Sensor InputConnector 3 3 retinet tenete oai eet dese 10 12 10 5 22 Measurement Point Connection ooocooocccccncccccncconononnnnncnnnnnnnoncnnnnnnnnnnnn nn eene 10 12 10 5 2 3 Grounding and Shielding 10 12 10 5 3 Operatlony ERE 10 13 10 5 3 1 Input Selecti n s t eee dee eti ed id rd de 10 13 10 5 3 2 Displaying Option Readings nennen 10 13 10 5 3 3 Curve Sel Conc order e Orem ed eo RH AREE D e eet 10 13 10 5 3 4 Range Selection indo e otn d a ere tet e tu erts 10 13 10 5 3 5 Temperature Coefficient sssssssssssssssssseesenee neret 10 13 10 5 3 6 Control Channel Changes e nett e en RE a Tee eser e DEF dde 10 13 10 5 4 Computer Interface Commands 10 13 10 5 5 ele IT EE 10 13 10 6 Model 3468 Eight channel Input Option Card 10 14 10 6 1 General ati neuere nein n eret tectis ta tinas 10 14 10 6 2 Option Installation 5 rerit p rar c rer ie RE e erede hh euo odo 10 14 10 6 3 Sensor Installati
82. 0 and 5 for QB4 5 This one time only command produces the library file qbib qlb The procedure is found in the National Instruments QuickBasic readme file Readme qb Start QuickBasic Type qb l qbib qlb Start QuickBasic in this way each time the IEEE interface is used to link in the library file Create the IEEE example interface program in QuickBasic Enter the program exactly as presented in Table 9 3 Name the file ieeeexam bas and save Run the program Type a command query as described in Paragraph 9 1 4 5 Type EXIT to quit the program Remote Operation 9 9 9 10 Lake Shore Model 340 Temperature Controller User s Manual National Instruments Primary GPIB Address Secondary GPIB Address Timeout setting Terminate Read on EOS Set EOI with EOS on Writes Type of compare on EOS Send EOI at end of Write System Controller Assert REN when SC Enable Auto Serial Polling Enable CIC Protocol Parallel Poll Duration Use this GPIB board Base I O Address Fl Help F6 Reset Value F9 Esc Return to Map Ctl PgUp PgDn Next Prev Board National Instruments Primary GPIB Address Secondary GPIB Address Timeout setting Serial Poll Timeout Terminate Read on EOS Set EOI with EOS on Writes Type of compare on EOS Send EOI at end of Write Enable Repeat Addressing Fl Help F6 Reset Value F9 Esc Return to Map Ctl PgUp PgDn Next Prev Board GPIBO Configuration DEV12 Co
83. 0 by the period to get the integral setting Enter the integral setting into the Model 340 and watch the load temperature approach the setpoint If the temperature does not stabilize and begins to oscillate around the setpoint the integral setting is too high and should be reduced by one half If the temperature is stable but never reaches the setpoint the integral setting is too low and should be doubled To verify the integral setting make a few small 2 to 5 degree changes in setpoint and watch the load temperature react Trial and error can help improve the integral setting by optimizing for experimental needs Faster integrals for example get to the setpoint more quickly at the expense of greater overshoot In most systems setpoint changes that raise the temperature act differently than changes that lower the temperature If it was not possible to measure the oscillation period of the load during proportional setting start with an integral setting of 20 If the load becomes unstable reduce the setting by half If the load is stable make a series of small two to five degree changes in the setpoint and watch the load react Continue to increase the integral setting until the desired response is achieved 2 7 4 Tuning Derivative If an experiment requires frequent changes in setpoint or data taking between changes in the setpoint derivative should be considered See Figure 2 3e A derivative setting of zero off is recommended when the co
84. 0 volt human threshold of awareness Discharges below this level cannot be seen felt or heard Service 11 1 Lake Shore Model 340 Temperature Controller User s Manual 11 2 1 Identification of Electrostatic Discharge Sensitive Components The various symbols used in the industry to label components as ESDS are shown as follows CAUTI ss 11 2 2 Handling of Electrostatic Discharge Sensitive Components In general all precautions necessary to ensure prevention of damage to ESDS components should be observed before attempting installation This means that the device and everything that contacts it must be brought to ground potential by providing a conductive surface and discharge paths As a minimum the following precautions must be observed 1 De energize or disconnect all power and signal sources and loads used with controller 2 Place controller on a grounded conductive work surface 3 Ground technician through a conductive wrist strap or other device using 1 MQ series resistor 4 Ground any tools such as soldering equipment that will contact controller Contact with operator s hands provides a sufficient ground for tools that are otherwise electrically isolated 5 When ESDS devices and assemblies are not in controller they must be on a conductive work surface or in a conductive container When a device or assembly is inserted or removed from a container operator must maintain contact with conductive portion of container O
85. 0258 0 55494 1 06702 1 59075 0 60275 1 07750 1 62622 0 63842 1 08781 1 65156 0 67389 1 08953 1 67398 0 70909 1 09489 1 68585 0 74400 1 09864 1 69367 0 77857 i 1 10060 1 69818 0 80139 1 10263 Curve Tables Lake Shore Model 340 Temperature Controller User s Manual Table A 2 Standard DT 500 Silicon Diode Curves Sensors are no longer in production Break D Curve Curve 2 E1 Curve Curve 3 point 0 19083 0 28930 0 24739 0 36220 0 36397 0 41860 0 42019 0 47220 0 47403 0 53770 0 53960 0 59260 0 59455 0 73440 0 73582 0 84490 0 84606 0 92570 0 95327 0 99110 1 00460 1 02840 1 04070 1 07460 1 07460 1 08480 1 09020 1 09090 1 09700 1 09810 1 10580 1 10800 1 11160 1 11500 1 11900 1 12390 1 13080 1 13650 1 14860 1 15590 1 17200 1 18770 1 25070 1 23570 1 35050 1 33170 1 63590 1 65270 1 76100 1 96320 1 90660 2 17840 2 11720 2 53640 2 53660 2 59940 2 59840 2 65910 OO JO Om P GO Table A 3 Standard Platinum Curves Break PT 100 Curve 4 PT 1000 Curve 5 point OO JO Om P GO Curve Tables Lake Shore Model 340 Temperature Controller User s Manual Table A 4 Type K Nickel Chromium vs Nickel Aluminum Thermocouple Curve AC o A E El point K point K point K point K 6 45774 6 02997 2 05503 29 0181 6 45733 6 00271 1 87703 29 7714 6 45688 5 97469 1 69672 30 5011 6 45632 5 94591 1 51427 31 2074 6 45565 5 91637 E 1 32972 31 8905 6 4549
86. 0K amp BS3T GaAlAs Diode TG 120 P 1 4 K to 325 K T242K amp BS5T GaAlAs Diode TG 120 PL 1 4 K to 325 K T gt 42K amp BS5T GaAlAs Diode TG 120 SD 1 4 K to 500 K T gt 42K amp BS5T Positive Temperature 100 O Platinum PT 102 3 14 K to 873 K T gt 40K amp BS25T Coefficient RTDs 100 O Platinum PT 111 14 K to 673 K T gt 40K amp BS25T 340 3462 Rhodium Iron RF 800 4 1 4 K to 500 K T gt 77K8B lt 8T Rhodium Iron RF 100T U 1 4 K to 325 K T gt 77K8B lt 8T Negative Cernox CX 1010 0 3 K to 325 IC T gt 2K amp BS19T Temperature Cernox CX 1030 HT 0 3 K to 420 K T2K amp Bs19T Coefficient RTDs Cernox CX 1050 HT 1 4 K to 420 K T gt 2K8B lt 19T 340 3462 Cernox CX 1070 HT 4 K to 420 K T gt 2K amp B lt 19T Cernox CX 1080 HT 20 K to 420 K T 2K amp Bs19T Germanium GR 200A 30 0 1Kto 5 KC Not Recommended Germanium GR 200A 50 0 2 K to 40 K Not Recommended Germanium GR 200A 100 0 3 K to 100 K Not Recommended Germanium GR 200A 250 0 5 K to 100 K Not Recommended Germanium GR 200A B 500 1 4 K to 100 K Not Recommended Germanium GR 200A B 1000 1 4 K to 100 K Not Recommended Germanium GR 200A B 1500 1 4 Kto 100 K Not Recommended Germanium GR 200A B 2500 1 4K to 100 K Not Recommended Carbon Glass CGR 1 500 1 4 K to 325 K T gt 2K8B lt 19T Carbon Glass CGR 1 1000 1 7 K to 325 K T gt 2K amp BS19T Carbon Glass CGR 1 2000 2 K to 325 k T gt 2K amp BS19T Rox RX 102 0 1 K to 40 K T gt 2K8B lt 10T Rox RX 103 1 4 K to 40 K T 2K amp Bs10T 1 4
87. 1 150 pF units 3 nanofarads 10 5 5 Specifications The 3465 Option Card input specifications are listed in Table 1 2 Options and Accessories 10 13 Lake Shore Model 340 Temperature Controller User s Manual 10 6 MODEL 3468 EIGHT CHANNEL INPUT OPTION CARD 10 6 1 General The 3468 option adds 8 sensor inputs to the Model 340 Temperature Controller The original standard inputs remain fully functional allowing the Model 340 to measure 10 sensors when the option is installed The optional inputs are broken into two groups of four and appear on the display as C1 C4 for Input C D1 D4 for Input D The option card includes two A D converters one for each group of four inputs and individual excitation for each sensor Each group of inputs must use the same sensor type but the two groups can be different Calibration for the option is stored on the card so it can be installed in the field without recalibration The 3468 option supports all the sensors as the Model 340 standard inputs Diode and Platinum configurations have similar specifications to the standard inputs reduced only slightly to account for multiplexing However the NTC RTD configuration is quite different than the standard inputs The option has a limited resistance range of 7 5 kQ with a fixed current excitation of 10 uA compared to the 300 kQ resistance range and voltage excitation available on the standard inputs This limitation significantly reduces the low temperatu
88. 10 pA 0 05 10 pV 10 pV 80 uV 0 005 of rdg 20 uV 340 3462 negative 0Vto7 5V 10 pA 40 05 10 pV 10 pV 80 uV 0 01 of rdg 20 uV PTC RTD positive 0 Oto 2500 1 mA 1mQ 1 mQ 0 002 Q 0 01 of rdg 2mQ 340 3462 positive 0 O to 500 Q 1 mA 1mQ 1mQ 0 002 Q 0 01 of rdg 2mQ positive 0Q to 2500Q 0 1 mA 10 mQ 10 mQ 0 03 Q 0 02 of rdg 20 mQ NTC RTD negative 0 Oto 100 100 pA 100 pO 1 mO 10 02 rng 0 1 rdg 2mQ 1 mv negative 0 Oto 300 30 pA 100 uQ 3 mA 0 02 rng 0 1 rdg 6 mQ 340 3462 negative 0 Q to 100 Q 10 uA 1mQ 10 mO 0 02 rng 0 1 rdg 20 mQ negative 0 Q to 300 Q 3 pA 1mQ 30 mQ 10 02 rng 0 1 rdg 60 ma negative 00to1kQ 1 pA 10 mO 0 10 0 02 rng 0 1 rdg 0 20 negative 0 O to 3 kO 300 nA 10 mO 0 30 10 02 rng 0 1 rdg 0 60 negative 0 Q to 10 kQ 100 nA 0 10 10 10 02 rng 0 1 rdg 20 negative 0 Q to 30 kQ 30 nA 0 10 30 0 02 rng 0 1 rdg 60 NTC RTD negative 0 Oto 300 300 pA 100 uQ 300 uQ 0 02 rng 0 05 rdg 600 uQ 10 mV negative 0 O to 100 0 100 pA 1mQ 1mQ 0 02 rng 0 05 rdg 2mQ 340 3462 negative 0 Q to 300 Q 30 uA 1 mQ 3mQ 0 02 rng 0 05 rdg 6 mQ negative 0 Q to 1 kO 10 pA 10 mQ 10 mQ 0 02 rng 0 05 rdg 20 ma negative 0 OQ to 3 kO 3 pA 10 mO 30 mQ 10 02 rng 0 05 rdg 60 ma negative 0 Q to 10 kQ 1 pA 0 10 0 10 10 02 rng 0 05 rdg 0 20 negative 0 Q to 30 kQ 300 nA 0 10 0 30 10 02 rng 0 05 rdg 0 60 negative 00to100kQ 100 nA 10 30 10 02 rng 0 05 rdg 60 negative 00to300kQ 30nA 10 300 10 02 rng 0 25 rdg 600 Thermocou
89. 3 0 73397 4 39529 0 68333 4 34147 0 3517 4 29859 0 2385 4 26887 0 078749 4 22608 0 139668 4 2018 0 426646 4 02151 0 546628 3 94549 0 858608 3 87498 0 938667 3 80464 1 3456 3 73301 1 7279 3 65274 1 76905 3 5937 2 20705 3 51113 2 51124 3 45023 2 69878 3 43451 2 94808 3 37842 3 13562 3 35469 3 43707 3 28237 3 85513 3 11919 4 17136 2 95269 4 28662 2 78168 4 64037 2 60639 4 68168 2 42737 This thermocouple is no longer sold by Lake Shore Curve Tables Lake Shore Model 340 Temperature Controller User s Manual Table A 8 Chromel AuFe0 07 Thermocouple Curve Break Temp Break Temp Break Ta point K point K point K Curve Tables 5 279520 5 272030 5 263500 5 253730 5 242690 5 229730 5 214770 5 196980 5 176250 5 150910 5 116700 5 049770 5 002120 4 938000 4 876180 4 801670 4 648620 4 569170 4 499080 4 435090 4 370520 4 303610 4 234290 4 164270 4 093560 4 022170 3 950100 3 877360 3 803960 3 729910 3 655230 3 579930 3 504020 3 427530 3 340820 3 253410 3 165360 3 076690 2 977480 2 877550 2 776950 2 675700 2 563610 2 450770 2 337230 2 223010 2 097700 1 971630 1 844890 1 706840 1 568040 1 428520 1 277520 1 114900 0 940599 0 754604 0 556906 0 358437 0 170179 0 041150 0 152699 0 163149 0 374937 0 542973 0 598604 0 774384 0 840638 1 126350 1 313400 1 511140 1 709250 1 928940
90. 3 1 5 2 Handling Cryogenic Storage Dewars sss eene 3 3 3 1 5 3 Liquid Helium and Nitrogen Safety Precautions sssee 3 3 3 1 5 4 Recommended First Aid 3 4 3 2 Rear Panel Definition 3 iia epe o eee na ee ve Lee dele Te eet egen 3 4 3 3 Line Iput Assembly RE aid dt dd db dd ld ett ld 3 5 3 3 1 Line Voltage imac e aie etaed dae ME Mei 3 5 3 3 2 Line Fuse and Fuse Holder ccccccecceceeeceeeeeceeeceeeeeeeceeaaanaeceeeeeeesenanaeeeeeeesesencaneeeeeeess 3 6 3 3 3 Power Ee MEET 3 6 3 3 4 Power SWIIGh oc a cesta tatio vatis e e lado 3 6 3 4 Standard Sensor inputs ia 3 6 3 4 1 Sensor Input Connector and Pinout cocccccccononocococnnccocononnonnnnnnnnnnnnnnnnnnnnnnnnnnnnnannnnnnnnnnnnnnnanns 3 6 3 4 2 Sensor Lead Cables tested crio 3 6 3 4 3 Grounding and Shielding Sensor Leads 0ocooconnncccnnnoccccnnnonccccononcncnnnoncccnn non nnnnnnn nn eee 3 7 3 4 4 eg Polarity EE 3 7 3 4 5 Four Lead Sensor Measurement cccceceeeeeeeeccceceeeeeececeaaeeeeeeeeeseecnnaeeeseseeeeeesenaeess 3 7 3 4 6 Two Lead Sensor Measurement sss eren enne 3 7 3 4 7 Lowering Measurement Noise sssssseseeeeeeeenee eene emen enne nennen enne 3 8 3 5 Heater Output Setup eiii ede eee ret etii etta oe tr cdit tube exeo ded Tad 3 8 3 5 1 Koop Be ue LEET 3 8 3 5 2 Heater Output Connector for Loop 3 8 3 5 3 Heater Output Wiring for Loop 1 ou cececcceecceceeeeeeeeeeeaeceeee e
91. 4 5 8861 1 12444 32 571 6 4541 5 85508 0 91675 S 33 2489 6 4531 i 5 82334 0 70686 33 9038 6 45201 5 78268 0 47553 34 5561 6 45073 5 74084 f 0 22228 35 2059 6 44934 5 69792 0 053112 35 8532 6 44774 5 6539 0 350783 36 4979 6 44601 E 5 60879 0 651006 f 37 14 6 44403 5 5626 0 973714 37 7596 6 44189 5 51535 1 31919 38 3767 6 43947 5 46705 1 70801 38 9915 6 43672 5 4177 2 14052 39 6038 6 43378 5 36731 2 69954 40 2136 6 43065 5 3159 3 75883 40 821 6 42714 E 5 26348 4 29687 41 4063 6 42321 5 19928 4 74986 41 9893 6 41905 5 13359 E 5 17977 E 42 5699 6 41442 4 5 06651 5 60705 43 1288 6 40952 E 4 99801 6 03172 43 6853 6 40435 4 92813 1 6 49428 44 2394 6 39841 4 85687 7 09465 44 7721 6 39214 4 78426 8 15226 45 3024 6 38554 4 71031 8 75291 45 8114 6 37863 4 63503 9 25576 46 3182 6 37077 4 55845 9 74087 46 8038 6 36253 4 48056 10 2285 47 2873 6 35391 4 38814 10 7186 47 7684 6 34422 4 29393 11 2317 48 2287 6 33408 4 19806 11 7883 48 6868 6 3235 4 10051 12 3888 49 1426 6 3117 4 00133 13 054 49 5779 6 29939 3 90053 13 7844 50 0111 6 2866 3 79815 14 5592 50 442 6 27241 3 6942 15 3786 50 8706 6 25768 3 58873 16 2428 51 2969 6 24239 3 46638 17 1518 51 721 6 22656 3 34204 18 1482 E 52 1428 6 21019 3 21584 19 2959 52 5623 6 19115 3 08778 20 8082 52 9795
92. 6 11 SETPOINT RAMPING The Model 340 generates a smooth setpoint ramp when the setpoint units are expressed in temperature The user can set a ramp rate in degrees per minute with a range of 0 to 100 and a resolution of 0 1 Once the ramp feature is turned on its action is initiated by a setpoint change When a new setpoint is entered the instrument changes the setpoint temperature from the old value to the new value at the ramp rate A positive ramp rate is always entered and it is used by the instrument for ramps up and down in temperature The ramping feature is useful by itself but it is even more powerful when used with other features Setpoint ramps are often used with zone control mode As temperature is ramped through different temperature zones control parameters are automatically selected for best control Ramps are initiated and status read back using a computer interface During computer controlled experiments the instrument generates the setpoint ramp while the computer is busy taking necessary data AutoTune does not function during a setpoint ramp because the ramp rate disguises the reaction of the cooling system and no valid tuning data can be taken To turn on the ramp feature and set a ramp rate press the Ramp key The RAMP SETUP screen is displayed with the control loop indicator highlighted in the top left hand corner Use the A or W key to select Loop 1 or 2 Press the Enter or Next Setting key The ramp setup information for that
93. 670 5 741100 5 704560 5 667130 5 628800 5 589590 5 549510 5 508560 5 466760 5 424100 5 380600 5 336260 5 291080 5 245070 5 188800 5 131290 5 072630 5 012780 4 951770 4 889610 4 826300 4 761840 4 696250 4 629530 4 561670 4 492700 4 422610 4 351390 4 266950 4 180930 4 093440 4 004430 3 913940 3 821970 3 728520 3 633620 3 537260 3 439460 3 340240 3 239610 3 122930 3 004370 2 884040 2 761910 2 638010 2 512340 2 384920 2 255770 2 124900 1 992320 1 858060 1 705090 1 549970 1 392820 1 233640 1 072450 0 909257 0 744065 0 576893 0 407776 0 217705 0 025325 0 188573 0 404639 0 623032 0 843856 1 067190 1 293090 1 521570 1 752660 1 986340 2 222600 2 461410 2 702740 2 946550 3 192800 3 441440 3 715300 3 991980 4 271300 4 553250 4 837770 5 148790 5 462770 5 779560 6 099160 6 421500 6 746540 7 099510 7 455590 7 814630 8 176630 8 541540 8 909320 9 306450 9 706830 10 1103 10 5169 10 9264 11 3664 11 8098 12 2564 12 7342 13 2155 13 7 14 1879 14 7079 15 2314 15 7583 16 2887 16 8224 17 3594 17 9297 18 5037 19 1116 19 7538 20 4611 20 8627 Lake Shore Model 340 Temperature Controller User s Manual Table A 7 Chromel AuFe0 03 Thermocouple Curve Breakpoint Temp K Breakpoint Temp K 4 6667 2 24537 4 62838 2 06041 4 60347 1 86182 4 58043 1 66004 4 53965 1 47556 4 47226 1 0904 4 4374
94. 8 lt input gt Specifies input to display in the field lt source gt Specifies input data to display Valid entries 1 kelvin 2 Celsius 3 sensor units 4 linear data 5 minimum data and 6 maximum data DSPFLD 2 A 1 term Displays kelvin reading for Input A in display field 2 Query Displayed Field DISPFLD lt field gt lt input gt lt data source gt Format ann n term Returns the parameters for a displayed field See the DISPFLD command for parameter descriptions lt field gt specifies which field to query Valid entries 1 8 Configure Main Display Parameters DISPLAY lt number of fields gt lt contrast gt lt backlight enable gt Nothing Configures the main display screen lt number of fields gt Specifies how many input fields to display lt contrast gt Specifies the display contrast percentage lt backlight enable gt Disables or enables the display backlight DISPLAY 3 60 term Displays 3 input fields and sets the contrast to 60 Query Main Display Parameters DISPLAY lt number of fields gt lt contrast gt lt backlight enable gt Format n nnn n term Returns main display parameters See the DISPLAY command for parameter descriptions Configure Digital Output Parameters DOUT lt mode gt lt bit weighting gt Nothing Configures the parameters of the digital output lt mode gt Specifies the mode of the digital output Valid entries O off 1 alarms 2 s
95. 8 interface have another option The Model 8000 can also be ordered with the calibrated sensor 2 3 SENSOR INSTALLATION This section highlights some of the important elements of proper sensor installation For more detailed information Lake Shore sensors are shipped with installation instructions that cover that specific sensor type and package The Lake Shore Temperature Measurement and Control Catalog includes an installation section as well To further help users properly install sensors Lake Shore offers a line of Cryogenic Accessories Many of the materials discussed are available through Lake Shore and can be ordered with sensors or instruments Mounting materials is discussed in Paragraph 2 3 1 Sensor location is discussed in Paragraph 2 3 2 Thermal conductivity is discussed in Paragraph 2 3 3 Contact area is discussed in Paragraph 2 3 4 Contact pressure is discussed in Paragraph 2 3 5 Lead wire is discussed in Paragraph 2 3 6 Lead soldering is discussed in Paragraph 2 3 7 Heat sinking leads is discussed in Paragraph 2 3 8 Finally thermal radiation is discussed in Paragraph 2 3 9 2 3 1 Mounting Materials Choosing appropriate mounting materials is very important in a cryogenic environment The high vacuum used to insulate cryostats is one source of problems Materials used in these applications should have a low vapor pressure so they do not evaporate or out gas and spoil the vacuum insulation Metals and ceramics do not have this
96. Britain These standards allow Lake Shore to calibrate sensors from 50 mK to above room temperature Calibrated sensors are more expensive than uncalibrated sensors Calibrated temperature sensors are the most accurate available from Lake Shore Errors from sensor calibration are almost always smaller than error contributed by the Model 340 The Lake Shore Temperature Measurement and Control Catalog has complete accuracy specifications for calibrated sensors Calibrated sensors include measured test data printed and plotted coefficients of a Chebychev polynomial fitted to the data and two tables of data points used as interpolation tables optimized for accurate temperature conversion The smaller table called a breakpoint interpolation table fits into instruments like the Model 340 where it is called a temperature response curve Install a curve into a Model 340 through a CalCurve Paragraph 2 2 4 or manually through the instrument front panel Note instrument specifications before ordering calibrated sensors A calibrated sensor is required when a sensor does not follow a standard curve if the user wishes to display in temperature Otherwise the Model 340 operates in sensor units like ohms or volts The Model 340 may not work over the full temperature range of some sensors The standard inputs are limited to operation above 300 mK even with sensors that can be calibrated to 50 mK 2 2 Cooling System Design Lake Shore Model 340 Temperature Co
97. DESCRIPTION The Model 340 is our most advanced temperature controller and offers unsurpassed resolution accuracy and stability for temperature measurement and control applications to as low as 100 mK Operating with diodes platinum RTDs and negative temperature coefficient NTC resistor sensors the Model 340 is expandable to ten sensor inputs or to operate with thermocouple or capacitance sensors It has two control loops with the first loop powered to 100 W 1 1 Sensor Inputs The Model 340 features two inputs with high resolution 24 bit analog to digital converter and low noise circuit design providing temperature readings with resolution as low as 0 1 mK at 4 2 K Sensors are optically isolated from other instrument functions for quiet and repeatable sensor measurements Appropriate sensor excitation and input gain can be selected from the front panel An autorange mode keeps the power in NTC resistors low to reduce self heating as sensor resistance changes by many orders of magnitude Automatic current reversal with rounded square wave excitation for NTC resistors eliminates the effect of thermal EMF Standard temperature response curves for silicon diodes platinum RTDs and many thermocouples are included Up to twenty 200 point CalCurves for Lake Shore calibrated sensors or user curves can be loaded into non volatile memory via a computer interface or the instrument front panel CalCurves can be installed at the factory when purc
98. Data Stop Read one character at a time Open port Wait loop Give up processor to other events Loop until Send button pressed Set Flag as false Get Command Clear response display Set all characters to upper case Get out on EXIT Send command to instrument Check to see if query Wait for response Add 1 to timeout if no character Wait for 10 millisecond timer False Timeout at 2 seconds Reset timeout for each character Read in one character Add next character to string Get characters until terminators Check if string empty Term 1 Strip terminators Send No Response Put response in textbox on main form Reset holding string Reset timeout counter Private Sub Timerl Timer frmSerial Timerl Enabled False End Sub Routine to handle Timer interrupt Turn off timer 9 18 Remote Operation Lake Shore Model 340 Temperature Controller User s Manual 9 2 7 2 Quick Basic Serial Interface Program Setup The serial interface program listed in Table 9 7 works with QuickBasic 4 0 4 5 or Qbasic on an IBM PC or compatible running DOS or in a DOS window with a serial interface It uses the COM1 communication port at 9600 Baud Use the following procedure to develop the Serial Interface Program in Quick Basic Start the Basic program Enter the program exactly as presented in Table 9 7 Adjust the Com port and Baud rate in the program as necessary Lengthen the TIMEOUT coun
99. EEP Input Returned Remarks BEEP Input Returned Remarks BEEPST Input Returned Remarks 9 26 Lake Shore Model 340 Temperature Controller User s Manual Configure Analog Output Parameters ANALOG lt output gt lt bipolar enable gt lt mode gt lt input gt lt source gt lt high value gt lt low value gt lt manual value gt Nothing Configures the analog output parameters lt output gt Specifies which analog output to configure lt bipolar enable gt Specifies whether the analog output is positive output only or bipolar lt mode gt Specifies data the analog output monitors Valid entries 0 off 1 input 2 manual 3 loop Loop is valid only if lt output gt 2 lt input gt Specifies which input to monitor if lt mode gt 1 lt source gt Specifies input data Valid entries 1 kelvin 2 Celsius 3 sensor units 4 linear equation If mode is 1 this parameter represents the data at which the analog output reaches 100 output If mode is 1 this parameter represents the data at which the analog output reaches 100 output if bipolar or 0 output if positive only manual value If mode is 2 this parameter is the output of the analog output ANALOG 1 1 2 25 5 term Sets analog output 1 to manual mode with 25 5 output 2 55 V ANALOG 2 0 1 A 1 100 0 0 0 term Sets analog output 2 to monitor Input A kelvin reading with 100 0
100. Input Setup with a Scan Mode Active ssssssssssssssseeeen eene 5 7 Manual Scanning WEE 5 7 Auto Scannllg 565i toe E a edn etie 5 8 SlaveScafinirig aiee e D an ene 5 8 Temperature Control Operation ee EEN EEN 6 1 i C Nr ITE 6 1 Control Loop Displays i eU rette A eee oo aed ee Set ete 6 1 Control Loops on the Normal Display 6 1 Loop Indication on the Normal Display sssssesesseeeee enn 6 1 Loop Indication on Setting Screens ssssssssseeeem emm 6 1 Control Output Display niente tt eet eee exe ee eb ei eee tl eun hato ally 6 2 GControl Eoop Enable 4 5 ege dee e OH EE enda aes Aetna 6 2 Control Eoop FEllter 1 5 i tede tos 6 2 Control Channel sn etd reitera eie eR eee do A aede uci 6 3 Control Modes 25 irae hi te oe cedi eade delit de de reel hei tides 6 3 Lake Shore Model 340 Temperature Controller User s Manual 6 6 Manual Setting of PID Control Parameters sssssssee eene eene 6 4 6 6 1 Proportional EL 2 1 ee eh ap ei eee aede a dee tae eee 6 4 6 6 2 Integral EE 6 4 6 6 3 Derivative Divinidad ta ecient ert einer aan ded et Met pup dtd 6 4 6 6 4 Manual Output tecto ete ee eben bee fo ee nal bate eee eee 6 4 6 7 Selecting an AutoTune Control Mode sssssseee ee ener enne 6 4 6 8 Zone Control Data Entry iaceat e aee eid er e aveo de av edd ee bed 6 5 6 9 Using Open Loop Control 1 rt reet ect ads 6 7 6 10 Setting a Setpoint and Setpoint Units ee
101. PT CRVSAV SCAL PGM PGM PGMDEL PGMRUN ANALOG DATETIME DATETIME Query Date and Time DISPFLD DISPLAY MNMXRST RELAYST CRVHDR PGMMEM PGMRUN Function Set Loop 1 Settle Query Loop 1 Settle Query Tuning Status Set Zone Query Zone System Commands Reset Alarms Set Analog Outputs Query Analog Outputs Query Analog Output Data Set Beeper Query Beeper Query Beeper Status Query Instrument Busy Status Set Serial Interface Query Serial Interface Set Date and Time Set To Factory Defaults Query Digital I O Status Set Display Field Query Display Field Set Display Query Display Set Digital Output Query Digital Output Set IEEE Interface Query IEEE Interface Query Keypad Status Set Lock out and Code Query Lock out and Code Reset Min Max Data Set Local Remote Mode Query Local Remote Mode Set Relay Query Relay Query Relay Status Query Revision Information Set External Scanner Query External Scanner Curve Commands Erase a Curve Set Curve Header Query Curve Header Set Curve Point Query Curve Point Save All Curves to Flash SoftCal Voltage Entry Program Commands Add a Program Line Query a Program Line Erase a Program Query Program Lines Left Run a Program Query Program Status Data Logging Commands Query PID LOG Set Ramp LOG Query Ramp LOGCNT Query Ramp Status LOGPNT Set Heater Range LOGPNT Query Heater Range LOGSET Set Setpoint LOGSET Query Setp
102. Panel Connector Details 100 mA of current providing a maximum of 1 W of power They can drive a resistive load of no less than 100 O The output is short protected so the instrument is not harmed if the heater resistance is too small It is not recommended because the additional load on instrument power supplies causes noise on internal circuits The connectors for the analog outputs are BNC sockets The inner conductor is the output voltage terminal the outer conductor is the outputs ground and is attached to chassis ground inside the instrument A coaxial cable with attached BNC plug is recommended for this output These connectors are not included with the Model 340 but are available from local electronic suppliers It is not recommended to attach the analog output ground to a ground outside the instrument The output should be read by an instrument with an isolated or differential input wherever possible Connecting to an external ground can cause noise in the analog output voltage or the sensor input measurement If this cannot be avoided try to keep the chassis of the two instruments at the same potential with a ground strap Installation 3 11 Lake Shore Model 340 Temperature Controller User s Manual 3 7 DIGITAL I O The connector labeled Digital I O on the DIGITAL I O rear panel of the Model 340 has terminal pins with digital inputs and outputs along with power supplies See Figure 3 7 The digital inputs and outputs can be used to i
103. Remarks 9 28 Returns the maximum output current for loop 1 when the Max Current Limit setting is set to User See CLIMI command for parameter descriptions This setting is only available in main firmware version 01 03 08 and later Configure Control Loop Limit Parameters CLIMIT lt loop gt lt SP limit value gt lt positive slope value gt lt negative slope value gt lt max current gt lt max range gt Nothing Configure control loop limits lt loop gt Specifies which loop to configure lt SP limit value gt Specifies loop setpoint limit and at what reading the loop turns off output lt positive slope value gt Specifies maximum positive change in output lt negative slope value gt Specifies maximum negative change in output lt max current gt Specifies maximum current for loop 1 heater output Paragraph 6 12 1 Valid entries 1 0 25 A 2 0 5 A 3 1 0 A 4 2 0 A 5 User User setting is only available in main firmware version 01 03 08 and later lt max range gt Specifies maximum loop 1 heater range Paragraph 6 13 3 Valid entries 0 5 CLIMIT 1 325 0 10 O term Control Loop 1 limits the setpoint to 325 turns off output when the reading based on the setpoint units reaches 325 limits the change in the output to 10 with no limit on the output going down Query Control Loop Limit Parameters CLIMIT lt loop gt lt SP limit value gt lt positive slope value gt lt
104. Screen key to store the changes in the Model 340 The default setting is Temp K 4 5 4 Control Loop Display The Model 340 has the ability to operate one or two temperature control loops The user has the option of displaying parameters from either one or both loops When both loops are displayed fewer parameters are shown on the normal display The hidden parameters can be viewed by pressing the Loop 1 or Loop 2 key they will also appear when being changed Displays Loop 1 parameters including P D and Manual Out Displays Loop 2 parameters including P D and Manual Out Displays setpoint control channel and percent output for both loops Heater Range for Loop 1 None Neither set of control loop parameters are shown To select a control loop display format press the Display Format key then press the More key to show the CONTROL DISPLAY FORMAT screen The control loops line will be highlighted so use the A or V key to select one of the choices Press the Enter or Next Setting key to continue with other settings Press the Save Screen key to store the changes in the Model 340 The default setting is Loop 1 4 5 5 Large Heater Display There are applications where the amount of power being driven into the control load is as important as the control temperature In this case the control loop output can be shown in large characters on the display The larger output will replace P D and Manual Output on the display The hi
105. Shore Model 340 Temperature Controller User s Manual Configure Curve Header CRVHDR lt curve gt lt name gt lt SN gt lt format gt lt limit value gt lt coefficient gt Nothing Configures the user curve header Paragraph 8 1 3 NOTE Curves are not permanently updated in the curve FLASH until a CRVSAV command is issued lt curve gt Specifies which curve to configure Valid entries 21 60 lt name gt Specifies curve name Limited to 15 characters lt SN gt Specifies the curve serial number Limited to 10 characters lt format gt Specifies the curve data format Valid entries 1 mV K 2 V K 3 Q K 4 log Q K 5 log Q log K Specifies the curve temperature limit in kelvin Specifies the curves temperature coefficient Valid entries 1 negative 2 positive CRVHDR 21 DT 470 00011134 2 325 0 1 term Configures User Curve 21 with a name of DT 470 serial number of 00011134 data format of volts versus kelvin upper temperature limit of 325 K and negative coefficient lt limit value gt lt coefficient gt Query Curve Header CRVHDR lt curve gt lt name gt lt SN gt lt format gt lt limit value gt lt coefficient gt Format aaaaaaaaaaaaaaa aaaaaaaaaa n nnn nnn n term Returns a standard or user curve header See the CRVHDR command for parameter descriptions lt curve gt specifies which curve to query Valid entries 1 60 Configure Curve Data Point CRVPT lt curve g
106. Some types of sensors behave in a very predictable manner and a standard temperature response curve can be created for them Standard curves are a convenient and inexpensive way to get reasonable temperature accuracy Sensors that have a standard curve are often used when interchangeability is important Some individual sensors are selected for their ability to match a published standard curve and sold at a premium but in general these sensors do not provide the accuracy of a calibrated sensor For convenience the Model 340 has several standard curves included in firmware 2 2 4 CalCurve The CalCurve service provides the user with a convenient way get the temperature response curve from Lake Shore calibrated sensors into instruments like the Model 340 It can be performed at the factory when calibrated sensors and instruments are ordered together The factory installed CalCurve option is Model 8001 and should be ordered with the calibrated sensor A CalCurve can be done in the field when additional or replacement sensors are installed Curve data is loaded into some type of non volatile memory that is installed into the instrument by the user In the case of the Model 340 the curve is loaded into a non volatile memory card that can be used for transfer into the instrument The field installed version is a Model 3405 128F CALCRV and it should be ordered with the calibrated sensor Customers that have a PC compatible computer with an RS 232C or IEEE 48
107. Specifies the record number The first record is numbered 1 Use the A or V key to increase or to decrease the record number The number keys followed by Enter can also be used to enter a record number directly 8 4 1 5 Dumping the Logged Data to the Serial I O Port Logged data can also be transferred to the Serial I O port Highlight Dump logged data and press the Enter key The following message will appear on the display To stop dumping press the Escape key The dumped data has the following format lt Timestamp gt Point 1 gt lt Point2 gt lt Point3 gt lt Point4 gt term where lt Timestamp gt Shows the timestamp of the record Refer to the DATETIME query for the string format lt Point n gt The Model 340 decodes the stored data depending on the point type 1 Input lt value gt lt status gt lt value gt is in either K or C or sensor unit depending on the input source lt status gt indicates input status and can have a value from O to 255 Each bit has its own meaning as shown below Bit 7 1 Input is DISABLed Bit 6 1 Input has NOCURVe Bit 5 1 Input is S OVER Bit 4 1 Input is S ZERO Bit 3 1 Input is T OVER Bit 2 1 Input is T UNDR Bit 1 1 Old reading Bit 0 1 Invalid reading 2 SP1 2 value value is in either K or C or sensor unit depending on the setpoint unit 3 Out1 value current power heater range value is in 9o lt current power
108. T3 value Specifies third temperature point lt U3 value Specifies third sensor units point SCAL 1 21 340000 4 2 1 6260 77 32 1 0205 300 0 0 5189 term Generates a three point SoftCal curve from standard curve 1 and saves it in user curve 21 Configure Control Loop Setpoint SETP lt loop gt value Nothing Configures the control loop setpoint loop Specifies which loop to configure value The value for the setpoint in whatever units the setpoint is using SETP 1 122 5 term Control Loop 1 setpoint is now 122 5 based on its units Query Control Loop Setpoint SETP loop value Format tnnn nnnE n term Returns the control loop setpoint See the SETP command for parameter descriptions loop specifies which loop to query Sets Loop1 Settle Parameters SETTLE lt threshold gt lt time gt Nothing Configures Loop 1 settle parameters Refer to description of Status Byte Register in Paragraph 9 1 3 1 lt threshold gt Specifies the allowable band around the setpoint Valid entries 0 0 100 00 lt time gt Specifies time in seconds the reading must stay within the band Valid entries 0 86400 SETTLE 10 0 10 term The Control Loop 1 input readings must be within 10 K of the setpoint for 10 seconds before the Within Control Limit flag is set Query Loop1 Settle Parameters SETTLE threshold time Format nnn nn nnnnn term Returns Control Loop 1 settle parameters S
109. Twisted shielded cable is recommended for wiring to the 3468 outside of the cryostat Cable shields should be connected to the shield S pins of the input connector There are enough shield pins in to connect an individual shield for each input if necessary The body of the connector is at earth ground and nat the options measurement common therefore it does not make an effective shield The connector body should not be connected to any signal or shield lines during measurement because it can cause ground loop noise 10 6 3 3 Reading Rate Both inputs update every 400 milliseconds when fully loaded with sensors Update rate improves with fewer active sensors in a group of four as shown below To disable unused sensor inputs use the Input Setup screen Paragraph 10 6 4 2 of enabled channels Update rate of readings second 20 20 10 14 Options and Accessories Lake Shore Model 340 Temperature Controller User s Manual 25 Pin Connector eps Input Connector Input C Input Connector Input D PIN DESC PIN DESC PIN DESC PIN DESC Pa nc lI Pas a sa a aj ae pepe po oe o ewe te cv 4 oi D s sl s r GE oa jaa Dove 19 Dav pps pave 22 o Alt 4 D4V D4V Com pm pa Dave 25 ba Figure 10 10 Sensor Input Connector FE GE a ca ot SE C2V 3l 3V CAL C4V 18 6 EM EL GM 8 2 ES 1 24 12 25 13 10 6 4 Operatio
110. V 9 500 mV 12 5V INTYPE A 2 term Sets Input A sensor type to GaAlAs diode INTYPE B 3 7 term Sets Input B sensor type to Platinum 100 but use a 30 pV excitation Input B now responds as a Special Remote Operation INTYPE Input Returned Remarks KEYST Input Returned Remarks KRDG Input Returned Remarks LDAT Input Returned Remarks LDATST Input Returned Remarks LINEAR Input Returned Remarks Example LINEAR Input Returned Remarks Remote Operation Lake Shore Model 340 Temperature Controller User s Manual Query Input Type Parameters INTYPE lt input gt lt type gt lt units gt lt coefficient gt lt excitation gt lt range gt Format n n n nn nn term Returns input type parameters See the INTYPE command for parameter descriptions lt input gt Specifies which input to query Query Keypad Status KEYST lt keypad status gt Format n term Returns keypad status since the last KEYST 1 key pressed 0 no key pressed KEYST returns 1 after initial power up Query Kelvin Reading for an Input KRDG lt input gt lt kelvin value gt Format nnn nnnE n term Returns the kelvin reading for an input lt input gt specifies which input to query Query Linear Equation Data for an Input LDAT lt input gt linear value Format nnn nnnE n term Returns the linear equation data for an input lt input gt specifies which inpu
111. Y key to select on or off Press Save Screen to store the changes in the Model 340 The default setting is On Room Temperature Calibration Procedure Field calibration of room temperature compensation is important Factory calibration is accurate to within 1 K Differences in thermocouple wire and installation technique account for most of that error Achieve the best accuracy by calibrating the thermocouple used If that is not possible use a thermocouple made from the same wire For less demanding applications a short across the input terminals will work Calibrate both inputs even if they use the same type of thermocouple 1 Attach thermocouple sensor or direct short across input terminals of input C or D Refer to Table 10 1 for polarity 2 Place the instrument away from drafts with an accurate room temperature thermometer near the thermocouple or terminal block Allow the instrument to warm up for at least one half hour without moving it or handling the sensor Insert the Thermocouple into the ice bath liquid nitrogen or helium dewar This temperature should be close to the measurement temperature The further away the operating temperature is from the Room Compensation temperature the greater the chance of error 5 Read the displayed temperature Standard laboratory practices are expected the temperature at the top of a dewar of liquid nitrogen is different from the bottom If the temperature display is not as expected check w
112. a current source and not a power source The Model 340 itself adds confusion with the number of available heater ranges There are three things that determine the full scale power of a given heater setup heater resistance maximum current parameter and the heater range parameter Some typical heater output powers are given in Table 6 2 to illustrate how these variables affect heater power The resistive heater is not included with the instrument The cooling system determines the physical size location and resistance of the heater refer to Paragraph 2 4 A heater must be chosen that can dissipate the full scale power available on the highest heater range that may be used It is recommended to use a heater with resistance between 10 Q and 100 Q The nominal resistance of the heater should be entered into the instrument so the display shows heater parameters properly in power units An incorrect setting of heater resistance does not change the operation of the heater output To enter a heater resistance press the Control Setup key and the CONTROL SETUP screen is displayed The control loop indicator is highlighted in the upper left hand corner Use the A or Y key to select Loop 1 Press the Enter or Next Setting key The control setup parameters for that loop appear on the screen Press the Next Setting key until the Htr Q field is highlighted Use the number keys to enter the resistance of the heater in ohms Press the Enter or Next Setting ke
113. able A parameter with enable as part of the name can use these values 0 disabled or 1 enable lt status A parameter with status as part of the name can use these values 0 off or disabled and 1 on or enabled lt value A parameter with value as part of the name is specified in floating point format This format can use scientific notation Example 2 45600E 3 bit weighting A number between 0 and 255 derived from the sum of all the weighted bit values Bit Weight 0 1 1 2 2 4 3 8 4 16 5 32 6 64 7 128 input Indicates which sensor input to use Sample values are A B and A3 loop Indicates which control loop to use Valid values are 1 2 lt offlon gt Indicates whether an item is turned off or turned on 0 is off and 1 is on lt output gt Indicates which analog output to use Valid values are 1 2 Remote Operation 9 21 Command Lake Shore Model 340 Temperature Controller User s Manual Function Command Common Commands CLS ESE ESE ESR IDN OPC OPC RST SRE SRE STB TST WAI Input Commands ALARM ALARM ALARMST CRDG FILTER FILTER INCRV INCRV INSET INSET INTYPE INTYPE KRDG LDAT LDATST LINEAR LINEAR MDAT MDATST MNMX MNMX RDGST SRDG Control Commands CDISP CDISP CFLIT CFLIT CLIMI CLIMI CLIMIT CLIMIT CMODE CMODE CSET CSET HTR HTRST MOUT MOUT PID PID RAMP RAMP RAMPST RANGE RANGE
114. ace so the computer is not slowed down by temperature control overhead Several math features are included to improve usability and aid in setting up experiments It is often useful to have reading filters and maximum and minimum calculations easily available on the front panel The Model 340 also computes a linear equation on reading data to allow flexibility in how the display represents experimental inputs 1 3 Interface The Model 340 can be fully involved in computer controlled experiments It is equipped with IEEE 488 and RS 232C interfaces Either interface can send settings to the Model 340 and collect reading data from it Even the analog outputs relays and Digital UO can be controlled by computer interface The Model 340 has several features to make it more valuable as part of a larger measuring system Two analog voltage outputs can be used to report a voltage that is proportional to the temperature of an input The outputs can be controlled manually as a voltage source for any other application Two relays can be used with the alarm setpoints in latching mode for error detection or in non latching mode for simple on and off control Digital I O can be used with an external scanner or manually OLine Input Assembly OData Card ORelays Heater Fuse GIEEE 488 Interface Analog Outputs Heater Output OSerial RS 232C 0 Standard Sensor Inputs OOption Slots ODigital I O 1 2 Introduction Lake Shore Model 340 Temperature Con
115. age caused by this product or its failure to work or any other incidental or consequential damages Use of our product implies that you understand the Lake Shore license agreement and statement of limited warranty FIRMWARE LICENSE AGREEMENT The firmware in this instrument is protected by United States copyright law and international treaty provisions To maintain the warranty the code contained in the firmware must not be modified Any changes made to the code is at the user s risk Lake Shore will assume no responsibility for damage or errors incurred as result of any changes made to the firmware Under the terms of this agreement you may only use the Model 340 firmware as physically installed in the instrument Archival copies are strictly forbidden You may not decompile disassemble or reverse engineer the firmware If you suspect there are problems with the firmware return the instrument to Lake Shore for repair under the terms of the Limited Warranty specified above Any unauthorized duplication or use of the Model 340 firmware in whole or in part in print or in any other storage and retrieval system is forbidden TRADEMARK ACKNOWLEDGMENT Many manufacturers and sellers claim designations used to distinguish their products as trademarks Where those designations appear in this manual and Lake Shore was aware of a trademark claim they appear with initial capital letters and the or symbol Apiezon is a trademark of Biddle
116. ailable only if Input is specified in the Type field Note Changing Input will erase stored records Source Specifies the source of the selected Input channel TEMP K TEMP C MAX MIN SENSOR LINEAR can be chosen This field is available only if Input is specified in the Type field Note Changing Source will erase stored records 8 4 1 2 Starting Data Logging To start data logging highlight Start logging data and press the Enter key The data logging starts immediately and the Status on the right bottom of the DATA LOGGING screen will indicate Logging The Record counter on the left bottom of the same screen will increment as records are stored in the SRAM Data Card NOTE Data logging will not start if the Data Card is write protected or it has full data and Continue is selected in the Start Mode with No Overwrite 8 4 1 3 Stopping Data Logging To stop data logging highlight Stop logging data and press the Enter key The data logging stops immediately and the Status on the right bottom of the DATA LOGGING screen will indicate Stopped The Record counter on the left bottom of the same screen shows the number of records that are currently stored in the SRAM Data Card Instrument Programming 8 15 Lake Shore Model 340 Temperature Controller User s Manual 8 4 1 4 Viewing the Logged Data To view the logged data on the display highlight View logged data and press the Enter key The VIEW DATA LOG screen will appear Record
117. al Sensor Installation In A Mechanical HRetrgerator 2 5 Examples of PID Control REESEN CAE ed ete e dae i sse adt te vu a eh dene ide cid 2 10 Typical Cryogenic Storage DEWA eene een nennen nennen 3 3 Model 340 Rear Panels iet e thereto tht Ed EES taria 3 4 Eine Input Assemlbly 3 2 a Db b o b herd lec Pise te bare bere certi dene 3 5 Fuse Data Legerids iic tete urea SEENEN EERSTEN 3 5 Model 3003 Heater output Conditioner nn nnnnn 3 9 Analog OUT 1 and 2 BNC Rear Panel Connector Details ssssesse 3 11 Digital I O DA 15 Rear Panel Connector Details 3 12 Relays LO and HI Rear Panel Connector emen 3 12 Model 340 Front Panel etre t qe gebe dee d 4 1 D ta Nee C 5 5 Record of Zone S6ettlrigs tcn talas tdi etta dti ee rb Eb ec PR ci la li 6 6 SoftCal Temperature Ranges for Silicon Diode Sensors eseeseereeeereseerrsserrrrssrerreses 8 4 SoftCal Temperature Ranges for Platinum Sensors ee 8 5 Sample Progra RN 8 13 GPIB Setting Configuration EE 9 5 DEV 12 Device Template Confouraton nano enne 9 5 Typical National Instruments GPIB Configuration from IBCONF ENEE 9 10 Serial Interface Connections terrent tere Eie tddi da 9 13 Model 2001 RJ 11 Cable Assembly sssssssseseeeeene eene 10 3 Model 2003 RJ 11 to DE 9 Adapter enne 10 3 Optional Model 2002 RJ 11 to DB 25 Adapnter nn 10 4 Model 3012 Rack Mount Kit 10 4 Cover and Option Plate Screws
118. allation into different systems Heater Resistance and power are discussed in Paragraph 2 4 1 Heater location is discussed in Paragraph 2 4 2 Heater types are discussed in Paragraph 2 4 3 Finally heater wiring is discussed in Paragraph 2 4 4 2 4 14 Heater Resistance and Power Cryogenic cooling systems have a wide range of cooling power The resistive heater must be able to provide sufficient heating power to warm the system The Model 340 can supply up to 100 W of power to a heater if the heater resistance is appropriate The Model 340 heater output current source has a maximum output of 2 A limiting maximum power to Max Power watts 2 Ay x Resistance ohms Even though the Model 340 output is a current source it has a voltage limit called the compliance voltage of 50 V which also limits maximum power 50 volts Max Power watts Resistance ohms 2 6 Cooling System Design Lake Shore Model 340 Temperature Controller User s Manual Heater Resistance and Power Continued Both limits are in place at the same time so the smaller of the two computations gives the maximum power available to the heater A heater of 25 Q allows the instrument to provide its maximum power of 100 watts A typical smaller resistance of 10 Q allows 40 watts of power while a typical larger resistance of 50 Q allows 50 watts The resistor chosen as a heater must be able to withstand the power being dissipated in it Pre packaged resisto
119. alm duero Ee Ec rere Pte dede eee RU Ee ied its 8 13 8 3 10 Clear Internal Program Memory ssssssseeeneeeneeene eene nnne nnne nns 8 14 8 4 Data Card Operation 3 t tH er RU AE Set e UHR e Dees dee 8 14 8 4 1 Data Logging To A Data Card ssssssssessseee eene eene eene nnne 8 14 8 4 1 1 Log Setup Siete ER Rd ie Nn e UR RED ert e ed vede 8 15 8 4 1 2 Starting Data Eogglrig is 2 2 iden ec e ot repudii i eed 8 15 8 4 1 3 Stopping Data Logging MEET 8 15 8 4 1 4 Viewing the Logged Data tete deer ed 8 16 8 4 1 5 Dumping the Logged Data to the Serial I O Port ssssse 8 16 8 4 1 6 Line Power LOSS iet rero e ee EP tatoo R 8 16 8 4 2 Reading From A Data Card cei ete eR deett tds 8 17 8 4 3 Writing To A Data Gatd in ede re i dert dal 8 17 8 4 4 Erasing A Daa Card i duin at tn o a e BORA PRORA icem ides 8 17 Remote Operation oit Eege seven cenanechsadencetstaaaes 9 1 9 0 General tte i to eta b dta t n itte etes 9 1 9 1 EEE 488 Interface conta ibeoiens gene oinnia ne 9 1 9 1 1 IEEE 488 Interface Settings Witt 9 1 9 1 2 IEEE 488 Command Structure sss nennen enemies 9 1 9 1 2 1 Bus Control Gommands doeet ede hne dedica iet ie e 9 2 9 1 2 2 Common Command Sorese aeaa ped Hed aded eti Dp cedet 9 2 9 1 2 3 Interface and Device Specific Commands 9 2 9 1 3 Status Reglsters ec i Ee eo da ue iat be edes 9 3 9 1 3 1 Status Byte Register and Service Request Enable Regis
120. ameters like control setpoint directly from the normal display Other instrument setup parameters have unique setting displays that conveniently combine several related parameters on one screen For details refer to Paragraph 4 4 Keypad Navigation 4 2 3 Data Entry Displays Data entry displays are special setting displays Their layout allows easy entry of data tables including temperature response curves They follow the same instructions as setting displays in Paragraph 4 4 Keypad Navigation 4 2 4 Error Displays Some error conditions are part of normal operation and do not prevent the instrument from operating Error messages for these will be shown on the normal display and the instrument will continue to operate until the situation is corrected Errors that prevent the instrument from functioning properly can result in an error display that replaces the normal display In this case the instrument will not try to operate until the error has been corrected Error messages are summarized in Paragraph 11 9 Some errors result from mistakes made when changing instrument settings or entering data If this happens read and follow the instructions shown Also verify the settings by going back to the setting screen after the instrument has shown a normal display 4 3 KEYPAD DESCRIPTION The Model 340 has 40 keys on its keypad which help prompt the operator in using the large number of powerful software features This section will help the
121. and corner Use the A or W key to select an input Press the Enter key or the Next Setting key to display the input parameters for that input Press the Next Setting key until the type field is highlighted and then use A or Y key to select special from the list of settings Press the Enter key or the Next Setting key and to advance to the next parameter Set the parameters of units temperature coefficient excitation and input range from the list in the table above If special setup was successful proceed to temperature response curve selection in Paragraph 5 2 by pressing the Previous Setting key or press the Save Screen key to store the changes in the Model 340 5 1 5 Turning an Input Off There are cases particularly when using scanned inputs that the user may wish to turn off an input This can be done from the input setup screen If an input that has been turned off is chosen for the display the DISABLE message will appear in the reading field To turn an input off press the Input Setup key The INPUT SETUP screen will appear with the input letter in the top left hand corner Use the A or Y key to select input A or B Press the Enter or Next Setting key until the Enable field is highlighted Use the A or W key to select OFF Press the Save Screen key to store the change in the Model 340 5 2 SELECTING A TEMPERATURE RESPONSE CURVE A temperature response curve is needed to convert a sensor reading in sensor units to temperature A curve is a
122. anda aAA RAO 2 1 2 1 2 SENSO SONSIIVIY de P tener shies 2 1 2 1 3 Environmental Condlitl fis 5 2 2 cte terit rtc eoe ed End eO esr edis io bra 2 2 2 1 4 Measurement AGCUFacy tiet mb ba t ER actam tena tacta a ee tU Re ARREST 2 2 2 1 5 i re ze P M 2 2 2 2 Calibrated Sensors e detta a ER ete qi la tL a Dd abet tea ine Dh udine 2 2 2 2 1 Re ge Ee le te EE 2 2 222 Stier O 2 3 2 2 3 otaridard NET 2 4 2 2 4 Elte 2 4 2 3 Sensor lIristallatlon 2 aio tirita ita 2 4 2 3 1 Mounting Materials ocio pt elsa 2 4 2 3 2 Sensor location ie oenar aena a eE K a e Ea Eaa EEO Aaa EE aa eE AEAEE A AARET ON oiy 2 4 2 3 3 Thermal e lee EE 2 5 2 3 4 Contact Ee 2 5 2 3 5 Contact Pressure ech ice ne cete ea trn he Rae FERE HEY Eu Nee Id SY EAR e HARE NA capes 2 5 2 3 6 EORUM EP 2 6 2 3 7 E EE 2 6 2 3 8 Heat Sinking Leads noce eet dd e Dee 2 6 2 3 9 Thermal RAdiation Ree Pm 2 6 2 4 Heater Selection and Installation ooooonnnicincnnnndnnnnnoccocconcnncnonnnnnonnnnnnnnnnnnnn non nnnncnnnnn naar nnnnnnns 2 6 2 4 1 Heater Resistance and Power sss eee eene nennen nnne 2 6 2 4 2 Heater LOCATION 5 o er ee E er dec oh il eaaet REY ado eR E RR ER eae ae REN ao Ee 2 7 2 4 3 Eater TYPOS CL em 2 7 2 4 4 Heater UI Sites cis cect ae Sess eden ta ta Ita ate 2 7 2 5 Consid
123. ange as sensitivity can minimize the effect of most error sources Install the sensor properly following guidelines in Paragraph 2 3 Have the sensor and instrument periodically recalibrated or in some other way null the time dependent errors Use a sensor calibration appropriate for the accuracy requirement 2 1 5 Sensor Package There are many types of sensor packages which generally determine sensor size thermal and electrical contact to the outside and sometimes limit temperature range Some sensors may be purchased as bare chips without a package When different packages are available for a sensor consider the sensor mounting surface and how leads will be heat sinked 2 2 CALIBRATED SENSORS It can be difficult to choose the right sensor calibrate it translate calibration data into a temperature response curve understandable to the Model 340 and load the curve into the instrument Lake Shore offers a variety of calibration and curve loading services to fit different accuracy requirements and budgets traditional calibration in Paragraph 2 2 1 SoftCal in Paragraph 2 2 2 standard curves in Paragraph 2 2 3 and the Lake Shore CalCurve Service in Paragraph 2 2 4 2 2 1 Traditional Calibration Calibration compares a sensor with an unknown temperature response to an accepted standard Lake Shore temperature standards are traceable to the U S National Institute of Standards and Testing NIST or the National Physical Laboratory in Great
124. aragraph 3 1 6 3 1 4 Inspection and Unpacking Inspect shipping containers for external damage All claims for damage apparent or concealed or partial loss of shipment must be made in writing to Lake Shore within five 5 days from receipt of goods If damage or loss is apparent please notify the shipping agent immediately Open the shipping containers A packing list is included with the system to simplify checking that the instrument sensor accessories and manual were received Please use the packing list and the spaces provided to check off each item as the instrument is unpacked Inspect for damage Be sure to inventory all components supplied before discarding any shipping materials If there is damage to the instrument in transit be sure to file proper claims promptly with the carrier and insurance company Please inform Lake Shore of such filings In case of parts or accessory shortages advise Lake Shore immediately Lake Shore cannot be responsible for any missing parts unless notified within 60 days of shipment The standard Lake Shore Warranty is included on the A Page immediately behind the title page of this manual 3 1 2 Repackaging For Shipment To return the Model 340 sensor or accessories for repair or replacement obtain a Return Goods Authorization RGA number from Technical Service in the United States or from the authorized sales service representative from which the product was purchased Instruments may not be accep
125. are several Source of data from the input The default is Temp K other parameters to set TempK Kelvin temperature reading from an input The sensor input must Temp C Celsius temperature reading from an input be chosen and the data Sensor Sensor units reading from an input source from the input Linear Linear equation data from an input Sensor input setup Reading data value that corresponds to 10 V when bipolar 0 V including operation of when unipolar The value may be set as a six digit floating point the linear equation is number The default setting is 0 discussed in Paragraph 5 3 3 Once the sensor input data is directed to an analog output there are two other parameters that must be set The low and high parameters define the 6 digit sensor input reading values that comprise the bottom and top of the analog output voltage range The scale factor can be selected as n u m k M or G Blank indicates a scale factory of x1 These parameters are included so the user can control the range and sensitivity of the output The example below demonstrates how the high and low parameters work To configure an analog output select the Mode and Bipolar setting then continue with the other parameters listed above Highlight the parameter field and select the appropriate setting values Press the Save Screen key when finished to save the changes The Value field that appears is not a settable parameter in this mode It reports the analog o
126. area Tal has been well ventilated If inhaled remove to fresh air If not breathing give artificial respiration If breathing is difficult give oxygen Get medical help Figure 3 1 Typical Cryogenic Storage Dewar e Liquid helium and liquid nitrogen can cause severe frostbite to the eyes or skin DO NOT touch frosted pipes or valves In case of frostbite consult a physician at once If a physician is not readily available warm the affected areas with water that is near body temperature The two most important safety aspects to consider when handling LHe and LN are adequate ventilation and eye and skin protection Although helium and nitrogen gases are non toxic they are dangerous in that they replace the air in a normal breathing atmosphere Liquid products are of an even greater threat since a small amount of liquid evaporates to create a large amount of gas Therefore it is imperative that cryogenic dewars be stored transfers accomplished and systems operated in open and well ventilated areas Persons transferring LHe and LN should make every effort to protect eyes and skin from accidental contact with liquid or the cold gas issuing from it Protect your eyes with full face shield or chemical splash goggles Safety glasses even with side shields are not adequate Always wear special cryogenic gloves Tempshield Cryo Gloves or equivalent when handling anything that is or may have been in contact with the liquid or cold gas o
127. as Slope Both are set in percent of output current per second The setting range is 0 to 100 with a resolution of 0 1 To change the output slope limit press the Control Setup key The control loop indicator is highlighted in the upper left hand corner Use the A or W key to select a control loop and press the Enter or Next Setting key The control setup parameters for that loop appear on the screen Press the Next Setting key until the slope field under the limits heading is highlighted Use the number keys to enter the maximum slope in percent per second Press the Enter or Next Setting key to continue with more settings or press the Save Screen key to store the changes in the Model 340 The default setting is O off 6 13 3 Heater Range Limit Accidental heater range settings are possible because the heater range can be set directly from the normal display of the Model 340 A heater range limit feature is intended to prevent heater range settings that could harm the control load The heater range can be set to the user specified limit setting but not above The range limit is accessed through control setup operation so it can not be changed unintentionally The range limit is only available for the heater output on Loop 1 The full scale power of a given heater range depends on the maximum current setting so the maximum current parameter should be set before the range limit To change the heater range limit press the Control Setup key The contr
128. at 300 K 50 uV 1mK at 4 2K 33 3 mK at 77 K 500 mK at 300 K 0 1 Q 0 04 of reading 1 mK at 4 2K 88 mK at 77 K 1 144 K at 300 K 9 mK at 4 2 Kt 138 mK at 77 Kt 1 284 K at 300 Kt Magnetic Field Use Recommended for Recommended for Recommended for Recommended for Recommended for T gt 60K8B lt 3T T gt 42K8B lt 5T T gt 40K amp BS25T T gt 40K amp B lt 2 5T T gt 2K8B lt 19T No longer available from Lake Shore d Typical sensor sensitivities were taken from representative calibrations for the sensor listed Specified accuracy includes no effect of thermal EMF voltages An error of 3 mQ results from each 1 uV of thermal EMF voltage In well designed systems thermal EMF voltage should be less than 10 pV Options and Accessories 10 17 Lake Shore Model 340 Temperature Controller User s Manual This Page Intentionally Left Blank 10 18 Options and Accessories Lake Shore Model 340 Temperature Controller User s Manual CHAPTER 11 SERVICE 11 0 GENERAL This chapter provides general service information for the Model 340 Temperature Controller There is no calibration procedure for the Model 340 There are no serviceable parts inside the Model 340 If you have any specific problems with your Model 340 please call Lake Shore General maintenance precautions are defined in Paragraph 11 1 Electrostatic discharge is defined in Paragraph 11 2 Changing power settings and fuse rating removal and replacement is descri
129. atastrophic instrument failure with heater fuse described below When setting up a temperature control system it is recommended that the lead wire for the heater be capable of carrying a continuous current that is greater than the maximum current or heater fuse rating Wire 3 8 Installation Lake Shore Model 340 Temperature Controller User s Manual manufacturers recommend 26 AWG or larger wire to carry 2 A of current but there is little advantage in using wire smaller than 20 to 22 AWG It is recommended to use twisted shielded cable for heater leads Large changes in heater current can induce noise in measurement leads and twisting reduces the effect It is also recommended to run heater leads in a separate cable from the measurement leads to further reduce interaction There is a chassis ground point at the rear panel of the instrument for shielding the heater cable The cable shield can be tied to this point with a single banana plug The shield should not be connected at the opposite end of the cable The Loop 1 heater output is isolated from chassis ground to reduce noise For best noise performance do not connect the resistive heater or its leads to ground Also avoid connecting heater leads to sensor leads or any other instrument inputs or outputs 3 5 4 Heater Protection and Fuse for Loop 1 The heater output of the Model 340 is a current source and has protection that prevents it from being damaged even if shorted The heater fuse on
130. ated by a semi colon Only one query is permitted per communication but it can be chained to the end of a command The total communication string must not exceed 64 characters in length A command string is issued by the computer and instructs the instrument to perform a function or change a parameter setting The format is lt command mnemonic gt lt space gt lt parameter data gt lt terminators gt Command mnemonics and parameter data necessary for each one is described in Paragraph 9 3 Terminators must be sent with every message string 9 14 Remote Operation Lake Shore Model 340 Temperature Controller User s Manual Message Strings Continued A query string is issued by the computer and instructs the instrument to send a response The query format is lt query mnemonic gt lt gt lt space gt lt parameter data gt lt terminators gt Query mnemonics are often the same as commands with the addition of a question mark Parameter data is often unnecessary when sending queries Query mnemonics and parameter data if necessary is described in Paragraph 9 3 Terminators must be sent with every message string The computer should expect a response very soon after a query is sent A response string is the instruments response or answer to a query string The instrument will respond only to the last query it receives The response can be a reading value status report or the present value of a parameter Response data formats are liste
131. ation with the Model 340 Allows the Model 340 to read four sensors and use any of them as a control sensor 1 5 2 3464 Dual Thermocouple Input Option Card Adds two new thermocouple inputs to the Model 340 appearing on the display as C and D The card has separate A Ds and excitation for each sensor A microprocessor on the card manages the A D and communication with the Model 340 Thermocouple inputs range from cryogenic temperature to 1000 C with built in room temperature compensation Curves for thermocouple types E K and AuFe 0 07 vs Cr are included The user can add other types 1 5 3 3465 Single Capacitance Input Option Card Adds a new capacitance input to the Model 340 appearing on the display as C The card has separate A D and excitation for the sensor A microprocessor on the card manages the A D and communication with the Introduction 1 3 Lake Shore Model 340 Temperature Controller User s Manual Model 340 The 3465 is intended to control temperature in strong magnetic fields using a Lake Shore Model CS 501 capacitance temperature sensor 1 5 4 3468 Eight Channel Input Option Card Adds eight sensor inputs to the Model 340 The optional inputs are broken into two groups of four and appear on the display as C1 C4 for Input C D1 D4 for Input D The 3468 includes two A D converters one for each group of four inputs and individual excitation for each sensor Each input group must use the same sensor type but the tw
132. ature Controller User s Manual 11 6 SERIAL INTERFACE CABLE AND ADAPTERS To aid in Serial Interface troubleshooting wiring information for the serial cable assembly and the two mating adapters are provided in Figures 11 10 through 11 12 The Model 2001 and 2003 are included with the Model 340 The Model 2002 is an option YELLOW GREEN RED BLACK C 340 11 8 eps Figure 11 10 Model 2001 RJ 11 Cable Assembly Wiring Details TxD Gnd Gnd 123456 9G vez DB 25 Connector Not Used For Customer supplied computer with DB 25 Serial Interface Connector configured as DCE If the interface is DTE a Null Modem Adapter is required to exchange Transmit and Receive lines Receptacle C 340 11 9 eps Figure 11 11 Model 2002 RJ 11 to DB 25 Adapter Wiring Details DB 9 Connector Not Used For Customer supplied computer with DE 9 Serial Interface Connector configured as DTE If the interface RJ 11 is DCE a Null Modem Adapter is required to exchange Transmit and Receive lines Receptacle C 340 11 10 eps Figure 11 12 Optional Model 2003 RJ 11 to DE 9 Adapter Wiring Details 11 8 Service Lake Shore Model 340 Temperature Controller User s Manual 11 7 TOP OF ENCLOSURE REMOVE AND REPLACE PROCEDURE WARNING To avoid potentially lethal shocks turn off controller and disconnect it from AC power line before performing this procedure Only qualified personnel should perform this procedure REMOVAL Se
133. ay Press the D key and the setting field for the D parameter is highlighted Use the number keys to enter a value and press the Enter key to save the change or the Escape key to return to the previous setting The default setting is O 6 6 4 Manual Output Manual output is a manual setting of control output It can function in two different ways depending on control mode In open loop control mode the manual output is the only output to the load The user can directly set control output from the front panel or over computer interface as described in Paragraph 9 3 In Manual PID control mode the manual output is added directly to the output of the PID control equation In effect the control equation operates about the manual output setting Manual output setting is in percent of full scale When using the heater on Loop 1 percent of full scale is defined as current or power on the selected heater range Manual Output setting range is 100 to 100 with a resolution of 0 0196 Negative values are not recommended with unipolar control outputs To enter a manual output value indicate the desired control loop by pressing the Loop 1 or Loop 2 key The control parameters for that loop appears in the lower portion of the display Press the Manual Output key and the setting field for the manual output parameter is highlighted Use the number keys to enter a value and press Enter to save the change or Escape to return to the previous setting Default settin
134. ays in the selected units Adjust the P control parameter when changing setpoint units from temperature to sensor Control channel readings can display in any units Display units need not match setpoint units When changing setpoint units while the control loop is active the Model 340 converts the control setpoint to the new control units for minimal disruption in control output To select setpoint units press Control Setup to display the CONTROL SETUP screen with the control loop indicator highlighted in the upper left hand corner Use the A or W key to select Loop 1 or 2 Press Enter or Next Setting to display control setup parameters for that loop Press Next Setting until the Setp Unit field highlights Use the A or Y key to select units Press Enter or Next Setting to continue with more settings or press Save Screen to store changes in the Model 340 Default is Temp K Setpoint resolution depends on sensor type and setpoint units With setpoint expressed in temperature setpoint resolution is 0 001 degree for setpoints below 1000 and 0 0001 for setpoints below 10 In sensor units the setpoint resolution matches the display resolution for the sensor input type given in the specifications Table 1 1 If auto ranging sensor enter a units multiplier of Q or KQ after the setpoint The instrument allows a large setpoint range to accommodate a variety of sensors and units With setpoint expressed in sensor units setpoint range is unlimited The u
135. be required to tightly cover the range from helium to room temperature but lowering the requirement on warm up may allow a less expensive one sensor solution Another factor to consider when choosing a temperature sensor is that instruments like the Model 340 are not able to read some sensors over their entire temperature range Lake Shore sells calibrated sensors that operate down to 50 millikelvin mK but the Model 340 is limited to 300 mK in its standard configuration 2 1 2 Sensor Sensitivity Temperature sensor sensitivity is a measure of how much a sensor signal changes when the temperature changes It is an important sensor characteristic because so many measurement parameters are related to it Resolution accuracy noise floor and even control stability depend on sensitivity Many sensors have different sensitivities at different temperatures For example a platinum sensor has good sensitivity at higher temperatures but has limited use below 30 kelvin K because its sensitivity drops sharply It is difficult to determine if a sensor has adequate sensitivity over the experimental temperature range This manual has specifications Table 1 1 that include sensor sensitivity translated into temperature resolution and accuracy at different points This is typical sensor response and can be used as a guide when choosing a sensor to be used with the Model 340 Cooling System Design 2 1 Lake Shore Model 340 Temperature Controller User s Manua
136. bed in Paragraph 11 3 Paragraph 11 4 provides general maintenance information Rear panel connector definitions are provided in Paragraph 11 5 Serial cable and adapters are described in Paragraph 11 6 A top of enclosure remove and replace procedure is provided in Paragraph 11 7 Software EPROM and Precision Option NOVRAM replacement is detailed in Paragraph 11 8 Error messages are described in Paragraph 11 9 Firmware IC replacement is described in Paragraph 11 10 Finally updating the master firmware from a data card is described in 11 11 11 1 GENERAL MAINTENANCE PRECAUTIONS The following are general safety precautions that are not related to any specific procedure and therefore do not appear elsewhere in this publication These are recommended precautions that personnel should understand and apply during the maintenance phase Keep away from live circuits Installation personnel shall observe all safety regulations at all times Turn off system power before making or breaking electrical connections Regard any exposed connector terminal board or circuit board as a possible shock hazard Components that retain a charge shall be discharged only when such grounding does not result in equipment damage If a test connection to energized equipment is required make the test equipment ground connection before probing the voltage or signal to be tested Do nat install or service equipment alone Personnel shall not under any circumstances reach into
137. bration points Accuracy increases with more points There are two ways to get SoftCal calibration data points O The user record the response of an unknown sensor at well controlled temperatures or O The user buys a Lake Shore SoftCal calibrated sensor There are advantages to both methods O User When the user can provide stable calibration temperatures with the sensor installed SoftCal calibration eliminates errors in the sensor measurement as well as the sensor Thermal gradients instrument accuracy and other measurement errors can be significant Calibration can be no better than user supplied data Purchased Lake Shore sensors with SoftCal calibration include a set of calibration points in the calibration report Lake Shore generates SoftCal calibration points in a controlled calibration facility for best accuracy The user enters the calibration points into the Model 340 to generate a curve If the user buys the CalCurve service with the calibrated sensor the factory generates the curve for later entry like any other curve 8 2 1 SoftCal and Silicon Diode Sensors Lake Shore Silicon Diode Sensors incorporate remarkably uniform sensing elements that exhibit precise monotonic and repeatable temperature response For example the Lake Shore DT 470 Series of silicon diode sensors has a repeatable temperature response from 2 K to 475 K These sensors closely follow the Standard Curve 10 response and routinely interchange with one anoth
138. camner and 3 manual lt bit weighting Specifies the manual digital output settings if mode is 3 DOUT 3 21 term Manually sets digital output lines D1 D3 and D5 to logic high and D2 and D4 to logic low Query Digital Output Parameters DOUT lt mode gt lt bit weighting gt Format n nnn term Returns the digital output parameters See the DOUT command for parameter descriptions Remote Operation FILTER Input Returned Remarks Example FILTER Input Returned Remarks HTR Input Returned Remarks HTRST Input Returned Remarks IEEE Input Returned Remarks Example IEEE Input Returned Remarks INCRV Input Returned Remarks Example Remote Operation Lake Shore Model 340 Temperature Controller User s Manual Configure Input Filter Parameters FILTER lt input gt lt off on gt lt points gt lt window gt Nothing Configures input filtering function lt input gt Specifies input to configure offlon Specifies whether the filter function is off or on lt points gt Specifies how many data points the filtering function uses lt window gt Specifies what percent of full scale reading limits the filtering function Reading changes greater than this percentage reset the filter FILTER B 10 2 term Filter input B data through 10 readings with 2 of full scale window Query Input Filter Parameters FILTER lt input gt
139. changes The default settings are CR LF EOI On and 12 9 1 2 IEEE 488 Command Structure The Model 340 supports several command types These commands are divided into three groups 1 Bus Control Described in Paragraph 9 1 2 1 a Universal 1 Uniline 2 Multiline b Addressed Bus Control 2 Common Described in Paragraph 9 1 2 2 3 Interface and Device Specific Described in Paragraph 9 1 2 3 Remote Operation 9 1 Lake Shore Model 340 Temperature Controller User s Manual 9 1 2 1 Bus Control Commands A Universal Command is a command that addresses all devices on the bus Universal Commands include Uniline and Multiline Commands A Uniline Command Message is a command which results in a single signal line being asserted The Model 340 recognizes two of these messages from the BUS CONTROLLER Remote REN and Interface Clear IFC The Model 340 sends one Uniline Command SRQ REN Remote Puts the Model 340 into a remote mode IFC Interface Clear Stops current operation on the bus SRQ Service Request Tells the bus controller that the Model 340 needs interface service A Multiline Command involves a group of signal lines All devices equipped to implement such commands do so simultaneously when the command is transmitted These commands are transmitted with the Attention ATN line asserted low There are two Multiline commands recognized by the Model 340 LLO Local Lockout LLO is sent to instrument
140. character is 10 bits long and contains data bits bits for character timing and an error detection bit The instrument uses 7 bits for data in the ASCII format One start bit and one stop bit are necessary to synchronize consecutive characters Parity is a method of error detection One parity bit configured for odd parity is included in each character ASCII letter and number characters are used most often as character data Punctuation characters are used as delimiters to separate different commands or pieces of data Two special ASCII characters carriage return CR ODH and line feed LF OAH are used to indicate the end of a message string Table 9 4 Serial Interface Specifications Transmission Three Wire Connector RJ 11 Modular Socket Timing Format Asynchronous Transmission Mode Half Duplex Data Interface Levels Transmits and Receives Using ElA Voltage Levels BPS Rate 300 1200 2400 4800 9600 19200 Parity 7 Data Odd Parity and 1 Stop 7 Data Even Parity and 1 Stop 8 Data No Parity and 1 Stop Terminators CR LF LF CR CR or LF 9 2 5 Message Strings A message string is a group of characters assembled to perform an interface function There are three types of message strings commands queries and responses The computer issues command and query strings through user programs the instrument issues responses Two or more command strings can be chained together in one communication but they must be separ
141. control parameter changes Other instructions are for timing and decision making The instrument can run the instructions in an internal program without operator interaction Since program status can be monitored with a computer interface internal programs can be used during computer controlled experiments The internal program feature works with control Loop 1 There is enough memory in the Model 340 to hold 100 programming instructions The instructions can be put in up to 10 different program locations The program locations are provided to help organize internal programming operations As many as 100 and as few as 2 or 3 instructions can be placed in a single program location The total number of instructions in all ten program locations must not exceed 100 An End instruction described in the next paragraph is included in each program location but does not take one of the 100 memory locations The following paragraphs provide details about the programming instructions offered in the Model 340 then gives an example of how to put the instructions together into a program A second example illustrates how programs in two or more program locations can be used together 8 6 Instrument Programming Lake Shore Model 340 Temperature Controller User s Manual 8 3 1 Program Instructions The Model 340 has 13 programming instructions divided into three categories output ramping direct setting operations and flow control The instructions are listed b
142. controlling well at one temperature may not control well at another temperature While nonlinearities exist in all temperature control systems they are most evident at cryogenic temperatures When the operating temperature changes the behavior of the control loop the controller must be retuned As an example a thermal mass acts differently at different temperatures The specific heat of the load material is a major factor in thermal mass The specific heat of materials like copper change as much as three orders of magnitude when cooled from 100 K to 10 K Changes in cooling power and sensor sensitivity are also sources of nonlinearity The cooling power of most cooling sources also changes with load temperature This is very important when operating at temperatures near the highest or lowest temperature that a system can reach Nonlinearities within a few degrees of these high and low temperatures make it very difficult to configure them for stable control If difficulty is encountered it is recommended to gain experience with the system at temperatures several degrees away from the limit and gradually approach it in small steps Keep an eye on temperature sensitivity Sensitivity not only affects control stability but it also contributes to the overall control system gain The large changes in sensitivity that make some sensors so useful may make it necessary to retune the control loop more often 2 8 Cooling System Design Lake Shore Model 340 Tem
143. covers slide them to the rear on the tracks REAR PANEL OPTION PLATE SCREWS Figure 10 5 Cover and Option Plate Screws Options and Accessories 10 5 Lake Shore Model 340 Temperature Controller User s Manual 6 With the instrument still standing on its face turn it to view the circuit board The upper half of the circuit board above the transformer assembly contains four holes where metal standoffs install Figure 10 6 Find Hole 1 to the left between C245 and C265 Find Hole 2 4 5 inches to the right of Hole 1 and just to the left of C298 and U154 Find Hole 3 4 5 inches to the right of Hole 2 and just to the left and below the Digital Option plug J9 Find Hole 4 2 5 inches above Hole 3 just to the left and above the Digital Option plug J9 Ignore hole to left and beneath Hole 4 Into each hole insert a 4 40 screw through the bottom of the circuit board and thread it into a metal standoff on the top of the circuit board 7 Just beneath the transformer assembly is the Analog Option plug J18 Plug either end of the ribbon cable into the Analog Option plug J18 Slide the arrow nub down the plug slot for correct positioning IGNORE HOLE 4 ANALOG OPTION PLUG TRANSFORMER ASSEMBLY Figure 10 6 Model 340 Mounting Holes and Analog Option Plug 8 Plug the other end of the ribbon cable into the 3462 Option Card plug J3 located on the lowe
144. d along with the associated queries in Paragraph 9 3 The response is sent as soon as possible after the instrument receives the query Typically it takes 10 ms for the instrument to begin the response Some responses take longer 9 2 6 Message Flow Control It is important to remember that the user program is in charge of the serial communication at all times The instrument can not initiate communication determine which device should be transmitting at a given time or guarantee timing between messages All of this is the responsibility of the user program When issuing commands only the user program should e Properly format and transmit the command including terminators as one string Guarantee that no other communication is started for 50 ms after the last character is transmitted e Notinitiate communication more than 20 times per second When issuing queries or queries and commands together the user program should e Properly format and transmit the query including terminators as one string Prepare to receive a response immediately Receive the entire response from the instrument including the terminators Guarantee that no other communication is started during the response or for 50 ms after it completes e Not initiate communication more than 20 times per second Failure to follow these simple rules will result in inability to establish communication with the instrument or intermittent failures in communication 9 2 7 Ser
145. d inside the Model 340 attaching the ground pin to external grounds can cause noise on the sensor input measurements The connector is a 15 pin D style socket This is a common socket P N 268 303 and mating plug P N 268 301 can be purchased from Lake Shore or any local EN A A Use electronic supplier in rear of Model 340 screwdriver to lock or unlock wires Screw Terminal 3 8 RELAYS Connector The Model 340 has one high and one low relay shown in Figure 3 B TOA dt 8 They are most commonly associated with the alarm feature The into slot relays can also be put in manual mode and controlled directly by the user from the front panel or over computer interface Refer to Paragraph 7 4 The relay status indicated on the relays and beeper screen is for monitoring the relay status It cannot be set by the user If PIN DESCRIPTION a relay is inactive Off it will be in its normal state of open or closed Low Normally Closed N C When the relay is active On it will be in the opposite state Low Common Low Normally Open N O High Normally Closed N C High Common High Normally Open N O The relay outputs have a detachable 6 pin terminal block connector The connector can be removed from its socket for convenient installation of wires The connector is included with the Model 340 P N 106 737 The connector manufacturer indicates that up to 12 AWG stranded copper wire can be used with the connector
146. d surrounding area Temperature 5 C to 40 C Maximum relative humidity 80 for temperature up to 31 C decreasing linearly to 50 at 40 C Power supply voltage fluctuations not to exceed 10 of the nominal voltage Ground the Instrument To minimize shock hazard the instrument chassis and cabinet must be connected to an electrical ground The instrument is equipped with a three conductor AC power cable The power cable must either be plugged into an approved three contact electrical outlet or used with a three contact adapter with the grounding wire green firmly connected to an electrical ground safety ground at the power outlet The power jack and mating plug of the power cable meet Underwriters Laboratories UL and International Electrotechnical Commission IEC safety standards Do Not Operate in an Explosive Atmosphere Do not operate the instrument in the presence of flammable gases or fumes Operation of any electrical instrument in such an environment constitutes a definite safety hazard Keep Away from Live Circuits Operating personnel must not remove instrument covers Component replacement and internal adjustments must be made by qualified maintenance personnel Do not replace components with power cable connected To avoid injuries always disconnect power and discharge circuits before touching them Do Not Substitute Parts or Modify Instrument Because of the danger of introducing additional hazards do not i
147. data from other devices through the bus The BUS CONTROLLER designates to the devices on the bus which function to perform The Model 340 performs the functions of TALKER and LISTENER but cannot be a BUS CONTROLLER The BUS CONTROLLER is your digital computer which tells the Model 340 which functions to perform The IEEE 488 interface capabilities of the Model 340 Controller are listed below as well as in mnemonic format on the rear panel of the controller SH1 Source handshake capability RL1 Complete remote local capability DC1 Full device clear capability DTO No device trigger capability CO No system controller capability T5 Basic TALKER serial poll capability talk only unaddressed to talk if addressed to listen L4 Basic LISTENER unaddressed to listen if addressed to talk SR1 Service request capability AH1 Acceptor handshake capability PPO No parallel poll capability E1 Open collector electronics e o e e o o 9 1 1 IEEE 488 Interface Settings If using the IEEE 488 interface the user must set the IEEE Terminator End Or Identify EOI and Address Press the Interface key to display the COMPUTER INTERFACE screen The user has the option to change the Terminator CR LF LF CR CR LF or none EOI On or Off and Address 1 32 Use the A or V key make selections Use the Next Setting key to advance to the next parameter Finally use the Save Screen key to accept the changes or the Cancel Screen key to decline the
148. dden parameters will still appear when being changed To turn the large output display on or off press the Display Format key then press the More key until you see the CONTROL DISPLAY FORMAT screen Press the Next Setting key until the Large Output line is highlighted then use the A or V key to select on or off Press the Enter or Next Setting key to continue with other settings Press the Save Screen key to store the changes in the Model 340 The default setting is Off NOTE The Large Output option will not be visible if Control Loops BOTH is selected Change the Control Loop setting back to Loop 1 or Loop 2 press the Enter key then the Large Output selection will be available Front Panel Operation 4 7 Lake Shore Model 340 Temperature Controller User s Manual 4 5 6 Heater Output Display Units The CONTROL DISPLAY FORMAT screen is also the place to select whether heater output is shown as POWER or CURRENT This setting will impact the heater output seen in the normal display and which units are used for the manual output MOut display If current is selected the heater output and range will appear as 20 100 W to indicate 20 output current for the selected 100 watt range If power is selected for the same output the heater output and range would appear as 4 of 100W to indicate 4 output power for the selected 100 watt range To change the heater display units press the Display Format key then press the More key until you see the
149. de section Used to return response Terminators Data string sent to instrument Device number used with IEEE Show main window Terminators are lt CR gt lt LF gt Clear return string Initialize the IEEE device Setup Repeat Addressing Do Do Wait loop DoEvents Give up processor to other events Loop Until gSend True Loop until Send button pressed gSend False Set Flag as False strCommand frmIEEE txtCommand Text Get Command strReturn Clear response display strCommand UCase strCommand Set all characters to upper case If strCommand EXIT Then Get out on EXIT End End If Call ibwrt intDevice strCommand amp term Send command to instrument If ibsta And EERR Then Check for IEEE errors do error handling if needed Handle errors here End If If InStr strCommand lt gt 0 Then Check to see if query strReturn Space 100 Build empty return buffer Call ibrd intDevice strReturn Read back response If ibsta And EERR Then Check for IEEE errors do error handling if needed Handle errors here End If If strReturn Then Check if empty string strReturn RTrim strReturn Remove extra spaces and Terminators Do While Right strReturn 1 Chr 10 Or Right strReturn 1 Chr 13 strReturn Left strReturn Len strReturn 1 Loop Else strReturn No Response Send No Response End If frmIEEE txtResponse Text strReturn Put response in text on main form End If Loop End Sub 9 8 Remot
150. del 340 A microprocessor on the card manages the A D and communication with the Model 340 3465 Single Capacitance Input Option Card Adds one capacitance input to the Model 340 A microprocessor on the card manages the A D and communication with the Model 340 3468 Eight Channel Input Option Card Adds eight additional inputs to the Model 340 Card has 2 Analog to Digital A D Converters one for each group of 4 sensors and individual excitation for each sensor A microprocessor on the card manages the A D and communication with the Model 340 The card allows the Model 340 to read a total of 10 sensors Includes the features below Eight channels divided into 2 groups of 4 Several sensor types are supported Eight individual current sources at 10 uA or 1 mA depending on sensor selection Each sensor is continuously excited Two A Ds one for each group 10 2 ACCESSORIES Accessories are devices that perform a secondary duty as an aid or refinement to the primary unit Model Description Of Model 340 Accessories 106 009 Heater Output Connector Dual Banana Jack Used for standard Heater Output G 106 233 Sensor Mating Connector 6 pin DIN Plugs used for sensor inputs 2 included 106 737 Terminal Block 6 pin Used for Relays Connector Accepts up to 12 AWG wire 115 006 Detachable 120 VAC Line Cord Accessories included with a new Model 340 Options and Accessories 10 1
151. der the Object dropdown list select General Add the statement Public gSend as Boolean b Double Click on cmdSend Add code segment under Private Sub cmdSend Click as shown in Table 9 2 c In the Code Editor window under the Object dropdown list select Form Make sure the Procedure dropdown list is set at Load The Code window should have written the segment of code Private Sub Form Load Add the code to this subroutine as shown in Table 9 2 11 Save the program 12 Run the program The program should resemble the following i IEEE Interface Program Type exit to end program Command Pile ES Response 13 Type in a command or query in the Command box as described in Paragraph 9 1 4 5 14 Press Enter or select the Send button with the mouse to send command 15 Type Exit and press Enter to quit Remote Operation Lake Shore Model 340 Temperature Controller User s Manual Table 9 2 Visual Basic IEEE 488 Interface Program Public gSend As Boolean Global used for Send button state Private Sub cmdSend Click gSend True End Sub Routine to handle Send button press Set Flag to True Private Sub Form Load Dim strReturn As String Dim term As String Dim strCommand As String Dim intDevice As Integer frmIEEE Show term Chr 13 amp Chr 10 strReturn Call ibdev 0 12 0 T10s 1 amp H140A intDevice Call ibconfig intDevice ibcREADDR 1 Main co
152. dicating a cold instrument The display does not show a logo or change from the logo An error window appears with a message about a hardware problem Refer to Paragraph 11 9 The alarm beeper does not sound Instrument does not respond to keys being pressed If any of these symptoms are observed please contact the factory Messages that indicate the need for further setup are common when first powering up the unit because many users do not have temperature sensors installed or sensor type selected Do not be concerned if the following appear overload condition no sensor attached no temperature response curve selected or words indicating a problem with the heater configuration in the area of the display that normally shows heater output These conditions will be resolved as instrument setup is completed C N ElLaeShae 34 Temperature Controller Na y 340 1 1 eps Figure 4 1 Model 340 Front Panel 4 2 DISPLAY FORMATS The Model 340 has an eight line by 40 character LCD graphic display capable of showing small 6 x 8 and large 12x 16 characters This display is very flexible and provides the user feedback at each step of operation The normal display of the Model 340 shows sensor readings and control status Other specialized displays are used for instrument settings data entry help and error messa
153. digital Sensor dependent refer to Input Specifications table Sensor dependent refer to Input Specifications table Up to 20 readings per s on an input 40 readings per s on all inputs Automatically selects appropriate NTC RTD range Forty 200 point CalCurves or user curves 1 7 SoftCal Improves accuracy of DT 470 diode or platinum RTD sensors Math Maximum and minimum of input readings and linear equation Filter Averages input readings to quiet display settable time constant Table 1 4 Sensor Input Configuration Diode RTD Thermocouple Capacitance Measurement 4 lead differential 2 lead room temperature 4 lead type compensated Excitation Constant current with current NA 4 88 kHz 1 V reversal for RTDs square wave Supported Diodes Silicon GaAlAs RTDs Most thermocouple types CS 501GR sensors 100 O Platinum 1000 O Platinum Germanium Carbon Glass Cernox and Rox Standard DT 470 DT 500D DT 670 PT Type E Type K Type T None curves 100 PT 1000 RX 102A RX AuFe 0 07 vs Cr 202A AuFe 0 0396 vs Cr Input 6 pin DIN Ceramic isothermal block 6 pin DIN connector 1 7 2 Control Control loops 2 Control type Tuning Control stability PID control setti Proportional Integral reset Derivative rate Manual outp Zone control Setpoint rampin Safety limits Lake Shore Model 340 Temperature Controller User s Manual Closed loop digital PID with manual heater power outp
154. e HEATER FUSE HEATER OUTPUT 254 Hi Lo O 99 0 N WARNING AX warna ERFACE Figure 10 9 Model 340 Rear Panel with Model 3464 Option Card Installed 10 4 3 1 Sensor Input Terminals Attach sensor leads to the screws on the off white ceramic terminal blocks on the 3464 There is one block for the C input and one for the D input Each block has two screw terminals one positive one negative Table 10 1 Thermocouple Polarity Positive H Chromel PUR Chromel YEL Alumel RED T Copper vs Copper Nickel Copper BLU Constantan RED Secure the positive TC wire under the screw in the terminal and the negative TC wire under the screw in the terminal Tighten the screws on the thermocouple wires and remove all insulation Keep the ceramic terminal blocks away from heat sources including sunlight and shield them from fans or room drafts 10 8 Options and Accessories Lake Shore Model 340 Temperature Controller User s Manual 10 4 3 2 Measurement Point Connection Thermocouples are commonly used in high temperature applications Cryogenic use of thermocouples offers some unique challenges Refer to Paragraph 2 3 for general installation guidelines Consider the following when using thermocouples at low temperatures e Thermocouple wire is generally more thermally conductive than other sensor lead wire Smaller gauge wire and more heat sinking may be needed to
155. e Input STB Returned lt STB bit weighting Format nnn term Remarks Acts like a serial poll but does not reset the register to all zeros The integer returned represents the sum of the bit weighting of the status flag bits that are set in the Status Byte Register Bit Bit Weighting Event Name 0 1 New A amp B 1 2 New Option 2 4 Settle 3 8 Alarm 4 16 Error 5 32 ESB 6 64 SRQ 7 128 Ramp Done 9 24 Remote Operation xTST Input Returned Remarks xWAI Input Returned Remarks ALARM Input Returned Remarks Example ALARM Input Returned Remarks ALARMST Input Returned Remarks ALMRST Input Returned Remarks Lake Shore Model 340 Temperature Controller User s Manual Query Self Test TST 0 or 1 Format n term The Model 340 performs a self test at power up 0 no errors found 1 errors found Wait to Continue WAI Nothing This command is not supported in the Model 340 Configure Input Alarm Parameters ALARM input lt off on gt lt source gt lt high value gt lt low value gt lt latch enable gt lt relay gt Nothing Configures the alarm parameters for an input lt input gt Specifies which input to configure lt offlon gt Determines whether the instrument checks the alarm for this input lt source gt Specifies input data to check Valid entries 1 kelvin 2 Celsius 3 sensor units 4 linear data lt high value Sets the val
156. e 6 3 Table 8 1 Table 8 2 Table 9 1 Table 9 2 Table 9 3 Table 9 4 Table 9 5 Table 9 6 Table 9 7 Table 10 1 Table 10 2 Table 10 3 Table 11 1 Table A 1 Table A 2 Table A 3 Table A 4 Table A 5 Table A 6 Table A 7 Table A 8 Table A 9 Lake Shore Model 340 Temperature Controller User s Manual LIST OF TABLES Title Page Sensor Temperature Range dd dat daba 1 4 Typical Sensor Performance iii deed t eed zd ge dde ok eT Ped de ca 1 6 Input SpeciicatiONns eR 1 7 Sensor Input eut e EU EE 1 8 Heater Output Specifications ict ed e d e e er va ee ede dena 1 8 Loop 1 Full Scale Heater Power at TvpicalResistance renee 1 9 Comparison of Liquid Helium to Liquid Nitrogen sssssssssenenensseesrrnnnenssrerrrnnrrnnsnrsrrrnrrn 3 3 AC Line Input Deflnitions titi Bees olent eerte e ele era e cada 3 5 Sensor Input A and B Connector Definition ooononooccnnnnncninnococccnncncccnonnnnoncnnnnnnnnnnn no nccnnnnnnns 3 6 Sensor Types Recognized by the Model 340 eee 5 1 Special Sensor Type Configuration ssssssessseee ener 5 3 Standard Curve Table iint Lar tette B LI QE dead 5 4 Control Mode Description tete toe t etiem ta Eee MS det E 6 3 Full Scale Heater Power at Typical Resistance eee 6 9 Example of Max Current Settings mener 6 10 Recommended Curve Parameter 8 2 Storage Capability for a 1MB Data Card sss 8 14 IEEE 488 Interface Program Control Propertie
157. e Input Type Parameters INTYPE lt input gt lt type gt lt units gt lt coefficient gt lt excitation gt lt range gt Nothing Configures input type parameters lt input gt Specifies input to configure lt type gt Specifies input sensor type Paragraph 5 1 1 Valid entries 0 Special 5 Platinum 1000 10 Germanium 1 Silicon Diode 6 Rhodium Iron 11 Capacitor 2 GaAlAs Diode 7 Carbon Glass 12 Thermocouple 3 Platinum 100 2500 8 Cernox 4 Platinum 100 5000 9 RuOx units Specifies input sensor units It is a predetermined value based on type If it is supplied type 0 Special Valid entries 1 volts 2 ohms coefficient Specifies input coefficient It is a predetermined value based on type If it is supplied type 0 Special Valid entries 1 negative 2 positive Specifies input excitation Paragraph 5 1 4 It is a predetermined value based on type If it is supplied type 0 Special Valid entries excitation 0 Off 3 300nA 6 10 pA 9 300 pA 12 1 mV 1 30nA 4 1ypgA 7 30 pA 10 1 mA 2 100 nA 5 3yA 8 100 pA 11 10 mV range Specifies the input range refer to Paragraph 5 1 4 This parameter has a predetermined value based on type If this parameter is supplied type changes to 0 Special Valid entries are given in volts 1 1mV 4 10mV 7 100 mV 10 1V 13 7 5V 2 2 5mV 5 25mV 8 250 mV 11 2 5V 3 5 mV 6 50 m
158. e Operation Lake Shore Model 340 Temperature Controller User s Manual 9 1 4 3 IEEE 488 Interface Board Installation for Quick Basic Program This procedure works on an IBM PC or compatible running DOS or in a DOS window This example uses the National Instruments GPIB PCII IA card oa F WN gt Install GPIB PCII IA card using National Instruments instructions Install NI 488 2 software for DOS Version 2 1 1 was used for the example Verify that config sys contains the command device gpib pc gpib com Reboot the computer Run IBTEST to test software configuration Do not install the instrument before running IBTEST Run IBCONF to configure the GPIB PCII IIA board and dev 12 Set the EOS byte to OAH and Enable Repeat Addressing to Yes See Figure 9 3 IBCONF modifies gpib com Connect the instrument to the interface board and power up the instrument Verify the address is 12 and terminators are CR LF 9 1 4 4 Quick Basic Program The IEEE 488 interface program in Table 9 3 works with QuickBasic 4 0 4 5 or Qbasic on an IBM PC or compatible running DOS or in a DOS window It assumes your IEEE 488 GPIB card is installed and operating correctly refer to Paragraph 9 1 4 3 Use the following procedure to develop the Serial Interface Program in Quick Basic Copy c gpib pc Qbasic qbib obj to the QuickBasic directory QB4 Change to the QuickBasic directory and type link Jo qbib obj oqlb4x lib where x 0 for QB4
159. e PID control equation It has a range of 0 to 1000 with a resolution of 0 1 Enter a value greater than zero for P to use closed loop control To enter a value for P press Loop 1 or Loop 2 to display control parameters for that loop in the lower portion of the display Press P to highlight the setting field for the P Enter a value with the number keys and press Enter to save the change or Escape to return to the previous value Default is 50 6 6 2 Integral I The integral parameter also called reset is the part of the PID control equation It has a range of 0 to 1000 with a resolution of 0 1 Setting to zero turns the reset function off The setting is related to seconds by 1000 seconds setting l To enter a value for press Loop 1 or Loop 2 to display control parameters for that loop in the lower portion of the display Press I to highlight the setting field for the parameter Enter a value with the number keys and press Enter to save the change or Escape to return to the previous value Default is 20 6 6 3 Derivative D The derivative parameter sometimes called rate is the D part of the PID control equation The range of the D setting is 0 to 1000 seconds with a resolution of 1 second Setting D to zero turns the derivative function off To enter a value for D indicate the desired control loop by pressing the Loop 1 or Loop 2 key The control parameters for that loop appear in the lower portion of the displ
160. e Shore d unauthorized modification or misuse e operation outside of the published specifications or f improper site preparation or maintenance TO THE EXTENT ALLOWED BY APPLICABLE LAW THE ABOVE WARRANTIES ARE EXCLUSIVE AND NO OTHER WARRANTY OR CONDITION WHETHER WRITTEN OR ORAL IS EXPRESSED OR IMPLIED LAKE SHORE SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OR CONDITIONS OF MERCHANTABILITY SATISFACTORY QUALITY AND OR FITNESS FOR A PARTICULAR PURPOSE WITH RESPECT TO THE PRODUCT Some countries states or provinces do not allow limitations on an implied warranty so the above limitation or exclusion might not apply to you This warranty gives you specific legal rights and you might also have other rights that vary from country to country state to state or province to province TO THE EXTENT ALLOWED BY APPLICABLE LAW THE REMEDIES IN THIS WARRANTY STATEMENT ARE YOUR SOLE AND EXCLUSIVE REMEDIES EXCEPT TO THE EXTENT PROHIBITED BY APPLICABLE LAW IN NO EVENT WILL LAKE SHORE OR ANY OF ITS SUBSIDIARIES AFFILIATES OR SUPPLIERS BE LIABLE FOR DIRECT SPECIAL INCIDENTAL CONSEQUENTIAL OR OTHER DAMAGES INCLUDING LOST PROFIT LOST DATA OR DOWNTIME COSTS ARISING OUT OF THE USE INABILITY TO USE OR RESULT OF USE OF THE PRODUCT WHETHER BASED IN WARRANTY CONTRACT TORT OR OTHER LEGAL THEORY AND WHETHER OR NOT LAKE SHORE HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES Your use of the Product is entirely at your own risk Some c
161. e Shore Model 340 Temperature Controller User s Manual This Page Intentionally Left Blank Lake Shore Model 340 Temperature Controller User s Manual TABLE OF CONTENTS Chapter Paragraph Title Page 1 Introduction ii tdt te re RE E TOTT 1 1 1 0 Product Descriptions iiu adria dina dada 1 1 1 1 Sensor puts mira idad E 1 1 1 2 Temperature Gontrol sc 5 ed be cer ettet adicta dba 1 2 1 3 hcec EE 1 2 1 4 Configurable Display 2 5 tei pe eot eee bei E qe etum bine ete ehe iore 1 3 1 5 Additional Inputs Available For Model 340 ssssssssssssssssseeeneemeeeene nnn 1 3 1 5 1 3462 Dual Standard Input Option Card sss 1 3 1 5 2 3464 Dual Thermocouple Input Option Card ssssssssssesene 1 3 1 5 3 3465 Single Capacitance Input Option Card 1 3 1 5 4 3468 Eight Channel Input Option Card sss eee 1 4 1 6 Sens r m P 1 4 1 7 reed 1 7 1 7 1 Thiermormetby s os cec secet eet rte etr amete te ee tu eet ieee RN 1 7 1 7 2 ln te ro enter doter ie te de tud usa is E dit tease eee rn aeu o dad 1 8 1 7 3 Front RN M Tcp 1 9 1 7 4 nte c 1 9 1 7 5 rura 1 10 1 7 6 Product Config ratiOn EES reete ete tele td eure eege RR pda 1 10 2 Cooling System RE e EE 2 1 2 0 General nd tdi REN 2 1 2 1 Temperature Sensor Selection teste tt ege re Teen E RA d HER ADR UE 2 1 2 1 1 Temperature Range x t irl
162. each step Any time the mechanical cooling action of a cryogenic refrigerator can be seen as a periodic temperature fluctuation the mass is too small or temperature too low to AutoTune Cooling System Design 2 13 Lake Shore Model 340 Temperature Controller User s Manual 2 9 ZONE TUNING Once the PID tuning parameters have been chosen for a given setpoint the whole process may have to be done again for other setpoints significantly far away that have different tuning needs Trying to remember when to use which set of tuning parameters can be frustrating The Model 340 has a Zone feature as one of its tuning modes that can help To use the Zone feature the user must determine the best tuning parameters for each part of the temperature range of interest These parameters are then entered into the Model 340 where up to ten zones can be defined with different P D heater range and manual output A setpoint setting is assigned as the maximum temperature for that zone The minimum temperature for a zone is the setpoint for the previous zone 0 K is the starting point for the first zone When the zone tuning mode is on appropriate control parameters are chosen automatically each time the setpoint is changed to a new temperature zone Control parameters can be determined manually or by using the AutoTune feature AutoTune is a good way to determine a set of tuning parameters for the control system that can then be entered as zones Once the paramete
163. ear a second control sensor The 4 88 kHz excitation of the 3465 option can interfere with the sensitive DC measurements of the standard inputs Tightly twist the lead wires of each sensor and separate them from the leads from the other sensor Test any system for sensor interference before it is permanently sealed 10 5 2 3 Grounding and Shielding For lowest measurement noise do not ground any sensor leads The instrument usually operates with more noise if one of the leads is grounded Grounding more than one lead is not recommended Shielded cable is recommended because of the AC excitation of the sensor Shielding reduces excitation noise transmitted into the measurement system Shielding outside the cryostat is recommended but it is difficult to use shields inside Connect a cable shield to the ground pin 3 of the input connector but do not connect at the other end Use driven shield pin 6 of the Input connector instead of pin 3 if attaching to pin 3 does not give the desired results Inside the cryostat tightly twist the sensor leads V to V and I to 10 12 Options and Accessories Lake Shore Model 340 Temperature Controller User s Manual 10 5 3 Operation 10 5 3 1 Input Selection After Model 3465 option installation front panel operation allows configuration of input C assigned to the capacitance input Without the option only A and B inputs are available For an example of option input selection press Input Setup to displa
164. eater current and range Heater Range Allows direct setting of Loop 1 heater range Heater Off Immediately turns off Loop 1 heater Control Channel Allows direct setting of the sensor feedback channel for a control loop Displays Control Loop 1 parameters and status on lower three lines of display Displays Control Loop 2 parameters and status on lower three lines of display Setpoint Allows direct setting of control setpoint Manual Output Allows direct setting of manual output control parameter Displays the INPUT SETUP screen which selects the sensor type and curve number Other sensor parameters can be overwritten but this changes sensor status to Special Only curves appropriate to the sensor type display SoftCal Displays the SOFTCAL screen which accepts and stores SoftCal curves Displays three screens use the More key to toggle between the screens 1 The READING DISPLAY FORMAT screen sets the number of readings 1 through Display F t 8 shown in the normal display and assigns an input and data source to each pray torma 2 The CONTROL DISPLAY FORMAT screen sets lower three lines of the display 3 The MISC DISPLAY FORMAT screen sets display contrast back lighting and keypad lock Displays the EXTERNAL SCANNER SETUP screen to set external scanner support C Ent Displays the CURVE ENTRY screen which edits copies or erases temperature urve entry response curves Interf Displays the COMPUTER INTERFACE screen which sets IEEE 488
165. ed when using 50 mV Range 5 3 FILTER AND MATH Some simple arithmetic features have been included in the Model 340 as a convenience to the user Filter Max Min and linear equation can be applied to an input reading As shown in Figure 5 1 the filter can be applied to all readings for an input The results of Max Min and linear equation can be shown on the display in combination with the actual input reading The display format screen is used to configure the display 5 3 4 Filter The Model 340 can apply an averaging filter to any sensor input The filter is designed to prevent electronic noise that is picked up on the sensor lead wires from showing on the display It is enabled or disabled for all of the reading formats of an input at the same time A number of readings filtered and filter reset window can be changed by the user to meet their application The come equation has a filter abet is enabled independently from the input filter To turn on the filter for an input press the Math Setup key The MATH COMPUTATIONS screen appears with the Input field highlighted Use the A or Y key to select an input Use the Enter or Next Setting key to move the cursor to FILTER Enable Use the A or V key to select ON The default setting is On The user may change filter behavior by changing the number filter readings Although more filter readings settle the display reading more it is not always appropriate to select many filter readings More
166. ediDI6 Acting as Digital Input TTL Input 8 nsv 48 volts Output 50 mA max s bn Digitarinputt TTLinput ca Gd gt gt y Figure 11 4 DIGITAL I O DA 15 Rear Panel Connector Details Slides into RELAYS slot in rear of Model 340 Use screwdriver to lock or unlock wires Insert wire into slot Screw Terminal Connector Lake Shore P N 106 737 PIN DESCRIPTION Low Normally Closed N C Low Common Low Normally Open N O High Normally Closed N C High Common High Normally Open N O Figure 11 5 RELAYS LO amp HI Rear Panel Connector Details 11 5 Lake Shore Model 340 Temperature Controller User s Manual ANALOG ANALOG OUT 1 OUT 2 DESCRIPTION EC HE Output Center Conductor Ground Connector Shell Figure 11 6 ANALOG OUT 1 amp 2 BNC Rear Panel Connector Details INPUT A INPUT B Current Voltage Driven Shield or Guard Voltage Current No Connection Figure 11 7 Sensor INPUT A amp B Rear Panel Connector Details HEATER OUTPUT HI LO SHIELD Ge DESCRIPTION SHED Figure 11 8 HEATER OUTPUT Rear Panel Connector Details 11 6 Service Lake Shore Model 340 Temperature Controller User s Manual 11 5 1 IEEE 488 Interface Connector Connection to the IEEE 488 Interface connector on the rear of the Model 340 Temperature Controller is made using cables specified in the IEEE 488 1978 standard document Briefly the cable has 24 conductors with
167. ee the SETTLE command for parameter descriptions Remote Operation SRDG Input Returned Remarks TUNEST Input Returned Remarks XSCAN Input Returned Remarks Example XSCAN Input Returned Remarks ZONE Input Returned Remarks Example ZONE Input Returned Remarks Lake Shore Model 340 Temperature Controller User s Manual Query Sensor Units Reading for an Input SRDG lt input gt lt sensor units value Format tnnn nnnE n term Returns the sensor units reading for an input lt input gt Specifies which input to query Query Control Loop 1 Tuning Status TUNEST lt tuning status gt Format n term Returns 0 if the loop is not tuning and 1 if it is tuning Configure External Scanner Mode Parameters XSCAN lt mode gt lt channel gt lt interval gt Nothing Configures the external scanner mode refer to Paragraph 5 4 lt mode gt Specifies scan mode Valid entries 0 off 1 manual 2 autoscan 3 slave lt channel gt Specifies scanned input to use if lt mode gt manual Valid entries 1 16 lt interval gt Specifies autoscan interval in seconds if lt mode gt autoscan Valid entries 0 999 XSCAN 2 5 term Sets the instrument to autoscan the inputs with an interval of 5 seconds Query External Scanner Mode Parameters XSCAN lt mode gt lt channel gt lt interval gt Format n nn nnn term Returns the external scanner mode
168. efer to Table 3 2 If the final destination of the instrument is known when it is shipped the line input is configured at the factory This configuration should always be checked because it is not unusual for an instrument to change hands before it reaches the end user All of the line voltages discussed are single phase Table 3 2 AC Line Input Definitions Indicator Line Voltage Range Fuse slow blow 90 105 VAC 108 126 VAC 198 231 VAC 216 252 VAC To verify the proper line voltage selection look at the indicator in the window of the line input assembly Line voltage should be in the range shown in Table 3 2 for that indicator If it is not change the line voltage selector as described in Paragraph 11 3 3 Installation 3 5 Lake Shore Model 340 Temperature Controller User s Manual 3 3 2 Line Fuse and Fuse Holder The line fuse is an important safety feature of the Model 340 a fuse ever fails it is important to replace it with the value and type indicated on the rear panel for the line voltage setting The letter T on the fuse rating indicates that the instrument requires a time delay or slow blow fuse Fuse values should be verified any time line voltage configuration is changed Instructions for changing and verifying a line fuse are given in Paragraph 11 3 3 3 3 Power Cord The Model 340 includes a three conductor power cord Line voltage travels across the outer two conductors The center conductor is a safety g
169. el the thermal EMF voltage which is present in the same polarity regardless of current direction The settling time associated with current reversal will reduce the update rate of a corrected input from 20 readings per second to 10 readings per second Thermal correction can be turned off but it is not recommended because reading errors will increase The default setting is ON Thermal correction can also be paused for a short time This feature is useful when the temperature system is stable and the user wants to make delicate experimental measurements with little disturbance entering the system The Reverse setting is for diagnostic purposes only Thermal correction parameter field will appear on the input setup screen when a sensor type using voltage excitation is selected To change the thermal correction parameter to on off or pause press the Input Setup key The input setup setting screen will appear with the Input letter in the top left hand corner Use the A or Y key to select an input Press the Enter key or the Next Setting key to display the input parameters for that input Press the Next Setting key until the thermal compensation field is highlighted and then use the A or Y key to select on off or pause Press the Next Setting key to continue with more settings or press the Save Screen key to store the changes in the Model 340 The default setting is On 5 1 4 Special Sensor Type Configuration The Model 340 allows sensors that do not ma
170. elow with paragraph references Command Display Paragraph Command Display Paragraph Output Ramping Flow Control Ramp Setpoint Absolute Ramp SP Abs 8 3 1 1 Wait Wait 8 3 1 8 Ramp Setpoint Relative Ramp SP Rel 8 3 1 2 Settle Settle 8 3 1 9 Ramp Manual Output Absolute Ramp MOut Abs 8 3 1 3 Repeat Repeat 8 3 1 10 Ramp Manual Output Relative Ramp MOut Rel 8 3 1 4 End Repeat End Repeat 8 3 1 10 Direct Settings Call Call 8 3 1 11 Control Parameters Parameters 8 3 1 5 End End 8 3 1 12 Digital Output Digital Output 8 3 1 6 No Operation NOP 8 3 1 13 Relays Relays 8 3 1 7 8 3 1 1 Ramp Setpoint Absolute Ramp the control setpoint from its present setting value to a new specified absolute setting value The setpoint units must be in temperature for this instruction to operate The ramp can be done at a specified ramp rate or in a specified length of time This instruction is used with a closed loop temperature control mode If the instrument is configured for Zone control mode the control parameters including heater range are updated as the setpoint temperature changes through new zones Setpoint ramps in an internal program override the stand alone setpoint ramp parameter Setpoint New Loop 1 control setpoint in temperature units Ramp SP Abs gt Setpoint 0 000K Hours Hours to ramp to new setpoint 0 to 23 Hours 0 Minutes Minutes to ramp to new setpoint 0 to 59 Minutes 0 Seconds Seconds to ramp to new setpoint 0 to 59 Seconds
171. er SoftCal is an inexpensive way to improve the accuracy of an already predictable sensor NOTE Standard Curve 10 is the name of the temperature response curve not its location inside the Model 340 Standard Curve 10 is stored in Curve Location 1 in the Model 340 A unique characteristic of DT SofCal Point 1 Sotal Point 2 SoftCal Point 3 400 Series diodes is that their Liquid Helium Liquid Nitrogen Room temperature responses pass Boiling Point Boiling Point Temperature Font through 28 K at almost exactly 42K 77 35 K SC the same voltage This improves SoftCal algorithm operation by 0 25 50 75 100 125 150 175 200 225 20 275 200 325 350 ken providing an extra calibration LI data point It also explains why 2 10K 50 100 K 200 325 K SoftCal calibration specifications Acceptable Temperature Range for Silicon Diode SoftCal Inputs are divided into two temperature ranges above and below 28 K See Figure 8 1 Figure 8 1 SoftCal Temperature Ranges for Silicon Diode Sensors Point 1 Calibration data point at or near the boiling point of helium 4 2 K Temperatures outside 2 K to 10 K are not allowed This data point improves between the calibration data point and 28K Points 2 and 3 improve temperatures above 28 K Point 2 Calibration data point at or near the boiling point of nitrogen 77 35 K Temperatures outside 50 K to 100 K are not allowed This data point improves accuracy between 28 K and 100 K Points 2 and 3 together
172. er release the drawer holding the line voltage selector and fuse Remove fuse and replace it with the appropriate slow blow fuse Re assemble the line input assembly in reverse order Verify voltage indicator in the line input assembly window Connect the instrument power cord Turn the power switch ON I 90 1 0 Ol CoN gt 11 4 GENERAL MAINTENANCE 11 4 1 Cleaning Clean the Model 340 periodically to remove dust grease and other contaminants Use the procedure below 1 Clean front and back panels and case with soft cloth dampened with mild detergent and water solution NOTE Do not use aromatic hydrocarbons or chlorinated solvents to clean the Model 340 They may react with the plastic materials used in the controller or the silk screen printing on the back panel 2 Clean surface of printed circuit boards PCBs using clean dry air at low pressure 11 5 REAR PANEL CONNECTOR DEFINITIONS e PIN DESCRIPTION The Serial I O Digital UO Relays Analog Outputs Serial In RxD Sensor Inputs and Heater Output connectors are Ponies Serial In RxD Serial Ground Serial Ground Serial Out TxD Serial Out TxD defined in Figures 11 3 through 11 8 respectively RJ 11 Receptacle Figure 11 3 SERIAL I O RJ 11 Rear Panel Connector Details 11 4 Service Service Lake Shore Model 340 Temperature Controller User s Manual DIGITAL UO 340 11 3 eps Pin Symbol Description Type or Limit 6 Reserv
173. er disabled A time out was put in the keypad so that the instrument would return to normal operation if a key happened to be unintentionally pressed The time out acts like an Escape or Cancel Screen key being pressed so that no accidental changes are made to settings Even with the time out we do not recommend you do long data entry operations while the instrument controls an experiment 4 4 Front Panel Operation Lake Shore Model 340 Temperature Controller User s Manual 4 4 7 Key Definitions Displays the AUTO TUNE screen to set Auto P Auto Pl or Auto PID control mode Z Setti Displays the ZONE SETTINGS screen which specifies P I D Manual Output and One Pegs Heater Range for up to 10 Temperature control zones Ramp Displays the RAMP SETUP screen which turns ramp on or off and selects ramp rate P Displays the PROGRAM MODE screen Allows the user to Run an internal program rogram Terminate a program Edit a program or Clear program memory Allows direct setting of the proportional P control parameter Il Allows direct setting of the integral I control parameter ID Allows direct setting of the derivative D control parameter Displays the CONTROL SETUP screen which enables the control loop establishes Control Set power up status and setpoint units sets heater resistance and control mode and turns up the filter on or off Press the More key to display the CONTROL LIMITS screen which sets the temperature slope maximum h
174. erations for Good Control 2 7 2 5 1 Thermal Gonductivity 3 AE er EP iaa 2 7 2 5 2 Thermal Eag oi ht re prd BEEF 2 8 2 5 3 Two Sensor Approach sssssssssessseseeeeee erret enn enne rrnr nnne nennen nns 2 8 2 5 4 gar anake AN E E EE S AE daa 2 8 Lake Shore Model 340 Temperature Controller User s Manual 2 5 5 System Nonlinearity cinereo te ede et tae v Hae ire e dede et eai Te ed ld te 2 8 2 6 PID CONTON giereg et tte eie ee eee e e ede aout ee re ad beeen 2 9 2 6 1 Proportional P 2 deerat redit dee ee eite ete a eet beet ied dts 2 9 2 6 2 nce c 2 9 2 6 3 Derivative D y zi e nee nee ee dl lae ei oer ea de e ded dete coe oie e eu dede e qb de detta 2 9 2 6 4 Manual Heater Output MED 2 11 2 7 Manual TUNISIA DE 2 11 2 7 1 Setting Heater Range e eat la otov e ee eed 2 11 2 7 2 Tuning dree Le LEE 2 11 2 7 3 TUNING Integral cnt 28 28 4 IRR TO O eum te 2 12 2 7 4 Tuning RL CEET 2 12 2 8 AUTO TUNING itcr deor E idet de tede iden eel ada ae 2 13 2 9 Zone TUNING A mee en 2 14 3 UE RE 3 1 3 0 General cutus UL LLL M LI E Rt E dic 3 1 3 1 Receiving the Model 241 EEN REENEN dl aieo da en d c dd aed ue ea 3 1 3 1 1 Inspection and Unpacking 3 1 3 1 2 Repackaging For Shipment inei Lade dd ede Fa edd 3 1 3 1 3 I II 3 2 3 1 4 Safety Symbols iiir id atii oa eid Deed dot e a ne e debe deae ag 3 2 3 1 5 Handling Liquid Helium and Liquid Nitrogen nmm 3 3 3 1 5 1 Beleg 3 3
175. esired input Then press the Enter key A sensor input can appear in as many reading fields as desired The default setting is A and B 4 6 Front Panel Operation Lake Shore Model 340 Temperature Controller User s Manual 4 5 3 Reading Source and Display Units Readings shown on the display are taken from the sensor inputs but a variety of digital processing can be done to the raw sensor data before it is displayed see Figure 5 10 One or more of these sources can be displayed at the same time for an active sensor input Sensor Raw sensor units as read from the temperature sensor Temp K Temperature in Kelvin Requires a temperature response curve selected in Input Setup Refer to Paragraph 5 1 Temp C Temperature in Celsius Requires a temperature response curve selected in Input Setup Refer to Paragraph 5 1 Man Maximum value read since last reset Refer to Paragraph 5 3 2 Mim Minimum value read since last reset Refer to Paragraph 5 3 2 Output of a linear equation Refer to Paragraph 5 3 3 To select a display reading source enter the sensor input above Press the Enter key to highlight the field next to the input use the A or V key to select a source for that reading display from the list If a temperature source is selected and no temperature response curve is present an error message will appear on the normal display NOCURV Press the Enter or Next Setting key to change the next reading display Press the Save
176. esistance 3 4 6 Two Lead Sensor Measurement There are times when crowding in a cryogenic system forces users to l read sensors in a two lead configuration because there are not V enough feedthroughs or room for lead wires If this is the case plus Two Lead voltage to plus current and minus voltage to minus current leads are PUR y attached at the back of the instrument or at the vacuum feedthrough The error in a resistive measurement is the resistance of the lead wire run with current and voltage together If the leads contribute 2 or 3 Q to a 10 KQ reading the error can Installation 3 7 Lake Shore Model 340 Temperature Controller User s Manual probably be tolerated When measuring voltage for diode sensors the error in voltage can be calculated as the lead resistance times the current typically 10 uA For example a 10 lead resistance times 10 pA results in a 0 1 mV error in voltage Given the sensitivity of a silicon diode at 4 2 K the error in temperature would be only 3 mK At 77 K the sensitivity of a silicon diode is lower so the error would be close to 50 mK Again this may not be a problem for every user 3 4 7 Lowering Measurement Noise Good instrument hardware setup technique is one of the least expensive ways to reduce measurement noise The suggestions fall into two categories 1 Do not let noise from the outside enter into the measurement and 2 Let the instrument isolation and other hardware features work
177. ess the Enter key The message Press SAVE SCREEN to continue CANCEL SCREEN to abort is displayed If you press the Save Screen key the data card is erased If you press the Cancel Screen key the erasure is canceled Instrument Programming 8 17 Lake Shore Model 340 Temperature Controller User s Manual This Page Intentionally Left Blank Instrument Programming Lake Shore Model 340 Temperature Controller User s Manual CHAPTER 9 REMOTE OPERATION 9 0 GENERAL Two computer interfaces are provided with the Model 340 Temperature Controller Either of these interfaces permit remote operation of the Model 340 The first is the IEEE 488 Interface described in Paragraph 9 1 The second is the Serial Interface described in Paragraph 9 2 The two interfaces share a common set of commands described in Paragraph 9 3 Only one of the interfaces should be used at a time 9 1 IEEE 488 INTERFACE The IEEE 488 Interface is an instrumentation bus with hardware and programming standards designed to simplify instrument interfacing The IEEE 488 Interface of the Model 340 complies with the IEEE 488 2 1987 standard and incorporates the functional electrical and mechanical specifications of the standard unless otherwise specified in this manual All instruments on the interface bus must be able to perform one or more of the interface functions of TALKER LISTENER or BUS CONTROLLER A TALKER transmits data onto the bus to other devices A LISTENER receives
178. ey to store the change in the Model 340 The default settings are On kelvin When the Max Min feature is setup it will not automatically appear on the display Use the display format screen to add a reading field to the display and select the input and math source for that new field Display format is discussed in Paragraph 4 5 To Pause the Max Min feature press the Math Setup key The math setting screen will appear with the input letter in the top left hand corner Use the A or Y key to select an input Press the Enter key or the Next Setting key to display the Max Min parameters for that input Press the Next Setting key until the Max Min enable field is highlighted and then use A or W key to select pause Press the Save Screen key to store the change in the Model 340 Changing back and fourth between on and pause will not reset the values To reset the Max Min values press the Math Reset key from the normal display Math reset is an immediate operation Measurement Operation 5 5 Lake Shore Model 340 Temperature Controller User s Manual 5 3 3 Linear Equation The Model 340 can calculate a linear equation as a special data processing feature The output of this calculation can be shown on the display or directed to an analog output for proportional control of other hardware in an experiment One computation can be done for each sensor input The output will not automatically show on the display use the display format setting screen desc
179. f a control actuator that can utilize a bipolar control output 7 2 Analog Digital Alarm amp Relay Operation Lake Shore Model 340 Temperature Controller User s Manual 7 1 4 Manual Mode Operation of the Analog Outputs During manual operation the user can set the voltage of an analog output giving them a controlled voltage source In manual mode all analog output parameters are ignored except the bipolar setting and the users output setting value The setting value is given in percent of full scale With bipolar on a setting value of 100 causes an output voltage of 10 V and a setting value of 100 causes an output voltage of 10 V With bipolar off unipolar a setting value of 0 causes an output voltage of 0 V and a setting value of 100 causes an output voltage of 10 V Negative setting values cause an output voltage of 0 V if bipolar is off The resolution of the analog output hardware is 1 25 mV or 0 0125 of full scale Setting resolution of the output value is 0 01 To set an analog output voltage press the Analog Outputs key and set the mode to manual and set bipolar setting as described in Paragraph 7 1 Press the Next Setting key until the value field is highlighted Use the number keys to enter the desired output then press the Enter key Press the Save Screen key to store the changes The default value is 0 7 2 DIGITAL INPUTS AND OUTPUTS I O The Model 340 has six digital inputs and five digital output
180. f specified curve parameters do not match the input the curve number defaults to 0 Valid entries 0 none 1 20 standard curves 21 60 user curves INCRV A 23 term Input A uses User Curve 23 for temperature conversion 9 33 INCRV Input Returned Remarks INSET Input Returned Remarks Example INSET Input Returned Remarks INTYPE Input Returned Remarks Example 9 34 Lake Shore Model 340 Temperature Controller User s Manual Query Input Curve Number INCRV lt input gt curve number Format nn term Returns the input curve number See the INCRV command for parameter descriptions input Specifies which input to query Configure Hardware Input Setup Parameters INSET lt input gt lt enable gt lt compensation gt Nothing Configures hardware input setup parameters lt input gt Specifies input to configure lt enable gt Specifies whether the input is allowed to be read lt compensation gt Specifies whether to use compensation for this input Valid entries 0 off 1 on 2 pause Field is only valid with NTC resistor or special INSET A 1 term Turns on compensation for Input A Query Input Hardware Setup Parameters INSET lt input gt lt enable gt lt compensation gt Format n n term Returns input hardware setup parameters See the INSET command for parameter descriptions lt input gt specifies which input to query Configur
181. f the analog output is 1 25 mV or 0 0125 of full scale The output can source up to 100 mA of current providing a maximum of 1 W of power They can drive a resistive load of no less than 100 Q The output is short protected so the instrument is not be harmed if the heater resistance is too small It is not recommended because the additional load on instrument power supplies will cause noise on internal circuits Paragraph 3 5 7 describes two ways to use an Analog Output as a control output If the output is used directly as a resistive heater driver be sure the heater has a resistance of 100 or more The maximum power out is 1 W at 100 If the output is used to program an external power supply the input resistance of the voltage programming input on the supply must be 100 Q or greater Setup and operation are otherwise similar To select control output as a source for an Analog Output press the Analog Outputs key The analog output indicator is highlighted in the upper left hand corner Use the A or V key to select analog output 2 Press the Enter or Next Setting key until the Mode field is highlighted Use the A or V key to select LOOP Press Enter or Next Setting to continue with more settings or the Save Screen key to save the changes to the Model 340 It is recommended to set the Analog Output to unipolar mode Few applications can use bipolar control output A thermoelectric cooling element is one example of a control actuator that can u
182. fault setting is Silicon Diode NOTE If the user changes any of the parameters listed for a standard sensor type the instrument assumes a special sensor type is required Paragraph 5 1 4 NOTE Use the display setup screen Paragraph 4 5 to show configured readings from an input on the display Measurement Operation 5 1 Lake Shore Model 340 Temperature Controller User s Manual 5 1 2 Voltage Excitation Current Autorange Several RTD sensor types have a nonlinear temperature response These sensors require special excitation so that their signal can be read with good resolution and at the same time not too much power is dissipated in the sensor When these sensors are being read by the Model 340 the current excitation is automatically ranged to keep the voltage across the sensor below that listed in the table above To illustrate the effect power can be expressed by either 2 Paper pos R Using these negative temperature coefficient resistors with resistance R and a constant current I excitation the power in the sensor will increase as temperature drops resistance increases but with constant voltage V excitation the power reduces as temperature drops Voltage excitation is indicated for several sensors in the table above that should be read using low power Other than using an autoranging current source voltage excitation often requires compensation for thermal EMF that is described below Note that thermal compensation
183. files in Steps 2 and 3 are not installed on your computer they may be copied from your National Instruments setup disks or they may be downloaded from www natinst com 4 Configure the GPIB by selecting the System icon in the Windows 98 95 Control Panel located under Settings on the Start Menu Configure the GPIB Settings as shown in Figure 9 1 Configure the DEV12 Device Template as shown in Figure 9 2 Be sure to check the Readdress box 9 4 Remote Operation Lake Shore Model 340 Temperature Controller User s Manual System Properties 2 xl General Device Manager Hardware Profiles Perform AT GPIB TNT Plug and Play Properties L ES General GPIB Settings Resources View devices by type View devices by col m Computer y AT GPIB TNT Plug and Play e CDROM H 6 Disk drives ISA PrP Serial Number O04D 7FAO a Display adapters Floppy disk controllers Interface Name r Termination Methods zz Hard disk controllers seien v Iv Send EOI at end of write 1 43 Keyboard D z 2 Monitor GPIB Address M Terminate Read on EOS H A Mouse i P P y National Instruments GPIB Interfaces Ga V Se EO with EOS on Write AT GPIB TNT Plug and Play 8 bit EOS Compare E 7 Network adapters Secondary E Ports COM amp LPT 10 EOS Byte BR System devices Seel D d 170 Timeout 10sec Properties Refresh Remove IV System Con
184. filter readings also slow display reading response to real temperature changes in the load To change on the filter readings points for an input press the Math Setup key You see the MATH COMPUTATIONS screen The Input field is highlighted Use the A or Y key to select an Input Use the Enter or Next Setting key to move the cursor to FILTER Points Use the A or Y key to select the desired number The minimum number of points is 2 the maximum is 64 The default setting is 10 Some users do not want the filter to slow the response of the display reading when large deliberate changes in temperature are made The filter window parameter allows the user to set the limit for a large temperature change If an unfiltered reading differs from the filtered reading by more than the filter window limit the filter will be restarted The filter window limit is set in percent of full scale range for the selected input type To change the filter window for an input press the Math Setup key You will see the MATH COMPUTATIONS screen The Input field will be highlighted Use the A or Y key to select an Input Use the Enter or Next Setting key to move the cursor to FILTER Window Use the A or Y key to select the desired percentage The minimum is 1 the maximum is 10 The default setting is 1 5 4 Measurement Operation Lake Shore Model 340 Temperature Controller User s Manual 0 Alarms Input Processing Filter Conversion
185. first attempt make several small 2 degree setpoint changes to see if better parameter values are calculated To select AutoTune mode press the AutoTune key The AUTOTUNE screen appears with the control loop indicator highlighted in the upper left hand corner of the screen Use the A or W key to select Loop 1 or 2 Press Enter or Next Setting to advance to tuning mode selection Only one control loop at a time may use AutoTune Use the A or V key to select a tuning mode and press Save Screen to store the change The default setting is Manual PID 6 8 ZONE CONTROL DATA ENTRY The Model 340 allows the user to establish up to 10 custom temperature zones where the controller automatically uses pre programmed PID settings and heater range The user should configure the zones using 1 as the lowest to 10 as the highest zone in kelvin K Make a copy of Figure 6 1 to plan your zones then use the manual to record final zone settings To program the zones from the front panel press the Zone Settings key Use the A or V key to set the Loop to 1 or 2 Use the Enter or Next Setting keys to advance to the first line of the zone settings Use the numerical keypad and the Enter key to enter new zone values Parameters that T d can be specified are Top of the zone in kelvin proportional P integral 1 derivative D Manual Output in percent and Heater Range Enter these parameters for each zone When complete press the Save Screen key Once
186. for returned string String is present if CR is seen Strip off terminators Print return string No string present if timeout Get next command Lake Shore Model 340 Temperature Controller User s Manual 9 1 4 5 Program Operation Once either example program is running try the following commands and observe the response of the instrument Input from the user is shown in bold and terminators are added by the program The word term indicates the required terminators included with the response E ENTER COMMAND IDN Identification query Instrument will return a string identifying itself RESPONSE LSCI MODEL340 123456 02032001 term TER COMMAND KRDG A Query Kelvin Reading for Input A Controller returns temperature reading in kelvin 077 350E 0 ENTER COMMAND HTR Query Heater Output Controller returns heater output in percent 050 0 ENTER COMMAND CMODE 1 1 Set Control Loop 1 to Manual PID ENTER COMMAND PID 1 Query Current PID Status Controller returns separate PID settings 0020 0 0010 0 0005 0 ENTER COMMAND PID 1 25 15 6 SetLoop 1 PID values to 25 15 and 6 E l E TER COMMAND BEEP 1 BEEP Combination command of setting the system beeper on and then requesting the system beeper status TER COMMAND The following are additional notes on using either IEEE 488 Interface program D If you enter a correctly spelled query without a nothin
187. ft hand corner Use the A or W key to select an input Press the Enter or Next Setting key to show the alarm parameters for that input Press the Next Setting key until the enable relay is highlighted Use the A or Y key to turn the relay parameter on or off for that input Use the Next Setting key to make more changes or press the Save Screen key to store the changes The default setting is Off Analog Digital Alarm amp Relay Operation 7 5 Lake Shore Model 340 Temperature Controller User s Manual 7 3 6 Input Alarm Reset The Alarm Reset key performs the immediate action of resetting all latched alarms If any alarm is latched active and the alarm condition has been corrected pressing the Alarm Reset key deactivates the alarm If the alarm condition is not corrected the alarm is not deactivated Non latching alarms deactivate when the alarm condition is corrected without the Alarm Reset function 7 3 7 Audible Beeper The audible alarm beeper can be turned on or off for the entire instrument To turn on or off the audible alarm beeper press the Options key and then press the More key and the RELAYS amp BEEPER SETUP screen appears Press the Next Setting key until the beeper field highlights Use the A or W key to turn the beeper on or off and press the Save Screen key to store the change The default setting is On 7 4 HIGH AND LOW RELAYS The Model 340 has one high and one low OFF Relay is set to Off relay See Figure 2 They are mos
188. g status are also shown on the bottom of the screen Use the Next Setting or Previous Setting key to select each menu item 8 14 Instrument Programming Lake Shore Model 340 Temperature Controller User s Manual 8 4 1 1 Log Setup To setup the data log highlight Setup data log and press the Enter key The SETUP DATA LOG screen appears Every Sets the interval for storing records as one record every 1 to 3600 readings or one record every 1 to 3600 seconds The interval number is set first followed by units readings seconds Selects the unit of the logging rate Every 20 readings equals 1 second because the Model 340 updates the readings 20 times a second Start Mode Selecting Clear clears old records before starting data logging Selecting Continue continues data logging and adds new records to existing data Overwrite Yes Data logging continues beyond the maximum number of records specified and overwrites old records with new No Data logging stops at the maximum number of records specified Type Specifies the data type of the specified Point Five data types are available to log 1 Input reading 2 SP1 Setpoint of Control Loop 1 3 SP2 Setpoint of Control Loop 2 4 Out Output of Control Loop 1 5 Out2 Output of Control Loop 2 If no data logging is necessary for the specified Point select None Note Changing Type will erase stored records Input Specifies Input channel to log This field is av
189. g and connecting to a bulk head connector at the vacuum boundary The lead wire must be a good electrical conductor but a poor thermal conductor or heat will transfer down the leads and change the temperature reading of the sensor Small 30 to 40 AWG wire made of an alloy like phosphor bronze is much better than copper wire Thin wire insulation is preferred and twisted wire should be used to reduce the effect of RF noise if it is present The wire used on the room temperature side of the vacuum boundary is not critical so copper cable is normally used 2 3 7 Lead Soldering When additional wire is soldered to short sensor leads care must be taken not to overheat the sensor A heat sink such as a metal wire clamp or alligator clip will heat sink the leads and protect the sensor Leads should be tinned before bonding to reduce the time that heat is applied to the sensor lead Solder flux should be cleaned after soldering to prevent corrosion 2 3 8 Heat Sinking Leads Sensor leads can be a significant source of error if they are not properly heat sinked Heat will transfer down even small leads and alter the sensor reading The goal of heat sinking is to cool the leads to a temperature as close to the sensor as possible This can be accomplished by putting a significant length of lead wire in thermal contact with every cooled surface between room temperature and the sensor Lead wires can be adhered to cold surfaces with varnish over a thin electrical
190. g is O 6 7 SELECTING AN AUTOTUNE CONTROL MODE The Model 340 AutoTune feature automates the tuning process of typical cryogenic systems Refer to Paragraph 2 8 for additional information about the AutoTune algorithm Before initiating AutoTune setup the cooling system with control sensor and heater capable of closed loop control Be sure to assign the control sensor with a valid temperature response curve Assign an appropriate heater range as described in Paragraph 2 7 1 To speed up the AutoTune process experiment with Manual PID tuning to choose good initial control parameters If no initial parameters are known start with the default values of P 50 and 20 It is better to set an initial P value that causes the system to be more active than desired Starting with a low P value can increase the time and number of attempts required to tune 6 4 Temperature Control Operation Lake Shore Model 340 Temperature Controller User s Manual Selecting An AutoTune Control Mode Continued There are three AutoTune modes each with different system characteristics For most applications Auto Pl is recommended Auto P Sets the P parameter value only and D are set to 0 no matter what the initial values are This mode is recommended for systems that have very long lag times or nonlinearity that prevents stable Pl control Expect some overshoot or undershoot of the setpoint and stable temperature control below the setpoint value Auto PI Sets
191. g will be returned Incorrectly spelled commands and queries are ignored Commands and queries should have a space separating the command and associated parameters Leading zeros and zeros following a decimal point are not needed in a command string but are sent in response to a query A leading is not required but a leading is required 9 1 5 Troubleshooting New Installation 1 Check instrument address 2 Always send terminators 3 Send entire message string at one time including terminators 4 Send only one simple command at a time until communication is established 5 Be sure to spell commands correctly and use proper syntax 6 Attempt both Talk and Listen functions If one works but not the other the hardware connection is working so look at syntax terminators and command format If only one message is received after resetting the interface check the repeat addressing setting It should be enabled Old Installation No Longer Working 8 Power instrument off then on again to see if it is a soft failure 9 Power computer off then on again to see if the IEEE card is locked up 10 Verify that the address has not been changed on the instrument during a memory reset 11 Check all cable connections Intermittent Lockups 12 Check cable connections and length 13 Increase delay between all commands to 50 ms to make sure instrument is not being over loaded 9 12 Remote Operation La
192. ge them The only front panel keys that are active when the keypad is locked are the Heater Off and Alarm Reset keys 4 6 DEFAULT VALUES It is sometimes necessary to reset instrument parameters to their factory default values These values can be cleared without affecting instrument calibration To reset the Model 340 parameters to factory default values press the Options key then press the More key until the Revision Information screen is displayed Up the A or W key to change the Set Defaults setting to Yes then press the Enter key Press the Save Screen key to complete the action The Model 340 will then restart using the factory default values 4 8 Front Panel Operation Lake Shore Model 340 Temperature Controller User s Manual CHAPTER 5 SENSOR INPUT AND TEMPERATURE MEASUREMENT OPERATION 5 0 GENERAL This chapter describes front panel operation for sensor input configuration and temperature measurement The user must setup temperature sensor input before a valid sensor reading can be made and select a temperature response curve to convert readings to temperature This chapter covers sensor input setup in Paragraph 5 1 selecting a temperature response curve in Paragraph 5 2 filter and math functions in Paragraph 5 3 and scanner support in Paragraph 5 4 5 1 SENSOR INPUT SETUP This section covers sensor type in Paragraph 5 1 1 voltage excitation in Paragraph 5 1 2 thermal EMF compensation with voltage excitation in Paragraph
193. ges The normal display is discussed in Paragraph 4 2 1 Setting displays is discussed in Paragraph 4 2 2 Data entry displays are discussed in Paragraph 4 2 3 Finally error displays are discussed in Paragraph 4 2 4 Front Panel Operation 4 1 Lake Shore Model 340 Temperature Controller User s Manual 4 2 1 Normal Display The normal display is what the instrument shows under normal operating conditions when the user is not changing a setting and there is not a hardware failure detected The top line of the display is dedicated to showing instrument status Status annunciators appear on the top line when applicable Annunciators that may be seen include Tune Logging Program Ramping Alarm Remote and Locked The next four lines are used to show sensor input readings This area is configurable by the user to show between one and eight readings From one to four readings can be shown in large characters five L to eight readings are shown using smaller characters Normal Display with One Loop Shown The bottom three lines show control settings and status This area is configurable to show information from one or two control loops If one loop is being displayed the heater output can be shown in large characters Some examples of normal display configurations are shown here Instructions on how to change the display configuration are provided in the following paragraphs 4 2 2 Setting Displays Users may enter common par
194. gister are continually changing Standard Event Status ESB Bit 5 When bit 5 is set it indicates if one of the bits from the Standard Event Status Register has been set Refer to Paragraph 9 1 3 2 Error Bit 4 This bit is set when there is an instrument error not related to the bus Alarm Bit 3 This bit is set when there is an alarm condition Settle Bit 2 This bit is set when the settle conditions have been reached New OPT Bit 1 New data is available from the optional inputs New A amp B Bit 0 New data is available from the two normal inputs 9 1 3 2 Standard Event Status Register and Standard Event Status Enable Register The Standard Event Status Register supplies various conditions of the Model 340 STANDARD EVENT STATUS REGISTER FORMAT EL E x6 else rcu ES A cde up 0c Weighing 128 64 32 16 8 4 2 1 Bit Name Bits 1 and 6 are not used The user is only interrupted with the reports of this register if the bits have been enabled in the Standard Event Status Enable Register and if bit 5 of the Service Request Enable Register has been set Remote Operation 9 3 Lake Shore Model 340 Temperature Controller User s Manual The Standard Event Status Enable Register allows the user to enable any of the Standard Event Status Register reports The Standard Event Status Enable command ESE sets the Standard Event Status Enable Register bits If a bit of this register is set then
195. hased with a Model 340 or they can be field installed using the data card slot A built in SoftCal algorithm can also be used to generate curves for silicon diodes and platinum RTDs for storage as user curves A 10 3401 1267954 P 1The Lake Shore SoftCal algorithm for silicon diode and platinum RTD sensors is a good solution for applications that need more accuracy than a standard sensor curve but do not warrant traditional calibration SoftCal uses the predictability of a standard curve to improve the accuracy of an individual sensor around a few known temperature reference points Introduction 1 1 Lake Shore Model 340 Temperature Controller User s Manual 1 2 Temperature Control The Model 340 offers two proportional integral derivative PID control loops A PID control algorithm calculates control output based on temperature setpoint and feedback from the control sensor Wide tuning parameters accommodate most cryogenic cooling systems and many small high temperature ovens Control output is generated by a high resolution digital to analog converter for smooth continuous control The user can manually set the PID values or the autotuning feature of the Model 340 can automate the tuning process The main heater output for the Model 340 is a well regulated variable DC current source Heater output is optically isolated from other circuits to reduce interference and ground loops Heater output can provide up to 100 W
196. hassis Gently lift the assembly and rest it on the chassis at an angle REAR PLASTIC BEZEL TOP COVER SCREWS SIDE COVER Remove bottom To remove top SCREWS cover screws also and bottom On Both Sides covers slide them to the rear on the tracks Service 11 11 Lake Shore Model 340 Temperature Controller User s Manual M340SV 7 Ss NOTE If there are only two inputs then no option card is installed Proceed to Step 10 If there are more 6 than two inputs then an Option Card is installed Perform the actions in Steps 6 through 9 Remove the ribbon cable that plugs into the Option Card plug J3 located on the lower right corner of the card Remove the four smaller Phillips head screws that secure the board to the stand offs These can be found on the side opposite the sensor plug and on the edge close to the J3 ribbon cable plug Remove the two Phillips head screws that secure the Option Board to the Model 340 rear panel The option board now can be lifted out CAUTION The EPROM is an Electrostatic Discharge Sensitive ESDS device Wear shock proof wrist 10 11 12 13 14 15 straps with a resistor that limits current to lt 5 mA to prevent injury to service personnel and to avoid inducing an Electrostatic Discharge ESD into the device Note the orientation of the notch on the M340MN Flash Memory U26 and M340SV EEPROM Memory U146 chips Gently pr
197. he Save Screen key to store the changes The default value is 00000 7 2 5 Digital Input Modes The digital input signals are always read by the Model 340 Their status is always available from the front panel or over computer interface The only defined application of the digital inputs is during external scanner operation refer to Paragraph 5 4 If external scanner operation is not being used the inputs are considered to be in manual mode 7 3 INPUT ALARMS Each input of the Model 340 has a high and low alarm setting Input reading data in temperature units sensor units or from linear equation can be compared to the alarm values If a reading is higher than the high alarm setting the high alarm is active for the input If a reading is lower than the low alarm setting the low alarm is active for the input The alarm feature can be enabled or disabled for each individual input Active alarms are indicated on the display with an annunciator The Alarm annunciator indicates that there is an input alarm enabled An Alarming annunciator indicates that an enabled alarm is active An audible beeper can also sound to indicate an alarm is active The audible beeper can be turned off for all alarms One or more sets of high and low alarms can be directed to the high and low alarm relays Parameters on the RELAY 8 BEEPER SETUP screen must be changed for the alarm relays and beeper to be active as described in Paragraph 7 4 The alarms can operate in la
198. he desired curve number with the A or Y key then press the Enter key The following message is displayed Press SAVE SCREEN to erase CANCEL SCREEN to abort If you press the Save Screen key the Saving user curves message appears for a few seconds then the display returns to the CURVE ENTRY menu If you press the Cancel Screen key the curve is not erased and you return to the CURVE ENTRY menu Instrument Programming 8 3 Lake Shore Model 340 Temperature Controller User s Manual 8 2 SOFTCAL The Model 340 performs inexpensive sensor calibrations with a two algorithms called SoftCal These algorithms work with DT 400 Series Silicon Diode sensors and Platinum Sensors They create a new temperature response curve from the standard curve and known data points entered by the user The new curve loads into one of the 40 user curve locations 21 through 60 These paragraphs describe the data points needed from the user and the expected accuracy of the resulting curves Both DT 400 and Platinum SoftCal algorithms require an existing standard curve in the Model 340 When the user enters the sensor type to calibrate the correct standard curve is selected When calibration is complete the user selects the new curve for an input the Model 340 does not automatically choose the newly generated curve for either input Enter calibration data points normally measured at easily reached temperatures Each algorithm operates with one two or three cali
199. heater is OFF 5 point type None 0 0 If there is no valid SRAM Data card mounted or data logging is in progress the Model 340 returns 0 0 0 0 0 0 0 0 Remarks Returns the record of the specified point of the specified record number lt record gt Specifies logged data record number Valid entries 1 value returned by LOGCNT lt point gt Specifies point number to be returned Valid entries 1 4 Remote Operation 9 37 MDAT Input Returned Remarks MDATST Input Returned Remarks MNMX Input Returned Remarks Example MNMX Input Returned Remarks MNMXRST Input Returned Remarks MODE Input Returned Remarks Example MODE Input Returned Remarks MOUT Input Returned Remarks Example 9 38 Lake Shore Model 340 Temperature Controller User s Manual Query Min Max Data for an Input MDAT lt input gt lt min value gt lt max value Format tnnn nnnE n nnn nnnE tn term Returns the minimum and maximum input data lt input gt specifies which input to query Query Min Max Data Status for an Input MDATST lt input gt lt min bit weighting gt lt max bit weighting gt Format nnn nnn term The integer returned represents the sum of the bit weighting of the input minimum maximum data status flag bits lt input gt specifies which input to query See RDGST Command Configure Minimum and Maximum Input Function Parameters MNMX lt
200. here the Thermocouple is contacting the liquid Or possibly add a thermal mass to the end of the Thermocouple that is being dipped 6 Press Input Type select input C or D and press Enter Press Next Setting until the Room Comp field highlights then press Enter Use the A or V key to select EXECUTE and press Enter 7 A pop up menu appears with the currently read temperature displayed Enter the true temperature that the Thermocouple should read If inputs are shorted then enter the actual room temperature measured by a thermometer device Press Save Screen to complete the calibration for that input The Model 340 turns internal room temperature compensation ON when calibration completes To verify calibration check that the temperature reading for the calibrated input matches the room temperature calibration setting value 10 4 5 Computer Interface Commands Most of the computer interface commands used by the Model 340 are independent of installed options or sensor type The following commands or formats change when the 3464 is installed 1 In command strings the input field accepts A B C or D instead of only A and B 2 Sensorunits for inputs C and D are millivolts mV 3 The INSET command changes to the following format The INSET query changes accordingly INSET lt input gt lt enable gt lt compensation gt lt input gt Specifies input to configure C or D lt enable gt Specifies whether input is allowed
201. hing while showering with warm water The patient should not drink alcohol or smoke Keep warm and rest Call a physician immediately 3 2 REAR PANEL DEFINITION This paragraph provides a summary of Model 340 rear panel connections See Figure 3 2 CAUTION e Verify that the AC Line Voltage shown in the window on the fuse holder corresponds to that marked on the rear panel and that both these settings are appropriate for the intended AC power input Also remove and verify the proper fuse is installed before inserting the power cord and turning on the instrument e Always turn off the instrument before making any rear panel connections This is especially critical when making sensor to instrument connections AREL dE ANALOG ANALOG o OUT 2 INPUT B D Lo DIGITAL UO NC C NO NC C NO 1 Line Input Assembly eeseseneerrncrerresrerrnrrrrisn Paragraph 3 3 2 DATA CARD S lot diete tdi d eed Paragraph 8 4 3 EEE 488 INTERFACE Connector Paragraph 9 1 and Figure 10 8 A SERIAL WO Connector A Paragraph 9 2 and Figure 10 2 5 DIGITAL VO Connector onsec Paragraph 3 7 and Paragraph 7 2 6 RELAYS LO and HI Connector ssss Paragraph 3 8 7 ANALOG OUT 1 and 2 Connectors Paragraph 3 6 and Paragraph 7 1 8 Sensor INPUT A and B Connectors Paragraph 3 4 9 Option Cutout
202. ial Interface Example Programs Two BASIC programs are included to illustrate the serial communication functions of the instrument The first program was written in Visual Basic Refer to Paragraph 9 2 7 1 for instructions on how to setup the program The Visual Basic code is provided in Table 9 6 The second program was written in Quick Basic Refer to Paragraph 9 2 7 2 for instructions on how to setup the program The Quick Basic code is provided in Table 9 7 Finally a description of operation common to both programs is provided in Paragraph 9 2 7 3 While the hardware and software required to produce and implement these programs not included with the instrument the concepts illustrated apply to almost any application where these tools are available Remote Operation 9 15 Lake Shore Model 340 Temperature Controller User s Manual 9 2 7 1 Visual Basic Serial Interface Program Setup The serial interface program works with Visual Basic 6 0 VB6 on an IBM PC or compatible with a Pentium class processor A Pentium 90 or higher is recommended running Windows 95 or better with a serial interface It uses the COM1 communications port at 9600 Baud Use the following procedure to develop the Serial Interface Program in Visual Basic 1 Start VB6 2 Choose Standard EXE and select Open 3 Resize form window to desired size 4 On the Project Menu click Components to bring up a list of additional controls available in VB6 5 Scroll through
203. ich DT 470 SD sensor leads are which It is important to follow these instructions for Diode Sensor Leads plus and minus leads polarity as well as voltage and current when applicable Diode sensors do not operate in the wrong polarity They look like an open circuit to the instrument Two lead resistors can operate with any lead arrangement and the sensor instructions may Cathode eg e nda not specify Four lead resistors can be more dependent on lead arrangement Follow any specified lead assignment for four lead resistors Mixing leads could give a reading that appears correct but is not the most accurate 3 4 5 Four Lead Sensor Measurement All sensors including both two lead and four lead can be I measured with a four lead technique The purpose of a V V four lead measurement is to eliminate the effect of lead Four Lead Four Lead resistance on the measurement If it is not taken out lead Platinum resistance is a direct error when measuring a resistive V V sensor In a four lead measurement current leads and voltage leads are run separately up to the sensor With separate leads there is little current in the voltage leads so their resistance does not enter into the measurement Resistance in the current leads will not change the current as long as the voltage compliance of the current source is not reached When two lead sensors are used in four lead measurements the short leads on the sensor have an insignificant r
204. ich sensor input to use as feedback for each control loop Loop 1 and Loop 2 settings are independent To select a control channel press Loop 1 or Loop 2 to display control parameters for that loop in the lower portion of the display Press Control Channel to highlight the setting field for the control channel sensor input Use the A or Y key to select the sensor input Press Enter to save the change or Escape to return to the previous setting The default setting is A 6 5 CONTROL MODES There are two ways to tune a closed loop PID control loop using the Model 340 manual and AutoTune Paragraphs 2 6 through 2 8 Once the control loop is tuned the control parameters chosen function for a given temperature range If more than one temperature range is required the user must change the control parameters depending on the setpoint temperature The Model 340 offers several options for doing so including zone control AutoTune or internal programming Table 6 1 Control Mode Description Description MANUAL PID The instrument can always be used in manual mode The user changes control parameters based on cooling system experience and knowledge AUTO PID The AutoTune feature can be left on It computes new control parameters after each setpoint change Auto Pl and Auto P are similar but they set only P and I or only P Zone control mode automatically enters pre selected control parameters when the setpoint is changed to a value outside the present
205. ified above the Warranty Period If Lake Shore receives notice of any such defects during the Warranty Period and the Product is shipped freight prepaid Lake Shore will at its option either repair or replace the Product if it is so defective without charge to the owner for parts service labor or associated customary return shipping cost Any such replacement for the Product may be either new or equivalent in performance to new Replacement or repaired parts will be warranted for only the unexpired portion of the original warranty or 90 days whichever is greater Lake Shore warrants the Product only if it has been sold by an authorized Lake Shore employee sales representative dealer or original equipment manufacturer OEM The Product may contain remanufactured parts equivalent to new in performance or may have been subject to incidental use The Warranty Period begins on the date of delivery of the Product or later on the date of installation of the Product if the Product is installed by Lake Shore provided that if you schedule or delay the Lake Shore installation for more than 30 days after delivery the Warranty Period begins on the 31st day after delivery This limited warranty does not apply to defects in the Product resulting from a improper or inadequate maintenance repair or calibration b fuses software and non rechargeable batteries c software interfacing parts or other supplies not furnished by Lak
206. igital output signals D1 to D4 report the active scan channel as shown in the table above seu cave Scanning Channel Di4 DIS D2 DM In some application it is necessary for the external scanner or other external hardware to select the active scan channel In scanner slave mode the Model 340 will change to the active scan channel to the channel indicated on the digital inputs The digital inputs do not need any special setup The active scan channel will follow the digital inputs as shown in the table below Digital input logic levels are described in Paragraph 7 2 5 8 Measurement Operation Lake Shore Model 340 Temperature Controller User s Manual CHAPTER 6 TEMPERATURE CONTROL OPERATION 6 0 GENERAL There are many steps involved in setting up and operating a control loop The earlier chapters of this manual discuss hardware setup and the basic principals of tuning the control parameters to an individual system This section describes operation of the instrument control features and how to set control parameters There are several parameters that must be set before the Model 340 can perform even simple temperature control functions Each of the parameters in this chapter should be considered before turning the heater on The user should also verify that the sensor inputs are reporting correct temperature readings before proceeding The Model 340 has the ability to run two independent control loops so it is called a two loop contr
207. iliary control loop with enough features to control a radiation shield or small sample heater Loop 2 has a different output from Loop 1 it uses Analog Output 2 as its actuator It is a variable DC voltage source that can vary from 10 V to 10 V The resolution of the analog output is 1 25 mV or 0 0125 of full scale The output can source up to 100 mA of current providing a maximum of 1 W of heater power 3 5 8 Loop 2 Output Resistance 2 The power delivered by the Loop 2 output is calculated as P is heater The output is rated for no more than 100 mA of current so for the maximum of 1 W output power use a 100 Q resistive heater with a power rating greater than 1 W Smaller resistance values should not be used but larger resistances can be used for lower power applications 3 5 9 Loop 2 Output Connector The connector for Loop 2 output which is Analog Output 2 is a BNC connector The inner conductor is the output voltage terminal the outer conductor is attached to chassis ground inside the instrument A coaxial cable with attached BNC terminal is recommended for this output The center conductor is capable of carrying the maximum current and the outer conductor acts as a shield Attaching the outer conductor to ground at the opposite end of the cable is not recommended These connectors are not included with the Model 340 but are available from local electronic suppliers 3 5 10 Loop 2 Heater Protection The output is short protec
208. improve thermal lag is to pay close attention to thermal conductivity both in the parts used and their junctions 2 5 3 Two Sensor Approach There is a conflict between the best sensor location for measurement accuracy and the best sensor location for control For measurement accuracy the sensor should be very near the sample being measured which is away from the heating and cooling sources to reduce heat flow across the sample and thermal gradients The best control stability is achieved when the feedback sensor is near both the heater and cooling source to reduce thermal lag If both control stability and measurement accuracy are critical it may be necessary to use two sensors one for each function Many temperature controllers including the Model 340 have two sensor inputs for this reason 2 5 4 Thermal Mass Cryogenic designers understandably want to keep the thermal mass of the load as small as possible so the System can cool quickly and improve cycle time Small mass can also have the advantage of reduced thermal gradients Controlling a very small mass is difficult because there is no buffer to adsorb small changes in the system Without buffering small disturbances can very quickly create large temperature changes There are Systems where it is necessary to add a small amount of thermal mass such as a copper block in order to improve control stability 2 5 5 System Nonlinearity Because of nonlinearities in the control system a system
209. inally Zone Tuning is covered in Paragraph 2 9 2 1 TEMPERATURE SENSOR SELECTION This section is intended to help the user ask the proper questions about sensor selection and not to give all the answers Additional useful information on temperature sensor selection is available in the Lake Shore Temperature Measurement and Control Catalog The catalog has a large reference section that includes sensor characteristics and sensor selection criteria Temperature range is discussed in Paragraph 2 1 1 Sensor sensitivity is discussed in Paragraph 2 1 2 Environmental conditions are discussed in Paragraph 2 1 3 Measurement accuracy is discussed in Paragraph 2 1 4 Finally sensor packages are discussed in Paragraph 2 1 5 2 1 1 Temperature Range Several important sensor parameters must be considered when choosing a sensor The first is temperature range The experimental temperature range must be known when choosing a sensor Some sensors can be damaged by temperatures that are either too high or too low Manufacturer recommendations should always be followed Sensor sensitivity is also dependent on temperature and can limit the useful range of a sensor It is important not to specify a range larger than necessary If an experiment is being done at liquid helium temperature and a very high sensitivity is needed for good measurement resolution that same resolution may not be required to monitor warm up to room temperature Two different sensors may
210. ing LOGPNT lt point gt lt point type gt lt input gt lt source gt Nothing Configures a data point for data logging lt point gt Specifies which point to configure Valid entries 1 4 lt point type gt Specifies the data type Valid entries 0 None 1 Input 2 SP1 3 SP2 4 Out1 5 Out2 Specifies input when lt type gt 1 Specifies input data to log when lt type gt 1 Valid entries 1 Kelvin 2 Celsius 3 sensor units 4 linear data 5 min data 6 max data lt input gt lt source gt Query a data point for data logging LOGPNT lt point gt lt point type gt lt input gt lt source gt Format n a n term Returns the specified data point setting for data logging See the LOGPNT command for parameter descriptions lt point gt Specifies which point to query Valid entries 1 4 Remote Operation Lake Shore Model 340 Temperature Controller User s Manual LOGSET Configure data logging parameters Input LOGSET lt log type gt lt interval gt lt overwrite gt lt start mode gt Returned Nothing Remarks Configures data logging parameters lt log type gt Specifies readings seconds Valid entries 1 readings 2 seconds lt interval gt Specifies number of readings between each record when lt log type gt 1 Specifies number of seconds between each record when lt log type gt 2 Valid entries 1 3600 lt overwrite gt Specifies whether overwrite enable
211. ining the latest version of the Master Firmware Before You Start 1 Stop your application while updating the software The update process may take as long as ten minu Disable the instrument from controlling digital UC and analog outputs 2 Press the Options key then press the More key until the REVISION INFORMATION SCREEN displ the current firmware revision information for both Master and Input processors If the instrument displ no version numbers please contact Lake Shore Instrumentation Service Department Loading New Master Firmware from the PCMCIA Data Card tes ays ays 1 Load the PCMCIA data card The data card slot is on the left bottom corner of the instrument rear Insert data card with the Lake Shore label face up Press firmly on the card until it securely engages the slot 2 The Data Card key on the right edge of the Model 340 keypad transfers the code from the data card to the flash memory Press Data card The display shows 4 choices highlight Read Data card and press Enter 3 The display shows the Read Data card options highlight M340 main code and press Enter If flash memory is OK a box appears with the message Updating code The system resets itself when load complete Service is 11 13 Lake Shore Model 340 Temperature Controller User s Manual This Page Intentionally Left Blank 11 14 Service Lake Shore Model 340 Temperature Controller User s Manual APPENDIX A CURVE TABLES A1 0
212. input measurements are isolated from earth ground to reduce the amount of earth ground referenced noise that is present on the measurement leads This isolation can be defeated by connecting sensor leads to earth ground on the chassis of the instrument or in the cooling system If one sensor lead must be grounded ground only one lead and ground it in only one place Grounding leads on more than one sensor prevents the sensor excitation current sources from operating Shielding the sensor lead cable is important to keep external noise from entering the measurement A shield is most effective when it is near the measurement potential so the Model 340 offers a driven shield that stays close to the measurement The shield of the sensor cable should be connected to the shield pin of the input connector It should not be terminated at the opposite end of the cable The shield should not be connected to earth ground on the instrument chassis or in the cooling system NOTE The shell of the connector is in contact with the chassis so the cable shield should never touch the outer shell of the connector The shield pin of the Model 340 input connector can be connected to the shield drive or the measurement ground The shield drive is recommended for cables over 20 feet in length To change the shield pin contact use JMP6 for Input B and JMP5 for Input A See Figure 11 11 3 4 4 Sensor Polarity Lake Shore sensors are shipped with instructions that indicate wh
213. installed and operating correctly refer to Paragraph 9 1 4 1 Use the following procedure to develop the IEEE 488 Interface Program in Visual Basic 1 Start VB6 2 Choose Standard EXE and select Open 3 Resize form window to desired size 4 On the Project Menu select Add Module select the Existing tab then navigate to the location on your computer to add the following files Niglobal bas and Vbib 32 bas 5 Add controls to form a Add three Label controls to the form b Add two TextBox controls to the form c Add one CommandButton control to the form 6 On the View Menu select Properties Window 7 Inthe Properties window use the dropdown list to select between the different controls of the current project iw IEEE Interface Program E 8 Set the properties of the controls as defined in Table 9 1 9 Save the program 9 6 Remote Operation Lake Shore Model 340 Temperature Controller User s Manual Table 9 1 IEEE 488 Interface Program Control Properties Current Name Property New Value Label Name IbIExitProgram Caption Type exit to end program Label2 Name IbICommand Caption Command Label3 Name IblResponse Caption Response Text1 Name txtCommand Text blank Text2 Name txtResponse Text blank Command1 Name cmdSend Caption Send Default True Form1 Name frmlEEE Caption IEEE Interface Program 10 Add code provided in Table 9 2 a Inthe Code Editor window un
214. insulator like cigarette paper They can also be wound onto a bobbin that is firmly attached to the cold surface Some sensor packages include a heat sink bobbin and wrapped lead wires to simplify heat sinking 2 3 9 Thermal Radiation Thermal black body radiation is one of the ways heat is transferred Warm surfaces radiate heat to cold surfaces even through a vacuum The difference in temperature between the surfaces is one thing that determines how much heat is transferred Thermal radiation causes thermal gradients and reduces measurement accuracy Many cooling systems include a radiation shield The purpose of the shield is to surround the load sample and sensor with a surface that is at or near their temperature to minimize radiation The shield is exposed to the room temperature surface of the vacuum shroud on its outer surface so some cooling power must be directed to the shield to keep it near the load temperature If the cooling system does not include an integrated radiation shield or one cannot be easily made one alternative is to wrap several layers of super insulation aluminized Mylar loosely between the vacuum shroud and load This reduces radiation transfer to the sample space 2 4 HEATER SELECTION AND INSTALLATION There is a variety of resistive heaters that can be used as the controlled heating source for temperature control The mostly metal alloys like nichrome are usually wire or foil Shapes and sizes vary to permit inst
215. ired parameters Number entry and setting selection are discussed first because these operations are needed for both direct settings and setting screens 4 4 4 Changing Parameters After highlighting the desired parameter use the middle group of keys to enter a new value into the highlighted field Press Enter to end data entry and accept the new value Press Escape to end data entry and restore the old value Press Help to view limits and resolution for most parameters NOTE Within setting screens press Save Screen to accept the entire screen Press Cancel Screen or let the keypad time out to return the screen parameters to pre setting values Use the A or Y key to toggle an On Off or Yes No toggle or select from a list of possible parameter settings Enter accepts the new setting and Escape restores the old setting 4 4 2 Direct Settings To save the operator time the most commonly used parameters can be set directly from the normal display screen These keys are located in the area of the front panel with a gray background Some direct functions happen immediately when the key is pressed These include the Heater Off Loop 1 Loop 2 Alarm Reset Math Reset and Local keys No other keys are required to complete these operations Pressing other keys with a gray background will highlight the parameter indicated on the key The parameter can then be set by entering a number or selecting a setting P I D Manual Output and Setpoint
216. is shown on the display to indicate which range is selected An A D converter in the heater output circuitry also allows the Model 340 to diagnose problems in the heater circuit If an error is detected a message appears in the control output field of the display These errors are summarized in Paragraph 11 9 Error messages are not possible for Loop 2 When Analog Output 2 is used for control output of Loop 2 the control output is reported in percent of full scale output voltage 6 2 CONTROL LOOP ENABLE As a Safety feature both Control Loop 1 and 2 default to the disabled state This state ensures that the heater output for Loop 1 is off and Analog Output 2 for Loop 2 is set to zero volts The user must enable a control output before it can be used If an output is disabled the message Disabled appears in the control output field of the display To enable or disable a control output press the Control Setup key The CONTROL SETUP screen is displayed The control loop indicator is highlighted in the upper left hand corner Use A or V key to select Loop 1 or 2 Press the Enter or Next Setting key The control setup parameters for that loop appear on the screen Press the Next Setting key until the Enable field is highlighted Use the A or Y key to select ON for enabled or OFF for disabled Press the Enter or Next Setting key to continue with more settings or press the Save Screen key to store the changes in the Model 340 The default setting is Off
217. itions 11 4 11 5 1 IEEE 488 Interface Connector eene nennen nnns 11 7 11 6 Serial Interface Cable and Adapters sss enne 11 8 11 7 Top of Enclosure Remove and Replace Procedure sse 11 9 11 8 EPROM and NOVRAM Replacement sssssssssssssssssee ener ennemi 11 9 11 9 Error Messages tue ec eet ede tke dr pide He aee Rie e bte d Ree e v Mte e te kde 11 10 11 10 Firmware IC Replacement sse nennen stent reertnn ens 11 11 11 11 Updating The Master Firmware From A Data Card sssssss eee 11 13 A1 APPENDIX A CURVE TABL E urere ente onere teret orent ariete rn reapse ix ERE ERE A1 vii Figure No Figure 2 1 Figure 2 2 Figure 2 3 Figure 3 1 Figure 3 2 Figure 3 3 Figure 3 4 Figure 3 5 Figure 3 6 Figure 3 7 Figure 3 8 Figure 4 1 Figure 5 1 Figure 6 1 Figure 8 1 Figure 8 2 Figure 8 3 Figure 9 1 Figure 9 2 Figure 9 3 Figure 9 4 Figure 10 1 Figure 10 2 Figure 10 3 Figure 10 4 Figure 10 5 Figure 10 6 Figure 10 7 Figure 10 8 Figure 10 9 Figure 10 10 Figure 11 1 Figure 11 2 Figure 11 3 Figure 11 4 Figure 11 5 Figure 11 6 Figure 11 7 Figure 11 8 Figure 11 9 Figure 11 10 Figure 11 11 Figure 11 12 Figure 11 13 viii Lake Shore Model 340 Temperature Controller User s Manual LIST OF FIGURES Title Page Silicon Diode Sensor Calibrations and CalCurve sssseseem 2 3 Typic
218. ke Shore Model 340 Temperature Controller User s Manual 9 2 SERIAL INTERFACE OVERVIEW The serial interface used in the Model 340 is commonly referred to as an RS 232C interface RS 232C is a standard of the Electronics Industries Association ElA that describes one of the most common interfaces between computers and electronic equipment The RS 232C standard is quite flexible and allows many different configurations However any two devices claiming RS 232C compatibility cannot necessarily be plugged together without interface setup The remainder of this paragraph briefly describes the key features of a serial interface that are supported by the instrument A customer supplied computer with similarly configured interface port is required to enable communication 9 2 1 Changing Baud Rate If using the Serial Interface the user must set the Terminator BPS and Parity Press the Interface key to display the COMPUTER INTERFACE screen The user has the option to change the Baud rate Parity and Terminator Refer to Table 9 4 Use the A or W key make selections Use the Next Setting key to advance to the next parameter Finally use the Save Screen key to accept the changes or the Cancel Screen key to decline the changes 9 2 2 Physical Connection The Model 340 has an RJ 11 connector on the rear panel for serial communication The original RS 232C standard specifies 25 pins but 9 pin 25 pin and RJ 11 connectors are commonly used in the computer
219. ke Shore Model 340 Temperature Controller User s Manual To select a heater output range indicate Loop 1 by pressing the Loop 1 key The control parameters for that loop appear in the lower portion of the display Press the Heater Range key and the setting field for heater range is highlighted Use the A or Y key to select a heater range Press the Enter key to save the change or the Escape key to return to the previous setting The default setting is Off Table 6 3 Example of Max Current Settings Range Couren Power NOTE The control output for Loop 1 must be enabled before the heater can be turned on Refer to Paragraph 6 2 816 mA The Model 340 has an immediate key operation for turning the heater off The Heater Off key is in a JODA CENA prominent place on the keypad for easy access and it 31 6 mA remains active when the keypad is locked To turn off the heater output press the Heater Off key 6 12 2 Analog Output As Loop 2 Control Output The only control output available for Loop 2 is Analog Output 2 When the analog output is used as a control output it has the same voltage range and resolution as it does when used for any other purpose Many of the settings and limits on the control setup and control limit screens apply to the Analog Output when used as a control output Heater range is the most obvious exception The analog outputs are variable DC voltage sources that can vary from 10 V The resolution o
220. l 2 1 3 Environmental Conditions Environmental factors such as high vacuum magnetic field corrosive chemicals or even radiation may limit the effectiveness of some sensors Lake Shore has devoted much time to develop sensor packages that withstand the environmental factors found in typical cryogenic cooling systems Magnetic field experiments are very common Field dependence is an important selection criteria for temperature sensors used in these experiments Table 1 1 states the field dependence of most common sensors The Lake Shore Temperature Measurement and Control Catalog includes detailed field dependence tables along with specific data on other environmental factors when available 2 1 4 Measurement Accuracy Temperature measurements have several sources of error that reduce accuracy Be sure to account for errors induced by both the sensor and the instrumentation when computing accuracy The instrument has measurement error in reading the sensor signal and error in calculating a temperature using a temperature response curve Error results from the sensor being compared to a calibration standard and the temperature response of a sensor will shift with time and with repeated thermal cycling from very cold temperatures to room temperature Instrument and sensor makers specify these errors but there are things a user can do to maintain good accuracy For example choose a sensor that has good sensitivity in the most critical temperature r
221. l Precision Cal Accuracy 375K 0 25K 30K to 60K 10K 12mK 20mK 20 25 K 0 55K 60K to 345 K 10K 12mK 20mK 0 25K 1 of Temp 40 25K 345K to lt 375 K 20K 15mK 25mK 1 0K 375Kto475K 30K 25mK 45mK 1 of Temp 50K 30mK 55mK 1 of Temp COMM 100K 25mK 50mK Temps down to 1 4 K only with 40 25 K 30 K to 60 K 300K 25mK 50mK Precision Calibrated Sensors 340K 100 mK 0 15K 60 K to lt 345 K 480K 100 mK To increase accuracy 0 25K 345 K to lt 375 K perform a SoftCal with the 1 0K 375 K to 475 K Lake Shore fits a curve to these controller and sensor After Enter the voltage at 2 or 3 data points and sends a detailed report sensor calibration the points into a SoftCal capable to the sensor that includes Raw custom curve for that sensor controller A calibration report is Temperature Dala Polynomial 10 User calculates break Generate a CalCurve for either CalCurve or points and manually enters SoftCal or Precision Calibration data into the controller H H Model Number 8001 8000 3405 128F CALCRV Breakpoint pairs Breakpoint pairs are Breakpoint pairs are factory loaded on a Floppy Disk are loaded in a loaded in non in ACSII format for Datacard for field volatile memory Customer downloading installation 340 2 1 eps Figure 2 1 Silicon Diode Sensor Calibrations and CalCurve Cooling System Design 2 3 Lake Shore Model 340 Temperature Controller User s Manual 2 2 3 Standard Curves
222. larms ca E ME 7 4 7 3 1 Enabling an PUAI ctas 7 4 7 3 2 Selecting an Input Alarm Source sse een een nennen nnns 7 5 7 3 3 Input Alarm High and Low Settings 7 5 7 3 4 Input Alarm Eatchihg ci ias 7 5 7 3 5 Input Alarm Relay Setup 2000 ode 7 5 7 3 6 Input Alarm Reset lb 7 6 7 3 7 Audible Beeper ai de rat edt edt O aang 7 6 7 4 High and Low Relays a A AAA 7 6 7 4 1 selecting a Relay Mode cui ia 7 6 7 4 2 Manually Setting a Relay renei RE cnc nano nn nennen E 7 6 Instrument Program MIN 2 cocina ii ii td 8 1 8 0 Generalitat AAA ed ea de no ede ref 8 1 8 1 Curve Entry From The Front Panel sssssssseeee enne enne enne 8 1 8 1 1 Curve Numbers and Storage sssssssssssseeeeeeeenen rca 8 1 8 1 2 Front Panel Curve Entry Operations ssssssseeeeee eene 8 1 8 1 3 Front Panel Curve Edit isaac ocacion stc eden nece eee e he eter vs Hed bid es Pe ee 8 2 8 1 4 Front Panel Curve Copy annee eene eade nee tede ev tet aita ev ttd de d tede nee e 8 3 8 1 5 Front Panel Curve Erase i nter eere et tees os ree etie e ed ater vs Mode bd thee dee 8 3 8 2 Slo e 8 4 8 2 1 SoftCal and Silicon Diode Sensors sss emm enne 8 4 8 2 2 SoftCal Accuracy with Silicon Diode Sensors sse 8 5 8 2 3 SoftCal and Platinum Sensors aiser E A EE eene nemen 8 5 8 2 4 SoftCal Accuracy with Platinum Sensors sss enm emen 8 5 8 2 5 Creating a SoftCal Calib
223. lean b Double Click on cmdSend Add code segment under Private Sub cmdSend Click as shown in Table 9 6 c In the Code Editor window under the Object dropdown list select Form Make sure the Procedure dropdown list is set at Load The Code window should have written the segment of code Private Sub Form Load Add the code to this subroutine as shown in Table 9 6 d Double Click on the Timer control Add code segment under Private Sub Timer1 Timer as shown in Table 9 6 e Make adjustments to code if different Com port settings are being used 13 Save the program 14 Run the program The program should resemble the following i Serial Interface Program Type exit to end program Command Response c Ol 15 Type in a command or query in the Command box as described in Paragraph 9 2 7 3 16 Press Enter or select the Send button with the mouse to send command 17 Type Exit and press Enter to quit Remote Operation 9 17 Lake Shore Model 340 Temperature Controller User s Manual Table 9 6 Visual Basic Serial Interface Program Public gSend As Boolean Global used for Send button state Private Sub cmdSend Click gSend True End Sub Routine to handle Send button press Set Flag to True Private Sub Form Load Dim strReturn As String Dim strHold As String Dim Term As String Dim ZeroCount As Integer Dim strCommand As String frmSerial Show Term Chr 13 amp
224. lease use the following procedure to replace either the EPROM or the NOVRAM CAUTION The EPROM and NOVRAM are Electrostatic Discharge Sensitive ESDS devices Shock proof wrist straps resistor limited to lt 5 mA must be worn to prevent injury to service personnel and to avoid inducing an Electrostatic Discharge ESD into the device 1 Follow the top of enclosure REMOVAL procedure in Paragraph 11 7 2 Locate EPROM U146 M340SV HEX or NOVRAM U28 on the main circuit board Note orientation of existing IC See Figure 11 13 Use IC puller to remove existing EPROM NOVRAM from socket Noting orientation of new EPROM NOVRAM use an IC insertion tool to place new device into socket M340SV HEX A 08 06 96 DEOS Le 01 01 01 PANE Match notch on Match notch on O SE re 1 iss Typical EPROM Typical NOVRAM 5 Follow the top of enclosure INSTALLATION procedure in Paragraph 11 7 Service 11 9 Lake Shore Model 340 Temperature Controller User s Manual JMP6 JMP5 alo Eao JMP4 JMP3 oea oa jeiu JeMod U28 NOVRAM e Slave EPROM Ut46 0 Front Ground 3 ES U80 No Connection MS Analog Output 10 volts Ground 3 MES u79 Flash JMP2 EPROM No Connection SNE Analog Output Watch Doy IMPI Watch Dog 10 volts Timer Normal Timer Test Jumpers shown in factory default configuration Please consult with the factory before changing any jumpers Figure 11 13 Location Of Internal Components 11 9 ERROR MESSAGES Model 340 erro
225. ling system at the desired setpoint If this is the case try the following Allow the load to cool completely with the heater off Set manual heater output to 5096 while in Open Loop control mode Turn the heater to the lowest range and write down the temperature rise if any Select the next highest heater range and continue the process until the load warms up to room temperature If the load never reaches room temperature some adjustment may be needed in heater resistance or maximum heater current The list of heater range versus load temperature is a good reference for selection the proper heater range It is common for systems to require two or more heater ranges for good control over their full temperature Lower heater ranges are normally needed for lower temperature The Model 340 is of no use controlling at or below the temperature reached when the heater was off Many systems can be tuned to control within a degree or two above that temperature 2 7 2 Tuning Proportional The proportional setting is so closely tied to heater range that it can be thought of as fine and coarse adjustments of the same setting An appropriate heater range must be known before moving on to the proportional setting Begin this part of the tuning process by letting the cooling system cool and stabilize with the heater off Place the Model 340 in Manual PID control mode then turn integral derivative and manual output settings off Enter a setpoint several degrees
226. loop appears on the screen Press the Next Setting key until the Ramp field is highlighted Use the A or Y key to turn the ramp feature On Press the Next Setting key to highlight the ramp rate field Use the number keys to enter a ramp rate value and press the Save Screen key to save the changes in the Model 340 The default setting is Off 0 1 To stop a ramp in progress press the Ramp key The RAMP SETUP screen is displayed with the control loop indicator highlighted in the top left hand corner Use the A or V key to select Loop 1 or 2 Press the Enter or Next Setting key The ramp setup information for that loop appears on the screen Press the Next Setting key until the Ramp field is highlighted Use the A or Y key to turn the ramp feature OFF Press the Save Screen key to stop the ramp Another method to stop the ramp is to press the Setpoint key then immediately press the Enter key 6 12 CONTROL OUTPUT The output from the PID control equation in Loop 1 is directed to the heater output The control output from Loop 2 can only be directed to Analog Output 2 This section discusses using the heater output and an Analog Output as a control output 6 12 1 Heater Output Parameter Settings and Heater Range Some difficulties may be encountered when configuring the heater output for the first time It may be difficult to judge the amount of heater power needed to control a cooling system before it tested Another problem is that the heater output is
227. low 30 K 0 25 K from 30 K to lt 60 K 0 25 K from 345 K to lt 375 K 0 15 K from 60 K to 345 K 1 0 K from 375 to 475 K Perform three point SoftCal calibrations at liquid helium 4 2 K liquid nitrogen 77 35 K and room temperature 305 K Accuracy for the DT 470 SD 13 diode sensor is as follows 0 5K 2Kto 30 0 25 K30 K to 60 K 0 25 K345 K to 375 K 0 15 K60 K to 345 K 1 0K 375t0475K 8 2 3 SoftCal and Platinum Sensors The platinum sensor is a well accepted temperature standard because of its consistent and repeatable temperature response above 30 K SoftCal gives platinum sensors better accuracy than their nominal matching to the DIN 43760 curve Use one two or three calibration data SofiCal Point 1 i j 2 i SoftCal Point 2 SoftCal Point 3 points If using one point the algorithm Liquid Nitrogen Room High shifts the entire curve up or down to Boiling Point Temperature Point Temperature Point meet the single point If using two 77 35 K 305 K 480 K points the algorithm has enough information to tilt the cu rve achieving o 50 100 150 200 20 300 350 400 450 500 550 600 een kelvin good accuracy between the data points L l The third point extends the improved 50 100 K 200 325 K 400 600 K accuracy to Span all three points Acceptable Temperature Range for Platinum SoftCal Inputs Point 1 Calibration data point at or Figure 8 2 SoftCal Temperature Ranges for Platinum Sensors near the boiling point
228. lt range gt Format n term Returns the heater range See the RANGE command for parameter descriptions Query Input Status RDGST lt input gt lt reading bit weighting gt Format nnn term The integer returned represents the sum of the bit weighting of the input status flag bits lt input gt specifies which input to query Bit Bit Weighting Status Indicator 0 1 invalid reading 1 2 old reading 4 16 temp underrange 5 32 temp overrange 6 64 units zero 7 128 units overrange Configure Relay Control Parameters RELAY lt high low gt lt mode gt lt off on gt Nothing Configures relay control lt high low gt Specifies which relay to configure Valid entries 1 high and 2 low lt mode gt Specifies relay settings mode Valid entries 0 off 1 alarms 2 manual lt off on gt Specifies the manual relay settings if lt mode gt 2 RELAY 1 2 1 term Manually turns on the high relay Query Relay Control Parameters RELAY lt high low gt modes off on Format n n term Returns relay control See the RELAY command for parameter descriptions lt high low gt specifies which relay to query Valid entries 1 high and 2 low Query Relay Status RELAYST lt high low gt status Format n term Returns specified relay status 0 off 1 on lt high low gt specifies which relay status to query Valid entries 1 high 2 low Query Revision Information REV master rev date
229. m 1 10 Example Remote Operation PGMRUN 1 term Begins execution of program 1 9 39 PGMRUN Input Returned Remarks PID Input Returned Remarks Example PID Input Returned Remarks RAMP Input Returned Remarks Example RAMP Input Returned Remarks RAMPST Input Returned Remarks RANGE Input Returned Remarks Example 9 40 Lake Shore Model 340 Temperature Controller User s Manual Query Program Status PGMRUN lt program gt lt status gt Format nn n term Returns the current program running and the status If lt program gt 0 no program is running Values for lt status gt include 0 No errors 3 Too many End Repeat commands 1 Too many Call commands 4 The control channel setpoint is not in temperature 2 Too many Repeat commands Configure Control Loop PID Values PID lt loop gt lt P value gt lt I value gt lt D value gt Nothing Configures control loop PID values lt loop gt Specifies loop to configure lt P value gt The value for P value The value for I lt D value gt The value for D PID 1 10 50 term Control Loop 1 P is 10 and is 50 Query Control Loop PID Values PID lt loop gt lt P value lt I value D value Format nnnn n nnnn n nnnn term Returns control loop PID values See the PID command for parameter descriptions loop specifies which loop to query Co
230. m Operation Once either example program is running try the following commands and observe the response of the instrument Input from the user is shown in bold and terminators are added by the program The word term indicates the required terminators included with the response ENTER COMMAND IDN Identification query Instrument will return a string identifying itself RESPONSE LSCI MODEL340 123456 02032001 term ENTER COMMAND KRDG A Query Kelvin Reading for Input A Controller returns temperature reading in kelvin 077 350E 0 ENTER COMMAND HTR Query Heater Output Controller returns heater output in percent 050 0 ENTER COMMAND CMODE 1 1 Set Control Loop 1 to Manual PID ENTER COMMAND PID 1 Query Current PID Status Controller returns separate PID settings 0020 0 0010 0 0005 0 ENTER COMMAND PID 1 25 15 6 SetLoop 1 PID values to 25 15 and 6 ENTER COMMAND BEEP 1 BEEP Combination command of setting the system beeper on and then requesting the system beeper status 1 ENTER COMMAND The following are additional notes on using either IEEE 488 Interface program Ifyou enter a correctly spelled query without a nothing will be returned Incorrectly spelled commands and queries are ignored Commands and queries should have a space separating the command and associated parameters Leading zeros and zeros following a decimal point are not needed in a command string
231. mK 10 6 mK Platinum RTD 14J 77K 20 38 Q 0 423 O K 2 4 mK 10 mK 22 mK 4 8 mK 500 O Full calibration 300K 110 35 Q 0 387 O K 2 6 mK 34 mK 57 mK 5 2 mK Scale 500 K 185 668 Q 0 378 Q K 2 7 mK 155 mK 101 mK 5 4 mK Cernox CX 1010 0 3K 2322 4 Q 10785 Q K 3 uK 0 2 mK 3 7 mK 6 uK SD with 0 5K 1248 2 Q 2665 2 O K 12 uK 0 5 mK 5 mK 24 UK 0 3L 4 2K 277 32 Q 32 209 QIK 94 uK 6 2 mK 11 2 mK 188 uk calibration 300 K 30 392 Q 0 0654 Q K 15 mK 540 mK 580 mK 30 mK Cernox CX 1050 1 4K 26566 Q 48449 kQ K 6 uK 0 4 mK 5 4 mK 12 uK SD HT with 42K 3507 2 0 1120 8 kO K 90 uk 3 4 mK 8 4 mK 180 uK 1 4M 77K 205 67 Q 2 4116 Q K 1 3 mK 68 mK 84 mK 2 6 mK calibration 420 K 45 03 Q 0 0829 Q K 12 mK 520 mK 585 mK 24 mK Germanium GR 200A 0 5K 29570 Q 221000 O K 14 uK 0 2 mK 4 5 mK 28 UK 250 with 1 4K 1376 Q 2220 Q K 140 uK 0 9 mK 4 9 mK 280 uK 0 5D 4 2K 198 9 Q 68 9 O K 440 uK 3 8 mK 7 8 mK 880 uK calibration 100 K 2 969 Q 0 025 Q K 40 mK 200 mK 216 mK 80 mK Germanium GR 200A 1 4K 8257 O 19400 kQ K 52 uk 0 6 mK 4 6 mK 104 uK 500 with 4 2K 520 Q 245 kQ K 410 uk 3 0 mK 7 mK 820 uK 0 5D 10K 88 41 Q 19 5 O K 515 uK 5 6 mK 10 6 mK 1 03 mK calibration 100 K 1 7510 0 014 Q K 72 mK 270 mK 286 mK 114 mK Carbon Glass CGR 1 500 1 4K 103900 Q 520000 Q K 58 uk 0 6 mK 4 6 mK 116 uK with 1 4L 4 2K 584 6 Q 422 3 Q K 24 uK 1 2 mK 5 2 mK 48 uK calibration 77K 14 33 0 0 098 O K 3 1 mK 140 mK 165 mK 6 2
232. mK 300 K 8 550 0 0094 O K 32 mK 1 1K 1 2K 64 mK Rox RX 102A 0 5K 3701 0 5478 O K 19 uK 0 7 mK 5 2 mK 38 UK AA with 1 4K 2005 Q 667 O K 45 uK 2 4 mK 7 4 mK 90 UK 0 3B 4 2K 13700 80 3 Q K 375 uK 16 mK 32 mK 750 uK calibration 40K 1049 Q 1 06 O K 29 mK 1 1K 1 2K 58 mK Thermocouple Type K 75K 5862 9 uV 15 6 uV K 26 mK 0 25 K Calibration not 52 mK 50 mV 3464 300 K 1075 3 uV 40 6 uV K 10 mK 0 038 K available from Lake 20 mK 600 K 13325 uV 41 7 uV K 10 mK 10 184 KY Shore 20 mK 1505 K 49998 3 uV 36 006 uV K 12 mK 0 73 KV 24 mK Capacitance CS 501GR 42K 6nF 27 pF K 7 4 mK 2 08 K Calibration not 14 8 mK 150 nF 3465 77K 9 1 nF 52 pF K 3 9 mK 1 14K available from Lake 7 8 mK 200 K 19 2 nF 174 pF K 1 mK 0 4 K Shore 2 mK 7 Typical sensor sensitivities were taken from representative calibrations for the sensor listed 8 Control stability of the electronics only in an ideal thermal system Non HT version maximum temperature 325 K 1 Accuracy specification does not include errors from room temperature compensation 1 6 Introduction Lake Shore Model 340 Temperature Controller User s Manual 1 7 Specifications Table 1 3 Input Specifications Sensor Input Range Excitation Display Measurement Electronic Accuracy Electronic Temperature Current Resolution Resolution Control Coefficient Stability Diode negative 0Vto2 5V
233. mp the manual output MOut from its present setting value to a new specified absolute setting value The setting is in percent of full scale output which is normal for the manual output parameter The ramp can be done at a specified ramp rate or in a specified length of time This instruction is used with the open loop temperature control mode Instrument Programming 8 7 Lake Shore Model 340 Temperature Controller User s Manual Output New Loop 1 control output in percent of full scale Ramp MOut Abs gt Output 0 00 Hours Hours taken to ramp to new output 0 to 23 Hours 0 Minutes Minutes to ramp to new output 0 to 59 Minutes 0 Seconds Seconds to ramp to new output 0 to 59 Seconds 0 Rate Ramp rate in percent per minute m from 0 to 100 with Rate 0 00 m 0 1 resolution NOTE Ramp time or ramp rate can be set but not both If ramp time and rate are both zero then the ramp is a step change 8 3 1 4 Ramp Manual Output MOut Relative Ramp the manual output MOut a specified difference relative from its present setting value The setting is in percent of full scale output which is normal for the manual output parameter The ramp can be done ata specified ramp rate or in a specified length of time This instruction is used with the open loop temperature control mode Dev Deviation in Loop 1 control output set in percent of Ramp MOut Rel gt Dev 0 00 full scale Hours 0 Hours Hours to make output de
234. n 10 6 4 1 General Operation When the 3468 option is installed the Model 340s front panel allows configuration of C1 C4 D1 D4 inputs on most menu screens along with the standard A and B inputs Follow instructions in this manual for the A and B inputs and C and D can be accessed from the setting screens when available For an example of option input selection press Input Setup to display the INPUT SETUP screen Use the Up Arrow and Down Arrow keys to select inputs A B C or D Select C or D and press Enter Use the Up Arrow and Down Arrow keys to select a channel 1 4 for the selected input Press Enter again to display available settings for the option 10 6 4 2 Input Setup In the INPUT SETUP screen Enable Curve and Type can be changed Only Enable and Curve can be different for the channels in an input group Type must be the same for all sensors in the group Sensor Unit Temp Coeff Excitation and Range of the selected sensor type are shown for references only and cannot be changed independent of the type setting 10 6 4 3 Temperature Control Any of the optional sensors can be chosen as the control channel for either control loop Control from an option input is not recommended in most applications because the multiplexing necessary to read all channels can disrupt control Good control performance can be achieved when the other three channels in an input group are disabled Options and Accessories 10 15 Lake Shore Model
235. n applications that involve auxiliary sensor input scanners These signals can also be used in manual rin Symbol Description Type or Limit_ mode to control and monitor external Digital Output 1 TTL Output events The power supplies are Diaital Output 2 TTL Output provided for external circuit e DM utpu applications that require low current 3 DO Digital Output 3 TTL Output 4 DO P Digital Output 4 TTL Output The diaital input E 5 DO Digital Output 5 TTL Output et Reserved DIG Acting as Digital Input6 TTL Input Transistor to Transistor Logic TTL 6 Reserved DI6 Acting as Digital Input 6 TTL Input voltage level compatible They are 5 Volts Output 100 mA max protected against short circuit and over 8 5v O 15 Volts Output e is SE E 9 Dm Digital Input 1 TTL Input aards ESD vollace High th Di2 Digitalimput2 TTL Input discharge ESD voltages higher than ge a dee ur de 5 volts or lower than ground Using 11 DI Digitalimput3_ TTLImput more current than the limits in Figure Digital Input 4 TTL Input 3 6 is not recommended because the Digital Input 5 TTL Input additional load on instrument power 15 Volt Output supplies causes noise on internal circuits All signals and power supplies iS Gnd J3 SA should be relumed tae ground pin Figure 3 7 DIGITAL UO DA 15 Rear Panel Connector Details whenever possible Even though the ground pin is connected to chassis groun
236. nal destination of the instrument is known when itis shipped the line input is configured at the factory This configuration should always be checked because itis not unusual for an instrument to change hands before it reaches the end user All of the line voltages discussed are single phase Table 11 1 AC Line Input Definitions Indicator Line Voltage Range Fuse slow blow 90 105 VAC 108 126 VAC 198 231 VAC 216 252 VAC To verify the proper line voltage selection look at the indicator in the window of the line input assembly Line voltage should be in the range shown in Table 11 1 for that indicator If it is not change the line voltage selector as described in Paragraph 11 3 3 11 3 2 Fuse Verification The fuse must be removed to verify its value Refer to Paragraph 11 3 4 for fuse replacement instructions Fuses are slow blow time delay type and should always be the value specified in Table 11 1 Fuse values are also printed on the rear panel of the instrument for convenience WARNING To avoid potentially lethal shocks turn off controller and disconnect it from AC power line before performing these procedures Only qualified personnel should perform these procedures CAUTION For continued protection against fire hazard replace only with the same type and rating of fuse as specified for the line voltage selected 11 3 3 Line Voltage Selection The following is the procedure to change the instrument line voltage selec
237. nds end with a question mark A list of Model 340 common commands is provided in Paragraph 9 3 9 1 2 3 Interface and Device Specific Commands Device Specific Commands are addressed commands The Model 340 supports a variety of Device Specific commands to allow the user to program the controller remotely from a digital computer and to transfer measurements to the computer Most of the Device Specific commands have a function that can also be performed from the front panel This section discusses Common and Device Specific commands The Device specific commands are further broken down into Interface Display Channel Control Process and Curve commands for user convenience A table of every command of each type is presented and is immediately followed by individual discussions of each command These discussions are handled in the format described below A list of Model 340 commands is provided in Paragraph 9 3 9 2 Remote Operation Lake Shore Model 340 Temperature Controller User s Manual 9 1 3 Status Registers There are two status registers The Status Byte Register is described in Paragraph 9 1 3 1 The Standard Event Status Register is described in Paragraph 9 1 3 2 9 1 3 1 Status Byte Register and Service Request Enable Register The Status Byte Register consists of a single byte of data containing six bits of information about the condition of the Model 340 STATUS BYTE REGISTER FORMAT Bit AAN Weighing 128 64 32 16 8
238. ne 6 7 6 11 SetpointRaripltig u eet ne atte aa dae ee an Aina iets 6 8 6 12 Cono Kei re mani e lea es on tee mn dut add te ta dde deese dei a ux 6 8 6 12 1 Heater Output Parameter Settings and Heater Range sse 6 8 6 12 2 Analog Output As Loop 2 Control Output 6 10 6 13 Control Output Tu 6 11 6 13 1 Setpoint WIM It x a A A AS A 6 11 6 13 2 Control Output Spe Lm EA 5 ten eto A ae ee 6 11 6 13 3 Heater Range Limit sce thot nae aie AT A A ee 6 11 Analog Output Digital I O Alarm And Relay Operation eene 7 1 7 0 Gerieral ele ee ead ttr lean dir het eae ede er dae died 7 1 7 1 Analog ele CT 7 1 7 1 1 Input Mode for Analog Output ccccceceeeeeeecceeeceeeeeeeeeceaaeceeeeeeesecaaaaeceeeeeeeseesicaeeeeeeeees 7 2 7 1 2 Example of Low and High Parameter Setting ooonnnocccinnncccnnnnccccnnnanccccnnnannccnnnancccnanncncnnnna 7 2 7 1 3 Loop 2 Mode for Analog Output 2 7 2 7 1 4 Manual Mode Operation of the Analog Outputs ssssssssssseeeeeeeee 7 3 7 2 Digital Inputs and Outputs O ssssssssseeeeeeenenenemeenen nennen ennemis 7 3 7 2 1 Digital Output Modes nue tee eget cea ee en De ge e ORE e ed 7 3 7 2 2 Digital Outputs in Alarm Mode ssssessseene eene 7 3 7 2 3 Digital Outputs in Scanner Mode ener enne 7 3 7 2 4 Digital Outputs in Manual Mode ssesseeeeeee eene enne 7 4 7 2 5 Digital Input Modes EE 7 4 7 3 Input A
239. nfiguration GPIB PC2 2A Ver 2 1 Select the primary GPIB address by using the left and right arrow keys This address is used to compute the talk and listen addresses which identify the board or device on the GPIB Valid primary addresses range from O to 30 00H to 1EH Adding 32 to the primary address forms the Listen Address LA Adding 64 to the primary address forms the Talk Address TA EXAMPLE Selecting a primary address of 10 yields the following EH 10 32 42 Listen address y 10 64 74 Talk address GPIB PC2 2A Ver 2 1 Select the primary GPIB address by using the left and right arrow keys This address is used to compute the talk and listen addresses which identify the board or device on the GPIB Valid primary addresses range from 0 to 30 00H to 1EH Adding 32 to the primary address forms the Listen Address LA Adding 64 to the primary address forms the Talk Address TA EXAMPLE Selecting a primary address of 10 yields the following 10 32 42 Listen address 10 64 74 Talk address IBCONF EXE eps Figure 9 3 Typical National Instruments GPIB Configuration from IBCONF EXE Remote Operation Lake Shore Model 340 Temperature Controller User s Manual Table 9 3 Quick Basic IEEE 488 Interface Program IEEEEXAM BAS EXAMPLE PROGRAM FOR IEEE 488 INTERFACE This program works with QuickBasic 4 0 4 5 on an IBM PC or compatible The example requires a properl
240. nfigure Control Loop Ramp Parameters RAMP lt loop gt lt off on gt rate value gt Nothing Configures the control loop ramp lt loop gt Specifies which loop to configure lt offlon gt Specifies whether ramping is off or on lt rate value gt Specifies how many kelvin per minute to ramp the setpoint RAMP 1 1 10 5 term When Control Loop 1 setpoint is changed ramp the current setpoint to the target setpoint at 10 5 K minute Query Control Loop Ramp Parameters RAMP lt loop gt off on rate value Format nnn n term Returns the control loop ramp parameters See the RAMP command for parameter descriptions loop specifies which loop to query Query Control Loop Ramp Status RAMPST loop ramp status Format n term Returns 0 if setpoint is not ramping and 1 if it is ramping loop specifies loop to query Configure Heater Range RANGE range Nothing Configure the heater range range specifies the heater range Paragraph 6 12 1 Valid entries 0 5 RANGE O term Turns off the heater Remote Operation RANGE Input Returned Remarks RDGST Input Returned Remarks RELAY Input Returned Remarks Example RELAY Input Returned Remarks RELAYST Input Returned Remarks REV Input Returned Remarks Remote Operation Lake Shore Model 340 Temperature Controller User s Manual Query Heater Range RANGE
241. ng operation Select one of the ten program locations from the program edit screen New programs appear empty with End as the first instruction Program entry follows the sequence insert a NOP change the NOP to the desired instruction enter appropriate instruction parameters To edit a program press Program to display the PROGRAM OPERATION screen Press Next Setting to highlight the Edit Program line Press Enter to display the edit screen with the program number field highlighted Use the A or V key to select the desired program then press Enter to display instructions existing in that program location if any The Edit Program screen is divided into two halves The left half is a list of instructions in the program location and the right half shows parameters for a single instruction when the instruction is highlighted Enter instructions like any other data table Next Setting and Previous Setting move up and down the table 8 10 Instrument Programming Lake Shore Model 340 Temperature Controller User s Manual There are three table entry commands listed at the bottom of the screen that make program entry more convenient Insert I Delete D and Paste P manipulate the instructions within a program The table entry commands use the P I and D keys normally associated with those control parameters The commands work only in the left screen Insert adds instruction space to a program location in order to add instructions Delete deletes
242. nic applications are Chromel AuFe K T and E The Model 340 with a 3464 option provides 5 standard curves Users may enter custom curves Each thermocouple has a different temperature range and environment although the maximum temperature varies with the diameter of the wire used in the thermocouple Special techniques are required to approach accuracy of 196 of temperature even without consideration for the effects of high magnetic fields or high radiation fluxes Options and Accessories 10 7 Lake Shore Model 340 Temperature Controller User s Manual 10 4 2 Option Installation The Model 340 instrument supports only one option board at a time To install the 3464 Option into a Model 340 follow the installation procedure in Paragraph 10 3 1 To verify if an option is installed simply view the Model 340 rear panel Options mount above the normal inputs marked A and B To identify an option installed in a Model 340 press Options then press More three times Option identification displays on the REVISION INFORMATION screen If options board are changed the Model 340 changes all parameter settings to default but erases no sensor curves entered for optional sensor types 10 4 3 Sensor Installation Sensor connection is important when using thermocouples because the measured signal is small Many measurement errors can be avoided with proper sensor installation CAUTION Do not leave inputs unconnected to float Short channels when not in us
243. nly use plastic bags approved for storage of ESDS material 6 Donot handle ESDS devices unnecessarily or remove them from packaging until actually used or tested 11 3 Line Input Assembly This section describes how to properly connect the Model 340 to line power Please follow these instructions carefully to ensure proper operation of the instrument and the safety of operators Power On Off Screwdriver Fuse Switch Slot Drawer Figure 11 1 Line Input Assembly 11 2 Service Lake Shore Model 340 Temperature Controller User s Manual Depending upon the date of manufacture the unit will have either of two fuse data legends printed under the Line Input Assembly Za LINE 10 5 FUSE 100 120 220 240 50 60 Hz DATA 20A 1 0A 190 VA MAX 25x1 25in T 5x20mm T 50 60 Hz DATA 20A 104 190 VA MAX 5x20mm T 5x20mm T Figure 11 2 Fuse Data Legends Only the dimensions of the 2 A fuse change the rating does not Line voltage is discussed in Paragraph 11 3 1 Fuse verification is discussed in Paragraph 11 3 2 Line voltage selection is discussed in Paragraph 11 3 3 Fuse removal and replacement is discussed in Paragraph 11 3 4 11 3 1 Line Voltage The line input assembly contains the line voltage selector line fuse holder and power cord connector It is important to verify that the Model 340 is set to the appropriate line voltage and has the correct line fuse before itis powered on for the first time Refer to Table 11 1 If the fi
244. nnemi eres 3 8 3 5 4 Heater Protection and Fuse for Loop 1 ccccceceeeeeceeeeeeeeeeeeeneeeeeeeeeseeeeaeeeeeeeeeeeenensaees 3 9 3 5 5 Loop 1 Heater Noise tit dt 3 9 3 5 6 Model 3003 Heater Output Conditioner sss 3 9 3 5 7 LOOP Ee e LTE 3 10 3 5 8 Loop 2 Output Resistance iua ere tt e e mod reta ctae doit tesa ud 3 10 3 5 9 Loop 2 Output Connector 2 re p ere e nio ae te eH o ee n ed 3 10 3 5 10 Loop 2 Heater Protection retrace itte e ede rei ea e oe Ped ha c ga 3 10 3 5 11 Boosting the Output Power ees nitet a er t riae Da ee rai a eer e e rar gd 3 10 3 6 Analog Outputs acted dere n tasa tee eruit see dite tee an e 3 11 3 7 Digitall Osmosis ii dite e rim ot en a ei Da ote tot Aa ses uc 3 12 3 8 Relays eti ricette ntu ti E rupes vio 3 12 4 Front Panel Operation iv ccciessacccsentceccsssssendecastentsnavvansccnsiencehsassunccnetencetaavuonccentzinetaneasaacaamnissaeceecese 4 1 4 0 erar E 4 1 Lake Shore Model 340 Temperature Controller User s Manual Turing Power ON a a ee ee 4 1 Display Formats E 4 1 Normal Display n aiat n eiecit en a aede ac bt t det bot v Ee e ee peru 4 2 Setting Displays 27 30 eat ere ette A dest se eda 4 2 Data Entry Displays eene en aede c eiae e oi de te arc ae AEN 4 2 Error Displays eee ete coat tied den die odie en a eaten 4 2 Keypad Description moi ides erbe A lada 4 2 Keypad Navigation 220 Age aeterne tr SE eel ed ie eh eel 4 3 Changing Parameters 2
245. nputs to establish a control temperature and stabilize the system in a low magnetic field Then shift control to the capacitance sensor before increasing field strength 10 5 1 OPTION INSTALLATION To install the 3465 Option into a Model 340 follow the installation procedure in Paragraph 10 3 1 Only one option board can be installed in the Model 340 at a time To verify which option if any is installed in a Model 340 press Options then press More three times Option identification displays on the REVISION INFORMATION screen If options change the Model 340 changes all parameter settings to default 10 5 2 SENSOR INSTALLATION 10 5 2 1 Sensor Input Connector A six pin connector on the 3465 attaches the four sensor leads and shields Capacitance temperature sensors are commonly two lead devices but four lead measurement is recommended Make the change from four lead to two lead as close to the sensor as practical Model 3465 Input Connector Capacitance temperature sensors are not polarized use either lead as the positive or negative lead However 3465 option measurement is polarity dependent be sure to attach the V and I to one sensor lead and the V and l to the other 10 5 2 2 Measurement Point Connection Refer to Paragraph 2 3 for general installation guidelines for any cryogenic sensor When using a capacitance sensor the AC excitation must also be considered It is often necessary to place the capacitance sensor very n
246. nstall substitute parts or perform any unauthorized modification to the instrument Return the instrument to an authorized Lake Shore representative for service and repair to ensure that safety features are maintained 3 1 4 Safety Symbols Direct current power line Equipment protected throughout by double insulation or reinforced insulation equivalent to Class II of IEC 536 see Annex H Caution High voltages danger of electric shock Background color Yellow Symbol and outline Black Alternating current power line Alternating or direct current power line Three phase alternating current power line Earth ground terminal Caution or Warning See instrument documentation Background color Yellow Symbol and outline Black gt e p Protective conductor terminal Frame or chassis terminal On supply Off supply j Fuse O H qe 3 2 Installation Lake Shore Model 340 Temperature Controller User s Manual 3 1 5 Handling Liquid Helium and Liquid Nitrogen Liquid Helium LHe and liquid nitrogen LN2 may be used in conjunction with the Model 340 Although not explosive the following paragraphs provide safety considerations in the handling of LHe and LN 3 1 5 1 Properties LHe and LN are colorless odorless and tasteless gases Gaseous nitrogen makes up about 78 of Earth s atmosphere while helium comprises only about 5 ppm Most helium is recovered from natural gas deposits
247. nstant of the load which is used in setting integral If all has gone well the appropriate proportional setting is one half of the value required for sustained oscillation See Figure 2 3b Ifthe load does not oscillate in a controlled manner the heater range could be set too low A constant heater reading of 100 on the display would be an indication of a low range setting The heater range could also be too high indicated by rapid changes in the load temperature or heater output with a proportional setting of less than 5 There are a few systems that will stabilize and not oscillate with a very high proportional setting and a proper heater range setting For these systems setting a proportional setting of one half of the highest setting is the best choice 2 7 3 Tuning Integral When the proportional setting is chosen and the integral is set to zero off the Model 340 controls the load temperature below the setpoint Setting the integral allows the Model 340 control algorithm to gradually eliminate the difference in temperature by integrating the error over time See Figure 2 3d An integral setting that is too low causes the load to take too long to reach the setpoint An integral setting that is too high creates instability and causes the load temperature to oscillate Begin this part of the tuning process with the system controlling in proportional only mode Use the oscillation period of the load that was measured above in seconds Divide 100
248. nstruction returns control to the calling program End gt 8 3 1 13 NOP The NOP instruction holds only memory space When a running program encounters a NOP instruction it ignores it but the instruction occupies a memory location The instruction is most often used to save a memory location in a for another instruction to be selected later NOP gt 8 3 2 Internal Programming Operations Below is a list of the four internal programming operations initiated from the PROGRAM MODE screen Terminate program End a program run and return instrument to normal operation Edit program Enter or change a program Clear program memory Clear program memory space Store and retrieve program memory from a data card as well Refer to Paragraph 8 4 Read DataCard Copy programs from a data card to internal program memory Write DataCard Copy the contents of configurable memory including program memory to a data card These operations are performed from the data card setting screen To begin a program operation press the Program key You see the following display Press the Next Setting or Previous Setting key until the desired operation is highlighted then press the Enter key A setting screen for that operation p appears on the display It may then be necessary to choose one of the ten program locations before continuing 8 3 3 Enter or Edit an Internal Program Program editing initiates as an internal programmi
249. nt setting has been added to the 340 with main firmware version 01 03 08 and later This setting is labeled as User When this setting is chosen a Max parameter appears on the display The Max I parameter can be set to a user defined current between 0 1 and 2 0 A to give the user the ability to limit the heater current to values in between the standard fixed settings of 2 A 1A 0 5 A and 0 25 A This setting is only available for control loop 1 Table 6 2 Full Scale Heater Power at Typical Resistance Heater Heater Maximum Current The Model 340 heater output Resistance Range 2A has five ranges Each range below the highest range reduces the full scale heater output power The ranges are spaced at approximate decades in power The heater range setting is available from the normal display so that it can be changed easily during an experiment For example with the maximum current set to 1 A and a heater resistance of 25 Q the heater output provides the full scale current and power shown in Table 6 3 The range is displayed as the maximum power computed with the maximum current setting and user specified resistance If the power does not change when you change the range the voltage compliance is limiting the maximum power If ranges are Maximum power available Power limited by voltage compliance skipped the heater range limit is set NOU AGOJ NOUR ATANWHAATIANWHAHA Temperature Control Operation 6 9 La
250. ntrol system is seldom changed and data is taken when the load is at steady state Compute a derivative setting in seconds as one fourth the measured oscillation period of the load in seconds If this period is unknown and the integral setting was determined experimentally the derivative setting in seconds is calculated as 1000 setting g 4x1 setting D Again do not be afraid to make some small setpoint changes halving or doubling this setting to watch the effect 2 12 Cooling System Design Lake Shore Model 340 Temperature Controller User s Manual 2 8 AUTOTUNING Choosing appropriate PID control settings can be tedious As systems may take several minutes to complete a setpoint change it is difficult to observe the display for that length of time watching for oscillation periods or signs of instability With the AutoTune feature the Model 340 automates the tuning process by measuring system characteristics Then combined with assumptions about typical cryogenic systems it computes setting values for P and D AutoTune works only with one control loop at a time and will not set manual heater output or heater range Setting an inappropriate heater range is potentially dangerous to some loads so the Model 340 does not attempt to automate that step of the tuning process When AutoTune mode is selected the Model 340 will evaluate the control loop similar to Manual Tuning Paragraph 2 7 The major difference is the Model 340
251. ntroller User s Manual 2 2 2 SoftCal SoftCal is a good solution for applications that do not require the accuracy of a traditional calibration The SoftCal algorithm uses the well behaved nature of sensors that follow a standard curve to improve the accuracy of individual sensors A few known temperature points are required to perform SoftCal Lake Shore sells SoftCal calibrated sensors that include both the large interpolation table and the smaller breakpoint interpolation table A CalCurve described in Paragraph 2 2 4 may be required to get the breakpoint table into a Model 340 where it is called a temperature response curve The Model 340 can also perform a SoftCal calibration The user must provide one two or three known temperature reference points The range and accuracy of the calibration is based on these points Lake Shore DT 400 Series Silicon Diode Temperature Sensor There are 3 ways to improve temperature sensor accuracy Standard SoftCal Calibration Precision Calibration Standard sensors are inter A 2 point SoftCal uses data Lake Shore can calibrate most changeable within the publish points at 77 35 K and 305 K A 3 sensors with up to 200 data points ed tolerance band Below are point SoftCal uses data points at and can concentrate data taking in Standard Curve 10 Tolerance 4 2 K 77 35 K and 305 K specific areas of interest Accuracy Bands for DT 470 Typical 2 Point Accuracy Typica
252. o groups can be different The multiplexed inputs provide new readings for all eight inputs twice each second The 3468 inputs are not recommended for temperature control because the reading rate is too slow to allow good stability A variety of sensor types are supported by the Model 3468 but not as many as the standard inputs Diode and platinum configurations have similar specifications to the standard inputs reduced only slightly to account for multiplexing However the NTC RTD configuration is quite different than the standard inputs The option has a limited resistance range of 7 5 KQ with a fixed current excitation of 10 pA This limitation significantly reduces the low temperature range of the inputs The option also does not support current reversal to reduce the effect of thermal EMF voltages The original standard inputs remain fully functional allowing the Model 340 to measure 10 sensors when the option is installed 1 6 Sensor Selection Table 1 1 Sensor Temperature Range Model Useful Range Magnetic Field Use Diodes Silicon Diode DT 670 SD 1 4 K to 500 K T260K amp Bs3T 340 3462 Silicon Diode DT 670E BR 30 K to 500 K T260K amp BS3T Silicon Diode DT 414 1 4 K to 375 K T260K amp BS3T Silicon Diode DT 421 1 4 K to 325 K T260K amp BS3T Silicon Diode DT 470 SD 1 4 K to 500 K T260K amp BS3T Silicon Diode DT 471 SD 10 K to 500 K T26
253. o make more changes or press the Save Screen key to store the changes The default values are Low 0 0 and High 1000 7 3 4 Input Alarm Latching To enable an alarm latching press the Alarm Setup key The ALARM SETTINGS screen appears with the input letter in the top left hand corner Use the A or V key to select an input Press the Enter or Next Setting key to show the alarm parameters for that input Press the Next Setting key until the enable field is highlighted Use the A or Y key to turn alarm latching on or off for that input Use the Next Setting key to make more changes or press the Save Screen key to store the changes The default setting is Off 7 3 5 Input Alarm Relay Setup The two relays on the Model 340 can be used for high and low alarm outputs One or more sets of high and low input alarms can be directed to the high and low relays To direct the alarms from an input to the relays set the relay parameter on the ALARM SETTINGS screen to On Parameters on the RELAY amp BEEPER SETUP screen must also be changed as described in Paragraph 7 4 When the alarms directed to a relay are not active status Off the relay is in the normal position If any one of the alarms directed to a relay is active status On the relay switches to the opposite position Relay connections are shown in Figure 3 7 To direct an alarm pair to the relays press the Alarm Setup key The ALARM SETTINGS screen appears with the input letter in the top le
254. od thermal conductivity is important in any part of a cryogenic system that is intended to be at the same temperature Most systems begin with materials that have good conductivity themselves but as sensors heaters sample holders etc are added to an ever more crowded space the junctions between parts are often overlooked In order for control to work well junctions between the elements of the control loop must be in close thermal contact and have good thermal conductivity Gasket materials should always be used along with reasonable pressure Cooling System Design 2 7 Lake Shore Model 340 Temperature Controller User s Manual 2 5 2 Thermal Lag Poor thermal conductivity causes thermal gradients that reduce accuracy but they also cause thermal lag that make it difficult for controllers to do their job Thermal lag is the time it takes for a change in heating or cooling power to propagate through the load and get to the feedback sensor Because the feedback sensor is the only thing that lets the controller know what is happening in the system slow information to the sensor slows the controller s response time For example if the temperature at the load drops slightly below the setpoint the controller gradually increases heating power If the feedback information is slow the controller puts too much heat into the system before it is told to reduce heat The excess heat causes a temperature overshoot degrading control stability The best way to
255. of variable DC power to control Loop 1 Features have been added to the Model 340 to minimize the possibility of overheating delicate sensors and wiring in cryostats These features include setpoint temperature limit heater current range limit internal heater diagnostics and a fuse in the heater output wiring The Model 340 also has the ability to run a second independent control loop intended to reduce the temperature gradients in one cooling system rather than to run two different cooling systems The setpoint ramp feature allows smooth continuous changes in setpoint This feature permits faster experiment cycles since data can be taken as the system is changing in temperature It can also be used to make a more predictable approach to a setpoint temperature The zone feature can automatically change control parameter values for operation over a large temperature range Values for ten different temperature zones can be loaded into the instrument which will select the next appropriate zone value on setpoint change The Model 340 can run a set of instrument instructions called an internal program Each program represents the temperature changes needed to conduct a user s experiment The setpoint can be changed or ramped up and down and other controller parameters can be programmed For simple experiments the internal program eliminates the need for computer control It is also common for the internal program to be used along with the computer interf
256. ograms is not available if external scanner operation is enabled Settings Refer to Paragraph 7 2 Digital Output gt Setting 00000 54321 8 3 1 7 Relays A Model 340 internal program can interact with experimental parameters other than temperature The high and low relays can be used to control outside events while a program is running Relays must be set to Manual for operation Relays High and low relays as described in Paragraph 7 4 Relays gt High OFF Low OFF 8 8 Instrument Programming Lake Shore Model 340 Temperature Controller User s Manual 8 3 1 8 Wait Temperature control systems often need time for temperature control to stabilize or temperature gradients to settle out A Wait instruction is used in a program to add a time delay Hours Hours taken for wait set from 0 to 23 Wait gt Hours 0 Minutes Minutes taken for wait set from 0 to 59 Minutes 0 Seconds Seconds taken for wait set from 0 to 59 Seconds 0 For a fixed wait time set the hours minutes and seconds parameters The program will not proceed to the next instruction until the wait time is over but the temperature control functions will operate normally 8 3 1 9 Settle Temperature control systems often need time for temperature control to stabilize or temperature gradients to settle out The Settle instruction is used in a program to add a time delay or let the control temperature settle Hours Hours to wait 0 to 23 Settle gt H
257. oint LOGVIEW Turn logging on and off Query logging status Query total number of logged records 36 Configure data point for data logging 36 Query a data point for data logging Configure data logging parameters Query data logging parameters Query record of logged data Remote Operation Lake Shore Model 340 Temperature Controller User s Manual 9 4 IEEE 488 SERIAL INTERFACE COMMANDS Alphabetical Listing 2 Input Returned Remarks CLS Input Returned Remarks xESE Input Returned Remarks Example xESE Input Returned Remarks xESR Input Returned Remarks xIDN Input Returned Remarks Process Last Query Received The response of the last query received by the instrument Used for the serial interface and is not necessary for IEEE Reprocesses the last query received by the instrument and sends a new response This command cannot be chained with other commands and must be sent by itself Clear Interface Command CLS Nothing Clears the bits in the Status Byte Register and Standard Event Status Register and terminates all pending operations Clears the interface but not the controller The controller related command is RST Configure Status Reports in the Standard Event Status Register ESE bit weighting Nothing Each bit is assigned a bit weighting and represents the enable disable status of the corresponding event flag bit in the Standard Event Status Regi
258. ol loop indicator is highlighted in the upper left hand corner Use the A or V key to select a control Loop 1 and press the Enter or Next Setting key The control setup parameters for that loop appear on the screen Press the Next Setting key until the range field under the limits heading is highlighted Use the A or V key to select a range limit Press the Enter or Next Setting key to continue with more settings or press the Save Screen key to store the changes in the Model 340 The default setting is the highest range Temperature Control Operation 6 11 Lake Shore Model 340 Temperature Controller User s Manual This Page Intentionally Left Blank Temperature Control Operation Lake Shore Model 340 Temperature Controller User s Manual CHAPTER 7 ANALOG OUTPUT DIGITAL I O ALARM AND RELAY OPERATION 7 0 GENERAL The Model 340 has several hardware features that enable it to interface with the experimental environment These hardware features defined the operation of the controller as related to temperature measurement and control but can also be controlled manually by the user from the front panel or over computer interface Analog outputs are described in Paragraph 7 1 Digital inputs and outputs I O are described in Paragraph 7 2 Input alarms are described in Paragraph 7 3 Finally high and low relays are described in Paragraph 7 4 7 1 ANALOG OUTPUTS The Model 340 has two analog outputs Analog Output 1 and Analog Output 2 The
259. oller Loop 1 is the primary control loop capable of sourcing more power and has additional software features The heater output for Loop 1 is a traditional control output for a cryogenic temperature controller Heater output is the most visible difference between the two control loops which are summarized in Table 1 1 Loop 2 is an auxiliary control loop with enough features to control a radiation shield or small sample heater Setting up hardware for the two control loops is discussed in Chapter 2 This section describes how to display control loop parameters and output or make parameter changes Control loop display is described in Paragraph 6 1 Control loop enable is described in Paragraph 6 2 Control loop filter is described in Paragraph 6 3 The control channel is described in Paragraph 6 4 Control modes are described in Paragraph 6 5 Manual setting of PID control parameters are described in Paragraph 6 6 Selecting an AutoTune control mode is described in Paragraph 6 7 Zone control data entry is described in Paragraph 6 8 Using an open loop control is described in Paragraph 6 9 Setting a setpoint and setpoint units are described in Paragraph 6 10 Setpoint ramping is described in Paragraph 6 11 Control output is described in Paragraph 6 12 Finally control output limits are described in Paragraph 6 13 6 1 CONTROL LOOP DISPLAYS This paragraph describes how the control parameters and control output are shown on the normal front panel dis
260. on ss ieri ta aaa een een 10 14 10 6 3 1 Sensor Input Connector 2 Eta e cio Le ita 10 14 10 6 3 2 Sensor Input Cablirigi desta ttt Hope iE DRE Rt EE tU RU 10 14 10 6 3 3 Reading Rate urit ot eor E EET REP E d 10 14 vi Lake Shore Model 340 Temperature Controller User s Manual 10 6 4 Operation NEE 10 15 10 6 4 1 General Operation mitico a id eed bata el hen ead tetas 10 15 10 6 4 2 lap t Setup eh ee ra Lele etl cies eee eae 10 15 10 6 4 3 Temperature Control 2ueckeebe teque dete e di dd 10 15 10 6 5 Computer Interface Commands sss eene ener 10 16 10 6 6 SPECHICALONS EE EE 10 16 11 SERVICE p 11 1 11 0 EE 11 1 11 1 General Maintenance Precautions cccccccceeeececceceeeeeeeetecaeceeeeeeesesenaeeeeeeeeeesesennisaeeeeeess 11 1 11 2 Electrostatic Discharge ii tute e ERREUR UM Re na MR IRA 11 1 11 2 1 Identification of Electrostatic Discharge Sensitive Components ssssss 11 2 11 2 2 Handling of Electrostatic Discharge Sensitive Components sssesesss 11 2 11 3 Eine Input Assembly ii e ee Pr Ack es INR dada Ra EE 11 2 11 3 1 Line Voltage eee ue ee Ra PU DRE RI O 11 3 11 3 2 Fuse Verification zt RU RE RUM E 11 3 11 3 3 Line Voltage Selection 2 2 2 1 pen ei dee etd eee coe 11 3 11 3 4 Fuse Removal and Replacement sss eene nnn 11 4 11 4 General Maintenance icono tee pterea leeds ees aa aie dada 11 4 11 4 1 Cleaning EE 11 4 11 5 Rear Panel Connector Defin
261. or enter any enclosure for the purpose of servicing or adjusting the equipment without immediate presence or assistance of another person capable of rendering aid 11 2 ELECTROSTATIC DISCHARGE Damage can occur to electronic parts assemblies and equipment from electrostatic discharge ESD ESD is defined as a transfer of electrostatic charge between bodies at different electrostatic potentials caused by direct contact or induced by an electrostatic field The low energy source that most commonly destroys Electrostatic discharge Sensitive ESDS devices is the human body which in conjunction with nonconductive garments and floor coverings generates and retains static electricity Simply walking across a carpet in low humidity can generate up to 35 000 volts of static electricity Trends in technology are toward greater complexity increasing packaging density and hence thinner dielectrics between active elements resulting in electronic devices becoming even more sensitive to ESD Various electronic parts are more ESDS than others These can be damaged by ESD levels generated by personnel testing handling repairing and assembling electronic components without their being aware that a discharge of static electricity has even occurred Many ESDS devises such as semiconductors thick and thin film resistors chips and hybrid devices and piezoelectric crystals can be damaged or destroyed by ESD levels of a few hundred volts which is far below the 400
262. ormat I eg Comment es Silicon Diode DT 470 0 00001 V GaAlAs Diode TG 120 0 00001 V Platinum 100 PT 100 Ohm K 0 001 Q Ruthenium Oxide Ohms logR K 325 Negative O 00001 logR 0 00001 logR Once curve identification parameters are entered it is time to enter curve breakpoints A breakpoint is the representation of the sensor calibration that is stored in the instrument Each breakpoint consists of one value in sensor units and one temperature value in kelvin From 2 to 200 breakpoints can be entered as a curve No special endpoints are required Sensor units are defined by the format setting in Table 8 1 Breakpoint setting resolution is six digits in temperature Most temperature values are entered with 0 001 resolution Temperature values of 1000 K and greater can be entered to 0 01 resolution Temperature values below 10 K can be entered with 0 0001 resolution Temperature range for curve entry is 1500 K 8 2 Instrument Programming Lake Shore Model 340 Temperature Controller User s Manual Setting resolution is also six digits in sensor units The curve format parameter defines the range and resolution in sensor units as shown in Table 8 1 The sensor type determines the practical setting resolution Table 8 1 lists recommended sensor units resolutions For most sensors additional resolution is ignored The breakpoints should be entered with the sensor units value increasing as point number increases
263. ot however be the best location for temperature control as discussed below 2 4 Cooling System Design Lake Shore Model 340 Temperature Controller User s Manual 2 3 3 Thermal Conductivity The ability of heat to flow through a material is called thermal conductivity Good thermal conductivity is important in any part of a cryogenic system that is intended to be the same temperature Copper and aluminum are examples of metals that have good thermal conductivity while stainless steel does not Non metallic electrically insulating materials like alumina oxide and similar ceramics have good thermal conductivity while G 10 epoxy impregnated fiberglass does not Sensor packages cooling loads and sample holders should have good thermal conductivity to reduce temperature gradients Surprisingly the connections between thermally conductive mounting surfaces often have very poor thermal conductivity To Room Temperature Vacuum Shroud Refrigerator Expander Vacuum Space Radiation Shield Dental Floss Tie Down Thermal Anchor or Bobbin Cryogenic Tape Refrigerator Second Stage Thermal Anchor Cryogenic Wire Bobbin small diameter large AWG Cold Stage and Sample Holder Sensor Drawing Heater Not To Scale wining not shown Optical Window y If Required 340 2 2 eps Figure 2 2 Typical Sensor Installation In A Mechanical Refrigerator 2 3 4 Contact Area Thermal contact area greatly affects
264. ountries states and provinces do not allow the exclusion of liability for incidental or consequential damages so the above limitation may not apply to you LIMITED WARRANTY STATEMENT Continued 9 EXCEPT TO THE EXTENT ALLOWED BY APPLICABLE LAW THE TERMS OF THIS LIMITED WARRANTY STATEMENT DO NOT EXCLUDE RESTRICT OR MODIFY AND ARE IN ADDITION TO THE MANDATORY STATUTORY RIGHTS APPLICABLE TO THE SALE OF THE PRODUCT TO YOU CERTIFICATION Lake Shore certifies that this product has been inspected and tested in accordance with its published specifications and that this product met its published specifications at the time of shipment The accuracy and calibration of this product at the time of shipment are traceable to the United States National Institute of Standards and Technology NIST formerly known as the National Bureau of Standards NBS FIRMWARE LIMITATIONS Lake Shore has worked to ensure that the Model 340 firmware is as free of errors as possible and that the results you obtain from the instrument are accurate and reliable However as with any computer based software the possibility of errors exists In any important research as when using any laboratory equipment results should be carefully examined and rechecked before final conclusions are drawn Neither Lake Shore nor anyone else involved in the creation or production of this firmware can pay for loss of time inconvenience loss of use of the product or property dam
265. ours 0 Minutes Minutes to wait 0 to 59 Minutes 0 Seconds Seconds to wait 0 to 59 Seconds 0 Band Temperature threshold for stability positive peak Band value from 0 to 10 K with 0 1 K resolution 0 00000K To wait for control stability the time parameters and Band are used together to set the stability criteria Stability is reached when the temperature of the control input sensor does not deviate from the setpoint by more than the Band value for the set time The Band is set in Kelvin The setpoint units must be in temperature for this instruction to operate 8 3 1 10 Repeat End Repeat The Repeat and End Repeat instructions work together to allow repetitive operations without repeating instructions The Repeat instruction is placed at the beginning of a group of instructions that are repeated and the End Repeat is placed at the end The group of instructions is repeated as many times as the user specifies in the count parameter of the Repeat instruction Count Number of times to repeat the instructions between Repeat gt Count 1 this instruction and its appropriate end repeat Infinite Loop OFF Infinite Loop Repeat the instructions an infinite amount of End Repeat gt times On or Off NOTE Nest up to 10 Repeat End Repeat sets 8 3 1 11 Call The Call instruction provides a way to put small programs together into a larger program A set of often repeated instructions called a subprogram may be entered into a p
266. pe the sensor is on System overheating can result if the wrong coefficient is chosen The user must select a temperature coefficient before control is switched to the 3465 input To select a temperature coefficient press Input Type 10 5 3 6 Control Channel Changes The 3465 option continues control at a stable temperature established with another sensor Allow temperature to stabilize for one hour after large temperature changes to allow capacitance sensor recovery When the control channel is changed to the capacitance input the Model 340 changes the control setpoint to the present capacitance reading It is not necessary for the user to write down the capacitance value and enter a new setpoint Control parameters P and l may need to be changed for stable control To change control channel press Control Channel 10 5 4 Computer Interface Commands Most of the computer interface commands used by the Model 340 are independent of installed options or sensor type The following commands or formats change when the 3465 is installed 1 In command strings the input field accepts A B or C instead of only A and B 2 The INTYPE command changes to the following format The TYPE query changes accordingly INTYPE input coefficient range input Specifies input to configure C excitation 0 coefficient Temperature coefficient 1 negative 2 positive type 11 Capacitance range Input range 0 15pF
267. pear in the right corner of the screen to indicate that the parameters would not fit on one screen Other parameters will be shown if the More key is pressed If the More key is pressed after changes are made to a screen a message prompts users to save or ignore the settings Example screen showing lt more gt 4 4 4 Data Entry Screens Data entry screens are similar to setting screens but they have data tables that are too long to fit on a screen Scroll up and down the data table instead of using the More key to change screens In the following example of entering a temperature response curve curve identification information is t entered like a setting screen then the curve data is Entering a Temperature Response Curve entered in a long table 4 4 5 The Help Key The Help key at the lower right corner of the keypad can be pressed while selecting a parameter The information shown on the display will tell the operator the intended use of the parameter then if the More key is pressed the setting limits and resolution of the parameter Next the help will show how to use the navigation keys discussed above as a reminder Pressing Cancel Screen or the Help key will return the instrument to its setting operation Pressing Help from the normal display shows how to use the navigation keys 4 4 6 Keypad Time out The Model 340 suspends some of its operation during keypad operation The control loop and computer interfaces are nev
268. perature Controller User s Manual 2 6 PID CONTROL The Model 340 Temperature Controller uses a algorithm called PID control for closed loop control operation The control equation for the PID algorithm has three variable terms a P or proportional term an or integral term and a D or derivative term See Figure 2 3 Changing these variables for best control of a system is called tuning The PID equation in the Model 340 is Heater Output Ple 0e dt D where error e Setpoint Feedback Reading Proportional P is discussed in Paragraph 2 6 1 Integral I is discussed in Paragraph 2 6 2 Derivative D is discussed in Paragraph 2 6 3 Finally the manual heater output is discussed in Paragraph 2 6 4 2 6 1 Proportional P The Proportional term also called gain must have a value greater than zero for the control loop to operate The value of the proportional term is multiplied by the error e which is defined as the difference between the setpoint and feedback temperatures to generate the proportional contribution to the output Output P Pe If proportional is acting alone with no integral there must always be an error or the output will go to zero A great deal must be known about the load sensor and controller to compute a proportional setting P Most often the proportional setting is determined by trial and error The proportional setting is part of the overall control loop gain and so are the heater range and cooling
269. play Control loops on the normal display are described in Paragraph 6 1 1 Loop indication on the normal display is described in Paragraph 6 1 2 Loop indication on setting screens is described in Paragraph 6 1 3 Finally control output display is described in Paragraph 6 1 4 6 1 1 Control Loops on the Normal Display Several control parameters are shown on the normal display so they can be changed quickly by the operator The CONTROL DISPLAY FORMAT screen configures the control parameter portion of the display The user can decide to show parameters from one or both loops depending on the experiment When one loop is in operation only that loop should be selected since more parameters are shown for that loop When two loops are shown the operator must tell the instrument which loop to use before a parameter can be changed Use the Display Format key to get to the CONTROL DISPLAY FORMAT screen 6 1 2 Loop Indication on the Normal Display When operating both control loops indicate which control loop changes by using the Loop 1 and Loop 2 keys The key functions are not dependent on the display format but the setting will default to the loop showing on the display when only one loop is present The Loop 1 key displays Loop 1 information The Loop 2 key displays Loop 2 information The lower three lines on either display show Loop parameters accessed from the normal display Parameters unavailable for Loop 2 do not display After a time out period
270. ple positive 125 mV NA 0 1 pV 0 2 uV 1 uV 0 05 of rdg 0 4 uV 3464 positive 150 mV NA 0 1 pV 0 4 uV 1 uV 0 05 of rdg 0 8 uV Capacitance positive or O nF to 150 nF 4 88 kHz 10 pF 2 0 pF 50 pF 10 1 of rdg 4 0 pF 3465 negative 1 V square wave positive or 0 nF to 15 nF 4 88 kHz 1 pF 0 2 pF 50 pF 0 1 of rdg 0 4 pF negative 1 V square wave Diode negative 0Vto2 5V 10 pA 0 05 100 pV 20 uV 160 uV 0 01 of rdg 40 pV 3468 negative 0Vto7 5V 10 pA 0 05 100 pV 20 uV 160 uV 0 02 of rdg 40 pV PTC RTD positive 00 to 250 Q 1 mA 0 3 10 mQ 2 mQ 0 004 Q 0 02 of rdg 4mQ 3468 positive 0 O to 500 Q 1 mA 20 3 10 mO 2mQ 0 004 Q 0 02 of rdg 4mQ positive 00to5000Q 1 mA 10 3 100 ma 20 mQ 0 06 Q 0 04 of rdg 40 mQ NTC RTD negative 0Qto 75000 10 yA 0 05 100 mQ 50 mQ 0 1 Q 0 04 of rdg 0 10 3468 1 Control stability of the electronics only in an ideal thermal system 12 Accuracy specification does not include errors from room temperature compensation 1 7 1 Number of inputs Input configuration Isolation AID resolution Input accuracy Measurement resolution Maximum update rate Autorange User curves Introduction Thermometry 2 included additional inputs optional Each input is factory configured as diode RTD Thermocouple and capacitance are optional and sold as additional input cards Sensor inputs optically isolated from other circuits but not from each other 24 bit analog to
271. power The proportional setting will need to change if either of these change 2 6 2 Integral I In the control loop the integral term also called reset looks at error over time to build the integral contribution to the output Output I elei dt By adding the integral to proportional contributions the error that is necessary in a proportional only system can be eliminated When the error is at zero controlling at the setpoint the output is held constant by the integral contribution The integral setting I is more predictable than the gain setting It is related to the dominant time constant of the load As discussed in Paragraph 2 7 3 measuring this time constant allows a reasonable calculation of the integral setting In the Model 340 the integral term is not set in seconds like some other systems The integral setting can be derived by dividing 1000 by the integral seconds setting 1000 Iseconds 2 6 3 Derivative D The derivative term also called rate acts on the change in error with time to make its contribution to the output de Output D PD put D di By reacting to a fast changing error signal the derivative can work to boost the output when the setpoint changes quickly reducing the time it takes for temperature to reach the setpoint It can also see the error decreasing rapidly when the temperature nears the setpoint and reduce the output for less overshoot The derivative term can be useful in fast
272. r messages during normal operation DISABL Input is not setup NOCURV Input has no curve S OVER Input is at over full scale S ZERO Input is zero does not show up for special or thermocouple sensors T OVER Temperature conversion went off the high end of the curve T UNDR Temperature conversion went off the low end of the curve System board error messages The slave input processor is not responding The curve FLASH chip is not responding Flash error code gt XXH lt Write down the error code number and call Lake Shore Service Heater error messages Message HTRST Return Value Description 00 No error Supply Over V 01 Power supply over voltage Supply Under V 02 Power supply under voltage Output DAC Error 03 Output digital to analog Converter error ILimit DAC Error 04 Current limit digital to analog converter error Open Heater Load 05 Open heater load Load 100 06 Heater load less than 10 ohms These error messages can be corrected by the user For all others contact Lake Shore Service 11 10 Service Lake Shore Model 340 Temperature Controller User s Manual 11 10 FIRMWARE IC REPLACEMENT This paragraph contains a procedure to replace the Master Firmware IC U26 and the Input Firmware IC U146 An update kit to perform this procedure is available from the Lake Shore Instrument Service Department The kit includes e 32 pin IC M340MN Flash Memory chip
273. r on the selected heater range Manual Output setting range is 100 to 100 with a resolution of 0 01 Change settings from the front panel or with a computer interface Negative values are not recommended when using the heater When using control Loop 2 and Analog Output 2 manual output parameter sets control output in percent of the 10 V range Manual Output setting range is 100 with a resolution of 0 01 Negative values are not recommended unless the output drives a device operating as a heating and cooling source In most cases configure Analog Output 2 as unipolar when using it for control output To enter a manual output value press Loop 1 or Loop 2 to display control parameters for that loop in the lower portion of the display Press Manual Output to highlight the MOut setting field Enter a value with the number keys and press Enter to save the change or Escape to return to the previous value Default is 0 6 10 SETTING A SETPOINT AND SETPOINT UNITS The control setpoint is the desired load temperature expressed in temperature or sensor units Use sensor units if no temperature response curve is selected for the sensor input used as the control channel The control setpoint has its own units parameter When the user selects sensor units as the setpoint units the instrument calculates the control equation in sensor units It calculates the control equation in temperature with setpoint units set to kelvin or Celsius The setpoint displ
274. r right corner of the card Figure 10 7 9 Place the 3462 Option Card on top of the metal standoffs in the instrument Fit the 3462 sensor inputs out the rear panel option opening Retrieve option plate screws from Step 5 and use to slightly tighten the 3462 Option Card to the rear panel 10 Align the holes in the card with the corresponding metal standoffs Insert a 4 40 screw through each 3462 Option Card hole and thread it into the metal standoff beneath Go back and tighten the two screws securing the option card to the rear panel INPUTS HOLE 4 HOLE 1 HOLE 2 ANALOG HOLE 3 PLUG Figure 10 7 Mounting Holes amp Analog Plug 10 6 Options and Accessories Lake Shore Model 340 Temperature Controller User s Manual 11 Stand instrument on face Slide top and bottom covers on Reposition rear plastic bezel then rethread all cover screws The completed installation should look like Figure 10 8 12 Replace power cord Turn on power switch To verify 3462 Option Card installation press Options then press More three times The Model 340 displays the 3462 option in the REVISION INFORMATION HEATER FUSE HEATER OUTPUT 25A HI Lo O O o O MODEL 3462 60V MAX NOU at FIRE SERV FOR REPI SE AZARD RELAYS ANALOG ANALOG OUT 1 lo m INPUTA INPUTB SERIAL UO DIGITAL I O NC C NO NC C NO Figure 10 8 Model 340 Rear Panel with Model 3462 Option Card Installed 10 3 2 Ope
275. r with DE 9 to DE 9 Adapter Serial Interface Connector configured as DTE If the interface is DCE a Null Modem Adapter is required to exchange Transmit and Receive lines LSCI Model 2001 RJ 11 Cable Assembly 340 9 2 CVS Figure 9 4 Serial Interface Connections Remote Operation 9 13 Lake Shore Model 340 Temperature Controller User s Manual 9 2 3 Hardware Support The Model 340 interface hardware supports the following features Asynchronous timing is used for the individual bit data within a character This timing requires start and stop bits as part of each character so the transmitter and receiver can resynchronized between each character Half duplex transmission allows the instrument to be either a transmitter or a receiver of data but not at the same time Communication speeds of 300 1200 2400 4800 9600 19200 Baud are supported The Baud rate is the only interface parameter that can be changed by the user Hardware handshaking is not supported by the instrument Handshaking is often used to guarantee that data message strings do not collide and that no data is transmitted before the receiver is ready In this instrument appropriate software timing substitutes for hardware handshaking User programs must take full responsibility for flow control and timing as described in Paragraph 9 2 6 9 2 4 Character Format A character is the smallest piece of information that can be transmitted by the interface Each
276. r with cold pipes or equipment Long sleeve shirts and cuffless trousers that are of sufficient length to prevent liquid from entering the shoes are recommended Installation 3 3 Lake Shore Model 340 Temperature Controller User s Manual 3 1 5 4 Recommended First Aid Every site that stores and uses LHe and LN should have an appropriate Material Safety Data Sheet MSDS present The MSDS may be obtained from the manufacturer distributor The MSDS specifies the symptoms of overexposure and the first aid to be used A typical summary of these instructions is provided as follows If symptoms of asphyxia such as headache drowsiness dizziness excitation excess salivation vomiting or unconsciousness are observed remove the victim to fresh air If breathing is difficult give oxygen If breathing has stopped give artificial respiration Call a physician immediately If exposure to cryogenic liquids or cold gases occurs restore tissue to normal body temperature 98 6 F as rapidly as possible then protect the injured tissue from further damage and infection Call a physician immediately Rapid warming of the affected parts is best achieved by bathing it in warm water The water temperature should not exceed 105 F 40 C and under no circumstances should the frozen part be rubbed either before or after rewarming If the eyes are involved flush them thoroughly with warm water for at least 15 minutes In case of massive exposure remove clot
277. rameter are set to defaults 10 4 4 2 Input Selection After installation the 3464 option adds 2 new inputs to standard front panel operations which allows configuration of inputs C and D assigned as thermocouple inputs For example press Input Setup to display the INPUT SETUP screen The A or Y key to cycle through inputs A B C or D If C or D is selected press Enter to display available settings for that thermocouple With no option present only A and B inputs are available 10 4 4 3 Displaying Option Readings Readings from option inputs C and D can be always be displayed in sensor units millivolts If a temperature response curve is selected for an input its readings can also be displayed in temperature To add an input reading to the display press the Display Format key Options and Accessories 10 9 Lake Shore Model 340 Temperature Controller User s Manual 10 4 4 4 Curve Selection To read temperature from the 3464 option select a temperature curve for the Model 340 If no curve is selected the Model 340 reads in sensor units millivolts and if the display is configured to show temperature for that channel a NO CURVE message displays for that channel To select a temperature response curve press Input Setup There are 5 standard thermocouple curves included in the Model 340 The user may enter curves of any thermocouple type Only curves in mV K data format display during curve selection Refer to Appendix A for list
278. ration This Model 340 unit now functions with two additional inputs called C and D All menus that allow input channel selection scroll from A to D and back again Example Press Display Format to show the Reading Display Format screen Press Enter to highlight the Disp field Use the A or W key to scroll through the inputs 10 3 3 Specifications The 3462 Option Card input specifications are the same as for standard inputs on the Model 340 main board listed in Table 1 2 10 4 MODEL 3464 DUAL THERMOCOUPLE INPUT OPTION CARD 10 4 1 General The Model 3464 Option Card adds two thermocouple inputs to the Model 340 Temperature Controller They appear on the Model 340 display as C and D Use them for temperature measurement and control with a wide variety of thermocouple sensors The standard instrument inputs remain fully functional The 3464 option using the Input Setup menu can select 2 distinct input ranges to accommodate both cryogenic and high temperature operation Turn the built in room temperature compensation on or off through the keypad or remote interfaces A thermocouple is a common sensor to measure temperature Two dissimilar metals joined at one end produce a small unique voltage at a given temperature The 3464 thermocouple hardware and software measures and interprets this voltage Thermocouples are available in different combinations of metals or calibrations The four most common thermocouples for cryoge
279. ration Curve sss emm ennemis 8 6 8 3 Internal Programmllg 2 3 zr e ada 8 6 Lake Shore Model 340 Temperature Controller User s Manual 8 3 1 Program tte TEE 8 7 8 3 1 1 Ramp Setpoint Absolute ieron i e r nn nn cn nnnnanannns 8 7 8 3 1 2 Ramp Setpoint Relative A 8 7 8 3 1 3 Ramp Manual Output MOut Absolute o oo ee eee ee ete eee ee entree nano ncncnnno nan rnnnn rca rra 8 7 8 3 1 4 Ramp Manual Output MOut Relative 8 8 8 3 1 5 Control Parameters ue p ede d deett eoe tare eel dert E bed etie d 8 8 8 3 1 6 Digital Output cu Ue iro yet edite eed cti d te ie ee eo vt iiia 8 8 8 3 1 7 Relays Ate egeat eie ge afit dur laudare diel tate s vci adi oceanus 8 8 8 3 1 8 Wallis ede nte tne ee det tide de eed 8 9 8 3 1 9 li deca iendiier dente de eatis 8 9 8 3 1 10 Repeat End Repeat dte tient denda tirada te e e ea dea 8 9 8 3 1 11 e E 8 10 8 3 1 12 O 8 10 8 3 1 13 NOP DT 8 10 8 3 2 Internal Programming Operations sese emere 8 10 8 3 3 Enter or Edit an Internal Program sss eene 8 10 8 3 4 Saving a Program zie tat acelin evened RU De RETE Rr eee 8 11 8 3 5 Summary of Key Operation in Program Mode sess 8 11 8 3 6 Example of an Internal Program Example 1 sssss mee 8 12 8 3 7 Example of Using Subprograms Example 2 sse 8 13 8 3 8 Runvan internalProgram z orenen toxic err AR FRE LO RR e corta dns 8 13 8 3 9 Stop a Running PrOGgE
280. re Lake Shore sells the following types of cryogenic wire WNC Nichrome Heater WSL Single Strand WQT Quad Twist WDT Duo Twist WDL Duo Lead WQL Quad Lead WMW Manganin and WHD Heavy Duty Please refer to the Lake Shore Catalog for details O o o o o o o 90 Kb O ET pi Cable Length 4 3 meters 14 feet 340 10 1 eps Figure 10 1 Model 2001 RJ 11 Cable Assembly WW G ZE seyoul gz 1 15 9 mm 60 3 mm 2 37 inches gt 0 63 inches 340 10 2 eps Figure 10 2 Model 2003 RJ 11 to DE 9 Adapter Options and Accessories 10 3 Lake Shore Model 340 Temperature Controller User s Manual ls seuoui 9172 ww gg Zo o o o o o o2 o o o o o9 N ea imd M 15 8 mm 1 69 inches 0 63 inches 340 10 3 eps Figure 10 3 Optional Model 2002 RJ 11 to DB 25 Adapter ltem Description P N Qty 1 Rack Mount Ear 107 049 2 2 Screw 6 32 x 1 2 Inch 0 035 4 FHMS Phillips 3 Rack Mount Handle 107 433 2 4 Screw 8 32 x 3 8 inch 0 081 4 FHMS Phillips NOTE Remove and discard four screws from front Replace with four longer screws Item 2 340 10 4 eps Figure 10 4 Model 3012 Rack Mount Kit 10 4 Options and Accessories Lake Shore Model 340 Temperature Controller User s Manual 10 3 MODEL 3462 DUAL STANDARD INPUT OPTION CARD The Model 3462 Input Card adds two
281. re Model 340 Temperature Controller User s Manual This Page Intentionally Left Blank 9 44 Remote Operation 10 0 GENERAL This chapter lists Lake Shore Model 340 Temperature Controller User s Manual CHAPTER 10 OPTIONS AND ACCESSORIES Model 340 Temperature Controller Options in Paragraph 10 1 and Accessories in Paragraph 10 2 Further installation details of the Model 3462 Dual Standard Input Option Card are provided in Paragraph 10 3 the Model 3464 Dual Thermocouple Input Option Card in Paragraph 10 4 the Model 3465 Single Capacitance Input Option Card in Paragraph 10 5 and the Model 3468 Eight Channel Input Option Card in Paragraph 10 6 10 1 OPTIONS Model Description Of Model 340 Options 3462 Dual Standard Input Option Card Adds two standard inputs to the Model 340 The card has separate A Ds and excitation for each sensor A microprocessor on the card manages the A D and communication with the Model 340 The card allows the Model 340 to read 4 sensors and use any 1 of the sensors as a control sensor Includes these features Standard inputs with the ability to select from the front panel to read the following sensors Diode Platinum Cernox Rox Germanium Carbon Glass or any thermistor lt 30 kQ Adds two additional inputs each with its own excitation and A D Specifications match the Model 340 standard inputs 3464 Dual Thermocouple Input Option Card Adds two thermocouple inputs to the Mo
282. re range of the inputs The option also does not support current reversal to reduce the effect of thermal EMF voltages 10 6 2 Option Installation The 3468 can be installed into a Model 340 at the factory or in the field To field install a 3468 option follow the installation procedure in Paragraph 10 3 1 Only one option board can be installed in the Model 340 at a time To verify which option if any is installed in a Model 340 press Options and then press More three times Option identification displays on the REVISION INFORMATION screen If options are changed the Model 340 changes all parameter settings to default 10 6 3 Sensor Installation 10 6 3 1 Sensor Input Connector Two 25 pin D subminiature receptacles hold connections for the C1 C4 and D1 D4 sensor inputs They mate with 25 pin D subminiature plugs Lake Shore P N 106 253 included with the option Additional mating connectors can either be ordered from Lake Shore or purchased from local electronics distributors Figure 10 10 illustrates pin assignments and pin numbering as seen from the rear of the option card Itis possible for an overload condition on one channel to affect the reading on another in the same input group so unused sensor inputs should have all four connections shorted together Wire redundant sensors in separate groups for best reliability Split fewer than eight sensors evenly between input groups for best reading efficiency 10 6 3 2 Sensor Input Cabling
283. rently at is displayed You should monitor the controller closely the first time you run a new program to ensure it performs as expected 8 3 9 Stop a Running Program To stop a program already running press the Program key Use the Next Setting key to highlight Terminate program Press the Enter key The program stops immediately To verify the program has terminated press the Program key The Status line displays Stopped and the Line number the program is currently on is zero Instrument Programming 8 13 Lake Shore Model 340 Temperature Controller User s Manual 8 3 10 Clear Internal Program Memory To clear the internal program memory press the Program key Use the Next Setting key to highlight Clear program memory Press the Enter key You now see the message Press SAVE SCREEN to clear CANCEL SCREEN to abort Press the Save Screen key to clear the internal program memory 8 4 DATA CARD OPERATION The Model 340 has a data card slot located on the left side of the real panel underneath the power input assembly Although the pins in the data card slot conform to the PCMCIA standard the slot is not a PCMCIA interface The data card slot has the ability to read and write to Flash Cards The data cards available from Lake Shore are detailed in Paragraph 10 2 Accessories Data card operation is provided in the following paragraphs Data logging is described in Paragraph 8 4 1 Reading from a data card is described in Paragraph 8 4 2 Wri
284. ribed in Paragraph 4 5 to change display settings If an analog output is being used its output scale must be set Paragraph 7 1 There are two different equations available In each M is a gain or slope X is an input reading and B is an offset or intercept not to be confused with input B The two equations are shown in the table below The difference between them is subtle The first equation is used to scale the raw reading of an input similar to a temperature response curve when the sensor has linear response The second is better at generating a control signal when a setpoint SP1 or SP2 is selected as B The control signal can then be directed to an analog output The second equation is also useful whenever a reading of deviation from setpoint is needed The columns settings in Table 5 4 are selected independently Number represents a number entered by the user X can be set to an input reading in sensor Table 5 4 Linear Equation Configuration Equation M X B units or temperature in kelvin or Celsius SP1 represents MX B Number tpoint of L 1 imilarly for other B settings setpoint of Loop 1 and similarly for other B settings M X B To setup a linear equation press the Math Setup key and the math setting screen will appear Press the More key to show the setting screen for linear equation with the input letter in the top left hand corner Use the A or V key to select an input Press the Enter key or
285. rogram location Another program called a main program can call one or more subprograms in any sequence A subprogram must occupy an entire program location It can only be called from the beginning of the program location and must run to the End instruction which returns control to the calling program A subprogram can call another subprogram but should not call itself or a subprogram that calls it The main program is in the program location that is run from the internal program setting screen It begins with the first instruction in the program location The program in location 1 does not have to be the main program The internal program stops when it reaches the End instruction of the main program Program Program location to be called Call gt Program 1 Instrument Programming 8 9 Lake Shore Model 340 Temperature Controller User s Manual 8 3 1 12 End An End instruction is included in each of the 10 program locations It does not take any of the 100 instruction memory locations When a program location is empty the End instruction occupies the first instruction line When a program runs from the internal program setting screen the instrument processes each instruction in sequence until it reaches the End instruction where the program stops then returns to normal operation Parameters like setpoint and P I and D values set in the program retain the last value set by the program If using the Call instruction is used the End i
286. rom any location to any user curve Copy curve location Curves cannot be copied into standard curve locations Paragraph 8 1 4 Erase allows the user to delete a curve from any user curve location Standard curves cannot be erased Paragraph 8 1 5 To begin a curve operation press the Curve Entry key and the above selections appear Press the Next Setting key until the desired operation is highlighted and press the Enter key A curve screen appears with the curve number highlighted Change to the desired curve number with the A or V key then press the Enter key to begin the desired curve operation Instrument Programming 8 1 Lake Shore Model 340 Temperature Controller User s Manual 8 1 3 Front Panel Curve Edit The Edit curve operation can be used to enter a new curve or edit an existing user curve Entering the identification parameters associated with the curve is as important as entering the breakpoints Only user curves numbers 21 to 60 can be changed Standard curves can only be viewed with the edit operation Identify curves with names of up to 15 characters The curve name cannot be changed during front panel curve entry To change curve names enter them over computer interface The default curve name is User xx where xx is the curve number Identify specific sensors with serial numbers of up to 10 characters The serial number field accepts both numbers and letters but the instrument front panel enters only numbers To
287. round and connects to the instrument metal chassis when the power cord attaches to the power connector For safety plug the cord into an appropriate grounded receptacle 3 3 4 Power Switch The power switch turns the instrument ON and OFF and is located in the line input assembly on the instrument rear When is raised on the switch the instrument is ON when O is raised the instrument is OFF Do not remove instrument covers without first disconnecting the power cord even if the instrument power switch is off 3 4 STANDARD SENSOR INPUTS This paragraph details how to connect sensors to the standard Model 340 inputs These inputs operate with most resistive and diode sensors Refer to Paragraph 5 1 to configure inputs for a sensor type with software Some sensor types require an optional input which is discussed in Chapter 10 This section covers sensor input connector and pinout in Paragraph 3 4 1 sensor lead cable in Paragraph 3 4 2 grounding and shielding sensor leads in Paragraph 3 4 3 sensor polarity in Paragraph 3 4 4 four lead sensor measurement in Paragraph 3 4 5 two lead sensor measurement in Paragraph 3 4 6 and lowering measurement noise in Paragraph 3 4 7 3 4 1 Sensor Input Connector and Pinout The input connectors are 6 pin DIN 45322 sockets The sensor output pins are defined in Table 3 3 Two mating connectors 6 pin DIN plugs are included in the connector kit shipped with the instrument These are common connectors so
288. rrent Heater Resistance Heater Range 2A 1A 0 5A 0 25A 100 5 40 W 10wW 2 5W 625 mW 4 4W 1W 250mW 62 5 mW 3 0 4 W 100 mW 25 mw 6 25 mW 2 40 mW 10 mw 2 5 mW 625 pW 1 4 mW 1 mw 250 WwW 62 5 pW 250 5 100 W 25 W 6 25 W 1 56 W 4 10 W 2 5W 625 mW 156 mW 3 1W 250 mW 62 5 mW 15 6 mW 2 100 mW 25 mW 6 25 mW 1 56 mw 1 10 mw 2 5mW 625 yw 156 pW 500 5 50W 50W 12 5W 3 12W 4 20W DW 1 25W 312 mw 3 2W 500 mW 125 mW 31 2 mW 2 200 mW 50 mW 12 5 mW 3 12 mW 1 20 mW 5 mW 1 25 mW 312 yw 1 7 3 Front Panel Display No of reading displays Display units Temp display resolution Sensor units display resolution Setpoint setting Resolution Heater output display Heater output resolution Keypad Front panel features 1 7 4 Interfaces IEEE 488 2 interface Features Reading rate Software support Serial interface Electrical format Max baud rate Connector Reading rate Alarms Number Data source Settings Actuators Relays Number Contacts Contact Rating Operation Connector Analog voltage outputs Number Introduction Graphic LCD with fluorescent backlight 1to8 Temperature in K C or sensor units 0 0001 K below 10 K 0 001 K above 10 K Sensor dependent to 6 digits Same as display resolution actual resolution is sensor dependent Numeric display in percent of full scale for power or current bar graph display of heater output available 0 1 numeric or 2 graphical
289. rs are chosen AutoTune is turned off and zone tuning takes over 2 14 Cooling System Design Lake Shore Model 340 Temperature Controller User s Manual CHAPTER 3 INSTALLATION 3 0 GENERAL This chapter provides a general layout for the Model 340 rear panel and information on how to make line power sensor heater and interface connections to the Model 340 Refer to Chapter 2 for cooling system wiring To experiment with software settings covered in the next chapter before doing a complete hardware setup the Model 340 can be powered with only line power connected CAUTION Before plugging in the Model 340 and turning it on read Paragraph 3 3 on line voltage settings An improper line voltage setting may damage the Model 340 check it carefully before powering the instrument for the first time This chapter covers receiving the Model 340 in Paragraph 3 1 rear panel control definitions in Paragraph 3 2 power line input assembly in Paragraph 3 3 hooking up standard sensor inputs in Paragraph 3 4 heater output setup in Paragraph 3 5 analog outputs in Paragraph 3 6 digital inputs and outputs in Paragraph 3 7 and relays in Paragraph 3 8 3 1 RECEIVING THE MODEL 340 This section covers inspection and unpacking in Paragraph 3 1 1 repackaging for shipment in Paragraph 3 1 2 environmental requirements in Paragraph 3 1 3 safety summary in Paragraph 3 1 4 safety symbols in Paragraph 3 1 5 and handling liquid helium and liquid nitrogen in P
290. rs have a power specification that is usually given for the resistor in free air This power may need to be derated if used in a vacuum where convection cooling cannot take place and it is not adequately heat sinked to a cooled surface 2 4 2 Heater Location For best temperature measurement accuracy the heater should be located so that heat flow between the cooling power and heater is minimized For best control the heater should be in close thermal contact with the cooling power Geometry of the load can make one or both of these difficult to achieve That is why there are several heater shapes and sizes 2 4 3 Heater Types Resistive wire like nichrome is the most flexible type of heater available The wire can be purchased with electrical insulation and has a predictable resistance per given length This type of heater wire can be wrapped around a cooling load to give balanced even heating of the area Similar to sensor lead wire the entire length of the heater wire should be in good thermal contact with the load to allow for thermal transfer Heat sinking also protects the wire from over heating and burning out Resistive heater wire is also wound into cartridge heaters Cartridge heaters are more convenient but are bulky and more difficult to place on small loads A typical cartridge is 74 inch in diameter and 1 inch long The cartridge should be snugly held in a hole in the load or clamped to a flat surface Heat sinking for good thermal con
291. rt the scanned channel if set to scanner mode Auto S The instrument sequences through enabled channels holding on each channel for a wo scan user specified interval Digital outputs report the scanned channel if set to scanner mode The external scanner selects the channel through the digital inputs All scan functions are disabled To select a scanner support mode press the Scan Setup key The Mode field will be highlighted Use the A or V key to select the appropriate scan mode Then press the Save Screen key The default setting is Off 5 6 Measurement Operation Lake Shore Model 340 Temperature Controller User s Manual 5 4 2 Input Setup with a Scan Mode Active When any of the scan modes are selected the input setup screen for the A input will change slightly The input field will allow setting of channel A1 through A16 and a temperature response curve can be entered for each channel Changing parameters other than enable and curve will act globally for all channels To select a scan channel for setup press the Input Setup key Use the A or V key to select input A Press the Enter key The scan channel number will be highlighted Use the A or W key to select the desired scan channel number 1 through 16 Press the Enter key The Enable field is now highlighted Use the A or V key to select ON Press the Enter key The Curve field is now highlighted Use the A or W key to select the desired sensor to temperature curve onl
292. s The digital inputs and outputs can be used to monitor instrument status in a pre programmed mode of operation or they can also be used in manual mode to control and monitor external events The connector pinout and hardware information about the digital signals is provided in Paragraph 3 7 The digital signal lines are protected against short circuit and over voltage but it is not recommended to expose the terminals to ESD or voltages higher than 5 V or lower than ground provided on the Digital I O connector 7 2 1 Digital Output Modes four modes croperaton orr AWdgtaoupussettozeo four modes of operation All digital outputs set to zero ALARMS Used to indicate the alarm status of the sensor inputs To Selecta digital output mode MANUAL Set by user from the front panel or computer interface press the Options key The DIGITAL I O screen appears SCANNER Used with an external scanner refer to Paragraph 5 4 with the output mode highlighted Use the A or V key to select the desired mode Press the Enter or Next Setting key to advance to other settings or press the Save Screen key to store changes The default setting is Off 7 2 2 Digital Outputs in Alarm Mode In alarm mode the digital outputs report the alarm status of the sensor input alarms The digital output is low logic 0 to indicate no alarm condition and high logic 1 to indicate an alarm condition exists Alarms for a given sensor input must be turned on for
293. s AA 9 7 Visual Basic IEEE 488 Interface Program 9 8 Quick Basic IEEE 488 Interface Program 9 11 Serial Interface Gpechfications esee enne 9 14 Serial Interface Program Control Properties eeeesesseeseerieseerrestrrsstrrsterrssrttrnssrtnnsnet 9 17 Visual Basic Serial Interface Program sssssessseeenm emm enne 9 18 Quick Basic Serial Interface Program 9 19 Thermocouple Polarily 7 eere dd de 10 8 Standard Thermocouple CurveS eee 10 10 Model 3468 Sensor Input Performance Chart 10 17 AC Line Input Definitions oA eegene raider een ei pe ter eid Debo aea Eia 11 3 Lake Shore DT 470 Standard Curve 10 Curve 1 in the Model 340 ssss A 1 Standard DT 500 Silicon Diode Curves eene A 2 Standard Platinum Curves ener nen eenerrerrnn nnn nnne nere A 2 Type K Nickel Chromium vs Nickel Aluminum Thermocouple Curve n se A 3 Type E Nickel Chromium vs Copper Nickel Thermocouple Curve ssssssssssisnseessreeeen A 4 Type T Copper vs Copper Nickel Thermocouple Curve ssssssssssrrnnseesrrrnrrnnnnnesrerrrnnn A 5 Chromel AuFe 0 03 Thermocouple Curve e A 6 Chromel AuFe 0 07 Thermocouple Cume nenne A 7 Standard DT 670 Diode Curve eee eeeececeaeeeeeeeeesecenaeeeeeeeeesensiceeeeeenes A 8 Lake Shore Model 340 Temperature Controller User s Manual This Page Intentionally Left Blank Lake Shore Model 340 Temperature Controller User s Manual CHAPTER 1 INTRODUCTION 1 0 PRODUCT
294. s Register upon completion of all pending selected device operations xOPC Query Operation Complete Input OPC Returned 1 Format n term Remarks Places a 1 in the controller output queue upon completion of all pending selected device operations Send this as the last command in a command string This is not the same function as the OPC command xRST Reset Instrument Input RST Returned Nothing Remarks Sets controller parameters to power up settings xSRE Configure Status Reports in the Service Request Enable Register Input SRE bit weighting Returned Nothing Remarks Each bit has a bit weighting and represents the enable disable status of the corresponding status flag bit in the Status Byte Register To enable a status flag bit send the command SRE with the sum of the bit weighting for each desired bit See the STB command for a list of status flags Example To enable status flags 0 3 4 and 6 send the command SRE 89 term 89 is the sum of the bit weighting for each bit Bit Bit Weighting Event Name 0 1 New A amp B 3 8 Alarm 4 16 Error 6 64 SRQ 89 xSRE Query the Configuration of Status Reports in the Service Request Enable Register Input SRE Returned SRE bit weighting Format nnn term Remarks The integer returned represents the sum of the bit weighting of the enabled bits in the Service Request Enable Register See the STB command for a list of status flags xSTB Query Status Byt
295. s of data points in each curve Table 10 2 Standard Thermocouple Curves 9 Chromel AuFe 0 03 3 50Kto500K 3 50 K to 500K Chromel AuFe 0 07 3 15Kto610K 3 15Kto610K Temperature ranges are without temperature compensation 10 4 4 5 Curve Data Format Users may enter temperature response curves for all types of thermocouples Enter curve data in mV K format with thermocouple voltage in millivolts and temperature in Kelvin The curve must be normalized to 0 mV at 273 15 K 0 C Thermocouple voltages in millivolts are positive when temperature is above that point and negative when temperature is below that point To convert curves published in Celsius to Kelvin add 273 15 to the temperature in Celsius The temperature range for some thermocouple types may extend below 1 K or above 1000 K The input voltage of the 3464 is limited to 50 mV so any part of the curve that extends beyond 50 mK is not usable by the instrument A message of S OVER or S UNDER on the display indicates that the input is over or under the 50 mV range 10 4 4 6 Range Selection The 3464 option inputs have two input voltage ranges 25 mV and 50 mV Range selection depends on the Thermocouple type and expected operating temperature 25 mV is recommended for cryogenic applications or higher temperatures that produce less than 500 K For temperatures above 500 K the 50 mV range is recommended because thermocouple voltage can exceed 25 mV on some
296. s to lock out prevent the use of their front panel controls DCL Device Clear DCL is used to clear Model 340 interface activity and put it into a bus idle state Finally Addressed Bus Control Commands are Multiline commands that must include the Model 340 listen address before they respond to the command in question Note that only the addressed device responds to these commands The Model 340 recognizes three of the Addressed Bus Control Commands SDC Selective Device Clear The SDC command performs essentially the same function as the DCL command except that only the addressed device responds GTL Go To Local The GTL command is used to remove instruments from the remote mode With some instruments GTL also unlocks front panel controls if they were previously locked out with the LLO command SPE Serial Poll Enable and SPD Serial Poll Disable Serial polling is used to obtain the Service Request SRQ Status Register This status register contains important operational information from the unit requesting service The SPD command ends the polling sequence 9 1 2 2 Common Commands Common Commands are addressed commands intended to make some commonalty between instruments on the bus Instruments that comply with the IEEE 488 2 1987 standard share these commands and their format Common commands begin with an asterisk They are usually related to bus and instrument status and identification Common query comma
297. se the A or W key to select an analog output Press the Next Setting key until the Mode field is highlighted Use the A or V key to select the desired mode Press the Next Setting or Enter key to make changes to other parameters or press the Save Screen key to store the changes The default setting is Off The analog output is capable of setting a bipolar positive or negative voltage When the bipolar parameter is on the analog output varies between 10 V Many inputs may be damaged by a negative voltage Setting the bipolar parameter to off prevents the analog output from setting a negative output voltage Only voltages between 0 and 10 V are set The bipolar setting is used for all of the analog output modes To set the bipolar parameter press the Analog Outputs key The ANALOG OUTPUTS screen is displayed With the output number highlighted in the top left corner use the A or W key to select an analog output Press the Next Setting key until the bipolar field is highlighted Use the A or Y key to select ON or OFF Press the Next Setting or Enter key to make changes to other parameters or press the Save Screen key to store the changes The default setting is Off Analog Digital Alarm amp Relay Operation 7 1 Lake Shore Model 340 Temperature Controller User s Manual 7 1 4 Input Mode for Analog Output When input mode is chosen for an analog Input Sensor Input used for input reading data The default setting is A output there
298. ser must determine suitability of a setpoint value In temperature units two safety features limit the setpoint value to help prevent load damage load The first limit is the part of the temperature response curve that shows maximum safe temperature in kelvin for the sensor package It can be verified by using the Curve Entry key Paragraph 8 1 The user may enter a second global limit Paragraph 6 13 1 Set it to the maximum safe temperature in kelvin for the entire system The setpoint is limited to a value less than or equal to the lower of the two safety limits After selecting setpoint units and limits enter the setpoint value Setpoint has a direct setting key because it changes often The setpoint value remains on the display any time control parameters for its control loop display If the setpoint value changes from the number entered when Enter is pressed it is likely the setpoint exceeds one of the above limits is inappropriate for the sensor type To enter a setpoint value press Loop 1 or Loop 2 to display control parameters for that loop in the lower portion of the display Press Setpoint to highlight the setpoint setting field Enter a value with the number Temperature Control Operation 6 7 Lake Shore Model 340 Temperature Controller User s Manual keys and press Enter to save the change or Escape to return to the previous value Select a scale factor of n u m k M or G Blank indicates a scale factor of x1 The default is 0
299. standard inputs to the Model 340 Temperature Controller The inputs appear as C amp D on the display The original standard inputs remain fully functional 10 3 1 Field Installation The Model 3462 Option kit adds two optional sensor inputs to the Model 340 instrument rear panel It includes 1 10 conductor ribbon cable 1 3462 Option Card 4 1 inch metal standoffs 8 4 40 machine screws Required tools Small Phillips head screwdriver and 5 64 inch Allen wrench CAUTION CAUTION The components on this board are electrostatic discharge sensitive ESDS SC D devices Wear shock proof wrist straps resistor limited to 5 mA to prevent injury to Vy service personnel and to avoid inducing an electrostatic discharge ESD into the device ESD Sensitive Device Turn Model 340 power switch OFF Unplug power cord from wall outlet then instrument 2 Stand the unit on its face Use the Allen wrench to remove the 4 screws on each side of the covers Figure 10 5 3 Usethe small Phillips screwdriver to remove any top and bottom cover screws instruments may have 1 or 2 screws on the top and bottom covers 4 Remove rear plastic bezel The covers are tracked Slide the top and bottom covers to the rear on the tracks to remove them 5 Remove rear panel option plate screws and set aside Remove rear panel option plate REAR PLASTIC BEZEL SIDE COVER iuret ae To remove top SCREWS and bottom On Both Sides PEN
300. ster To enable an event flag bit send the command ESE with the sum of the bit weighting for each desired bit See the ESR command for a list of event flags To enable event flags 0 3 4 and 7 send the command ESE 143 term 143 is the sum of the bit weighting for each bit Bit Bit Weighting Event Name 0 1 OPC 3 8 DDE 4 16 EXE 7 128 PON 143 Query the Configuration of Status Reports in the Standard Event Status Register ESE ESE bit weighting Format nnn term The integer returned represents the sum of the bit weighting of the enable bits in the Standard Event Status Enable Register See the ESR command for a list of event flags Query Standard Event Status Register ESR lt ESR bit weighting gt Format nnn term Queries for various Model 340 error conditions and status The integer returned represents the sum of the bit weighting of the event flag bits in the Standard Event Status Register Bit Bit Weighting Event Name 0 1 OPC 2 4 QYE 3 8 DDE 4 16 EXE 5 32 CME 7 128 PON Query Identification IDN lt manufacturer gt lt model number gt lt serial number gt lt firmware date gt Format LSCI MODEL340 aaaaaa nnnnnn term Identifies the instrument model and software level Remote Operation 9 23 Lake Shore Model 340 Temperature Controller User s Manual xOPC Operation Complete Command Input OPC Returned Nothing Remarks Generates an Operation Complete event in the Standard Event Statu
301. t lt index gt lt units value gt lt temp value gt Nothing Configures a user curve data point Paragraph 8 1 3 NOTE Curves are not permanently updated in the curve Flash until a CRVSAV command is issued lt curve gt Specifies which curve to configure Valid entries 21 60 lt index gt Specifies the points index in the curve Valid entries 1 200 lt units value gt Specifies sensor units for this point to 6 digits lt temp value gt Specifies the corresponding temperature in kelvin for this point to 6 digits CRVPT 21 2 0 10191 470 000 term Sets User Curve 21 second data point to 0 10191 sensor units and 470 000 K Query Curve Data Point CRVPT lt curve gt lt index gt units value temp value Format tnnn nnnE tn nnn nnnE tn term Returns a standard or user curve data point See CRVPT command for parameter descriptions curve Specifies which curve to query Valid entries 1 60 index Specifies the points index in the curve Valid entries 1 200 Update Curve Flash CRVSAV Nothing Updates the Curve Flash with the current user curves May take several seconds use the BUSY command to determine when complete Remote Operation CSET Input Returned Remarks Example CSET Input Returned Remarks DATETIME Input Returned Remarks Example Lake Shore Model 340 Temperature Controller User s Manual Configure Control Loop Parameters CSET lt loop gt lt
302. t MANUAL Relay manual control Paragraph 7 4 2 commonly associated with the alarm feature discussed in Paragraph 7 3 The relays can also be put in manual mode and controlled directly by the user from the front panel or over computer interface Relay parameters are shown on the Relays and Beeper Setup screen which is accessed by pressing the Options key then pressing the More key The relay and beeper Status shown on the right side of the screen is for monitoring only and cannot be changed by the user ALARMS Relay triggered by alarm Paragraph 7 3 5 7 4 4 Selecting a Relay Mode To select a relay mode press the Options key and then press the More key and the RELAYS amp BEEPER SETUP screen appears Press the Next Setting key until the appropriate relay mode field is highlighted Use the A or V key to select a mode for that relay Use the Next Setting or Enter key to make more changes or press the Save Screen key to store the changes The default setting is Off 7 4 2 Manually Setting a Relay To manually control a relay it must be in the manual mode as described in Paragraph 7 4 1 A relay setting of Off puts the relay in its normal state while On puts the relay in the opposite state To change a relay setting press the Options key and then press the More key and the RELAYS amp BEEPER SETUP screen appears Press the Next Setting key until the appropriate relay setting field is highlighted Use the A or Y key to select
303. t if necessary Save the program Run the program Type a command query as described in Paragraph 9 2 7 3 o Jo om Fab Type EXIT to quit the program Table 9 7 Quick Basic Serial Interface Program CLS Clear screen PRINT SERIAL COMMUNICATION PROGRAM PRINT TIMEOUT 2000 Read timeout may need more BAUDS 9600 TERMS CHR 13 CHR 10 Terminators are lt CR gt lt LF gt OPEN COM1 BAUDS O 7 1 RS FOR RANDOM AS 1 LEN 256 LOOP1 LINE INPUT ENTER COMMAND or EXIT CMDS Get command from keyboard CMD UCASES CMDS Change input to upper case IF CMDS EXIT THEN CLOSE 1 END Get out on Exit CMD CMDS TERMS PRINT 1 CMDS Send command to instrument IF INSTR CMD lt gt 0 THEN Test for query RS If query read response N 0 Clr return string and count WHILE N TIMEOUT AND INSTR RS TERM 0 Wait for response INS INPUTS LOC 1 1 Get one character at a time IF INS THEN N N 1 ELSE N 0 Add 1 to timeout if no chr RSS RSS INS Add next chr to string WEND Get chrs until terminators IF RS lt gt THEN See if return string is empty RS MIDS RS 1 INSTR RS TERMS 1 Strip off terminators PRINT RESPONSE RS Print response to query ELSE PRINT NO RESPONSE No response to query END IF END IF Get next command GOTO LOOP1 Remote Operation 9 19 Lake Shore Model 340 Temperature Controller User s Manual 9 2 7 3 Progra
304. t liquid nitrogen 77 35 K room temperature 305 K and high temperature 480 K Accuracy for the PT 102 PT 103 or PT 111 platinum sensor is 250 mK from 70 K to 325 K and 250 mK from 325 K to 480 K 8 2 5 Creating a SoftCal Calibration Curve Once the calibration data points have been obtained you may create a SoftCal calibration Press SoftCal Use the A or V key to select the Standard curve that the SoftCal will be based on Press the Enter key Use the numerical keypad to enter the location where the new user curve will be stored Press the Enter key Use the numerical keypad to enter from 1 to 10 digits for a sensor serial number Press the Enter key Enter the first temperature and corresponding sensor reading Press the Enter key Repeat the process for the next two temperature points When complete press the Save Screen key You see a brief Generating Curve message followed by a longer Saving user curves message The SoftCal curve has now been generated The new curve has the name SCAL XXY where XX is DT for diodes and PT for platinum and Y specifies how many points were used to generate the curve Once the curve is generated you must remember to select the curve for the desired input Refer to Paragraph 5 2 8 3 INTERNAL PROGRAMMING Internal programming allows the user to enter a set of simple instructions called a program into the instrument Some instructions mimic front panel operations like setpoint ramps and
305. t power switch to Off O and disconnect power cord from rear of unit If attached remove 19 inch rack mounting brackets Use a Phillips screwdriver to remove two flat head screws from center rear top and bottom of enclosure Use 5 64 hex key to remove four screws attaching top panel to unit Use 5 64 hex key to loosen four screws attaching bottom panel to unit Carefully remove the back bezel by sliding it straight back away from the unit Slide the top panel back and remove it from the unit INSTALLATION Slide the top panel forward in the track provided on each side of the unit Carefully replace the back bezel by sliding it straight into the unit Use a Phillips screwdriver to install two flat head screws from center rear top and bottom of enclosure Use 5 64 hex key to install four screws attaching top panel to unit Use 5 64 hex key to tighten four screws attaching bottom panel to unit If required reattach 19 inch rack mounting brackets Connect power cord to rear of unit and set power switch to On I N 001200 Noc BO OV Rp om 11 8 EPROM AND NOVRAM REPLACEMENT Part of the operating software for the Model 340 is contained on one Erasable Programmable Read Only Memory EPROM Integrated Circuit IC The reference designator for the EPROM is U146 See Figure 11 13 The EPROM will have a sticker on top with the label SV HEX and the date A Non Volatile Ram Access Memory NOVRAM IC U28 is also included in the Model 340 P
306. t to query Query Linear Equation Data Status for an Input LDATST lt input gt A bit weighted integer from 0 255 Format nnn term The integer returned represents the sum of the bit weighting of the input linear equation data status flag bits lt input gt specifies which input to query See RDGST Command Configure Input Linear Equation Parameters LINEAR lt input gt lt equation gt lt varM value gt lt X source gt lt B source gt lt varB value gt Nothing Configures the linear equation for an input lt input gt Specifies input to configure lt equation gt Specifies linear equation to use Valid entries 1 y mx b 2 y m x b lt varM value gt Specifies a value for m in the equation X source gt Specifies input data to use Valid entries 1 kelvin 2 Celsius 3 sensor units lt B source gt Specifies what to use for b in the equation To use a setpoint set its units to the same type specified in X source Valid entries 1 a value 2 SP1 3 SP1 4 SP2 5 SP2 lt varB value gt Specifies a value for b in the equation if lt B source gt is 1 LINEAR A 1 1 0 1 3 term The linear data for Input A is calculated from the kelvin reading of the input using the equation y 1 0 x SP1 Query Input Linear Equation Parameters LINEAR lt input gt lt equation gt lt varM value gt lt X source gt lt B source gt lt varB value gt Format
307. tact is again important Foil heaters are thin layers of resistive material adhered to or screened on to electrically insulating sheets There are a variety of shapes and sizes The proper size heater can evenly heat a flat surface or around a round load The entire active area should be in good thermal contact with the load not only for maximum heating effect but to keep spots in the heater from over heating and burning out 2 4 4 Heater Wiring Small 30 AWG copper wire is recommended for heater leads inside of a vacuum shroud Larger wire causes too much heat to leak These leads should be heat sinked similar to sensor leads so that heat leak does not warm the load when the heater is not running The lead wires should be twisted to minimize noise coupling between the heater and other leads in the system Outside the vacuum shroud larger copper cable should be used but twisting is still recommended 2 5 CONSIDERATIONS FOR GOOD CONTROL Most of the techniques discussed above to improve cryogenic temperature accuracy apply to control as well There is an obvious exception in sensor location A compromise is suggested below in the Two Sensor Approach Thermal conductivity is discussed in Paragraph 2 5 1 Thermal lag is discussed in Paragraph 2 5 2 The two sensor approach is discussed in Paragraph 2 5 3 Thermal mass is discussed in Paragraph 2 5 4 Finally system nonlinearity is discussed in Paragraph 2 5 5 2 5 1 Thermal Conductivity Go
308. tch a pre programmed type Configure input excitation and input range selections to meet specific needs Users may set the temperature coefficient to allow a specially configured input as a control channel display units in volts or ohms and create and select a response curve for the special input or use a linear equation to compensate for the raw reading The Model 340 pre programmed settings do not include every combination of excitation and input range Setting combinations not included in pre programmed conditions do not have published specifications The user must determine input configuration suitability for their application 5 2 Measurement Operation Lake Shore Model 340 Temperature Controller User s Manual Table 5 2 Special Sensor Type Configuration Excitation mput Range Temperature Coefficient Units Positive Negative The columns in the above table can be selected independently When voltage units are selected the input range is as listed in the table When resistance units are selected resistance range can be computed as R V I Again it is up to the user to determine the suitability of a special input configuration Input configurations that indicate a resistance range of more than 1 MQ are not recommended because the instrument itself will begin to cause measurement errors To select a special sensor type press the Input Setup key The input setup setting screen will appear with the input letter in the top left h
309. tching or non latching mode In non latching mode an active alarm becomes inactive when the alarm condition is corrected This mode is often used in control applications where an alarm event is triggered inside the normal operating range of the input sensor In latching mode an active alarm is held active even after the alarm condition is corrected This mode is most often used as a safety feature to discontinue an external activity if the input sensor is outside of a safe operating range The Alarm Reset key is used to reset a latched alarm 7 3 4 Enabling an Input Alarm To enable an input alarm press the Alarm Setup key The ALARM SETTINGS screen appears with the input letter in the top left hand corner Use the A or V key to select an input Press the Enter or Next Setting key to show the alarm parameters for that input Press the Next Setting key until the Enable field is highlighted Use the A or V key to turn the alarm on or off for that input Use the Next Setting key to make more changes or press the Save Screen key to store the changes The default setting is Enable Off 7 4 Analog Digital Alarm 8 Relay Operation Lake Shore Model 340 Temperature Controller User s Manual 7 3 2 Selecting an Input Alarm Source Once an input is selected a data E source from that input is set The following selections are available s SENSOR Raw sensor units as read from the input sensor o select an input alarm data source press
310. ted so the instrument is not harmed if the heater resistance is too small It is not recommended because the additional load on instrument power supplies causes noise on internal circuits The second control loop has fewer features than the first including software protection and limits The user must be careful to build a robust system and account for the voltage range and power up state of the control output 3 5 11 Boosting the Output Power There are temperature control systems that require more power than the Model 340 can provide An auxiliary DC power supply can be used to boost the output of the Model 340 Programmable power supplies are available that use a low current programming voltage as an input to control a high current voltage output Analog output 2 used for Loop 2 output provides an ideal programming voltage for an auxiliary power supply The only drawback with using the analog output to program auxiliary supplies is it only has one voltage range The heater output for Loop 1 has several ranges that can improve resolution but its output is in current not voltage A programming resistor can be placed across the heater output to produce a programming voltage The programming voltage is related to output current by V program Rorogram X output The resistor must be chosen to convert a full scale current from the highest heater output range being used to the full scale programming voltage of the auxiliary supply For example it the a
311. ted without a RGA number When returning an instrument for service Lake Shore must have the following information before attempting any repair Instrument model and serial number User name company address and phone number Malfunction symptoms Description of system Returned Goods Authorization RGA number Softer Version Master Input Options OuRwWN gt Wrap instrument in a protective bag and use original spacers to protect controls Repack the system in the Lake Shore shipping carton if available and seal it with strong paper or nylon tape Affix shipping labels and FRAGILE warnings Write the RGA number on the outside of the shipping container or on the packing slip Installation 3 1 Lake Shore Model 340 Temperature Controller User s Manual 3 1 3 Safety Summary The following general safety precautions must be observed during all phases of operation service and repair of this instrument Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended use of the instrument Lake Shore Cryotronics Inc assumes no liability for Customer failure to comply with these requirements The Model 340 protects the operator and surrounding area from electric shock or burn mechanical hazards excessive temperature and spread of fire from the instrument Environmental conditions outside of the conditions below may pose a hazard to the operator an
312. ter sssssssss 9 3 9 1 3 2 Standard Event Status Register and Standard Event Status Enable Register 9 3 9 1 4 IEEE Interface Example Programs erases ott e er e IRR tete 9 4 9 1 4 1 IEEE 488 Interface Board Installation for Visual Basic Program 9 4 9 1 4 2 Visual Basic IEEE 488 Interface Program Setup sse 9 6 9 1 4 3 IEEE 488 Interface Board Installation for Quick Basic Program 9 9 9 1 4 4 Quick Basic Program inci rero pde be rte edes 9 9 9 1 4 5 Program Operation e Len EE ee EES 9 12 9 1 5 Troubleshooting 12 51 t tir ria 9 12 9 2 Serial Interface Overview miii ind tada 9 13 9 2 1 Changing Baud Rale miii ert Rr te e ee AL I Te ei ns 9 13 9 2 2 Physical Connection eec ie o Lr tea ee qe ta dad e Dites 9 13 9 2 3 Hardware SUppOLt 2 n netto RI EB ERE E ET 9 14 9 2 4 Character FOnmMat eite tt eite deter abia 9 14 Lake Shore Model 340 Temperature Controller User s Manual 9 2 5 Message ln EE EE 9 14 9 2 6 Message Flow Gontrol nire ida ie 9 15 9 2 7 Serial Interface Example Programs sss een enm nennen 9 15 9 2 7 1 Visual Basic Serial Interface Program Setup sss 9 16 9 2 7 2 Quick Basic Serial Interface Program Setup sssse eee 9 19 9 2 7 3 Program Operation si eter e ee o dee eed E e vta titel ate ad 9 20 9 2 8 Troubleshooting mermisi o tet eset pete et ed tete eg ctl i yo EE et ad 9 2
313. that function is enabled To set a bit send the command xESE with the bit weighting for each bit you want to be set added together Also refer to the ESE command discussion The Standard Event Status Enable Query ESE reads the Standard Event Status Enable Register kESR reads the Standard Event Status Register Once this register has been read the bits are reset to zero Power On PON Bit 7 This bit is set when an controller off on off transition has been detected Command Error CME Bit 5 If bit 5 is set a command error has been detected since the last reading This means that the controller could not interpret the command due to a syntax error an unrecognized header unrecognized terminators or an unsupported command Execution Error EXE Bit 4 If bit 4 the EXE bit is set an execution error has been detected This occurs when the controller is instructed to do something not within its capabilities Device Dependent Error DDE Bit 3 A device dependent error has been detected if the DDE bit is set The actual device dependent error can be found by executing the various device dependent queries Query Error QYE Bit 2 The QYE bit indicates a query error It occurs rarely and involves loss of data because the output queue is full Operation Complete OPC Bit 0 This bit is generated in response to the OPC common command It indicates when the Model 340 has completed all selected pending operations
314. the Next Setting key to display the equation parameters for that input Use the A or W key to select one of the two equations from the highlighted equation field Press the Next Setting key and continue to select parameter settings for M X and B A number setting field will appear next to the field for B if number is selected from the B setting list The scale factor can be selected as n p m k M or G Blank indicates a scale factory of x1 Press the Save Screen key to store the change in the Model 340 The default settings are M X B 1 K SP1 5 4 SCANNER SUPPORT The Model 340 supports a user supplied sensor scanner external to the instrument Scan up to 16 sensors of the same type into input A The sensors must be the same type because only one sensor type setting can be made for the A input Each of the 16 sensors channels can have a unique temperature response curve There are different modes of scan operation that allow for active scan channel selection If a channel is not actively read the last valid reading for that channel either displays or reports over the computer interface Four lead sensor measurement is always recommended when scanning temperature sensors 5 4 1 Scan Modes Scanner support has different modes for selecting which of the channels is actively being read Each mode allows for a different scanner applications The user manually selects the scan channel over front panel or computer interface Digital outputs repo
315. the controls and select Microsoft Comm Control 6 0 Select OK In the toolbar at the left of the screen the Comm Control will have appeared as a telephone icon 6 Select the Comm control and add it to the form 7 Add controls to form a Add three Label controls to the form b Add two TextBox controls to the form c Add one CommandButton control to the form d Add one Timer control to the form 8 On the View Menu select Properties Window 9 In the Properties window use the dropdown list to select between the different controls of the current project Label1 Command1 is Serial Interface Program Label3 Label2 10 Set the properties of the controls as defined in Table 9 5 11 Save the program 9 16 Remote Operation Lake Shore Model 340 Temperature Controller User s Manual Table 9 5 Serial Interface Program Control Properties Current Name Property New Value Label1 Name IbIExitProgram Caption Type exit to end program Label2 Name IbICommand Caption Command Label3 Name IblResponse Caption Response Text1 Name txtCommand Text blank Text2 Name txtResponse Text blank Command1 Name cmdSend Caption Send Default True Form1 Name frmSerial Caption Serial Interface Program Timer1 Enabled False Interval 10 12 Add code provided in Table 9 6 a Inthe Code Editor window under the Object dropdown list select General Add the statement Public gSend as Boo
316. the zones are programmed you must place the controller in zone mode To do this press the Control Setup key Use the Next Setting key to move to the Control Mode entry then use the A or V key to select Zones Once Zone is turned on the instrument updates the control settings each time the setpoint is changed to a new zone If the settings are changed manually the controller uses the new setting while it is in the same zone then updates to the zone table settings when the setpoint is changed to a value outside that zone Temperature Control Operation 6 5 Lake Shore Model 340 Temperature Controller User s Manual This feature is most effective when combined with the ramp rate feature The user can potentially do a ramp through all 10 zones from 1 4 K to room temperature by only changing the setpoint The controller automatically changes the PID and heater range settings as the temperature setpoint passes through the different zones Zone Setting WorkSheet Zone 10 ron owe Setpoint Gain P Reset I Rate D Manual Output Heater Range Zone 09 Setpoint Gain P Reset I Rate D Manual Output Heater Range Zone 08 d4 Setpoint Gain P Reset I Rate D Manual Output Heater Range Ho Setpoint Gain P Reset I Rate D Man
317. ther is not the same as copying or downloading a curve from a data card to the Model 340 The data card curve downloading procedure is provided in Paragraph 8 4 To copy a curve press the Curve Entry key Press the Next Setting key until Copy curve is selected then press the Enter key Change to the desired curve number with the A or V key then press the Enter key The cursor jumps to the To selection Again use the A or V key to select the user curve number 21 to 60 the curve will be copied to Empty user curves have zeros for data NOTE The copy routine allows you to overwrite an existing user curve Please ensure the curve number you are writing to is correct before proceeding with curve copy Once the curve number to copy to has been selected press the Enter key The following message is displayed Press SAVE SCREEN to copy CANCEL SCREEN to abort If you press the Save Screen key the Saving user curves message appears for a few seconds then the display returns to the CURVE ENTRY menu If you press the Cancel Screen key the curve is not copied and you are returned to the CURVE ENTRY menu 8 1 5 Front Panel Curve Erase When curves are no longer needed they can be edited over or erased Curves erase sets all identification parameters to default and blanks all breakpoint values To erase a curve press the Curve Entry key Press the Next Setting key until Erase curve is selected then press the Enter key Change to t
318. thermal conduction because a larger area has more opportunity to transfer heat Even when the size of a sensor package is fixed thermal contact area can be improved with the use of a gasket material A soft gasket material forms into the rough mating surface to increase the area of the two surfaces that are in contact Good gasket materials are soft thin and have good thermal conductivity They must also withstand the environmental extremes Indium foil and cryogenic grease are good examples 2 3 5 Contact Pressure When sensors are permanently mounted the solder or epoxy used to hold the sensor act as both gasket and adhesive Permanent mounting is not a good solution for everyone because it limits flexibility and can potentially damage sensors Much care should be taken not to over heat or mechanically stress sensor packages Less permanent mountings require some pressure to hold the sensor to its mounting surface Pressure greatly improves the action of gasket material to increase thermal conductivity and reduce thermal gradients A spring clamp is recommended so that different rates of thermal expansion do not increase or decrease pressure with temperature change Cooling System Design 2 5 Lake Shore Model 340 Temperature Controller User s Manual 2 3 6 Lead Wire Different types of sensors come with different types and lengths of electrical leads In general a significant length of lead wire must be added to the sensor for proper heat sinkin
319. this feature to operate The sensor input alarms are mapped to the digital output signals as follows Input Alarm Any Other B High A High Digital Output Number Digital VO Connector Pin 5 4 3 2 1 Any Other indicates that an alarm is active on any one of the installed optional inputs 7 2 3 Digital Outputs in Scanner Mode Digital outputs can be used to report the scan channel when an external scanner is being used The digital outputs must be put in scanner mode as described in Paragraph 7 2 1 External scanner operation is described in Paragraph 5 4 Analog Digital Alarm amp Relay Operation 7 3 Lake Shore Model 340 Temperature Controller User s Manual 7 2 4 Digital Outputs in Manual Mode In manual mode the digital outputs are controlled directly by the user The digital output signals can be set to any combination of high logic 1 or low logic 0 Digital output can only be set using the 0 and 1 keys For example a setting of 00011 causes digital outputs 1 and 2 to be high logic 1 and digital outputs 3 4 and 5 to be low logic 0 To manually set a digital output set the digital output mode to manual as described in Paragraph 7 2 1 Press the Options key and the Digital I O screen appears Press the Next Setting key until the Reading line is highlighted Use the number keys 0 and 1 to enter a setting that corresponds to the digital output numbers shown below the setting on the display Press t
320. tilize a bipolar control output The AutoTune feature will not operate with Loop 2 configured for Bipolar Control To set unipolar operation for an Analog Output press the Analog Outputs key The analog output indicator is highlighted in the upper left hand corner Use the A or W key to select analog output 2 Press the Enter or Next Setting key until the Bipolar field is highlighted Use the A or V key to select OFF Press the Enter or Next Setting key to continue with more settings or the Save Screen key to save the changes to the Model 340 Once the Analog Output is setup the control loop must be setup Control channel control mode PID control parameters setpoint units and setpoint are described in the heater output Paragraph 6 12 1 The AutoTune feature will only work with one loop at a time Heater range and other features noted in Table 1 1 are not available Control output limits other than heater range limit described in Paragraph 6 13 work with any control output 6 10 Temperature Control Operation Lake Shore Model 340 Temperature Controller User s Manual 6 13 CONTROL OUTPUT LIMITS Control limits were added to the Model 340 as added protection to prevent parameter settings that can damage the cooling system 6 13 1 Setpoint Limit Setpoint temperature limit is a global limit for a control loop Setpoint values above the limit are rejected and the setpoint defaults to the limit value The limit is entered in kelvin and works
321. ting screen Enter Move from left to right side of setting screen I Insert Insert an instruction line when on the left side D Delete Delete an instruction line when on the left side Move from right to left side of setting screen P Paste Insert the previously deleted instruction when on the left side Instrument Programming 8 11 Lake Shore Model 340 Temperature Controller User s Manual 8 3 6 Example of an Internal Program Example 1 This example illustrates the typical use of an internal program It represents the preconditioning of a sample in temperature Figure 8 3 illustrates the program loaded into location 1 To run this program follow the run procedure detailed in Paragraph 8 3 8 and specify Program 1 Edit Program 01 1 Parameters 2 Ramp SP Abs 3 Settle 4 Repeat 5 Ramp SP Rel 6 Wait 7 Ramp SP Rel 8 Wait 9 End Repeat 10 Ramp SP Abs 11 End 8 12 gt V Channel Mode P I D Htr Range Setpoint Hours Minutes Seconds Rate Hours Minutes Seconds Band Count A MANUAL PID 50 0 20 0 12 25W 50 000K 30 1 00000K 3 Infinite Loop OFF Dev Hours Minutes Seconds Rate Hours Minutes Seconds Dev Hours Minutes Seconds Rate Hours Minutes Seconds Setpoint Hours Minutes Seconds Rate 10 000K OK m 0 1 0 0 0 1 0 10 000K 0 1 0 0 0K m 0 1 0 1
322. ting to a data card is described in Paragraph 8 4 3 Finally erasing a data card is described in Paragraph 8 4 4 8 4 1 Data Logging To A Data Card The Model 340 can store reading data or control data in an SRAM Data Card with the data logging feature Stored data can be viewed on the display or read over computer interface at a later time Data is taken in groups called records Each record consists of a timestamp and up to four points of data in any combination of the input readings setpoints or control outputs The Model 340 can utilize SRAM Data Cards from 64K to 1M byte Larger data cards can be used but only the first 1M byte is utilized by the instrument Table 8 2 indicates the maximum number of records that can be stored in a 1MB SRAM Data Card based on the number of data points in a record Table 8 2 Storage Capability for a 1MB Data Card To enter the data log functions insert an SRAM Data Card into the data card slot and press the Data Card Key The Identifying Card message is displayed followed by the DATACARD screen It shows the recognized Data Card type and its capacity on the bottom of the screen together with its battery and the WriteProtect switch status Note Batteries are not included with SRAM Data Cards purchased from Lake Shore Highlight Data Logging and press the Enter key The DATA LOGGING screen is displayed with five menu items Number of Records already logged in the SRAM Data Card and its loggin
323. to Temperature Linear Equation PID Control Maximum Minimum Heater Out E Software Hardware 340 5 1 eps Figure 5 1 Data Flow 5 3 2 Max Min The Model 340 will save the highest Max and lowest Min reading of a sensor input when the Max Min feature is turned on The feature can be paused to save these stored values after the observation period is over A source for Max Min must be selected on the math setup screen There are four possible sources for the Max Min feature The input reading in sensor units kelvin Celsius or the result of the linear equation can be chosen Max Min will work with one source for an input but different inputs can have different sources Max and Min will not automatically show on the display Use the Reading Display Format screen described in Paragraph 4 5 to show Max and Min on the display To use the Max Min feature press the Math Setup key The math setting screen will appear with the input letter in the top left hand corner Use the A or V key to select an input Press the Enter key or the Next Setting key to display the Max Min parameters for that input Press the Next Setting key until the Max Min enable field is highlighted and then use A or V key to select on Press the Next Setting key or the Enter key to advance to the source field Use the A or W key to select one of the four sources Press the Next Setting key to make other changes Press the Save Screen k
324. to read lt compensation gt Room temperature compensation not thermal EMF compensation 4 The INTYPE command changes to the following format The TYPE query changes accordingly INTYPE lt input gt lt range gt lt input gt Specifies input to configure C or D lt range gt Specifies input voltage range 1 25mV 2 50mV Options and Accessories 10 11 Lake Shore Model 340 Temperature Controller User s Manual 10 4 6 Thermocouple Temperature Curves Refer to Appendix A for lists of data points in each curve and Table 1 2 for thermocouple sensor performance 10 4 7 Specifications The 3464 Option Card input specifications are listed in Table 1 2 10 5 MODEL 3465 SINGLE CAPACITANCE INPUT OPTION CARD This option adds a capacitance input to the Model 340 Temperature Controller The new input appears on the display as C lt controls temperature in strong magnetic fields using Lake Shore Model CS 401 or CS 501 capacitance temperature sensors The standard inputs remain in the instrument and are fully functional The Model 340 does not support temperature conversion for the capacitance input The temperature response of capacitance sensors shifts with thermal cycling making calibration unpredictable All 3465 option measurement and control must be done in sensor units With this option we recommend operating the Model 340 with two sensors installed at the control point Use a diode or resistive sensor in one of the standard i
325. tor Verify the fuse value whenever line voltage is changed Service 11 3 Lake Shore Model 340 Temperature Controller User s Manual Identify the line input assembly on the instrument rear panel Turn the line power switch OFF O Remove the instrument power cord With a small screwdriver release the drawer holding the line voltage selector and fuse Slide out the removable plastic fuse holder from the drawer Rotate the fuse holder until the proper voltage indicator shows through the window Verify the proper fuse value Re assemble the line input assembly in the reverse order Depending upon the date of manufacture the instrument may use fuses of different physical sizes as described in Paragraph 11 3 An additional fuse drawer has been supplied in the connector kit if this is the case Be sure to use the correct fuse drawer for the fuse selected 9 Verify the voltage indicator in the window of the line input assembly 10 Connect the instrument power cord 11 Turn the line power switch ON I RANA INS 11 3 4 Fuse Removal and Replacement Below is the procedure to remove and replace a line fuse Use slow blow fuses with the value shown in Table 11 1 To change line input from the factory setting use the appropriate fuse in the connector kit shipped with the instrument Locate the line input assembly on the instrument rear panel Turn the power switch OFF O Remove the instrument power cord With a small screwdriv
326. trol theory experts lt describes a few basic rules of thumb to help less experienced users get started This technique will not solve every problem but it has worked for many others in the field This section assumes the user has worked through the operation sections of this manual has a good temperature reading from the sensor chosen as a control sensor and is operating Loop 1 It is also a good idea to begin at the center of the temperature range of the cooling system not close to its highest or lowest temperature AutoTune Paragraph 2 8 is another good place to begin and do not forget the power of trial and error Setting the heater range is discussed in Paragraph 2 7 1 Manually tuning Proportional P is discussed in Paragraph 2 7 2 Manually tuning Integral I is discussed in Paragraph 2 7 3 Finally manually tuning Derivative D is discussed in Paragraph 2 7 4 2 7 1 Setting Heater Range Setting an appropriate heater output range is an important first part of the tuning process The heater range should allow enough heater power to comfortably overcome the cooling power of the cooling system If the heater range will not provide enough power the load will not be able to reach the setpoint temperature If the range is set too high the load may have very large temperature changes that take a long time to settle out Delicate loads can even be damaged by too much power Often there is little information on the cooling power of the coo
327. troller OK Cancel Figure 9 1 GPIB Setting Configuration System Properties 2 x General Device Manager Hardware Profiles Performance l View devices by type lI National Instruments GPIB Interfaces Properties 27 x Computer General Device Templates z CDROM 2 83 Disk drives y National Instruments GPIB Interfaces a Display adapters Floppy disk controllers Hard disk controllers Device Name 3 Keyboard 5 89 Monitor H A Mouse National Instruments GPIB Interface 8 GG MP Network adapters DEV12 Attributes e Ports COM amp LPT Interface r Termination Methods Timeouts m System devi nai System devices sen zl Send EOI at end of write hoy 10sec h GPIB Address v Terminate Read on EDS Ser Primar V Set EO with EOS on Write 2 a aer 12 y a Properties Refresh R 8 bit EOS Compare Secondary NONE y fio EOS Byte v Readdress Figure 9 2 DEV 12 Device Template Configuration Remote Operation 9 5 Lake Shore Model 340 Temperature Controller User s Manual 9 1 4 2 Visual Basic IEEE 488 Interface Program Setup This IEEE 488 interface program works with Visual Basic 6 0 VB6 on an IBM PC or compatible with a Pentium class processor A Pentium 90 or higher is recommended running Windows 95 or better It assumes your IEEE 488 GPIB card is
328. troller User s Manual 1 4 Configurable Display The Model 340 includes a graphic LCD with fluorescent backlight display that is fully configurable and can display up to eight readings Ramr iT 00327 Tur SI Ip me This shows a variation of the display with a large loop 1 heater output graphic bar where the PID parameters are not displayed but the heater output is more prominent READING DISPLAY FORMAT The user can display 1 to 8 readings from any of the available inputs The units available are the sensor units of mV V O kQ nF or temperature units of C or K Results of the math feature can also be selected Input B Enable Therm Come The user can select the sensor type and the controller will automatically select the sensor units excitation and range If special type is selected the user can choose any available excitation and input range 1 5 Additional Inputs Available For Model 340 The following optional inputs are available for the Model 340 Only one can be installed at a time and the standard inputs stay in the instrument and remain fully functional Calibration for the option is stored on the card so it can be installed in the field without recalibration 1 5 1 3462 Dual Standard Input Option Card Adds two standard inputs to the Model 340 appearing on the display as C and D The card has separate A Ds and excitation for each sensor A microprocessor on the card manages the A D and communic
329. ture updates If a standard curve location is in use the curve can be viewed using the edit operation Standard curves can not be changed by the user and reserved locations are not available for user curves The Model 340 has 40 user curve locations numbered 21 through 60 Each location can hold from 2 to 200 data pairs breakpoints including a value in sensor units and a corresponding value in Kelvin Using fewer than 200 breakpoints will not increase the number of available curve locations SoftCal generated curves are stored in user curve locations No specific curve endpoints are required The instrument will show an error message on the display if the sensor input is outside the range of the breakpoints Each curve has a set of parameters that are used for identification and to allow the instrument to use the curve effectively The parameters must be set correctly before a curve can be used for temperature conversion or temperature control Please note that if instrument power is lost when new curves are being stored or erased Save Screen has been pressed all user curves may be lost 8 1 2 Front Panel Curve Entry Operations There are three operations associated with front panel curve entry Edit curve Copy curve copy Erase curve as detailed below Edit allows the user to see any curve and enter or edit a curve at any user curve location Standard curves cannot be changed Paragraph 8 1 3 Copy allows the user to copy a curve f
330. ual Output Heater Range Zone 06 Gain P Reset I Rate D Manual Output Heater Range Zone 05 Setpoint Gain P Reset I Rate D Manual Output Heater Range Zone 04 Setpoint Gain P Reset I Rate D Manual Output Heater Range Gain P Reset I Rate D Manual Output Heater Range gt Setpoint Gain P Reset I Rate D Manual Output Heater Range Zone 01 d 9 9 9 9 M Setpoint Gain P Reset I Rate D Manual Output Heater Range 340 6 1 eps Figure 6 1 Record of Zone Settings 6 6 Temperature Control Operation Lake Shore Model 340 Temperature Controller User s Manual 6 9 USING OPEN LOOP CONTROL Directly setting control output is called open loop control because there is no feedback from a load sensor to close the control loop Load temperature setpoint and control parameters are ignored Use open loop control for experiments requiring constant control output regardless of load temperature for initial cooling system tuning or for when a computer calculates the control equation and sends output information to the instrument To use open loop control set control mode to open refer to Paragraph 6 5 When using Control Loop 1 and the heater output select an appropriate heater range The manual output parameter sets the control output as percent of full scale current or powe
331. ue the source is checked against to activate the high alarm lt low value gt Sets the value the source is checked against to activate low alarm lt latch enable gt Specifies a latched alarm remains active after alarm condition correction lt relay enable gt Specifies how the activated alarm affects relays NOTE Does not guarantee the alarm activates the relays See the RELAY command ALARM A O term Turns off alarm checking for Input A ALARM B 1 1 270 0 1 term Turns on alarm checking for input B activates high alarm if kelvin reading is over 270 and latches the alarm when kelvin reading falls below 270 Query Input Alarm Parameters ALARM lt input gt lt offlon gt lt source gt lt high value gt lt low value gt lt latch enable gt lt relay enable gt Format n n tnnn nnnE tn tnnn nnnE tn n n term Returns the alarm parameters of an input See the ALARM command for parameter descriptions lt input gt specifies which input to query Query Input Alarm Status ALARMST lt input gt lt high status gt lt low status gt Format n n term Returns the alarm status of an input lt input gt specifies which input to query Clear Alarm Status for All Inputs ALMRST Nothing Clears both the high and low status of all alarms including latching alarms Remote Operation 9 25 ANALOG Input Returned Remarks Example ANALOG Input Returned Remarks AOUT Input Returned Remarks B
332. uency range of 30 kHz so the backlight power supply can be turned off Please note that the display is unreadable when the backlight is off To turn the display backlight off press the Display Format key then press the More key to show the MISC DISPLAY FORMAT screen Press the Next Setting key until the line for backlight is highlighted then use the A or Y key to turn the backlight off Press the Save Screen key to store the changes Default setting is On To turn the display backlight back on press any key on the keypad 4 5 9 Locking the Keypad The Model 340 has a keypad lock feature to prevent accidental changes to instrument parameters and minimize the disturbances of curious onlookers A simple 3 number sequence is the code needed to lock and unlock the keypad The factory default code is 123 and it can only be changed using a computer interface To lock or unlock the keypad press the Display Format key then press the More key to show the Misc Display Format screen Press the Next Setting key until Lock is highlighted then use the A or V key to toggle the lock setting Press the Enter key A small setting window will appear for entering a three digit number code Use the number keys to enter the code then press the Enter key Press the Save Screen key to store the lock status in the Model 340 The default setting is unlocked code 123 When the keypad is locked you can still see values for the various parameters you just cannot chan
333. ument Busy Status BUSY lt instrument busy status gt Format n term Indicates that the instrument is busy performing a lengthy operation like generating a SoftCal curve writing to the Flash chip etc Commands that use the Instrument Busy Status say so in their description Configure Control Loop Display Parameters CDISP lt loop gt lt number of loops gt lt resistance gt lt current power gt lt large output enable gt Nothing Configures control loop portion of the display lt loop gt Specifies which loop to configure lt number of loops gt Specifies how many loops to display Valid entries 0 no loops 1 loop 1 2 loop 2 3 both loops Specifies heater load resistance Valid entries 1 1000 Specifies whether heater output displays in current or power Valid entries 1 current 2 power lt large output enable gt Disables or enables the large output display CDISP 1 1 25 0 1 term Control Loop 1 displays using 25 Q to determine maximum power output The output displays in current and in large numbers lt resistance gt lt current power Query Control Loop Display Parameters CDISP lt loop gt lt number of loops gt lt resistance gt lt current power gt lt large output enable gt Format n nnnn n n term Returns parameters for a control loop display See the CDISP command for parameter descriptions lt loop gt specifies which loop to query Configure Control Filter
334. user understand the keypad layout and how to quickly get to the features of interest The Model 340 keypad is divided into three groups The group of 16 keys near the display is used for temperature control features The middle group of 16 keys has two functions The key surfaces are labeled with numbers and symbols for number entry Above these keys are labels for temperature measurement display and interface features The last group of 8 keys is used for navigating in setting screens and has a few spare keys for features that the operator may need quickly 4 2 Front Panel Operation Lake Shore Model 340 Temperature Controller User s Manual Keypad Description Continued Aside from the key location the color of the panel behind the key is also important Direct settings made with the normal display showing are initiated using keys with a gray background The number keys and the gray backed Enter Escape up A or down V keys are used to complete these operations when needed The keys with a white background initiate a setting screen One or more associated parameters are grouped on the setting screen The white backed Next Setting Previous Setting Save Screen Cancel Screen and More keys are used to move around within setting screens Once the desired parameter is highlighted it can be set with the number entry keys Examples are given below in keypad navigation 4 4 KEYPAD NAVIGATION This section gives specifics on how to set des
335. ut or open loop Autotune one loop at a time manual PID zones Sensor dependent to 2x measurement resolution in an ideal thermal system ng gain ut 0 to 1000 with 0 1 setting resolution 1 to 1000 with 0 1 setting resolution 1 to 1000 s with 1 s resolution 0 to 100 with 0 01 setting resolution 10 temperature zones with P I D manual heater power out and heater range g 0 1 K per min to 100 K per min Setpoint limit curve temp limits heater output slope limit heater range limit power up heater off and short circuit protection Table 1 5 Heater Output Specifications Loop 1 Loop 2 Heater output type Variable DC current source Variable DC voltage Heater output D A resolution 18 bit 14 bit Max heater power 100W 1W Max heater output current 2A 0 1A Heater output compliance 50V 10V Heater source impedance NA 0 01 Q Heater output ranges 5 decade steps in power 1 Heater load type Resistive Resistive Heater load range 10 O to 100 O recommended 100 O minimum Heater load for max power 25 O 100 O Heater noise 1 kHz RMS 50 uV 0 001 of output voltage 0 3 mV Isolation Optical isolation between output and other circuits None Heater connector Dual banana BNC 1 8 Introduction Lake Shore Model 340 Temperature Controller User s Manual Table 1 6 Loop 1 Full Scale Heater Power at Typical Resistance Maximum Cu
336. utput status in percent of full scale 7 1 2 Example of Low and High Parameter Setting With the analog output set Low High to linear mode the Input A Temperature K 0 500 1000 temperature input data and voltage output data Unipolar Output V 0 5 10 are related as shown The first figure results in a Low High wide temperature range Input A T t K 7 but sensitivity is poor The ios EE E Li pem jase i Km nos c i g resulting sensitivity is 0 01 V K or 10 mV K Unipolar Output V 0 5 10 If the application does not require a wide temperature range the user can change the value of the low and high parameters to improve sensitivity This setup has a narrow range with much improved sensitivity of 0 2 V K or 200 mV K Please note that in any application the resolution of the analog output voltage is always 1 25 mV as specified The second figure shows how sensitivity improves when working at liquid nitrogen temperature 77 K 7 1 3 Loop 2 Mode for Analog Output 2 Discussion about using Analog Output 2 as the control output for Loop 2 is contained in the control operation chapter Loop 2 must be chosen as the mode for analog output 2 and the bipolar setting should match the capability of the control system It is recommended to set the Analog Output to unipolar mode Few applications can use bipolar control output A thermo electric cooling element is one example o
337. uxiliary supply has a full scale programming voltage of 10 V and the maximum current for the highest heater output range being used is 0 25 A the programming resistor should be 10 V 0 25 A 40 Q The programming resistor must be rated for the power being dissipated in it which is Power bo XR program OF 2 5 W Lower heater output current ranges can be selected to reduce the power dissipated in the programming resistor 3 10 Installation Lake Shore Model 340 Temperature Controller User s Manual 3 6 ANALOG OUTPUTS Analog Output 1 and Analog Output 2 on the rear panel of the ANALOG ANALOG Model 340 are voltage outputs that can be used for monitor and OUT 1 OUT 2 control applications See Figure 3 6 Their most basic function f is a temperature monitor where they put out a voltage that is proportional to temperature They can be configured to monitor the output of a linear equation which allows the user to select an offset and gain ANALOG OUT 2 can be used as the control output for Loop 2 The analog outputs can also be controlled manually by the user for any application that requires a programmable voltage source DESCRIPTION PIN ES Analog Output Center Conductor Ground Connector Shell 1 2 Both analog outputs are variable DC voltage sources that can vary from 10 V to 10 V The resolution of the analog output is Figure 3 6 ANALOG OUT 1 and 2 1 25 mV or 0 0125 of full scale The output can source up to BNC Rear
338. values are entered as numbers Heater Range and Control Channel are set with A or W key from a list of settings Then press the Enter key to Normal Display with Temperature Setpoint Highlighted accept or Escape key to cancel Front Panel Operation 4 3 Lake Shore Model 340 Temperature Controller User s Manual 44 3 Using Setting Screens Use setting screens to change less used parameters Press keys with a white background to display the parameter setting screen associated with that key The setting screen title displays on the center of the top line On screens that contain parameters associated with sensor inputs or control loops the top left corner will show the sensor input or control loop This field must be set correctly before proceeding Use the A or V key to select the appropriate sensor input or control loop and then press enter The correct parameters will then be shown on the setting screen The Next Setting and Previous Setting keys are used to move around within the setting screen Once a parameter has been chosen and it is highlighted the data entry discussed above should be used to make changes The Next Setting and Previous Setting keys will act like the Enter key and end the setting operation After making changes to a screen press Save Screen to store the changes into the Model 340 Press Cancel Screen or let the keypad time out to return screen parameters to pre setting values A lt more gt annunciator may ap
339. viation 0 to 23 Minutes 0 Minutes Minutes to make output deviation 0 to 59 Seconds 0 Seconds Seconds to make output deviation 0 to 59 Rate 0 00 m Rate Ramp rate in percent per minute m from 0 to 100 with 0 1 resolution NOTE Ramp time ramp rate and deviation are related The instrument calculates a ramp rate based on deviation and ramp time If ramp time and rate are both zero then the ramp is a step change 8 3 1 5 Control Parameters During many experiments it may be necessary to change control parameters This need is particularly great when making large changes in temperature Common control parameters can be set with this instruction The AutoTune control mode is not available during internal program operation Setpoint units are not changeable the setpoint units parameter should be set to temperature before running an internal program Channel Loop 1 control channel Parameters gt Channel A Mode Loop 1 control mode Mode MANUAL PID P 1 D Loop 1 control parameters Set with zone feature P 0 0 if zone control mode is selected above I 0 0 Htr Range Loop 1 heater output range Set maximum D 0 heater current before running an internal program Htr Range OFF 8 3 1 6 Digital Output A Model 340 internal program can interact with experimental parameters other than temperature The digital outputs can be used to control outside events while a program is running Using digital outputs in pr
340. will not initiate changes to the control settings or setpoint for the purpose of tuning Since unexpected or unwanted disturbances to the control system can ruin experimental data being taken by the user the Model 340 only gathers data and changes control settings after the user changes the setpoint When the user selects a new setpoint the Model 340 logs the change in temperature at the load and the change in heater output that was required to make the load temperature change The old control settings are used while data is being logged so a good initial guess of settings can improve the efficiency of the AutoTune feature Once the load temperature is at or near the new setpoint the Model 340 looks at the logged data to calculate the best P and D setting values The values are then loaded and used as the control parameters so the control loop can stabilize at the new setpoint AutoTune does not work during a ramp because the dominant time constant of the load is disguised by the ramp rate The user can tell when data is being logged because the Tune annunciator changes to Tuning When the annunciator returns to Tune the process is complete and will not begin again until the user changes the setpoint If AutoTune does not give desired results the first time make a few small 2 to 5 degree changes in setpoint and let the Model 340 complete the tuning cycle each time This allows the AutoTune feature to zero in on a better set of control settings
341. with setpoint units of kelvin or Celsius The limit does not work when sensor units are chosen for the setpoint The Model 340 turns off the control output if the temperature of the control sensor exceeds the global limit The global setpoint limit works along with the individual limits that can be entered in a temperature response curve The curve limits are only active when a sensor using that curve is chosen as a control sensor while the global limit is active all the time The lower of the two is used to limit the setpoint To change the setpoint temperature limit press the Control Setup key The control loop indicator is highlighted in the upper left hand corner Use the A or V key to select a control loop and press the Enter or Next Setting key The control setup parameters for that loop appears on the screen Press the Next Setting key until the setpoint field under the limits heading is highlighted Use the number keys to enter the maximum setpoint in kelvin Press the Enter or Next Setting key to continue with more settings or press the Save Screen key to store the changes in the Model 340 The default setting is 475 K 6 13 2 Control Output Slope Limit Some experiments can not tolerate fast changes in control output The slope limit feature keeps changes in control output below a user specified rate of change There is a different limit for rising and falling slope The rising slope limit is shown as Slope the falling slope limit is shown
342. y are voltage sources that can be used to output a voltage representation of sensor input reading Analog Output 2 can also be used as the control output for Loop 2 as described in Paragraph 7 1 3 The user can select the source of the analog output data and scale the relationship of data reading to output voltage independently for the two analog outputs The analog outputs are variable DC voltage sources that can vary from 10 V The resolution of the analog output is 1 25 mV or 0 0125 of full scale The output can source up to 100 mA of current providing a maximum of 1 W of power They can drive a resistive load of no less than 100 Q The output is short protected so the instrument is not harmed if the load resistance is too small This is not recommended because the additional load on the power supplies in the instrument causes noise on the internal circuits The analog output connector and pinouts are shown in Figure 10 5 d SE dias Ge OFF Output voltage is set to 0 volts meter dependen ine med parameters depend on the mode INPUT Analog output voltage is tied to a sensor input that is selected A list of analog LOOP Control Loop 2 Control output Analog Output 2 only output operating modes is shown MANUAL Manual setting of the analog output voltage to the right To select an analog output mode press the Analog Outputs key The ANALOG OUTPUTS screen is displayed With the output number highlighted in the top left corner u
343. y configured National Instruments GPIB PC2 card The REM SINCLUDE statement is necessary along with a correct path to the file QBDECL BAS CONFIG SYS must call GPIB COM created by IBCONF EXE prior to running Basic There must be QBIB QBL library in the QuickBasic Directory and QuickBasic must start with a link to it All instrument settings are assumed to be defaults Address 12 Terminators lt CR gt lt LF gt and EOI active To use type an instrument command or query at the prompt The computer transmits to the instrument and displays any response If no query is sent the instrument responds to the last query received Type EXIT to exit the program REM INCLUDE c gpib pc qbasic qbdecl bas CLS PRINT IEEE 488 COMMUNICATION PROGRAM PRINT CALL IBFIND dev12 DEV12 TERMS CHR 13 CHR 10 INS SPACES 2000 LINE INPUT ENTER COMMAND or EXIT CMD CMD UCASES CMD IF CMD EXIT THEN END CMD CMDS TERMS CALL IBWRT DEV12 CMD CALL IBRD DEV12 INS ENDTEST INSTR IN CHR 13 IF ENDTEST gt 0 THEN INS MIDS INS 1 ENDTEST 1 PRINT RESPONSE INS ELSE PRINT NO RESPONSE END IF GOTO LOOP2 Remote Operation Link to IEEE calls Clear screen Open communication at address 12 Terminators are lt CR gt lt LF gt Clear for return string Get command from keyboard Change input to upper case Get out on Exit Send command to instrument Get data back each time Test
344. y curves appropriate to the sensor type display Press the Save Screen key The default settings are Channel 1 and Enable On Once the channels are setup and enabled use Display Format to actually display the results of the scan channels on the front panel Refer to Paragraph 4 5 5 4 3 Manual Scanning Once the individual input channels have a designated curve the user can manually select the channel to be scanned The Model 340 can set its digital outputs to the corresponding scan channel If the external scanner has digital control inputs the Model 340 can be used to select a channel This is a convenient way to synchronize the scanned readings or automate the scan operation using only the interface of the Model 340 To manually select a scan channel for reading EXTERHAL GC ER SETUP press the Scan Setup key The Mode field will be highlighted Use the A or V key to select MANUAL Press the Enter key The Channel selector will appear Use the A or W key to select the appropriate channel and press the Save Screen key to store the change in the Model 340 The default setting is A1 The digital outputs must be set to scan mode to report the scan channel Refer to Paragraph 7 2 for digital output mode setting When the digital outputs are set to work with the scanner and manual scan mode selected digital output signals D1 to D4 report the active scan channel as shown below Digital output logic levels are described in Paragraph 7
345. y the INPUT SETUP screen Use the A or W key to select inputs A B or C Select C and press Enter to display available settings for the option 10 5 3 2 Displaying Option Readings Readings from option input C display in sensor units nanofarads nF To add an input reading to the display press Display Format 10 5 3 3 Curve Selection The Model 340 with a 3465 option does not support temperature conversion so no temperature response curves can be selected Any feature of the Model 340 that requires temperature to operate is not supported with the 3465 option Selecting temperature units results in a NO CURVE message or display OK 10 5 3 4 Range Selection The Model 3465 option input has two input voltage ranges 15 nF and 150 nF The lower range is specified to 15 nF but can read up to 25 nF and is recommended for CS 401 series sensors The higher range is specified to 150 nF but can read up to 250 nF and is recommended for CS 510 series sensors To select an input range press Input Type 10 5 3 5 Temperature Coefficient Capacitance sensors can have both a positive and negative temperature coefficient slope They have a positive temperature coefficient at very low temperatures and a negative temperature coefficient at warmer temperature Sensor data sheets detail where the coefficient changes There is often a temperature range where the sensor is not usable Temperature control is impossible if the Model 340 does not know which slo
346. y the chips from both ends Once removed install the new memory chips with the same notch orientation Press firmly on the center of the chip for good socket connection Inspect the newly installed chips for bent pins or improper alignment There should be a pin for every socket hole Verify the notch orientation Replace the Option Card if present Replace but do not secure the cover Plug in the power cord and turn ON the instrument If the unit powers up and works normally the update is successful Use the options key to check firmware revision information for both Master and Input processors The REVISION INFORMATION SCREEN shows the current version of the Model 340 If there are any problems unplug the instrument and open the cover Inspect the chip pins and notch orientation Press firmly on the center of the chip to ensure it securely engages the socket Replace cover and retry If unsuccessful contact the Lake Shore Instrumentation Service Department Upon successful update power down the instrument replace the rear plastic bezel and replace and tighten all cover screws 11 12 Service Lake Shore Model 340 Temperature Controller User s Manual 11 11 UPDATING THE MASTER FIRMWARE FROM A DATA CARD This paragraph contains a procedure to update the Master Firmware from a Data Card The update kit to perform this procedure is available from the Lake Shore Instrument Service Department The kit includes PCMCIA Data Card conta
347. y to continue with more settings or press the Save Screen key to store the changes in the Model 340 The default setting is 25 O 6 8 Temperature Control Operation Lake Shore Model 340 Temperature Controller User s Manual The maximum current parameter is included in the Model 340 to make it more compatible with existing cooling systems Even though this instrument is capable of sourcing two amps of heater current there are many control loads that will not tolerate that much current Lower maximum current settings let the instrument source less current without loosing heater ranges or resolution Maximum current choices 2 A 1A 0 5 A 0 25 A and User User setting is only available in main firmware version 01 03 08 and later To select a maximum heater current press the Control Setup key and the CONTROL SETUP screen is displayed Press the More key until the CONTROL LIMITS screen is displayed The control loop indicator is highlighted in the upper left hand corner Use the A or W key to select Loop 1 Press the Enter or Next Setting key The control setup parameters for that loop appear on the screen Press the Next Setting key until the Max Htr I maximum heater current field is highlighted Use the A or V key to select from the list of currents Press the Enter key or next setting key to continue with more settings or press the Save Screen key to store the changes in the Model 340 The default setting is 1 A A new maximum heater curre

Model 340 - Lake Shore Cryotronics, Inc.

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