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User`s Manual - Cryogenic Control Systems, Inc.

1. 56 Model 32 32B User s Manual Specifications Features and Functions Supported Sensor Types A complete list of the sensor types supported by the Model 32 is shown below Sensor Type Max Voltage Bias Excitation Typical Use yp Resistance EE BEE yp Diode f SS ae 5V 10nA f Silicon Diode GaAs Diode Diode bats Dione os oema o a ee C Razma s20 co roma Pross SSCS C Risma i20 co toma Rrodiumion teen mv o 80mv thermocouple wcw sm o 0m hemo C snn oo 0 T Bisabie input chan Table 19 Supported Sensor Configurations Bias types are CI Constant Current sensor excitation CV Constant Voltage sensor excitation Voltages of 10 0mV 3 3mV and 1 0mV RMS may be selected Excitation current autoranges from 1 0mA to 10nA in order to maintain the selected voltage Silicon Diode Sensors Silicon Diode sensors 2 volt diodes are configured with a 10uA current source excitation and a 2 5 Volt unipolar input voltage range Gallium Arsenide Diode Sensors Gallium Arsenide Diodes or 6 Volt Diodes can be used down to a minimum temperature of about 25K This limitation is imposed by the fact that the controller s maximum input voltage is 2 25 Volts Gallium Arsenide sensors do not fit standard calibration curves therefore the user must provide a sensor specific curve before using this type sensor To use diodes Gallium Arsenide select th
2. Cryo con Utility Software Cryo con provides a PC compatible utility software package with all instruments This is available on CD or on the Internet Utility software can be used to control and configure any Cryo con instrument via the RS 232 LAN USB or IEEE 488 interface It runs under all versions of the Windows operating system This software provides several useful functions including 1 Real time strip charts of temperature 2 Data Logging This function allows the user to record data from the instrument at a specified sample rate The resulting file is compatible with most spreadsheet and data analysis software 3 Download or upload sensor calibration curves The software will accept curves in Cryo con CRV Lakeshore 340 or Scientific Instrument s txt format In fact it will read almost any table of temperature vs sensor units 4 Cryo con s CalGen function is implemented This function allows the user to fit an existing sensor calibration curve to one two or three user specified points The result is a high accuracy sensor calibration at low cost 5 Upload and download PID tables to a Cryo con temperature controller These tables can be generated by using a simple text editor and downloaded to the controller Configuration of any of the instrument s remote interfaces Flexible Help interface that documents all instrument remote commands with a cut and paste type interface 8 Interactive
3. Table 1 Model 32 Instrument Accessories Model 32 32B User s Manual Preparing the controller for use Cryogenic Accessories Cryo con fee Part Description 700 700 series Silicon Diode Temperature Sensors Temperature range 1 4 to 495K CP 100 CP 100 series Ceramic Wound RTD 1000 GP 100 GP 100 series Glass Wound RTD 100Q CPX 100 CPX 100 series Thin Film Platinum RTD 100Q CPX 1K CPX 1K series Thin Film Platinum RTD 1 000Q Cartridge Heater Silicon free 25Q 25 Watt 1 4 x 1 1 8 Temperature range to 1 600K 3039 016 Cartridge Heater Silicon free 50Q 50 Watt 1 4 x 1 1 8 Temperature range to 1 600K 4039 011 Pre cut Nichrome wire heater w connectors 25Q 4039 012 Pre cut Nichrome wire heater w connectors 50Q Pre cut Nichrome wire heater w connectors Custom ee Specify length or resistance Bulk Nichrome Heater Wire 32AWG 3039 006 Polyamide insulation 100 Table 2 Cryogenic Accessories Model 32 32B User s Manual Preparing the controller for use Returning Equipment If an instrument must be returned to Cryo con for repair or recalibration a Return Material Authorization RMA number must first be obtained from the factory This may be done by Telephone FAX or e mail When requesting an RMA please provide the following information 1 2 3 4 Instrument model and serial number User contact information Return shipping address If the return is for ser
4. 201 Model 32 32B User s Manual Remote Operation INSTCAL OFFSET Sets or queries offset calibration factor that is applied to the specified input channel OFFSET is an integer that is in ADC counts and may be either positive or negative There is an OFFSET factor for each calibration type within a channel Therefore before the INST OFFSET is used the INST TYPE command should be used to set the calibration type Command Syntax INSTCAL lt chan gt OFFSET lt offset gt Where lt chan gt is the input channel indicator and lt offset gt is the desired offset calibration factor Command Example INST B OFFSET 321 Sets the offset calibration factor for input channel B to 321 Query Syntax INSTCAL lt chan gt OFFSET Where lt chan gt is the input channel indicator Query Response lt offset gt Where lt offset gt is the offset calibration factor Query Example INSTCAL B OFFSET Example Response 23 Indicates that the offset calibration factor for input channel B is 23 Short Form INST lt chan gt OFFS 202 Model 32 32B User s Manual Remote Operation Remote Command Summary IEEE Common Commands ESE The ESE command sets and queries the Standard Event Status ESE Enable ESE Register bits ESR Returns the Standard Event SEV register IDN Returns Instrument Identification String OPC Set the operation complete bit in the Standard Event SEV status register when all pendin
5. 217 Model 32 32B User s Manual Appendix B Troubleshooting Guide Control Loop and Heater Problems TEA Overtemp displayed The control loops were disengaged by detection of an excessive internal temperature Possible causes Shorted heater Check heater resistance Selection of a heater resistance that is much greater than the actual heater resistance Refer to the Control Loop Setup menu section Selection of an AC Power line voltage that is much less than the actual voltage Refer to the Fuse Replacement and Voltage Selection section Check that the instrument s fan is running and that the sides and rear panel allow easy air flow Readback displayed The control loops were disengaged by the heater current read back monitor Most likely cause is an open heater SensorFLT displayed The control loops were disengaged by a sensor fault condition Correct the input sensor fault condition to proceed The control loops will only engage when there is a valid temperature reading on their input The exception is when a loop is assigned a control mode of Off or Manual OTDisconn displayed The control loops were disengaged by the Over Temperature Disconnect monitor This was done to protect user equipment from damage due to overheating To configure the monitor refer to the System Functions Menu section The heater output current This is normal and does not indicate unstable heater power The monitor is jumping up and output current
6. Each entry of a curve contains a sensor reading and the corresponding temperature Sensor readings are in units specified by the units of the curve using the CALDATA UNITS command These units may be OHMS VOLTS or LOGOHM Temperature is always in Kelvin The format of an entry is lt sensor reading gt lt Temperature gt Where lt sensor reading gt is a floating point sensor reading and lt Temperature gt is a floating point temperature in Kelvin Numbers are separated by one or more white spaces NOTE Using the RS 232 interface each line must be terminated by a New Line a Carriage Return a Line Feed or a Null character This character is not used with the GPIB interface since the end of a line is signaled by the interface itself Here lines are transmitted to the controller by using sequential write commands Floating point numbers may be entered with many significant digits They will be converted to 32 bit floating point This supports about six significant digits The last entry of a table is indicated by a semicolon character with no values in the numeric fields NOTE All curves must have a minimum of two entries and a maximum of 200 entries Entries may be sent to the controller in any order The unit will sort the curve in ascending order of sensor reading before it is copied to Flash RAM Entries containing invalid numeric fields will be deleted before they are stored 183 Model 32 32B User s Manual
7. Choices are 0 5 1 0 2 0 4 0 8 0 16 0 32 0 and 64 Seconds The time constant selected is applied to all channels and is used to smooth data in noisy environments The filtering only applies to displayed data it is not used by the control loops 41 Model 32 32B User s Manual Front Panel Menu Operation Display Resolution Enumeration Default 3 The Display Resolution line SYS Display RS is used to set the temperature resolution of the front panel display Settings of 1 2 or 3 will fix the number of digits to the right of the decimal point to the specified value A setting of FULL will left justify the display to show maximum resolution possible Note that the Display Resolution setting only formats the display as a user convenience The internal resolution of the Model 32 is not affected by this setting Display Brightness Enumeration Default 2 The SYS Brightness field is used to control the brightness of the display Selections are 0 1 2 and 3 with O being the brightest This control does not take effect until the next power up Over Temperature Disconnect The Over Temperature Disconnect OTD feature is configured using the OTD lines This feature allows the user to specify an over temperature condition on any of the input channels Whenever an over temperature condition exists on the selected channel the heaters outputs are disconnected and the Loop Status indicator is set to OTDisconn Both loops
8. Note Use of the D gain term can add significant noise In most cryogenic applications it is set to Zero Command Syntax LOOP lt no gt DGAIN lt value gt Where lt no gt is the loop number 1 or 2 and lt value gt is the desired D term for the selected control loop in inverse Seconds Query Syntax LOOP lt no gt DGAIN Query Response lt value gt Command Example LOOP 1 DGAIN 4 3 Sets control loop 1 differentiator feedback term to 4 3 Seconds Query Example LOOP 1 DGAIN Example Response 8 23 Indicates that the D feedback term for loop 1 is 8 23 Seconds Short Form LOOP DGA LOOP OUTPWR Control loop Output Power Queries the output power of the selected control loop This is a numeric field that is a percent of full scale Query Syntax LOOP lt no gt OUTPWR Where lt no gt is the loop number 1 or 2 Query Response lt value gt Where lt value gt is the selected control loop output power setting in percent Query Example LOOP 2 0UTP Example Response 75 000 Indicates that the control loop 2 is attempting to output 75 of full scale power Short Form LOOP OUTP 176 Model 32 32B User s Manual Remote Operation LOOP HTRREAD Heater read back current Queries the actual output power of either control loop The output current of the heaters in the Model 32 is continuously monitored by an independent read back circuit Read back power will be reported as a percent of full scale The a
9. Query Syntax INPUT lt channel gt ALARM LOENA Where lt channel gt is the input channel indicator Query Response lt status gt Where lt status gt is the setting of the low temperature alarm enable for lt channel gt lt status gt will be either YES or NO Command Example INPUT A ALARM LOENA YES Enables the low temperature alarm for input channel A Query Example INP B ALARM LOEN Example Response NO Query Example INP B ALARM HIENA LOENA Example Response YES NO The high temperature alarm enable for input channel B is reported followed by the low temperature alarm enable Short Form INP lt channel gt ALAR LOEN 163 Model 32 32B User s Manual Remote Operation INPUT ALARM FAULT Alarm on Sensor Fault Sets or queries the sensor fault alarm enable for the specified input channel An alarm must be enabled before it can be asserted Command Syntax INPUT lt channel gt ALARM FAULT lt status gt Where lt channel gt is the input channel indicator and lt status gt is the status of the sensor fault alarm enable lt status gt may be either YES or NO Query Syntax INPUT lt channel gt ALARM FAULT Where lt channel gt is the input channel indicator Query Response lt status gt Where lt status gt is the setting of the sensor fault alarm enable for lt channel gt lt status gt will be either YES or NO Command Example INPUT A ALARM FAULT YES Enables the sensor fault alarm for input
10. 1 0 to 10 0mV AC LogOhm Ruthenium Oxide 1 0 to 10 0mV AC LogOhm 1 010 10 0mV AG LogOhm Table 21 NTC Resistor Sensor Configuration 58 Model 32 32B User s Manual Specifications Features and Functions Thermocouple Sensors The Model 32 can be ordered with optional thermocouple support Thermocouple inputs on the Model 32 feature e Universal thermocouple input supports all types including user supplied e High accuracy built in Cold Junction compensation e Open sensor detection For more information on using thermocouples please refer to the sections Thermocouple Sensor Connections and Using Thermocouple Sensors 59 Model 32 32B User s Manual Specifications Features and Functions Sensor Performance Summary Input 16KQ 10nA T x 100Q Platinum 1000Q Platinum 10KQ Platinum oe DIN43760 DIN43760 DIN43760 Configuration 800K 0 36Q K 300K 0 39Q K 77K 0 42Q K 30K 0 19Q K 300K 2 4mV K 77K 1 9mV K 4 2K 30mV K Sensor Sensitivity Measurement Accuracy Temperature Measurement Accuracy Measurement Resolution Temperature Resolution 800K 300K 77K 30K 30K 77K 5 1mK 4 7mK 1 1mK 2 4mK 3 7uW 20uW Control Stability 4 2K 77K 17uW 124W Magneto resistance Power Dissipation 2 5V 10A 625Q 1 0mA 31259 1004A 600K 3 7Q K 300K 3 9Q K 77K 4 2Q K 30K 1 9Q K 300K 77K 30K 39Q K 42Q K 19Q K 300K 77K 30K 4mK 0 5mK 1 0
11. Aborted Autotune was aborted by user intervention such as pressing the Stop key 84 Model 32 32B User s Manual Basic Setup and Operating Procedures Temperature Ramping Operation The Model 32 will perform a temperature ramp function using a specified ramp rate and target setpoint Once placed in a ramping control mode a ramp is initiated by changing the setpoint The unit will then progress to the new setpoint at the selected ramp rate Upon reaching the new setpoint ramp mode will be terminated and standard PID type regulation will be performed Ramping may be independently performed on control loop The procedure for temperature ramping is as follows 1 Set the Ramp Rate in the Heater Configuration Menu This parameter specifies the ramp rate in Units Per Minute where Units are the measurement units of the input channel controlling the heater For example if the input channel units are Kelvin the ramp rate is in K min 2 Select a ramping Control Mode There are two types 1 RampP which will perform a ramp using the current PID parameters and 2 RampT which will ramp using PID parameters derived from a specified PID Table The RampP mode will perform a ramp and then perform temperature regulation using the standard PID mode The RampT function will perform a ramp then perform regulation using the PID Table control mode 3 Press CONTROL Now the controller will begin temperature regulation at the current setp
12. It shows the selected input channel the current temperature in real time and the current units An example is shown here A 77 123 KN To change the sensor units use the right and left arrow keys gt or 4 to scroll through the available options When the desired units are shown press the Enter key to make the selection The display will now show the current temperature with the new units Next go to the sensor selection field by pressing the down arrow key This field is ASen Pt100 385 used to select the actual sensor type In the example shown here the input channel is currently configured for a standard Platinum 100 sensor Use the right and left arrow keys or 4 to scroll through the available options When the desired sensor is shown press the Enter key to make the selection Asummary of sensor selections is shown here 11 Model 32 32B User s Manual A Quick Start Guide Sensor Description O OC None input disabled Cryocon S700 Cryo con S700 series Silicon Diode Range 1 4 to 495K Lakeshore Silicon Diode Curve 11 for DT 670 series diodes Range A 1 4 to 500K LS DT 470 Lakeshore Silicon Diode Curve 10 for DT470 series diodes Range 1 4 to 495K CD 12A Diode Cryo Industries CD 12A Silicon Diode Range 1 4 to 325K SI 410 Diode Scientific Instruments Inc 410 Diode Curve Range 1 5 to 450K Pt100 385 DIN43760 standard 100Q Platinum RTD Range
13. Where lt no gt is the loop number 1 or 2 and lt chan gt is the designator of the controlling input channel Query Syntax LOOP lt no gt SOURCE Query Response lt chan gt Where lt chan gt is the designator of the controlling input channel Command Example LOOP 1 SOUR CHA Sets the control loop feedback loop to be controlled by input channel A Command Example LOOP 1 SOUR CHB SETPT 123 4 PGAIN 120 This command will set control loop 1 s setpoint to 123 4 the proportional gain term to 120 and the control input channel to B Query Example LOOP 2 SOURCE Example Response CHB Which indicates that the control loop 2 is being controlled by input channel B Short Form LOOP SOUR 169 Model 32 32B User s Manual Remote Operation LOOP SETPT Control loop Setpoint Sets and queries the selected control loop s setpoint This is a numeric value that has units determined by the display units of the controlling input channel Allowed values are OK to 1000K Command Syntax LOOP lt no gt SETPT lt temp gt Where lt no gt is the loop number 1 or 2 and lt temp gt is the desired setpoint Query Syntax LOOP 1 SETPT Query Response lt temp gt Where lt temp gt is the setpoint temperature in units of the controlling input channel Command Example LOOP 1 SETPT 100 4 Sets loop 1 s setpoint to 100 4 If the controlling input channel units are Kelvin this command will result in a setpoint of 100
14. characters to simplify programming The truncated form of a keyword is the first four characters of the word except if the last character is a vowel If so the truncated form is the first three characters of the word SCPI Status Registers The Instrument Status Register The Instrument Status Register ISR is queried using the SYSTEM ISR command The ISR is commonly used to generate a service request GPIB when various status conditions occur In this case the ISR is masked with the Instrument Status Enable ISE register The ISR is defined as follows ISR ew ene Jens em B ene emi ew Model 32 32B User s Manual Remote Operation Where Bit7 Alarm Indicates that an alarm condition is asserted Use the ALARM commands to query individual alarms Bit4 Htr Indicates a heater fault condition Use the HEATER commands to query the heater Bit1 to Bit0 SFx Indicates that a sensor fault condition is asserted on an input channel Use the INPUT commands to query the input channels The Instrument Status Enable Register The Instrument Status Enable ISE Register is a mask register It is logically anded with the contents of the ISR in order to set the Instrument Event IE bit in the Status Byte STB register This can cause a service request GPIB to occur Bits in the ISE correspond to the bits in the ISR defined above The Standard Event Register The Standard Event Register ESR is
15. lt channel gt is the input channel indicator Query Response lt temp gt Where lt temp gt is the statistical variance of temperature Query Example INP B VAR Example Response 1 2223 Short Form INP lt channel gt VAR INPUT SLOPE Slope of best fit straight line Queries the input channel statistics SLOPE is the slope of the best fit straight line passing through all temperature samples that have been collected since the STATS RESET command was issued SLOPE is in degrees per Minute Query Syntax INPUT lt channel gt SLOPE Where lt channel gt is the input channel indicator Query Response lt temp gt Where lt temp gt is the temperature slope Query Example INP B SLOPE Example Response 1 2323 Short Form INP lt channel gt SLOP 167 Model 32 32B User s Manual Remote Operation INPUT OFFSET Offset of best fit straight line Queries the input channel statistics OFFSET is the offset of the best fit straight line passing through all temperature samples that have been collected since the STATS RESET command was issued OFFSET is in degrees Query Syntax INPUT lt channel gt OFFSET Where lt channel gt is the input channel indicator Query Response lt temp gt Where lt temp gt is the temperature offset Query Example INP B OFFSET Example Response 124 25 Short Form INP lt channel gt OFFS INPUT TIME Accumulation time Queries the time duration over whic
16. s temperature coefficient A value of 1 selects a Negative Temperature Coefficient sensor while a value of 1 selects a Positive Temperature Coefficient The Unit field selects the units used in the calibration curve Choices are Volts Ohms or LogOhm Checking the Save as crv will save the curve to disk as a Cryo con crv file 107 Model 32 32B User s Manual Cryo con Utility Software The sensor curve may be viewed as a graph by clicking the Display Curve button An example plot is shown here De Sensor Curve b 3 N 3 Output Volts iS 3 amp 3 0 100 200 300 400 500 600 Temperature K After completing any desired changes in the Edit Curve Header dialog box click Accept to proceed Then the curve number dialog box will appear Auser Calibration curve should be entered here x For the Model 32 user 7 curves are 1 through 4 For Please check user manual for the number of user curves for the Model 34 and Model the target model The user curves are after the factory 62 user curves are 1 curves in Sensor Setup through 12 Enter user curve number fi Cancel 108 Model 32 32B User s Manual Cryo con Utility Software When OK is selected the sensor calibration curve will be downloaded to the instrument During the transfer curve data points will be displayed in the window s ma
17. wan Doan Prony ose o o Phony oske osr o C o osk osr oT 5 Wait for the system to stabilize If the resultant heater power output reading is less than 10 of full scale select the next lower heater range setting A range change will not require re tuning t Note In systems where there is high thermal noise including cryocoolers a Dgain value of zero is often used The Dterm is a derivative action which can introduce additional noise into the control process 228 Model 32 32B User s Manual Appendix D Tuning Control Loops Alternate Methods There are various other methods to manually tune PID loops Most are based on graphical techniques and all use a stimulus response technique For further reading Automatic Tuning of PID controllers Instrument Society of America 67 Alexander Dr PO Box 12277 Research Triangle Park NC 27709 229 Model 32 32B User s Manual Appendix E Sensor Calibration Curve Tables Appendix E Sensor Calibration Curve Tables Cryocon 700 Silicon Diode The Cryocon S700 Silicon Diode sensor with a 10uA excitation current Volts Temp K Volts Temp K Volts Temp K 1 0 1633 475 0000 41 0 6393 260 0000 81 1 2510 18 00000 2 0 1733 470 0000 42 0 6586 250 0000 82 1 2720 17 00000 B 0 1834 465 0000 43 0 6807 240 0000 83 1 2950 L6 00000 4 0 1935 460 0000 44 0 7040 230 0000 84 1 3280 15 00000 5 0 2038 455 0000 45 0 7238 220 0000 85 1 3650
18. 23 to 1023K 1mA excitation 1000Q at 0 C Platinum RTD using DIN43760 standard calibration curve Range 23 to 1023K Pt10K 385 10KQ at 0 C Platinum RTD Temperature coefficient 0 00385 Range 23 to 475K RhFe 27 1mA Rhodium lron resistor 27 Ohms at 0 C 1mA DC excitation Scientific Instruments Inc RO 105 Ruthenium Oxide sensor with Kee constant voltage AC excitation Scientific Instruments Inc RO 105 Ruthenium Oxide sensor with Bem ee E 1A constant current 10yuA DC excitation RO 600 AC Scientific Instruments Inc RO 600 Ruthenium Oxide sensor with constant voltage AC excitation User Sensor1 User supplied sensor t User Sensor2 User supplied sensor UserSensor3 User supplied sensors o o Table 3 Input Sensor Selections Before one of the user supplied sensors can be used the sensor s calibration curve and configuration data must be installed This is best done by using Cryo con s utility software This completes the process of configuring an input channel Press the Home key to return to the Home Status display Configuring the Loop 1 Output Before using the Loop 1 main heater control output it is essential that the proper load resistance and output range be selected This is done using the Control Loop Setup menu as follows Q Press the Loop 1 key to go to the Control Loop Setup menu for Loop 1 a Use the up
19. 32 32B User s Manual Cryo con Utility Software Example CalGen Procedure A complete procedure for calibrating a diode sensor at three points is shown here Before the procedure can be started the instrument must be connected and have a valid sensor connected The CalGen procedure will require the user to stabalize the input temperature at three user selected points It will capture data at each of these points and then generate a new curve from that data When a 3 point CalGen is started for a Silicon Diode sensor the reference curve must first be selected This is the curve that will be rotated and shifted to fit the selected points open ll BX Look in E CalCryostat e ee EJ E d1041 crv d1043 crv 067201 crv Files of type Curve Files crv Cancel Wi 115 Model 32 32B User s Manual Cryo con Utility Software When the curve has been selected the following dialog box will appear Enter three reference points x Enter a reference point close to 4 2K Temperature fo Voltage fo Enter a reference point close to 77K Temperature fo Voltage fo Enter a reference point close to 300K Temperature fo Voltage fo Cancel Vapor Pressure The process requires you to completely fill out this dialog box by selecting a temperature and then copying the voltage or resistance reading corresponding to that temperature from the instrument Note that the Vapor P
20. 32 0 5035 320 0000 72 0941 34 00000 112 1 8630 1 75000 33 0 5148 315 0000 73 0974 32 00000 LI 1 8660 1 50000 34 0 5261 310 0000 74 1011 30 00000 25 OU S373 305 0000 75 1054 28 00000 36 0 5485 300 0000 76 1108 26 00000 36 0 5596 295 0000 77 1238 24 00000 38 0 5707 290 0000 78 1650 22 00000 39 0 5900 280 0000 719 2070 20 00000 40 0 6131 270 0000 80 22290 19 00000 700 Silicon Diode Connections The S700BB is a Silicon Diode temperature sensor Connection is made using a color coded four wire 36 AWG cryogenic ribbon cable Wires may be separated by dipping in Isopropyl Alcohol and then wiping clean 231 Model 32 32B User s Manual Appendix E Sensor Calibration Curve Tables Insulation is Formvar and is difficult to strip Techniques include use of a mechanical stripper scrapping with a razor blade and passing the wire quickly over a low flame S Cable Color Codes Table 39 S700 Cable Color Codes 700 Mounting The S700BB bobbin is easily mounted with a 4 40 brass screw A brass screw is recommended because thermal stress will be reduced at cryogenic temperature The mounting surface should be clean A rinse with Isopropyl Alcohol is recommended First apply a small amount of Apiezon N grease to the threads of the screw and on the mounting surface of the sensor package Next place the bobbin on the mounting surface insert screw through bobbin and lightly tighten 232 INDEX AG P
21. 32B User s Manual Remote Operation INPUT ALARM LOWEST Alarm Low Setpoint Sets or queries the temperature setting of the low temperature alarm for the specified input channel When the input channel temperature is below this an enabled low temperature alarm condition will be asserted Temperature is assumed to be in the display units of the selected input channel There is a 0 25K hysteresis in the assertion of a high or low temperature alarm condition Command Syntax INPUT lt channel gt ALARM LOWEST lt temp gt Where lt channel gt is the input channel indicator and lt temp gt is the alarm setpoint temperature Temperature is a floating point string that may be up to 20 characters Query Syntax INPUT lt channel gt ALARM LOWEST Query Response lt temp gt Where lt channel gt is the input channel indicator and lt temp gt is the temperature setting of the low temperature alarm for lt channel gt Temperature is reported to the full precision of 32 bit floating point Command Example INP A ALARM LOW 100 5 Sets the low temperature alarm setpoint for input channel A to 100 5 Query Example INP B ALARM LOW Example Response 25 43210 If the display units setting for input channel B are Celsius this response is also in units of Celsius Short Form INP lt channel gt ALAR LOW 161 Model 32 32B User s Manual Remote Operation INPUT ALARM HIENA Alarm High Enable Sets or queries the high tempe
22. 50 segment bar chart that shows the measured output of a selected loop output The bar is composed of ten blocks with five segments Therefore output current can be read to an accuracy of 2 Note that the bar chart does not have a loop number indicator Some examples are Loop ON zero output Loop OFF Htr Off Loop ON 50 output c Note The Model 32 uses an independent circuit to read current actually flowing through the load The heater bar graph shows this measured current If the unit is controlling temperature but the bar graph indicates zero current flow an error condition exists possibly an open heater 26 Model 32 32B User s Manual Front Panel Menu Operation Front Panel Menu Operation Instrument Setup Menus The various instrument setup menus are accessed by pressing one of the Setup Menu keys The display must be in Home Status in order for these keys to be active The user may exit a Setup Menu and return to the Home Status display at any time by pressing the Home key The first one or more characters on a line identify the specific menu For example the first character of every line in the Loop 1 setup menu is the loop identifier which is a superscripted 1 Menus contain several lines so the display must be scrolled by using the amp and keys The last character of each line in a setup menu is the format indicator The indicator will be blank until the cursor is move
23. A Query Example INP B ALARM AUDIO Example Response NO Short Form INP lt channel gt ALAR AUD Where AUDIO can be truncated to four characters then to three characters because the fourth character is a vowel 165 Model 32 32B User s Manual Remote Operation INPUT MINIMUM Statistical Minimum Queries the minimum temperature that has occurred on an input channel since the STATS RESET command was issued Query Syntax INPUT lt channel gt MINIMUM Where lt channel gt is the input channel indicator Query Response lt temp gt Where lt temp gt is the minimum temperature Query Example INP B MIN Example Response 90 2322 Short Form INP lt channel gt MIN INPUT MAXIMUM MAXIMUM Statistical Maximum Queries the Maximum temperature that has occurred on an input channel since the STATS RESET command was issued Query Syntax INPUT lt channel gt MAXIMUM Where lt channel gt is the input channel indicator Query Response lt temp gt Where lt temp gt is the maximum temperature Query Example INP B MAX Example Response 90 2322 Short Form INP lt channel gt MAX 166 Model 32 32B User s Manual Remote Operation INPUT VARIANCE Statistical Variance Queries the temperature variance that has occurred on an input channel since the STATS RESET command was issued Variance is calculated as the Standard Deviation squared Query Syntax INPUT lt channel gt VARIANCE Where
24. Appendix B Troubleshooting GUNG Gc iecsnceccsdsorinasersdntanasdaonemasdancidanedcnstcnavin 217 Enor DEE iN a es 217 Control Loop and Heater Problems seriiicississirsrnnnisiiiei ense 218 Temperature Measurement Errors cccccccccceeeeeeeeeeeeeeeeeeeeeeeeeeees 220 Remote VO SPIE I S seisis wands chndadtoburse danni bidenindaunneaaeindavandedddonis 221 General OT DIS TIGS snein E E ERA 222 Appendix C Application Note on Signal Dither ccccccseeeeeeeeeeeeeeees 223 Using Dither in Digital Control LOO DS ccctccssssenccsecnnvestcancamvanccenvarsaatcaaaes 223 Appendix D Tuning Control LOOPS soscescussssetccntencsseescsdsatsuvancensnberneneeanaeanns 221 WO e i e a PAEA A E E A ET A TE E N 227 Various methods for obtaining PID coefficients 227 Manual Tuning PTOCGUIES ie aint cidsenncedivenccenne sunisstanaereeeardedeiamninbenetens 228 Appendix E Sensor Calibration Curve Tables c ceeeeeeeeeeeeeeeees 231 Giyocon S7090 Silcon Ne 0265s iaisanaiaeanunlaansentninaaaadenpmecanonnamuaaaaans 231 Model 32 32B User s Manual Index of Tables Table 1 Model 32 Instrument ACCESSOIICS cccccccceeeeeeeeeeeeeeeeeeeeeeeaees 7 Table 2 Cryogenic ACCESSONICS ccceceeceeeceeeeeeneeeeeeseeneeeeeeeenineeeeeeeeeeees 8 Table 3 Input Sensor Selections ccceccecccceceeeeeeeeeeeeeeeseeeeeeeeeeenaas 12 Table 4 Loop 1 Output SUMMAL ccceceeeeeeeeenneeeeeeeen
25. Calibration Type 110UA and V10UA requires voltage references of 0 5 and 1 5 Volts DC and a resistance standard of 100KQ e The Constant Voltage AC resistance ranges Type AC10UA AC100UA and AC10UA require the use of 100KQ 10KQ 1KO 1000 and 100 resistances e The 100Q Platinum range Type R1MA requires a 1000 and a 100 resistor e The 10000 range Type R100UA requires 1K Q and 100 Q resistors e The 10 000Q range Type R10UA requires 10KQ and 1KQ resistors e The 80mV thermocouple optional range requires voltages of 0 075 and 0 075 Volts The test equipment recommended for complete calibration is a Fluke 5700A DMM calibrator The Basic Calibration Sequence You must first connect the Model 32 to a computer via the RS 232 Serial or IEEE 488 GPIB interface and then run the Utility Software provided with the controller The Utility Software must be version 7 4 2 or higher From the start up menu of the Utility Software click the Connect button in the bottom of the Short Cuts toolbar The software will connect to the instrument and display the connection status below the button In case of an error please correct the port connection settings and try again From the main menu select Operations gt Unit Cal The program will read the current calibration values from the instrument and display a calibration screen as shown below All calibration operations can be performed by using this screen 124 Model 32 32B
26. DC 0 2 5VDC 100uA Platinum RTDs DC measurement of 10K Ohm Platinum RTDs or other resistor WEEE eevee 10pA sensors that use DC current excitation 80mV to Thermocouple measurements Valid VTC80 N A only when optional thermocouple 80mV f ae input is installed 128 Model 32 32B User s Manual Instrument Calibration Calibration of Silicon Diodes Silicon Diode sensors require the application of a precision 10pA current followed by reading the voltage drop across the device Therefore calibration of a diode requires two steps 1 Calibration of the input voltage reading and 2 Calibration of the 10uA current source Note that the voltage calibration must always be done first since the current source calibration requires a precision voltage reading Diode Voltage Calibration To calibrate the diode voltage range click on the SI Diode V tab and follow the sequence described above to send Gain and Offset values to the instrument The upper target requires connection of a 1 9 Volt source The actual value is between 1 0 Volts and 2 4 Volts If you do not have a precision voltage source you can use a 1 5 Volt battery by using a high precision volt meter to measure it s actual voltage The lower target requires connection of a 0 5 Volt source The actual value is between zero Volts and 0 6 Volts If you do not have a precision voltage source you can short the input channel for zero volts Constant current Source Calibratio
27. EEA A E 39 ErrorS r aa ei ae AE Eai aaie 92 selectiiraiiann oaa edda RT 39 Grounded ccccceeeeeeeeeeeeeeeeeeteeeeeeeeeeeeneees 94 Utility Software wild Offset Calibration 93 VIED GIS Play eenaa aE A peice oferta aa 17 OPONSE Ae 6 ZONE tablero ee oat aie aa ere ak 44 TYPOS lib css beara ae rald Nat 73 IDNZ aaneen nania ae N it 138 203 Unit Names Tosse a a a 147 TORG 2 ie Sheesh a a i 138 203
28. Issues section Use AC bias if necessary to cancel the offset error A four wire measurement is not being used Some cryostats use a to a two wire measurement internally This can cause offset errors due to lead resistance Thermocouples These sensors will often have DC offset errors Use the CalGen feature to generate a new sensor calibration curve that corrects for these errors No temperature reading Review the Error Displays section above 220 Model 32 32B User s Manual Appendix B Troubleshooting Guide Remote I O problems Can t talk to RS 232 Possible causes interface Ensure that the RS 232 port is selected Press the Sys key and scroll down to the RIO Port field Ensure that the baud rate of the controller matches that of the host computer To check the controller s baud rate press the Sys key and scroll down to the RIO RS232 field Ensure that the host computer settings are 8 bits No parity one stop bit The RS 232 port does not have an effective hardware handshake method Therefore terminator characters must be used on all strings sent to the controller Review the RS 232 Configuration section Ensure that you are using a Null Modem type cable There are many variations of RS 232 cables and only the Null Modem cable will work with Cryo con controllers This cable is detailed in the RS 232 Connections section Debugging tip Cryo con utility software can be used to talk to the controller over
29. LED status indicator on the Model 32 front panel The default condition for this indicator is OFF Note that the Remote LED is automatically handled by the GPIB interface but must be turned on and off when using the RS 232 interface Command Syntax SYSTEM REMLED lt status gt Where lt status gt is either ON or OFF A lt status gt of ON will illuminate the front panel Remote LED Query Syntax SYSTEM REMLED Query Response lt status gt Query Example SYSTEM REMLED Example Response OFF Indicating that the Remote LED is OFF Short Form SYST REML SYSTEM LOOP Control Loop On Off Reports the status of the two temperature control loops A status of OFF indicates that both loops are disabled and the output power levels are zero A status of ON indicates that the loops are engaged and actively controlling temperature Command Syntax N A The CONTROL command is used to engage the control loops and the STOP command is used to disengage them Query Syntax SYSTEM LOOP Query Response lt status gt Query Example SYSTEM LOOP Example Response OFF Indicating that both control loops are disengaged Short Form SYST LOOP 141 Model 32 32B User s Manual Remote Operation SYSTEM BEEP Sound the audible alarm Asserts the audible alarm for a specified number of seconds Command Syntax SYSTEM BEEP lt Sec gt Where lt Sec gt is the number of seconds to beep the audible alarm Command Example SY
30. LOWEST setpoint for a specified relay RELAYS HIENA Sets or queries the high temperature enable for the specified relay RELAYS HIENA RELAYS LOENA Sets or queries the low temperature enable for the specified relay RELAYS LOENA RELAYS FAULT Sets or queries the sensor fault enable for the specified relay RELAYS FAULT Sensor Setup Commands CALDATA Sets or queries the name string for a user installed sensor CALDATA NAME CALDATA NAME CALDATA TYPE Sets or queries the sensor type for a user installed sensor CALDATA TYPE CALDATA MULTIPLY Sets or queries the Multiplier for a user installed sensor CALDATA MULTIPLY SENTYPE Queries the name string for a factory installed sensor Please refer SENTYPE NAME to Appendix A SENTYPE NAME 208 Model 32 32B User s Manual Remote Operation Autotune Commands AUTOTUNE DELTAP Sets and queries the maximum allowed change in heater output AUTOTUNE DELTAP power that is allowed during the process modeling phase of the autotuning process AUTOTUNE TIMEOUT Sets and queries the timeout value of the autotune process AUTOTUNE TIMEOUT AUTOTUNE START Initiates the autotune sequence AUTOTUNE EXIT Aborts and exits the autotune process When an autotune sequence has successfully completed this AUTOTUNE SAVE command will save the generated PID values to the control loop PID values and change the autotune state from complete to idle RUTOTUNE PGAIN AUTOTUNE IGAIN AUTO
31. Mode provides interactive communication with the instrument over any of the remote interfaces 9 Instrument calibration using a simple step by step menu driven process 10 Uploading and downloading instrument firmware Updates may be obtained on CD or on the Internet Installing the Utility Software From a CD the utility software package does not require installation It can be executed from the CD directly by running the UTILITY EXE program When the software is downloaded off of the Internet it is in a self extracting ZIP format and must first be un zipped onto hard disk 103 Model 32 32B User s Manual Cryo con Utility Software Connecting to an Instrument The desired remote interface connection may be selected by clicking Comm gt Port Select from the main menu Sensor Lurve Download FID Table Downoad Port Select Dialog i Trterect nteract Data Logging Upload Date Log Select the desired communications port and then click OK Click on the Connect button of the shortcut menu bar or on Comm gt Connect from the main menu to connect to the instrument 104 Model 32 32B User s Manual Cryo con Utility Software After a short delay the connect LED should light and the instrument type will be displayed Also most of the grayed out fields on the menu bars should activate Using the Interactive Terminal The Utility Software s Interactive Terminal mode allows the
32. Model 32 will mate with either DIN 5 or DIN 6 plugs Wiring is identical If a DIN 6 plug is used Pin 6 is not connected Do not connect to pin 3 of either connector 70 Model 32 32B User s Manual Specifications Features and Functions Recommended color codes for a sensor cable are as follows Color Code Signal Pin White _ Excitation C Green Excitation Red sems 4 Black Sense 2 Table 28 Dual Sensor Cable Color Codes The cable used is Belden 8723 This is a dual twisted pair cable with individual shields and a drain wire The shields and drain wire are connected to the DIN 5 s connector s metal backshell in order to complete the shielding connection A four wire connection is recommended in order to eliminate errors due to lead resistance Cryogenic applications often use fine wires made from specialty metals that have low heat conduction This results in high electrical resistance and therefore large measurement errors if the four wire scheme is not used Four wire connection to Diode and Resistive type sensors is diagrammed below F V V Four Wire Four Wire Diode Sensor Resistor HE Sensor y Figure 5 Diode and Resistor Sensor Connections 71 Model 32 32B User s Manual Specifications Features and Functions Cryo con 700 Silicon Diode Connections The S700BB is a Silicon Diode temperature sensor Connection is made using a colo
33. Setup Menu The first line of this menu includes the Sensor Index 18 and the name User Sensor 3 This line may be scrolled through all of the available sensor types including factory installed sensors Press Enter to select the displayed sensor In order to install a new sensor one of the four user sensors should be selected Next the Type of sensor must be defined Choices include Silicon Diodes various resistors and thermocouples This selection will identify the excitation current and voltage input range that the controller must use to interface with the sensor Selections are given in Table 2 above The Multiplier field specifies a multiplier that is applied to the sensors calibration curve The sign of this field indicates the temperature coefficient This coefficient is only used when the user is attempting to control on sensor units such as Ohms or Volts Most commonly the multiplier field contains a value of plus or minus 1 0 This causes the controller to apply the sensor calibration curve directly without first scaling it Further a negative value will indicate that the sensor has a negative temperature coefficient and a positive value will indicate a positive coefficient Diode sensors will generally have a Multiplier of 1 0 since their temperature coefficient is negative and no scale is applied to the calibration curve 78 Model 32 32B User s Manual Basic Setup and Operating Procedures 100 Platinum sens
34. Setup and Execution The Autotune menu for either control loop is accessed by pressing the Auto Tune key from the Home Operate Screen Upon entry the autotune state variable will be set to Idle and the P and D fields on the bottom of the display will be blank As described above various setup conditions must be met before autotune can be performed 1 The Model 32 must be in Control mode 2 Both the output power and the process temperature must be stable The user must stabilize the process before the autotune function can accurately model it If the process is not stable erroneous values of P and D will be generated 3 The input control channel units must be in temperature not sensor units of Volts or Ohms This is because PID control is a linear process and sensor output is generally non linear Note that the Model 32 can be manually tuned using sensor units but autotuning cannot be performed 82 Model 32 32B User s Manual Basic Setup and Operating Procedures Autotune Menu Sets the loop number for autotuning Each control loop must be tuned Autotune Loop 2 P4 separately Choices are Loop 1 and Loop 2 The selected loop is displayed in all following lines of this menu Sets the maximum power delta allowed 2 ZAT DeltaP 20 during the tuning process Value is a percent of full scale output power for the selected loop Sets autotuning mode Choices are P 3 ZAT Mode PI PI or PID PI is recommend
35. Table 20 PTC Resistor Sensor Configuration c csceeceeeeeeeeeeeeeeeee 58 Table 21 NTC Resistor Sensor Configuration ccecceeeseeeeeeeeeeeeeeee 58 Table 22 Sensor Performance for Diodes and Pt Sensots 08 60 Table 23 Sensor Performance for NTC SeNnsSOIS cceeeeeeeeeeeeeeeeeeeees 61 Table 24 Sensor Performance for Thermocouple Sensors 008 62 Table 25 Loop 1 Heater output ranges cceceeeeeeeseeeeeeeeeesetteeeeeeeeeaees 64 Table 26 AC Power Line FUSES ccccccceceeeeeeeeeeeteseeeeceneeeeeeeeeeeeeeeees 69 Table 27 Input Connector Pin OUt cccccceceeeeeeeeeeeeeeeeeeeeaeneeeeeeeeees 70 Table 28 Dual Sensor Cable Color Codes ccccccceecceeeeeeeeeeeeeeeeees 71 Table 29 Thermocouple Types 2 e ecececceeeeeeeeeeeeeseeeeeeeenentnneeeeeeees 73 Table 30 RS 232 DB 9 Connector PinOUt ccccceceeeeeeeeeeeeeeeeeeeeeeeeee 73 Table 31 Sensor Setup MeNnu ccccccccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeaaeeeeeeeeeeeea 78 Table 32 Autotune Menu 2 eeeececceeeeeeeeeeeeeeeteceeeeeeneaeaeeeeeaaneeteeees 83 Table 33 First CalGen Menu Diode Senso 000eeeeeeeeeeeeeees 97 Table 34 CalGen Menu 2 point Diode Sensot cccccceeeeeeeeeeeees 98 Table 35 CalGen New Curve Menu cccccccceeeeeeeeeeeeeeeeeeettnneeeeeaes 99 Table 36 R
36. The Model 32 allows for the entry of four independent PID Tables Each table may contain up to 16 temperature zones In the Ramp control mode the controller will approach a new setpoint at a user specified rate When this setpoint is reached the controller will revert to PID control 66 Model 32 32B User s Manual Specifications Features and Functions Alarm Outputs Alarm outputs include a LED indicator an audible alarm on screen display and remote reporting Alarms may be asserted based on high temperature low temperature input sensor fault or heater fault conditions There is a 0 25K hysteresis built into the high and low temperature alarms Remote Interfaces IEEE 488 2 and RS 232 interfaces are standard All functions and read outs available from the instrument may be completely controlled by any of these interfaces The Serial port is an RS 232 standard null modem with male DB9 connector Rates are 300 1200 4800 9600 19 200 and 38 400 Baud The GPIB is fully IEEE 488 2 compliant Connection is made at the rear panel using the IEEE 488 standard connector The programming language used by the Model 32 is identical for all interfaces and is SCPI language compliant The Standard Command Protocol for programmable Instruments SCPI is a sub section of the IEEE 488 2 standard and is a tree structured ASCII command language that is commonly used to program laboratory instruments 67 Model 32 32B User s Man
37. The final and most laborious method of tuning a control loop is manual tuning This involves generating values for P and D by observing the system s response to the stimulus of the heater output Various methods of manually tuning the controller are described below Manual Tuning Procedures Manually tuning a PID control loop is relatively simple It is greatly assisted by use of a data logging program such as the Cryo con utility software package described in the Cryo con Utility Software section Ziegler Nichols Frequency Response Method This method is based on the assumption that a critically damped system is optimal and the fact that stability and noise must be traded for response time It requires driving your system into temperature oscillation Care should be taken so that this oscillation does not cause damage Enable the Over Temperature Disconnect feature of the controller if you are concerned about possible damage from overheating 1 Enter a setpoint value that is a typical for the envisaged use of the system Select a heater range that is safe for your equipment Set initial PID values of Pgain 0 1 Igain 0 and Dgain 0 Engage the control loops by pressing the Control key Increase the Pgain term until the system is just oscillating Note the Pgain setting as the Ultimate Gain Kc and the period of oscillation as the Ultimate Period Tc 4 Set the PID values according to the following table control Type Poan
38. To set this parameter press the Loop 1 key and refer to the Control Loop Setup menu section The controller has an over temperature disconnect feature that monitors a selected input and will disconnect both control loops if the specified temperature is exceeded This feature should be enabled in order to protect your equipment from being over heated To enable press the Sys key and refer to the System Functions Menu section Model 32 32B User s Manual Preparing the controller for use Factory Default Setup A controller with factory default settings will have an operational display like the one shown here The dash or dot characters indicate that there is no sensor connected 1 Off Hi Off 10W Note that in some cases there will be an erratic temperature display when no sensor is connected This is not an error condition The high input impedance of the controller s input preamplifier causes erratic voltage values when unconnected Input Channel factory defaults are Sensor Units Kelvin Sensor Type LS DT 670 Lakeshore DT 670 Curve 11 Silicon Diode Bias Type DC Alarm Enables Off To change these press the ChA or ChB key and refer to the Input Channel Setup Menu section Control Loop factory defaults are Setpoint 100K P gain 5 0 gain 28 0 Seconds D gain 8 0 Manual output power Pman 5 Control input channel A for Loop 1 B for Loop 2 Loop 1 Range Low Control Type Manual Heater Resistan
39. Where lt channel gt is the input channel parameter and lt ix gt is the desired sensor index Query Syntax INPUT lt channel gt SENIX Where lt channel gt is the input channel indicator Query Response lt ix gt Where lt ix gt is the sensor index for the selected input channel Command Example INPUT B SENIX 0 This command sets the sensor index for input channel B to zero disabled Query Example INP A SENIX Example Response 02 This indicates that sensor 02 is assigned to input channel A The name and configuration of sensor 02 may be accessed using the SENTYPE commands Short Form INP SEN 158 Model 32 32B User s Manual Remote Operation INPUT ALARM Input Channel Alarm Status Queries the alarm status of the specified input channel Status is a two character string where indicates that no alarms are asserted SF indicates a Sensor Fault condition HI indicates a high temperature alarm LO indicates a low temperature alarm There is a 0 25K hysteresis in the assertion of a high or low temperature alarm condition The user selectable display time constant filter is applied to input channel temperature data before alarm conditions are tested Query Syntax INPUT lt channel gt ALARM Query Response lt alarm gt Where lt channel gt is the input channel indicator and lt alarm gt is the alarm status indicators for that channel Query Example INP A ALARM Example Response Which indi
40. adrs gt Command Example SYSTEM ADRS 14 Sets the Model 32 IEEE 488 2 address to 14 Query Example SYSTEM ADRS Example Response 12 Indicates that the current GPIB address is 12 Short Form SYST ADRS 143 Model 32 32B User s Manual Remote Operation SYSTEM REMOTE Select Remote Interface Queries or selects the port that the Model 32 will use for all remote communication Available ports are GPIB for the IEEE 488 2 port RS232 for the RS 232 port Command Syntax SYSTEM REMOTE lt port gt Where lt port gt is the remote port selection The Model 32 will first disable all remote ports then initialize and re enable the selected port This command can be used as a port reset Query Syntax SYSTEM REMOTE Query Response lt port gt Command Example SYSTEM REMOTE GPIB Selects the GPIB remote port If the GPIB is already selected it is re initialized and enabled Query Example SYSTEM REMOTE Example Response RS232 Indicates that the current remote port is RS 232 Short Form SYST REMO SYSTEM RESEED Re seed the display filters Re seeds the input channel s averaging filter allowing the reading to settle significantly faster The display filter may have filter time constants that are very long The RESEED command inserts the current instantaneous temperature value into the filter history thereby allowing it to settle rapidly Command Syntax SYSTEM RESEED Command Example SYSTEM RESEED S
41. aie aen eaae EE ALLE 64 Remolie MGS AG Sniekie nenea ESEE 67 Rear Panel CONMSCWONS pecsiisrancvrecndntacammannessadcdennheasavidiviiaacsdarvwediounenses 68 Mechanical Form Factors and Environmental c ccecccseeeeeeees 74 Basic Setup and Operating Procedures ccccceceeeeeeeeeeeteeeseeees TT COMIGUENIE a SEIS ON osica 77 Adding a New Sensor Typeset 77 PUTT NI ea aes etn E eS 80 Temperature Ramping aecenas ere ene 85 Cryocooler Signature Subtraction c ccccccccceeessescceeseeeenccernenseneceees 87 Using an external power DOOSICT ii scscetceresseceteciaassousnetvenstennteeees 90 Using Thermocouple SSNS0lS cd cusiccnmmnnvmaiewimncienisneaa 92 CalGen Calibration Curve Generation cccsccsccccasscsearcaiisesssanearsceernnaeee 96 system Shielding and Grounding ISSUGS ii ccccsseencecssss ences snseesereeeeeeenesss 101 Grounding SETI IG ewe arta ee ena aan 101 Model 32 32B User s Manual RRO Cry UNY OTT A sit sa sitcscd oandihoagindee e a aa ai 103 Installing the Utility Software ss s nnsssenresesrrrreserrunnnnnnnnnnnnnnnnnnnnnnnnna 103 Gonnecting to an nstumeNb sssnisursnenann naa 104 Using the Interactive Terminal irerissrraniiai 105 Downloading or Uploading a Sensor Calibration Curve 106 Using the Real Time Strip ChartS ceisisiirrisisidnnriinririinarenaini 110 Paa LOOO eia 111 Remote VO command HELP a sscssccconsicdvgsyendiepa tease wemadnnrvemedien 113 CalGen Cal
42. and is useful with sensors whose resistance vs temperature curve is logarithmic Selecting the EDIT CAL CURVE field will cause the screen to go to the Calibration Curve menu for the selected sensor Here the calibration curve may be viewed or edited The Calibration Curve menu The Calibration Curve menu is the first screen used in the process of building a sensor calibration curve Note that these curves can have up to 200 points requiring the entry of 400 floating point numeric values For lengthy curves you may want to consider using one of the remote interfaces Cryocon provides a free PC utility that will upload or download curves that can be created by a text editor The entry of a sensor calibration curve is essentially identical to the process used to enter PID Tables The procedure for entering or editing a calibration curve is summarized as follows 1 The sensor s calibration curve is accessed from the Sensor Setup menu detailed above 2 Data points in the selected curve are entered by first entering the entry index then values for sensor readings vs corresponding Temperature 3 When all data points have been entered the SaveCurve amp Exit field is selected to save the curve Once complete the controller will condition the curve by rejecting invalid entries then sorting the curve in order of ascending sensor unit values Therefore an entry may be deleted by placing a zero or negative number in either the t
43. are disconnected when an over temperature condition exists A mechanical relay is used so that the load is protected even if the condition was caused by a fault in the controller s output circuitry The OTD must first be configured to monitor one of the input channels Note that the OTD feature is completely independent of control loop function and may monitor any input Next an OTD Setpoint must be specified This is the temperature at which an over temperature shut down will be asserted Temperature units are taken from the source input channel Finally the OTD function must be enabled Important The Over Temperature Disconnect is an important cryostat protection feature The user is encouraged to apply it 42 Model 32 32B User s Manual Front Panel Menu Operation Remote I O Port Configuration The RIO lines are used to configure the Remote I O interfaces including the GPIB and RS 232 Note that GPIB is used to indicate the controller s IEEE 488 2 interface Port Select RIO Port is an enumeration field that sets the active remote port The controller can only have one active port at a given time Inactive ports are disabled Choices are RS 232 and GPIB The factory default is RS 232 The address line RIO Address is a numeric field that may have a value between 1 and 31 The factory default is address 12 This field is used by the GPIB interface to select individual instruments It is the user s re
44. arrow and down arrow keys amp and to scroll to the Htr Resistance field An example is shown here iHtr Resistance 50Q 12 Model 32 32B User s Manual A Quick Start Guide a 25 Ohm heater and then press the Enter key Q Use the up arrow and down Q Use the left and right arrow keys or 4 to select between a 50 Ohm and arrow keys amp and to scroll to the Range field and then 1Range HI select Hi Mid or Low Be sure to select a range that does not exceed the ratings of your cryostat A summary of full scale output power for the various ranges is given here Max Output Power 25 Watts 50 Watts 2 5 Watts 5 0 Watts Low 0 25 Watts 0 50 Watts Table 4 Loop 1 Output Summary Next the control type should be set by scrolling to the Type field and i Type PID M selecting the desired loop operating mode 13 Model 32 32B User s Manual A Quick Start Guide Asummary of control types is given here Control loop is disabled Manual control mode Here a constant heater output power is applied The Pman field selects the output power as a percentage of full scale Table PID control mode where the PID coefficients are generated from a stored user supplied PID table PID Standard PID control Temperature ramp control Uses PID control to perform a temperature ramp RampP Table 5 Control Type Summary Caution The Mode
45. at room temperature then a second reading with the sensor in Liquid Nitrogen Since a thermocouple s sensitivity is relatively constant above room temperature this procedure will give good accuracy over a wide range of temperature AC Power Line Noise Pickup AC power noise pickup is indicated by temperature measurements that are significantly in error In extreme cases there may be no valid measurements at all 93 Model 32 32B User s Manual Basic Setup and Operating Procedures Thermocouples have relatively high resistance leads and each lead is made from a different material Therefore they are much more sensitive to AC pickup than sensors using copper wires Aground loop will cause significant AC coupling into the sensor However if the connection procedures described above are carefully followed ground loops through the sensor leads will be avoided When a grounded sensor is used a poor quality ground may have sufficient AC voltage to exceed the input range of the controller This can often be corrected by running a copper connection from a point near the sensor ground and the chassis ground of the controller Defective building wiring or insufficient grounding is usually the root cause of this type problem Most common AC noise pickup problems are caused by capacitive or magnetic coupling into the sensor wires Again the thermocouple s high resistance leads make this type coupling very efficient General recommenda
46. channel A Query Example INP B ALARM FAULT Example Response NO Indicating that the sensor fault alarm enable for channel B is disabled Query Example INP B ALARM HIENA LOENA FAULT Example Response YES NO NO Indicates that channel B high temperature alarm is enabled low temperature alarm is disabled and sensor fault alarm is disabled Short Form INP lt channel gt ALAR FAUL 164 Model 32 32B User s Manual Remote Operation INPUT ALARM AUDIO Audible Alarm Enable The Model 32 contains an audible alarm This alarm may be optionally sounded when any alarm condition is asserted The INPUT ALARM AUDIO command is used to set or query the audible alarm enable for the selected input channel Command Syntax INPUT lt channel gt ALARM AUDIO lt status gt Where lt channel gt is the input channel indicator and lt status gt is the status of the audible alarm enable lt status gt may be either YES or NO Query Syntax INPUT lt channel gt ALARM AUDIO Where lt channel gt is the input channel indicator Query Response lt status gt Where lt status gt is the setting of the audible alarm enable for lt channel gt lt status gt will be either YES or NO Command Example INPUT A ALARM AUDIO YES Enables the audible alarm for input channel A alarm conditions Command Example INPUT A ALARM HIEN OFF AUDIO OFF This command will disable the high temperature alarm and disable the audio alarm for input channel
47. effectively cancelled CalGen Initial Setup To start the CalGen process either select CalGen from the shortcut bar or select Operations gt CalGen from the main menu This will initiate the process of generating a new sensor curve Using CalGen With Diode Sensors Options for generating Diode calibration curves are 5 One point near 300K The portion of a Diode Sensor curve above 30K will be fit to a user specified point near 300K This is a two point fit where the 30K point is taken from the existing calibration curve The portion of the curve below 30K is unaffected 6 Two points 300K and 77K Here two user specified points are taken to fit the diode curve region above 30K The entire curve is offset to match the 77K point then the gt 30K region is fit to the two points 7 Three points 300K 77K and 4 2K Two points above 30K are fit as in the selection above Then a third point is used to fit a single point in the high sensitivity region below 20K 8 One point near 4 2K This is a two point fit where the 20K point is taken from the existing calibration curve The portion of the curve above 20K is unaffected Using CalGen With Resistor Sensors The calibration curve generation procedure for Platinum or other resistor sensors is the same as for the diode However these sensor curves are generated using two user specified points Therefore the selection of the number of points is not required 114 Model
48. engage the control loops Remote I O transactions The last two lines of the SYS menu are the Remote I O input and output lines These are used to assist in debugging programs that use the controller over one of its remote interfaces The remote input line gt shows the last complete command received and parsed by the controller The remote output line lt shows the response that the command generated 43 Model 32 32B User s Manual Front Panel Menu Operation PID Tables Menu The Model 32 can store four user generated PID tables Each table may have up to sixteen setpoint zones Each setpoint zone in a table requires the entry of a setpoint along with corresponding values for P I D and full scale heater range When controlling in the Table mode the Model 32 will derive control loop PID coefficients and heater range by interpolation of the PID Table zones based on that zone s setpoint PID Tables can be used with both control loops Building a table from the front panel requires the entry of several numeric values For this reason the user may want to consider using one of the remote interfaces The start and top level of this process is the PID Tables menu Two menu screens below this are used to enter numeric data Here is an overview of the process 1 The PID Tables menu is used to select the PID Table number zero through three 2 Once the table is identified selecting the EDIT PID TABLE line will t
49. existing unit reading and associate it with the 300K point The value will be displayed on line 1 above The exact temperature at a point near E 77 000 Capture 77K is entered here Pressing the Enter key will capture the existing unit reading and associate it E Unit 1 28257V with the 77K point The value will be displayed on line 3 above Pressing the Enter key will initiate the Table 34 CalGen Menu 2 point Diode Sensor The two temperature points one near 300K and the other near 77K may be entered in any order To enter the 300K point change the field 300 000 to the exact required temperature Then allow the temperature measurement to stabilize When the measurement is stable select the Capture field next to the temperature field This will cause the Model 32 to capture the sensor reading and associate it with the specified temperature When a sensor reading has been captured the actual reading will be displayed in place of the word Capture Note that the user may capture a new reading by selecting this field again even if it already contains a reading The Unit field of this screen will display the actual sensor reading in real time This will allow the user to determine when the unit is stable at the required temperature Next the second temperature must be entered in the same way as before 98 Model 32 32B User s Manual Basic Setup and Operating Procedures When both temperature points ha
50. grounding issues can be found below in the Using Thermocouple Sensors section below i e Succ Lee Fe Pupe Chome _Constantan_ K Yelow Chrome Aluminum U White Copper Copper Table 29 Thermocouple Types Loop 1 Heater Connections Rear panel Primary Heater Output Loop 1 connections are made using the two pin banana plug shown here Pin One of this block HI _ is the positive output and Pin Two Lo is the uN ee ground return The shield of the output cable bons Loop 1 u should be connected to the third uninsulated J O O o i banana plug Fe Hi Lo Loop 2 Output Connections Rear panel connections to the Loop 2 output are made using the two pin pluggable 0 200 terminal block shown above Pin One of this block left hand pin is the positive output and Pin Two is the return The shield of the output cable may be connected to Pin Two The two pin heater terminal block plug is an Augat part number 2ESDV 02 It is available from Cryo con as part number 04 0301 IEEE 488 2 Connections Rear panel connection to the IEEE 488 2 is performed using the GPIB connector GPIB cables are available in various lengths However only shielded type assemblies should be used Many of the molded GPIB cables are actually unshielded and can introduce excessive noise into your instrumentation environment RS 232 Connections The Model 32 uses a Female DB 9 connector for RS 232 serial communications
51. is usually a 16 or 18 bit Digital to Analog converter Since this DAC has much less resolution than the earlier stages it generally establishes the accuracy of the accuracy of the entire loop A loop output value has been generated to a very high precision but the DAC throws away most of this precision to fit its available output levels Like the color synthesis example above signal dithering can be applied to the digital control loop so that the average output value converges to the high precision value computed before output quantization The result is much greater control accuracy Conventional Control Loop Output The diagram to the right shows the conventional method of generating an analog output from a digital control loop Here a high precision loop output value is computed then the value is truncated or rounded to fit the precision of the output DAC Precision above the resolution of the DAC is lost 223 Model 32 32B User s Manual Appendix C Application Note on Signal Dither In this example the output DAC has four ye se reseeseeeeeeeeeeeeecteetetteeten tense nse tententettenennenscnsey i quantization levels labeled Q1 through Q4 i Q4 Dashed lines show the mid points between adjacent levels Bee ee See et Here the desired high precision control Q3 x xxx x XX loop output o is between levels Q2 ibaa ono Seron and Q3 For simplicity ten output Co EAren ee ee intervals of a DC level are shown Q2 Using an
52. kal 136 137 203 ESR enrian 135 136 138 203 Factory Defaults ccecceceseeeseneeeeeeeeeeeeeeeees 5 FOSIONING ien a aici nein etnies 15 FIPTMWAPE Looe eee cece ccceestecceeesseeeeeesstseeasaeaaeseeeeeeeees forcing COWNIOAd ccccceeeeeeeteeeeteeteneeeeee 16 revision level 0ceee 1 6 138 148 204 Updater ima necdyainle en Maelo 103 118 fuse replacement cccceeseeeeesteeeeeeeeees 69 TUSOS h e ween teva e a e da r TR dacs 69 75 GPIB 43 67 134 135 136 137 143 144 Hardware Revision Level 000cee 6 147 HI Ate lise ve ctscene van dos tusavtsaritevssuh ae cdeveesntavevandeaed cacles control mMod ss wv acsnnacniieeea Ales 36 Dalla naninira 34 35 fathia aad eaa 65 67 146 lga eaaet T aa R ake 34 35 lO d irna ean RE aiik 38 load reSistaNnCe ccceceeeeeseeeeeeeeeeeees 34 64 maximum output 4 37 173 177 178 179 maximum setpoint 0cee 35 37 179 QUID Ute moeien aeara i an 64 65 Pg iNssiesane ered cere eee 34 35 Pmam erena eins a a N 34 35 reale s EE E 36 44 46 64 66 173 PEAM DACK cc ecccccccecceseesesesssseteeeeeeaees 65 177 resistance Selection ccccccceeeesseeeeeeeee 38 Safe Operating Area 64 setpoint 11 21 34 46 169 170 207 228 SEPON Sass dan ll eden tae er aaa 35 setpoint Ontry ccccceeeeeeeteeeeesteeeeeeeeeeees 27 Shut JOWN asd ivwes isc a aaa 64 source SEIECH
53. loss of signal energy 55 Model 32 32B User s Manual Specifications Features and Functions Available voltage selections are 10 0mV 3 33mV and 1 0mV RMS The maximum and minimum sensor resistance that can be read is a function of the selected voltage bias Resistance Range Table Voltage Min Bias Resistance i P bias Table 17 Voltage Bias Selections Max Resistance Power dissipation in the sensor is computed by Sensor Excitation current sources used with constant voltage bias are calibrated from 1 0mA to 0 1uA so that the accuracy of resistance measurement will be 0 1 Accuracy will steadily degrade at lower excitation currents down to the minimum available output current of 10nA where the accuracy of resistance measurement is about 0 7 The tradeoff in measurement accuracy vs minimum sensor excitation current is taken for two reasons 1 The sensitivity of NTC resistor sensors is extremely high in the low temperature end of their range Therefore the reduced measurement accuracy does not degrade temperature measurement accuracy 2 The low current settings are required since sensor self heating at low temperature is a very significant source of errors In order to minimize large jumps in self heating the Model 32 uses current sources to cover the 1 0mA to 10nA in steps of 5 power Resistance Measurement Accuracy Table 18 NTC Resistor Measurement Accuracy
54. lt freq gt Where lt freq gt is the AC Power Line Frequency and may be either 50 or 60 for 50Hz or 60Hz Command Example SYSTEM LINEFREQ 60 Sets the AC Power Line Frequency setting to 60 Hz Query Syntax SYSTEM LINEFREQ Query Response lt freq gt Where lt freq gt is the line frequency setting Query Example SYSTEM LINEFREQ Example Response 50 Short Form SYST LIN 148 Model 32 32B User s Manual Remote Operation SYSTEM DRES Display Resolution Sets or queries the controller s display resolution Choices are FULL The VFD will display temperature with the maximum possible resolution 1 2 or 3 The VFD display will display the specified number of digits to the right of the decimal point NOTE This command only sets the number of digits displayed on the front panel VED It does NOT affect the internal accuracy of the instrument or the format of measurements reported on the remote interfaces The main use for this command is to eliminate the flicker in low order digits when the controller is used in a noisy environment Command Syntax SYSTEM DRES lt res gt Where lt res gt is the display resolution as follows FULL 1 2 3 Command Example SYSTEM DRES 2 Causes the VFD display to show temperature with two digits to the right of the decimal point Query Syntax SYSTEM DRES Query Response lt res gt Where lt res gt is the display resolution Query Example SYSTEM DRES Example Resp
55. manufacturer for assistance Taking PID values from a different controller If the PID values required to control a system are known from a different type controller these values may be useful The Proportional or P term is a unit less gain factor There is no industry standard definition for it and therefore it can vary significantly from one manufacturer to another If the P term does not work well when used directly try a using the value divided by ten For further assistance please contact Cryo con support The Integral or term is in units of Seconds and should be the same for different controllers Note however that some manufacturers use a Reset value instead of directly using an Integral term In this case the Integral term is just the inverse of the Reset value The Derivative or D gain term is in units of inverse Seconds and should be the same for various controllers Using Factory Default PID values Controllers are shipped from the factory with very conservative PID values They will give stable control in a wide range of systems but will have very slow response times Often the factory values provide a good start for the autotune process The values are P 0 1 15 0 and D 0 0 Autotuning Autotuning is the easiest way to obtain PID values or optimize existing ones Please review the Autotuning section of this manual 227 Model 32 32B User s Manual Appendix D Tuning Control Loops Manual Tuning
56. monitor is coarsely quantized and is displayed only for down by about 1 an indication of proper function The controller should be The output indicated on the display is the actual measured output applying power but the power of the control loop A reading of 0 while the controller is display is showing 0 attempting to output power usually indicates an open heater output 218 Model 32 32B User s Manual Appendix B Troubleshooting Guide Symptom Condition Unstable control If the system is oscillating try de tuning the PID values by decreasing P increasing and setting D to zero If the oscillations cannot be stopped by this procedure the cause is likely that your system has an excessive time delay Linear control algorithms including PID cannot control systems with excessive time delay These problems often occur in systems that use heat pipes or depend on gas flow between the heater and temperature sensor elements The only solution to such systems is to re design the equipment to reduce the time delay or to externally implement a time delay compensation algorithm such as a Smith Predictor Do not try to control on Ohms or Volts The controller will work correctly with either of these sensor units but the PID values required are significantly different and most sensors are non linear Furtherer there is no advantage to controlling in sensor units Optimize the control loop parameters by using the Autotune f
57. mount kit Since the controller is an industry standard size you can mount any similar size instrument next to it in the rack Note that the rack mount extends the height of the controller from 2U 37 to 3U 5 To mount the controller first remove the plastic feet and instrument bail on the bottom of the unit Next lay the controller on the shelf and slide forward to line up with the front cutout Use four 6 1 4 screws to secure the controller using the same threaded holes as the plastic feet used Warning When rack mounting do not use screws that protrude into the bottom of instrument more than Otherwise they can touch internal circuitry and damage it Model 32 32B User s Manual Preparing the controller for use Initial Setup and Configuration Before attempting to control temperature the following instrument parameters should be checked 1 The Loop 1Heater resistance setting should match the actual heater resistance that you are going to use Choices are 50Q and 25Q A heater resistance of less than 25Q should use the 25Q setting Using the 50Q setting with a heater resistance much less than 50Q may cause the instrument to overheat and disengage the control loops Set the heater resistance by pressing the Loop 1 key and refer to the Control Loop Setup menu section The Loop 1 heater range should be set to a range where the maximum output power will not damage your equipment
58. possible signal to noise ratio resulting in a faster and more accurate solution However it is important in some systems that the user constrains the amplitude and duration of the heater output waveform by using the DeltaP and Timeout parameters Small values for DeltaP will force the use of small changes in heater power This will make the process model more susceptible to corruption by noise Large values of DeltaP will allow the use of large heater power swings but this may also drive the process into non linear operation which will also corrupt the tuning result Worse it may allow application of too much heater power and may cause an over temperature condition Experience indicates that most cryogenic systems will autotune properly using a DeltaP of 10 whereas a noisy system will require 20 or more Acommon example of a noisy cryogenic system is one where a Silicon Diode sensor is used with a setpoint near room temperature System Noise and Tuning Modes Three modes of autotuning may be selected They are P only PI and PID Using P only autotuning will result in the maximum value for P that will not cause oscillation The process temperature will stabilize at some point near the setpoint Using PI or PID control will result in stable control at the setpoint 80 Model 32 32B User s Manual Basic Setup and Operating Procedures The Derivative or D term in PID is used to make the controller more responsive to change
59. requires setting a upper target value on the input channel Depending on the calibration range selected this will be in Volts or Ohms First establish a voltage or resistance on the selected input channel that is near the recommended value Then enter the actual value in the box provided Click the Capture button on Line 2 The software will wait for the reading to stabilize and then will capture the reading and display it in the edit box on Line 2 While waiting for a stable reading the following dialog box will be displayed Capturing Data in Progress Capturing input data from instrument Wait for the process to complete Press the Abort button to terminate the process When the capture is complete dismiss the following dialog Cryo con Utility So fe 5 Captured Upper Yalue Line 3 requires setting a lower target value on the input channel Depending on the calibration range selected this will be in Volts or Ohms First establish a voltage or resistance on the selected input channel that is near the recommended value Then enter the actual value in the box provided Click the Capture button on Line 4 The software will wait for the reading to stabilize and then will capture the reading and display it in the edit box on Line 4 127 Model 32 32B User s Manual Instrument Calibration When the above procedure is complete you will have established upper and lower target values as well as upper and lo
60. sensors use a DC measurement scheme Therefore the only effective method of minimizing Thermocouple DC offsets is to wire temperature sensors so that connections between dissimilar metals are grouped together For example the connection between sensor leads and cryostat wiring should be kept close together This way the Thermocouple junctions formed by the connection will have equal but opposite voltages and will cancel each other 63 Model 32 32B User s Manual Specifications Features and Functions Frequently sensor leads are made from the same material as the cryostat wires Therefore there is no significant Thermocouple formed by this connection In a four wire measurement scheme only connections in the voltage sense lines can cause measurement errors So the sense wires should have adjacent contacts in a multi pin connector in order to minimize any temperature difference between them Usually the connection to copper in a cryostat is made at the top of the cryostat After this point Thermal EMFs cannot be generated AC Excitation When a sensor type of ACR or AC Resistance is selected the Model 32 uses a 1 25Hz square wave sensor excitation This eliminates DC offsets by computing the sensor resistance at two different excitation points This method will not work diode sensors Control Outputs Control Loop 1 Primary Heater Output The Loop 1 heater output is a short circuit protected linear current sou
61. should be set to at least two or three times the estimated maximum time constant of the process 83 Model 32 32B User s Manual Basic Setup and Operating Procedures tz Note Depending on the setup configuration the autotune algorithm may apply full scale heater power to the process for an extended time Therefore care should be taken to ensure that autotune does not overheat user equipment If overheating is a concern the Over Temperature Disconnect Monitor should be configured to disconnect the heater and abort the autotune process when an input temperature exceeds the specified maximum The autotune sequence is initiated by selecting the Go field If the initialization of process modeling is successful the status display line will change from idle to Running If initialization is not successful one of the above listed conditions has not been met When the tuning process is successfully completed a status of Complete will be indicated and the values of P and D will be updated with the generated values To accept these values and save them as the loop PID coefficients select the Save amp Exit field To reject the values and exit press the ESC key Autotune may always be aborted by pressing the ESC key An unsuccessful autotune will be indicated by one of the following status lines 1 Failed This indicates that the process model did not converge or that PID values could not be generated from the result 2
62. substitute parts or perform any unauthorized modification to the product For service or repair return the product to Cryo con or an authorized service center Model 32 32B User s Manual Table of Contents Preparing the controller TOF USC a resesecdsscasmcandatesdmeciiarpemtuctosssesased ssassistnnnas 1 SUPPI ISMS rossis eS anaE ee Ae MaEMEGR NON 1 Verify the AC Power Line Voltage Selection ccceeeesseeserseeeeeeees 1 Apply Power to the COMUNE cacssccssxsccnscaisverexmwaudaeenmnnseriarinnaworonoranes 1 ESTEI EN S E EE A E N T E EA T 3 initial Setup and ConiiguratoM capasicieaidunsncdossesnnaentcrad wiadelessidannbennasienss 4 COTS and Accessories arias cccsadacinicoaaanacnidediansaniaedadsnetncodanstbanntaradweens 7 Returning EQUI ITIO NI eos siecnadesnetvennacaunrennnmadeecuiansa Wad eenaa keiken 9 A Guick Start GUA Ea ainiai iaae 11 A Quick Start Guide to the User Interface s nsesssreecscerrrrrirrnrnrnnnnna 11 Frnt Panel persian xcntesucsra ein E aan 17 TEE A a phate bade baaaetintsighoanlasikbinkannay 17 meyro DOPIN eN dire cheatinteninhehtndadalids Ze Front Panel Ment Ci Gratiot ciscasis voscansssisockes anak ci escaner NinniR RSA RANNE 27 STU EIT Setup MonySescssiierinien ian RETRE 27 Specifications Features and FuNCTIONS ccccccccssesessseeeeeseeeeeeeeseeeeeeeaes 51 Speciation SUMMARY esos ennen nE erenn Eat 51 UU ANNES os cess cicccesedeiniieeseedassaoiegeni ees eda eda 55 Comal DMOS
63. the user configurable parameters for the selected control loop The Loop 1 menu is used to perform the setup of the primary 25 50 Watt heater output This display was designed to provide all of the information required to tune heater parameters and is therefore rather complex The Loop 2 menu is used to perform the setup of the secondary output For a standard Model 32 this is a zero to 10 Volt output For a Model 32B this is a 10 Watt current source The first character on each line of the control loop setup menu is always the loop identifier which is a superscripted 1 or 2 for Loop 1 or Loop 2 33 Model 32 32B User s Manual Front Panel Menu Operation Loop 1 Loop 2 Setup Menu Numeric setpoint entry The temperature of the controlling input is shown on the left and is continuously 1 77 123K 5 79 000K updated Use the keypad to enter a new setpoint and then press the Enter key Control loop setpoints may also be accessed from the Set Pt key 2 Proportional gain or P term for PID Pgain 25 0000 i Integrator gain term in Seconds for iIgain 71 0000S lea Fi Derivative gain term in inverse 4 1 Dgai n 71 0000 S Seconds for PID control Output power as a percent of full scale 5 iPman 25 00 Pa Pe AE when controlling in the Manual mode 6 iIn pu t ChA M Control input channel ChA or ChB Output power range For loop 1 this will be HI Mid or Low For loop 2 ona 7 4Range HI Mod
64. to select a table for editing Below this is N the number of valid entries in the table This number was generated when the user entered table and cannot be changed using this menu 45 Model 32 32B User s Manual Front Panel Menu Operation The PID Table Edit Menu The EDIT PID TABLE line is selected to enter and edit zones within the selected table This will take the display to the PID Table Edit Menu shown below The first four characters of the PID Table Edit Menu show the selected table index followed by TWO vertical bars PID Table Edit Menu s Sets the line number index to edit 1 01 11TX 2 OTTTSP 100 0000 Linwseiontens Ps OTL1P 20 0000 eran ony Pa OTL1E 10 0000 irern oan s o1t D 2 0000 2 Sets the heater range This entry is 6 01I Range Low N f Save the table and exit by pressing the 01 SaveTable amp Exit Enterkey Exit without saving by pressing the Esc or Home key Table 14 PID Table Edit Menu Pressing the Esc key from this menu will abort the line entry process and return the display to the PID Table Menu above Any edits made to the line will be lost When an index is selected all of the lines on this menu will be updated to show the selected index Any data in the selected index will be displayed on the following lines The following data can be entered into the PID zone Setpoint SP Proportional gain P Integral gain I Derivative gain D and heater
65. used to minimize overshoot to a new setpoint without affecting the PID loop operation 2 Noise filtering on the derivative term The D term will provide better control stability but is often not used because without filtering it can make the control loop too sensitive to noise 3 Integrator wind up compensation While slewing to a new setpoint the integrator in the PID loop can build up to a very large value If no compensation is applied overshoot and time to stability at the new setpoint can be delayed for an extremely long time This is especially true in cryogenic environments where process time constants can be very long 4 Dithering and filtering the outputs in order to increase output resolution and improve control stability The PID Table control mode is a PID control loop just as described above However it is used to look up P I D and heater range values based on the specified setpoint This is useful where a process must operate over a wide range temperature range since optimum PID values usually change with temperature To use the Table mode effectively the user must first characterize the cryogenic process over the range of temperature that will be used then generate PID and heater range values for various temperature zones This is usually done using the autotune capability Once the information is placed into a PID Table the Model 32 will control in Table mode by interpolating optimum PID values based on setpoint
66. user to send commands to the instrument and view the response Terminal mode is selected by selecting Comm gt lInteract from the main menu or Interact from the shortcut bar This will result in the display shown below To interact with the instrument type a remote command into the dialog box and click Send The command will be transmitted to the instrument and a response if any will be displayed on the background window To exit terminal mode click the Quit button on the dialog box s Cryo con Utility Software dloader File Comm Firmware Calibration Table PID Table Yiew DataLogging Help Serial Terminal Enter Command Send 1DN 105 Model 32 32B User s Manual Cryo con Utility Software Downloading or Uploading a Sensor Calibration Curve Sensor calibration curves may be transferred between the PC and the instrument by using the Calibration Table menu To download a curve send it from the PC to the instrument either select Sensor Curve Download from the shortcut bar or Operations gt Sensor Curve gt Download Ce le Look in Model 34 ex FE l aufeO cr crv l pt1003902 crv Edl TCTypeT cry Cryocalb3 cry Ei PT1K375 crv curveld cry PT1K385 crv El Curvel L crv 5 SI410 crv CX1030E1 crv Ei TCTypeE crv PT100385 crv El TCTypeK cry Files of type Curve Files crv 340 Cancel Wi from the main menu This will cause a file selection dialog box to appe
67. when AC power is applied Environmental and Safety Concerns Safety The Model 32 protects the operator and surrounding area from electric shock or burn mechanical hazards excessive temperature and spread of fire from the instrument e Keep Away From Live Circuits Operating personnel must not remove instrument covers There are no internal user serviceable parts or adjustments Refer instrument service to qualified maintenance personnel Do not replace components with power cable connected To avoid injuries always disconnect power and discharge circuits before touching them e Cleaning Do not submerge instrument Clean exterior only with a damp cloth and mild detergent only e Grounding To minimize shock hazard the instrument is equipped with a three conductor AC power cable Plug the power cable into an approved three contact electrical outlet only 15 Model 32 32B User s Manual Specifications Features and Functions Safety Symbols O O A Direct current power line Equipment protected throughout by A m double insulation or reinforced Alternating current power line insulation equivalent to Class II of Alternating or dirrect current power line IEC536 Three phase alternating current power line Caution High voltages danger of A electric shock Background color Earth ground terminal Yellow Symbol and outline Black Protective conductor terminal Caution or Warning See A instrum
68. while the cursor is on any of the statistics lines The Accum line shows the length of time that the channel history has been accumulating It is in units of Minutes The Minimum and Maximum temperature lines show the temperatures from during the accumulation time Values are shown in the currently selected display units S2 is the temperature variance which is computed as standard deviation squared The M and b fields display the slope and the offset of the LMS best fit straight line to the temperature history data Bias Voltage Selection Enumeration Default 10mV The Model 32 supports constant voltage AC excitation for resistor sensors Other sensors including diodes are supported by DC constant current excitation Sensor type ACR indicates an AC resistor sensor that uses constant voltage bias Here the Bias Voltage field will show selections of 10 0mV 3 3mV and 1 0mV to indicate the voltage that is held on the sensor The Model 32 has an autoranging current source that will maintain the selected voltage For sensor types other than ACR the Bias Voltage field will show N A for not applicable Additional information on excitation voltages and currents is given in the section Input Channels 32 Model 32 32B User s Manual Front Panel Menu Operation The Control Loop Setup Menu The control loop setup menus are selected by pressing the Loop 1 or Loop 2 key from a Home Status Display These menus contain all of
69. 0 1200 4800 9600 19 200 and 38 400 Baud IEEE 488 GPIB Full IEEE 488 2 compliant Language Remote interface language is IEEE SCPI compliant National Instruments LabVIEW drivers available for all interfaces User Setups Two User Setups are available that save and restore the complete configuration of the instrument Firmware Internal firmware and all data tables are maintained in FLASH type memory and may be upgraded via the remote interface ports Instrument firmware updates are available on the Internet General Ambient Temperature 25 C 5 C for specified accuracy Mechanical 8 5 W x 3 5 H x 12 D One half width 2U rack Instrument bail standard rack mount kit optional Weight 9 Lbs Enclosure Aluminum Extrusion Machined Aluminum front and rear panels Power Requirement 100 120 220 or 240VAC 5 10 50 or 60Hz 150VA max 54 Model 32 32B User s Manual Specifications Features and Functions Input Channels There are two independent multi purpose input channels each of which can separately be configured for use with any supported sensor The Sensor Type is selected by the user via the microprocessor Values of excitation current voltage gain etc will be determined by the microprocessor and used to automatically configure the channel There are no internal jumpers or switches Constant Current Sensor Excitation Cryogenic sensors including Diode and Platinum devices require a constant
70. 10 Volt programming voltage The value of the programming resistor is R 10 Volts 0 1mA 100 Ohms Also note that the resistor must be capable of dissipating power Watts 10 Volts 0 1mA 1 0 Watts 90 Model 32 32B User s Manual Basic Setup and Operating Procedures Using a booster supply with Loop 2 of a Model 32 is simple since the loop outputs 0 to 10 Volts and can be connected directly to most programmable power supplies However Loop 2 of a Model 32B is more difficult since it is designed to output 10 Watts To use a booster supply with the Loop 2 of the Model 32B setup as follows 1 Loop 2 of a Model 32B outputs 450mA at up to 25 Volts Therefore to generate a zero to 10 Volt output you must use a 25 Ohm programming resistor that can dissipate at least 10 Watts Therefore this resistor will get very hot during normal operation 2 Connect the Loop 2 output to the booster supply s programming and set up the supply according to the manufacturer s documentation 91 Model 32 32B User s Manual Basic Setup and Operating Procedures Using Thermocouple Sensors Thermocouple sensors have low sensitivity and are very susceptible to electrical noise Therefore they are often difficult to apply In order to obtain the best possible measurement accuracy the recommendations given here should be carefully applied Direct Connection The Model 32 supports direct connection to Thermocouple s
71. 10K to 325K excitation 1000Q at 0 C Platinum RTD using DIN43760 standard calibration curve Range 23 to 1023K 100uA excitation 10KQ at 0 C Platinum RTD Temperature coefficient 0 00385 Range 23 to 475K 104A excitation Rhodium lron resistor 27 Ohms at 0 C 1mA DC excitation Scientific Instruments Inc RO 600 Ruthenium Oxide sensor with 0 600 AC ese constant voltage AC excitation Scientific Instruments Inc RO 105 Ruthenium Oxide sensor with ROSS RE 109A constant current 10uA DC excitation R500 Cryocon R500 Ruthenium Oxide sensor with constant voltage AC excitation Cryocon R400 Ruthenium Oxide sensor with constant current 10uA DC excitation TC type K Only available when thermocouple option is installed thermocouples TC type E type K E and T Direct input to the controller Range Type T 3 5 to TC type T 673K Type E 3 5 to 1273K Type K 3 5 to 1643K AuFe 0 07 La ES a 45 Table 38 Factory Installed Sensors Note that Thermocouple devices only appear on units ordered with the thermocouple option 213 Model 32 32B User s Manual Appendix A Installed Curves The isenix remote command is used to set factory installed sensors For example the command INPUT B ISENIX 33 would set input B to use the RO 600 sensor INPUT A ISENIX 1 would set input A to use the S700 Diode INPUT A ISENIX 0 would turn input A off by setting the sensor to none User Installed Sensor Curves The us
72. 14 00000 6 0 2141 450 0000 46 0 7461 210 0000 86 1 4150 13 00000 7 0 2246 445 0000 47 0 7682 200 0000 87 1 4700 12 00000 8 2S5 440 0000 48 0 7916 90 0000 88 1 5270 11 00000 9 0 2458 435 0000 49 0 8133 80 0000 Co ee bow L0 00000 10 0 2565 430 0000 50 0 8338 70 0000 OO 1 5990 9 50000 dts O 2673 425 0000 51 0 8547 60 0000 91 1 6230 9 00000 12 0 2781 420 0000 52 0 8753 50 0000 92 1 6540 8 50000 13 O28 92 415 0000 53 0 8977 40 0000 93 1 6670 8 00000 14 0 3001 410 0000 54 0 9198 30 0000 94 1 6840 7 50000 15s 028111 405 0000 59 7 0 593 73 20 0000 95 1 7080 7 00000 Lea 033222 400 0000 56 0 9542 10 0000 96 1 7310 6 50000 17 0 3334 395 0000 57 0 9768 00 0000 97 1 7500 6 00000 18 0 3446 390 0000 58 0 9865 95 00000 98 7690 5 50000 19 0 3558 385 0000 59 80 9950 90 00000 99 17850 5 00000 20 03671 380 0000 60 0050 85 00000 LOO 1 7970 4 75000 21 0 3784 375 0000 61 0144 80 00000 L01 1 8000 4 50000 22 0 3897 370 0000 62 0241 75 00000 L02 1 8090 4 25000 23 0 4011 365 0000 63 0325 70 00000 L03 1 8160 4 00000 24 0 4125 360 0000 64 0420 65 00000 L04 1 8210 3 75000 25 0 4239 355 0000 65 0506 60 00000 L05 1 8270 3 50000 26 0 4353 350 0000 66 0587 55 00000 L06 1 8340 3 25000 27 0 4467 345 0000 67 0673 50 00000 LO7 b 8390 3 00000 28 0 4581 340 0000 68 0753 45 00000 L08 1 8460 2 75000 29 0 4695 335 0000 69 0842 40 00000 109 1 8520 2 50000 30 0 4808 330 0000 70 0870 38 00000 110 1 8560 2 25000 31 0 4922 325 0000 71 0904 36 00000 L11 1 8590 2 00000
73. 2B User s Manual Appendix B Troubleshooting Guide Appendix B Troubleshooting Guide Error Displays Input channel voltage measurement is out of range Ensure that the sensor is connected and properly wired Ensure that the polarity of the sensor connections is correct Refer to the Sensor Connections section Many sensors can be checked with a standard Ohmmeter For resistor sensors ensure that the resistance is correct by measuring across both the Sense and Excitation contacts For a diode sensor measure the forward and reverse resistance to ensure a diode type function Input channel is within range but measurement is outside the limits of the selected sensor s calibration curve Check sensor connections as described above Ensure that the proper sensor has been selected Refer to the Input Channel Setup Menus section Change the sensor units to Volts or Ohms and ensure that the resulting measurement is within the selected calibration curve Refer to the section on Sensor Setup to display the calibration curve The controller s firmware has been corrupted Invalid Checksum Re load the unit s firmware Refer to the section Reading Record 9000 Downloading Instrument Firmware Errors 00 The input temperature measurement circuitry has failed Contact Cryo con technical support ADC Failure The self test procedure detected an error in the controller s RAM memory Contact Cryo con Support Memory Error
74. 32 with one standard input plus one universal thermocouple input Ordering Information Controller with two standard multi function sensor Model 32 Model 32B input channels Model 32 T Model 32B T Controller with one standard input and one universal thermocouple input Technical Assistance Trouble shooting guides and user s manuals are available on our web page at http www cryocon com Technical assistance may be also be obtained by contacting Cryo con as follows Cryogenic Control Systems Inc PO Box 7012 Rancho Santa Fe CA 92067 Telephone 858 756 3900x100 FAX 858 759 3515 e mail techsupport cryocon com For updates to LabVIEW drivers Cryo con utility software and product documentation go to our web site and select the Download area Current Firmware Revision Level As of December 2006 the current firmware revision level for the Model 32 series is 6 10 Current Hardware Revision Level As of December 2006 the current hardware revision level for the Model 32 series is H Hardware cannot be upgraded in the field 6 Model 32 32B User s Manual Preparing the controller for use Options and Accessories Instrument Accessories Cryo con ee 4034 031 Two instrument shelf rack mount kit 4034 032 One instrument shelf rack mount kit RS 232 Null Modem Cable 6 Required for downloading 04 0420 f firmware to the instrument products 4034 035 Shielded IEEE 488 2 Interface Bus Cable 6 6
75. 4K Multiple Command Example LOOP 2 SETPT 123 4 PGAIN 120 This command will set the loop 2 setpoint to 123 4 and the proportional gain term to 120 Query Example LOOP 1 SETPT Example Response 143 1293 Short Form LOOP SETP 170 Model 32 32B User s Manual Remote Operation LOOP TYPE Control loop Control Type Sets and queries the selected control loop s control type Allowed values are Off loop disabled PID loop control type is PID Man loop is manually controlled Table loop is controlled by PID Table lookup RampP loop is controlled by PID but is in ramp mode Command Syntax LOOP lt no gt TYPE lt type gt Where lt no gt is the loop number 1 or 2 and lt type gt is the loop s control type from the above list Query Syntax LOOP lt no gt TYPE Query Response lt type gt Where lt type gt is the loop type from the above list Command Example LOOP 1 TYPE PID Sets the loop 1 control mode to PID Query Example LOOP 1 TYPE Example Response TABLE Which indicates that the Loop 1 is controlling based on PID Table lookup Short Form LOOP TYPE 171 Model 32 32B User s Manual Remote Operation LOOP TABLEIX Control loop PID Table number Sets and queries the number of the PID table used when controlling in Table mode Six PID tables are available to store PID parameters vs setpoint Command Syntax LOOP lt no gt TABLEIX lt number gt Where lt no gt is the
76. Cryogenic systems will usually require different PID values at different setpoint temperatures Therefore the pre tuning process should result in a temperature near the desired setpoint Pre tuning does NOT require that the user establish stable control at the target setpoint This is the job of the autotuning algorithm and is much more difficult than the stability required by pre tuning One method of pre tuning is to use PID control with a small initial value for P and zero for and D This will result in stability at a temperature of the setpoint minus some constant offset Increasing the P value will reduce the offset amount When P is too large the system will oscillate Another pre tuning technique is to Manual control mode with some fixed value of output power When the system becomes stable at a temperature corresponding to the set heater power level a system characterization process is performed using that temperature as an initial setpoint System Characterization System characterization is the process of using autotune to generate optimal PID coefficients for each setpoint over a wide range of possible setpoints 81 Model 32 32B User s Manual Basic Setup and Operating Procedures The characterization process is performed once Then the setpoints and corresponding generated PID values are transferred to an internal PID table Thereafter the system is efficiently controlled by using the Table control mode Autotune
77. E Cryocooler Four SYSTEM DRES Sets or queries the controller s display resolution Choices are SYSTEM DRES Full 1 2 or 3 SYSTEM HWREV Queries the instrument s hardware revision level SYSTEM FWREV Queries the instrument s firmware revision level SYSTEM ERROR Queries the instrument s error queue SYSTEM CJTEMP Queries the internal Cold Junction Compensation temperature for thermocouple sensors SYSTEM PUCONTROL Sets or queries the power up in control mode setting SYSTEM PUCONTROL SYSTEM LINEFREQ Sets or queries the AC Power Line frequency setting SYSTEM LINEFREQ be restored on the next power up Set or query the contrast of the front panel VFD display Model SYSTEM CONTRAST 34 62 Only 204 Model 32 32B User s Manual Remote Operation Command Fumon SSS S Input Channel Commands INPUT Query the current temperature reading on any of the input INPUT TEMPER channels INPUT UNITS Sets or reports the display units of temperature used by the INPUT UNITS specified input channel INPUT ISENIX Sets or queries the sensor index number assigned to an input INPUT ISENIX channel Applies to factory installed sensors Refer to Appendix A INPUT USENIX Sets or queries the sensor index number assigned to an input INPUT USENIX channel Applies to user installed sensors Refer to Appendix A INPUT SENIX Obsolete Use USENIX or ISENIX commands described above INPUT SENIX Sets or queries the sensor index number a
78. E DIODE This command assigns the Silicon Diode sensor type to the user installed sensor at index 3 Query Example CALDATA 1 TYPE Example Response TC80 This response indicates that the sensor at index 1 is a thermocouple Short Form CALD TYP 191 Model 32 32B User s Manual Remote Operation CALDATA MULTIPLY Calibration Curve Multiplier Sets or queries the Multiplier field for a user installed sensor The multiplier field is a floating point numeric entry and is used to specify the sensor s temperature coefficient and to scale the calibration curve Negative multipliers imply that the sensor has a negative temperature coefficient The absolute value of the multiplier scales the calibration curve For example the curve for a Platinum sensor that has 100Q of resistance at 0 C may be used with a 1000Q sensor by specifying a multiplier of 10 0 Default is 1 0 for sensors with a positive temperature coefficient and 1 0 for a negative coefficient Command Syntax CALDATA lt index gt MULTIPLY lt val gt Where lt index gt is the index to user installed sensor 0 through 3 and lt val gt the multiplier lt index gt is an integer and lt val gt is floating point with a range of 100 0 Command Example CALD 1 MULT 10 1 This command sets the calibration table multiplier for user installed sensor 1 to 10 1 and identifies it as having a negative temperature coefficient Query Syntax CALDATA lt index gt MU
79. ION cccccccecesseeeeeesteeeeeees 35 status HOME key IEEE 488 5 67 103 131 137 143 144 203 222 IEEE24 88s 0cts2asanecn ream wa in ae Addres Sine tha Mina 143 CONNECCION niue ars iniaa nadah a Taa Ek 73 input channels 55 153 205 INPUT COMMANGG ccceeseeeeeeeeeeeteeeeees 153 input protection eeren eseese nnee 63 INPUUSGLUD PE E E T 30 inputstatisticsS ikinni ea aa 32 Instrument Calibration Instrument Calibration Calibration Interval Calibration Services Password PrOCCGUNG 2 o pean Eene An Instrument Status Enable 0 134 135 Instrument Status Register ee 134 integrator gain term 175 ISE 134 135 136 ISR 134 135 136 Keypad KeCYS cceecceeeeseeeeeeeeeneeeeeaeeeeeeeeeeeaee 20 LOGORIMS 3 E cece etinas eens aseeten ote 79 LOOP TFA eet vate ae ee i 4 64 CONNECHON eee cieecntdenshhi nates gabe teed Ab 73 range SClCCtiON cccceeceeeeeeeeeeeeeetteeeeeeees 36 SOUP AT PEA ea ete ai leds 33 Coop 2 iiet aa EAR RNE oaas 33 CONNECTION ccececeeeeeeceeeeeeeeeeeeeeeeeteeenaeeee 73 LOOP comman d5s c cccccceeeeeeeeeeeeteeeeee 169 loop Status iis soni ena ea tea 25 manual control mode 35 36 66 180 181 Multiplier field ce eeeeeeeeeeeeeeeeees 47 58 78 NTC resistor anomaan 56 OPC COMMANG ccceeccetceeeeeeeteeettteeeeeeeees 138 Operate Display ccccceeseeeeeseeeeee
80. Kelvin Temperature Displays A typical Input Channel Temperature Display is shown here It consists of the input channel designator a Temperature reading and the current temperature units The input channel designator is a superscripted A or B The temperature is a seven character field and is affected by the Display Resolution setting in the Sys menu This setting A87 4567K may be 1 2 3 or Full Settings of 1 2 or 3 indicate the number of digits to the right of the decimal point to display whereas the Full setting causes the display to be left justified in order to display the maximum number of significant digits possible 23 Model 32 32B User s Manual Front Panel Operation The Display Resolution setting does not affect the internal accuracy of arithmetic operations It is generally used to eliminate the display of unnecessary digits that are beyond the sensor s actual resolution If the Input Channel has been disabled a blank display is shown Temperature units are selected in the individual input channel setup menus ChA or ChB Temperature Units may be K C or F When Sensor Units S is selected the raw input readings are displayed These will be in Volts or Ohms Table 7 Temperature Units Sensor Fault Display Asensor fault condition is identified by a temperature display of seven dash characters as shown here The sensor is a K open disconnected or shorted Temperature Out o
81. LOOP lt no gt MAXSET Query Response lt MaxSet gt Command Example LOOP 1 MAXSET 300 Sets the maximum allowed setpoint on Loop 1 to 300 Query Example LOOP 1 MAXSET Example Response 250 Short Form LOOP MAXS 179 Model 32 32B User s Manual Remote Operation LOOP PMANUAL Control Loop Manual Power Output Setting Sets and queries the output power level used by the selected control loop feedback when it is in Manual control mode This value may be changed at any time but is only used during Manual operation PMANUAL is a numeric field that is a percent of full scale selected control loop output current Actual selected control loop output power will depend on the selected control loop range setting Command Syntax LOOP lt no gt PMANUAL lt value gt Where lt no gt is the loop number 1 or 2 and lt value gt is the desired selected control loop output current as a percent of full scale Query Syntax LOOP lt no gt PMANUAL Query Response lt value gt Where lt value gt is the desired output power as a percent of full scale Command Example LOOP 1 PMAN 50 Sets the control loop 1 s output power to 50 of full scale when the loop is in manual control mode Query Example LOOP 1 PMAN Example Response 25 000 Indicates that loop 1 has a manual output power setting of 25 Short Form LOOP PMAN 180 Model 32 32B User s Manual Remote Operation OVERTEMP commands These commands are a
82. LTIPLY Query Response lt val gt Where lt index gt is the index and lt val gt is the sensor type multiplier Query Example CALD 2 MULT Example Response 1 000000 This response indicates that the sensor at index 2 has a positive temperature coefficient and a calibration curve multiplier of 1 0 Short Form CALD MULT 192 Model 32 32B User s Manual Remote Operation AUTOTUNE commands Autotuning via the remote interface requires the following sequence 1 The Model 32 must be controlling temperature and the loop must be stable in terms of both temperature and output power Values for Delta Power and Timeout should be set The Autotune process model is initiated by the command AUTOTUNE START Status can be monitored using the AUTOTUNE STATUS command When a status of complete is indicated the generated values for P and D may be read Execution of the AUTOTUNE SAVE command will transfer the generated PID coefficients to the actual loop coefficients and continue controlling the process in PID mode Execution of the AUTOTUNE EXIT command at any time will abort the autotune process and discard any generated PID values Refer to the section on autotuning for information about this process 193 Model 32 32B User s Manual Remote Operation AUTOTUNE DELTAP Maximum Delta in Power Sets and queries the maximum allowed change in heater output power that is allowed during the process modeling phase of
83. Loop 1 Primary Heater Output Type Short circuit protected linear current source Maximum compliance is 50V Connection Dual Banana Plug Ranges Three output ranges of 1 0A 0 33A and 0 10A full scale which correspond to 50W 5 0W and 0 5W when used with a 50Q load Load Resistance 25Q or 50Q Heaters down to 102 can be used with the 250 range Minimum Load 10Q in 25Q setting 40Q in 50Q setting Digital Resolution 1 0PPM of full scale corresponding to 20 bits Readback Heater output power Heatsink temperature Loop 2 Output Standard Model 32 Type Voltage output 0 to 10 Volts Input impedance 500Q Connection Two pin 3 5mm detachable terminal block Digital Resolution 1 0PPM of full scale corresponding to 20 bits Loop 2 Heater Output Model 32B Type 10 Watt short circuit protected linear current source Maximum output is 0 4A at 25V Load Resistance 62 5Q 10Watts 50Q 8Watts 25Q 4 Watts or 10 1 6 Watts Digital Resolution 1 0PPM of full scale corresponding to 20 bits Readback Heater output power 53 Model 32 32B User s Manual Specifications Features and Functions Status Outputs Audible and Visual Alarms Independent audible and visual alarms Status reported via Remote Interface Sensor fault Heater over temperature fault Remote Interfaces Remote interfaces are electrically isolated to prevent ground loops RS 232 Serial port is an RS 232 standard null modem Rates are 30
84. OWeri a stents ieaveves ee i 17 21 74 CONNECCION siiani ne ei asl 68 CONG eoa ebria e diet tard lent aN 7 74 75 frequency 5 41 43 87 88 148 fuses 69 low voltage 222 NOISC sss caserersteeaees 93 power entry module 101 requirements 04 smart on off re WA 69 18 Voltage Selection Adding a new sensor Audible negrer nianie 67 165 205 Clearing diaa a aa aah 28 CONAI ONS naneo rarae enaa niaan eah 32 enable iaa o i aa 30 162 high Setpoint sserrep 30 hysteresis esi iii ee ee 32 hysterisis 00 cccceeeeeeeeeeees 159 160 161 late disan ere taaan 30 32 LED Atann ada era a 22 IOW Setpoint sna upaa aka 30 OUtPUT nein ee A ited adi 67 sensor tailts 2 scc eaiiaucnadii wanes 164 setpoint 30 160 161 163 SOU PEE AE ATENT 32 SAUS it r tein 19 159 VIGWING o narii a a a has 28 ASCI adrenn aa 133 138 autocalibrate sseo0seeeeeeoeennnesennnnne 145 204 Autotune 66 194 195 196 197 198 209 AUtotuUn sass a desi ene as remote COMMANGG cccecceeceeeesteeeeeeees AUNING edia a eira eae aae MODES Snid adits a a PFe tUNING aiui pa ee SOLU Parts ete ena E A EE OE Beep COMMANA cccccceeeeeeeteeeeteeeeteeeeeee bias voltage selection CALCUR commands we f CALDATA COMMANGS ccccccceeeeeeeeeeeeenees CalGEn nisinsin 31 63 93 96 103 114 CalG6n skied a e nd Diode Senso reiner aya 97 Pt S
85. Remote Operation The following is an example of a calibration curve transmitted to the controller via the GPIB interface CALCUR 1 Good Diode Diode 1 0 volts 0 34295 300 1205 0 32042 273 1512 0 35832 315 0000 1 20000 3 150231 1 05150 8 162345 0 53234 460 1436 The controller would sort the above table in ascending order of volts then write it to FLASH memory as user curve 1 The curve name will be Good Diode and the native units are volts When a complete curve is received it is conditioned sorted and copied to FLASH memory This process can take as long as 250 milliseconds with a long table c Note When using the RS 232 interface a time delay should of about 500mS should be inserted after sending the last line of a calibration table This will allow the flash memory update to complete Other remote interfaces do not require a delay cz Note Factory installed calibration curves may not be changed or deleted with these commands 184 Model 32 32B User s Manual Remote Operation CALCUR Calibration Curve Set or Query Sets or queries sensor calibration curve data Command Syntax CALCUR lt index gt lt sensor name gt lt sensor type gt lt multiplier gt lt curve units gt lt sensor reading 1 gt lt Temperature 1 gt lt sensor reading 2 gt lt Temperature 2 gt e lt sensor reading N gt lt Temperature N gt c Note A new line n character must be
86. Resolution User selectable to seven significant digits Input Channels There are two input channels each of which may be independently configured for any of the supported sensor types Sensor Connection 4 wire differential DIN 5 input connectors mate with either DIN 5 or DIN 6 plugs Connections are described in the Sensor Connections section Supported Sensors Include Type Excitation ___ Temperature Range Thermistors Constant Voltage AC 70 to 325K Germanium __ Constant Voltage AC 0 3K to 100K__ Silicon Diode 51 Model 32 32B User s Manual Specifications Features and Functions Sensor Selection Front Panel or remote interface There are no internal jumpers or switches Sensor Resolution Sensor Dependent See Sensor Performance Data table Sensor Excitation Constant current mode 1mA 100uA or 10uA Constant voltage mode 10mV 3 333mV and 1 0mV RMS Excitation Current 1 0mA to 10nA in steps of 5 of power Resistance Measurement type Ratiometric bridge Resistance Range Constant voltage Maximum resistance 10mV 1MQ 3 3mV 430KQ 1 0mV 100KQ AC Excitation Frequency Resistor sensors in constant voltage mode 1 25Hz bipolar square wave Sample Rate 10Hz per channel in all measurement modes Measurement Resolution Sensor Dependent See Sensor Performance Data table Digital Resolution 24 bits Measurement Drift lt 15ppm C Measurement Filter 0 5 1 2 4 8 16 32 an
87. STEM BEEP 10 Sounds the audible alarm for 10 seconds Short Form SYST BEEP SYSTEM DISTC Display Filter Time Constant The SYSTEM DISTC command is used to set or query the display filter time constant The display filter is applied to all reported or displayed temperature data Available time constants are 0 5 1 2 4 8 16 32 or 64 Seconds Command Syntax SYSTEM DISTC lt tc gt Where lt tc gt is the display filter time constant in seconds selected from the following list 0 5 1 2 4 8 16 32 64 Query Syntax SYSTEM DISTC Query Response lt tc gt Command Example SYSTEM DISTC 8 This command will set the display time constant to 8 Seconds Query Example SYSTEM DISTC Example Response 2 Which indicates that the display filter has a 2 Second time constant Short Form SYST DIST 142 Model 32 32B User s Manual Remote Operation SYSTEM ADRS GPIB address Selects the address that the IEEE 488 2 remote interface will use The address is a numeric value between 1 and 31 The factory default is address 12 The addresses assigned to units must be unique on each GPIB bus structure Multiple units with the same address on a single bus structure will cause errors Command Syntax SYSTEM ADRS lt adrs gt Where lt adrs gt is the desired unit address The IEEE 488 2 interface on the Model 32 will be re initialized using lt adrs gt as it s address Query Syntax SYSTEM ADRS Query Response lt
88. Syntax lt oc gt AUTOTUNE TIMEOUT lt value gt Where lt oc gt is the output channel to tune and may be either LOOP 10r LOOP 2 lt value gt is the timeout period in seconds Query Syntax lt oc gt AUTOTUNE TIMEOUT Query Response lt value gt Where lt oc gt is the output channel to tune and may be either LOOP 2or LOOP 2 lt value gt is the timeout period in seconds Command Example LOOP 2 AUTOTUNE TIMEOUT 200 Sets the autotune timeout period to 200 Seconds Query Example LOOP 1 AUTOTUNE TIME Example Response 250 000 Identifies the autotune timeout period as 250 seconds Short Form AUT TIM AUTOTUNE START Initiate Autotune Initiates the autotune sequence Command Syntax lt oc gt AUTOTUNE START Where lt oc gt is the output channel to tune and may be either LOOP 10r LOOP 2 Command Example LOOP 1 AUTOTUNE START Initiates autotuning the heater Short Form AUT STAR 195 Model 32 32B User s Manual Remote Operation AUTOTUNE EXIT Abort Autotune Aborts and exits the autotune process Command Syntax lt oc gt AUTOTUNE EXIT Where lt oc gt is the output channel to tune and may be either LOOP 1or LOOP 2 Command Example LOOP 2 AUTOTUNE EXIT Aborts autotuning Short Form AUT EXIT AUTOTUNE SAVE Save PID Coefficients When an autotune sequence has successfully completed this command will save the generated PID values to the control loop PID values and change the auto
89. T Example Response OFF Indicating that the control loops are OFF or disengaged Short Form CONT 139 Model 32 32B User s Manual Remote Operation SYSTEM commands SYSTEM commands are a group of commands associated with the overall status and configuration of the Model 32 rather than a specific internal subsystem SYSTEM LOCKOUT Keypad Lockout Sets or queries the remote lockout status indicator This command is used to enable or lock out the front panel keypad of the Model 32 thereby allowing or preventing keypad entry during remote operation The default condition for this indicator is OFF Command Syntax SYSTEM LOCKOUT lt status gt Where lt status gt is either ON or OFF A lt status gt of ON will lock out the front panel keypad Query Syntax SYSTEM LOCKOUT Query Response lt status gt Query Example SYSTEM LOCKOUT Example Response OFF Indicating that the front panel keypad is enabled Short Form SYST LOCK SYSTEM NVSAVE Save NVRAM to flash Save NV RAM to Flash This saves the entire instrument configuration to flash memory so that it will be restored on the next power up Generally only used in environments where AC power is not toggled from the front panel This includes remote and rack mount applications Command Syntax SYSTEM NVSAVE Short Form SYST NVS 140 Model 32 32B User s Manual Remote Operation SYSTEM REMLED Front Panel Remote LED Sets or queries the remote
90. TUNE DGAIN AUTOTUNE STATUS Doo CCFILTER STATUS CCFILTER TYPE Set or query filter type Types are OFF Input or Cancel CCFILTER TYPE CCFILTER STEP Set or query the filter adaptation step size CCFILTER STEP CCFILTER LOOP Set or query the control loop number controlled by the cryocooler CCFILTER LOOP filter CCFILTER NTAPS Set or query the number of taps in the filter CCFILTER NTAPS CCFILTER RESET Reset the Cryocooler filter Table 37 Remote Command Summary 209 Model 32 32B User s Manual EU Declaration of Conformity EU Declaration of Conformity According to ISO IEC Guide 22 and EN 45014 Product Category Measurement Control and Laboratory Product Type Temperature Measuring and Control System Model Numbers Model 32 Manufacturer s Name Cryogenic Control Systems Inc Manufacturer s Address P O Box 7012 Rancho Santa Fe CA 92067 Tel 858 756 3900 Fax 858 759 3515 The before mentioned products comply with the following EU directives 89 336 EEC Council Directive of 3 May 1989 on the approximation of the laws of the Member States relating to electromagnetic compatibility 73 23 EEC Council Directive of 19 February 1973 on the harmonization of the laws of Member States relating to electrical equipment designed for use within certain voltage limits The compliance of the above mentioned product with the Directives and with the following essential requirements is hereby c
91. The pin out of this connector is as follows Pin 5 NC i Ee 6 NC a 7 8 Ne 9 NC Table 30 RS 232 DB 9 Connector Pinout 73 Model 32 32B User s Manual Specifications Features and Functions The cable used to connect the Model 32 to a computer serial port is a Dual Female Null Modem cable An example is Digikey Inc part number AE1033 ND The wiring diagram for this cable is shown below Note that communication with the Model 32 only requires connection of pins 2 3 and 5 All other connections are optional Eee Model 34 PC pep 1 i bcp EC eS TX 3 3 TX DTR 4 4 DTR GND fo 5 GND DSR 6 6 DSR Ae pe We cts 8 8 cts RI 9 iea 81 DB9 DB9 DB9 DB9 Male Female Female Male Figure 7 RS 232 Null Modem Cable Mechanical Form Factors and Environmental Display The display is a two line by twenty character dot matrix VFD Enclosure The Model 32 enclosure is standard 2 U half width 17 inch rack mountable type that may be used either stand alone or incorporated in an instrument rack Dimensions are 8 5 W x 3 5 H x 12 D Weight is 9 Lbs An instrument bail and feet are standard Rack Mount kits are available from Cryo con for both single instrument or side by side dual configurations A rack mount kit is optional AC Power The Model 34 requires single phase AC power of 50 to 60 Hz Voltages are set by the line voltage selector in the Power Entr
92. User s Guide Model 32 amp 32B Cryogenic Temperature Controller CRYOGENIC CONTROL SYSTEMS INC P O Box 7012 Rancho Santa Fe CA 92067 Tel 858 756 3900 Fax 858 759 3515 www cryocon com Copyright 2008 2011 Cryogenic Control Systems Inc All Rights Reserved Printing History Edition 6f April 1 2011 Certification Cryogenic Control Systems Inc Cryo con certifies that this product met its published specifications at the time of shipment Cryo con further certifies that its calibration measurements are traceable to the United States National Institute of Standards and Technology NIST Warranty This product is warranted against defects in materials and workmanship for a period of one year from date of shipment During this period Cryo con will at its option either repair or replace products which prove to be defective For products returned to Cryo con for warranty service the Buyer shall prepay shipping charges and Cryo con shall pay shipping charges to return the product to the Buyer However the Buyer shall pay all shipping charges duties and taxes for products returned to Cryo con from another country Warranty Service For warranty service or repair this product must be returned to a service facility designated by Cryo con Limitation of Warranty The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by the Buyer Buyer supplied products
93. User s Manual Instrument Calibration x Si Diode V i Diode 1mA DC 100uA DC 10uADC 10uAAC 100uA AC 1mA AC T of FS Steps m Calibration Reults Channel fas H Current Step Calibrating CHA Silicon Diode Volt Calibrate 1 h Apply 1 97 and enter actual volt Status Curent 2 Capture Abort Gain 3 0 5 Apply 0 5V and enter actual volt 4 Capture Abort Cancel Offset 0 Figure 8 Instrument Calibration Screen r Note Newer Cryo con instruments will require a password before calibration data can be saved The utility software will allow you to enter and change the password The default password is cryocon On the far right of the screen a drop down box selects the channel to be calibrated Be sure you have selected the correct channel In order to perform a complete calibration you will need to calibrate each channel individually Along the top of the screen there are tabs that show the types of calibration that are supported by the instrument To perform a complete calibration of a single input channel all calibration types must be calibrated Note the Calibration Results box on the screen The Status field will initially be set to Current and the Gain and Offset values shown will be those read from the instrument c Note If your calibration procedure requires saving historical values you will want to record the Gain and Offset val
94. User s Manual Specifications Features and Functions Heater output power displays are based on the heater read back circuitry which measures output current independently of the actual heater circuitry Thus heater fault conditions can be detected and their corresponding alarms asserted The temperature of the internal heater heat sink is continuously monitored used to generate over temperature fault conditions that will result in shut down of the control loop The absolute resolution of output heater current is 0 0015 of full scale Sixteen bits However this resolution is significantly extended through the use of a dither signal that is applied to the Digital to Analog Converter and averaged by analog filtering in the output stage The resulting output is an interpolation between the available quantization levels See Appendix C Application Note on Signal Dither for details c Note Heater output displays are given as a percentage of output power not output current In order to compute actual output power multiply this percentage by the full scale power of the selected range However to compute actual output current you must first take the square root of the percentage and then multiply by the full scale current Connection to the heater output is made on the rear panel using the banana plug block provided Caution The Model 32 has an automatic control on power up feature If enabled the controller will automati
95. VO 115 HI 2 654 10H 5 Auto Alarm Sensors Table Tune o eo Cai ee aa Tes Power Stop Control Home Enter Display Alam Set Pt wW ee eR ES Figure 2 Model 32 Front Panel Layout The Keypad Function Keys The Function Keys on the Model 32 are Power Stop Control Home and Enter as shown here Power a Control Home Enter The Power key is used to turn AC power to the controller on or off Note that this key must be pressed and held for one second in order to toggle AC power cz Note The Model 32 uses a smart power on off scheme When the power button on the front panel is pressed to turn the unit off the instrument s configuration is copied to flash memory and restored on the next power up If the front panel button is not used to toggle power to the instrument the user should configure the controller and cycle power from the front panel button one time This will ensure that the proper setup is restored when AC power is applied 17 Model 32 32B User s Manual Front Panel Operation The Stop and Control keys are used to disengage or engage the instrument s output control loops Pressing Control will immediately turn on all enabled heater outputs and pressing Stop will turn them both off To enable or disable an individual loop go to the Control Loop Setup menu and select the desired Type The Home key is used to take the display to one of the Home Status displays These displays sho
96. act Cryogenic Control Systems Inc directly Q Model 32 32B Cryogenic Temperature Controller Q User s Manual PN 3038 029 QO Cryo con software CD PN 4034 029 QO Connector kit PN 4038 015 consisting of Two DIN 5 input connectors PN 04 0436 A Dual banana plug heater connector PN 04 0433 A Terminal block plug Loop 2 connector PN 04 0301 Q Detachable 120VAC Line Cord 04 0310 Certificate of Calibration Verify the AC Power Line Voltage Selection The AC power line voltage is set to the proper value for your country when the controller is shipped from the factory Change the voltage setting if it is not correct The settings are 100 120 220 or 240 VAC For 230 VAC operation use the 220 VAC setting On the rear panel of the instrument the AC voltage selection can be seen on the power entry module If the setting is incorrect please refer to section Fuse Replacement and Voltage Selection to change it Apply Power to the Controller Connect the power cord and turn the controller on by pressing the Power key for a minimum of 0 5 Seconds The front panel will show a Power Up display with the model number and firmware revision While the Power Up display is Cryo con Model 32B shown the controller is performing Firmware Rev 6 04H a self test procedure that verifies the proper function of internal data and program memories remote interfaces and input output channels If an error is detected during
97. ake the menu used to edit individual lines of the selected table 3 To enter or edit an entry set the desired entry index and enter the zone data on the following lines 4 The last line of this menu is used to save the table when line entry is complete When a table is saved it is automatically conditioned so that it can be used directly by the control loop software The conditioning deletes all entries with setpoint values of zero or less and sorts the table based on setpoint Therefore an entry may be deleted by setting the setpoint to any negative number 44 Model 32 32B User s Manual Front Panel Menu Operation The PID Table Menu The PID Table Menu is accessed by pressing the PID Table key from the Home Display The first three characters of each line on the initial PID Table menu are a two digit index followed by a single vertical bar The index identifies the currently selected table and will change whenever the table number is updated PID Table Menu Sets the PID table number for editing 01 l PID Table 1 i Selections are 0 to 3 Displays the number of zones in the 2 selected PID table Note This number is generated from the selected table and cannot be changed in this menu Pressing the Enter key on this line will take the display to the second level 01 Edit PID Table a menu where the selected table is entered Table 13 PID table Menu The first line 01 is the table index This field is used
98. and sets the Standard Event Status Enable ESE Register bits The ESE Register contains a bit mask for the bits to be enabled in the Standard Event Status SEV Register A one in the ESE register will enable the corresponding bit in the SEV register A zero will disable the bit The ESE Query returns the current contents of the ESE register Command Syntax ESE lt mask gt Query Syntax ESE Command Example ESE 32 Query Response lt mask gt This will set the CME or Command Error bit enable Therefore when a command error occurs the event summary bit ESB in the Status Byte Register will also be set Query Example ESE Query Response 16 Bit 4 or the Execution Error bit has been enabled All other standard events are disabled 137 Model 32 32B User s Manual Remote Operation ESR Query Event Status Register Query Event Status Register The ESR query returns the contents of the Standard Event SEV status register Query Syntax ESR Query Response lt status gt Where status is a number between 0 and 255 IDN Query unit Identification Query unit identification string The IDN Query will cause the instrument to identify itself The Model 32 will return the following string Cryocon Model 32 Rev lt fimware rev code gt lt hardware rev code gt Where lt fimware rev code gt is the revision level of the unit s firmware and lt hardware rev code gt is the hardware revis
99. annel B press the ChB key This will take you to the Input Channel Setup menu for the selected channel The first line of this display will show the current temperature in real time and allow you to select the desired display units Press the or 4 keys to sequence through the available options and press the Enter key to make the selection 2 Press the key to go down to the Sen filed Here you will use the or 4 key to scroll through all of the sensor types available When the desired sensor is displayed press the Enter key to configure the instrument Select None to disable the input channel At the end of the factory installed sensors four user installed selections will be shown The default name for these is User Sensor N However this name can be changed to give a better indication of the sensor type that is connected For most sensor types installation is now complete and the Home key can be pressed to return to the Home Status display The exceptions are NTC resistor sensors that use constant voltage AC excitation With these types of sensors you will need to scroll down to the Bias Voltage field and select the desired constant voltage excitation level c Note NTC resistor sensors require the selection of a Bias Voltage Selections are 10mV 3 3mV and 1 0mV Generally 10mV works well for most sensors down to about 1K Below that the lower settings may be used to minimize errors from sensor self heating However u
100. any time by use of the following sequence 1 Turn power to the Model 32 OFF 2 Press and hold the Enter key while turning power back ON 15 Model 32 32B User s Manual A Quick Start Guide Forcing a Firmware Download The Model 32 may be powered up in a mode where it will wait for a firmware update via the serial port This is not normally necessary because the Cryo con utility software will set this mode when a firmware update is being processed However if the instrument has crashed during a firmware download or has otherwise become corrupted following this procedure will set the firmware download mode 1 Turn AC power OFF 2 Press and hold the STOP key while turning the AC power back ON Keep the key pressed until the firmware download display is seen The initial firmware download screen Record 000 of 502 is shown here Errors 000 3 Use the Utility Software package to download new firmware over the RS 232 port Instructions are detailed in the section Downloading Instrument Firmware 16 Model 32 32B User s Manual Front Panel Operation Front Panel Operation The user interface of the Model 32 Cryogenic Temperature Controller consists of a two line by 20 character Vacuum Florescent display and a keypad All features and functions of the instrument are accessed via this simple and intuitive menu driven interface eR240 CONn 32 Temperature Controller Esc ChA 4123 456K 8321 234K O
101. appended to each line when using the RS 232 serial port They should not be included when using the GPIB interface The maximum number of entries in a curve is 200 and the minimum is 2 lt index gt is a numeric index to the user calibration curve list Values are 1 through 4 in the Model 32 and 1 through 12 in the Model 34 and 62 lt curve name gt is a name to be assigned to the calibration curve It is a minimum of 4 and a maximum of 15 ASCII characters lt sensor type gt is from the following list Diode ACR 31kR 3 1kKR 312R 625R TC80 TC40 and None If the sensor type cannot be identified Diode is used Sensor Types are described in the section on Supported Sensor Configurations above lt multiplier gt is the temperature coefficient and curve multiplier If this field cannot be identified a value of 1 0 is assumed This field is described in the section Sensor Setup Menu above lt curve units gt is the units of the curve Choices are OHMS VOLTS or LOGOHM The last entry in a calibration curve must be a single semicolon Query Syntax CALCUR lt index gt Query Response lt calibration curve gt Short Form CALC 185 Model 32 32B User s Manual Remote Operation PIDTABLE commands The PIDTABLE commands are used to transfer PID tables between the Model 32 and the host controller PID Tables are referenced by their index number which is between 0 and 5 Table data corresponding to a speci
102. ar as follows From this screen the desired calibration curve is selected Cryo con calibration curves have the file extension of CRV Lakeshore curves with the extension 340 may also be selected Scientific Instruments txt files may be downloaded by first selecting a file type of and then selecting the desired calibration curve file Cryo con CRV files are ASCII text files that may be edited by any text editor 106 Model 32 32B User s Manual Cryo con Utility Software After selecting the file and clicking on Open the selected file will be read and the Edit Curve Header dialog box will appear This box contains information extracted from the curve file header that can be modified if desired before the curve is downloaded x Sensor Name TC AuFe 7pct Sensor Type rce0 Multiplier 1 Unit Volts Number of Pts 101 p Sensor Name is any 15 character string and is only used to identify the sensor Sensor type can be selected from a pull down menu or entered directly Note that different models of Cryo con instruments support different types of sensors Therefore it is important to enter a sensor type that is supported by the specific product If the instrument receives a sensor type that it does not support the Diode type is selected The section titled Supported Sensor Configurations gives complete information on sensor types The Multiplier field is used to select the sign of the sensor
103. arithmetic rounding scheme if the desired output is above the mid point between two quantization levels Q1 the DAC output will be at the higher level If the value is below the mid point the DAC will output the lower level Therefore the DAC output x for the input shown will simply be Q3 As can be seen the average value of the DAC output is equal to the nearest quantization level In this example the output Q3 is slightly higher than the value required to accurately control at the selected setpoint Therefore the control loop will integrate downwards until the DAC output jumps down to Q2 This process of jumping between Q2 and Q3 will continue establishing an oscillation with an amplitude of one quantization level and a frequency related to the system s closed loop time constant The Dither Algorithm The signal dithering algorithm used in Cryo con s digital control loop first generates a dither signal that is a random number within the range of 0 5 of a quantization level This is then added to the loop output value just before placing it in the DAC If the sum of the desired output plus the dither value is above the midpoint between Q2 and Q3 the DAC will output Q3 If 2 seeeeee eee e eee eeeeeee en ee nrm neneme meneen it is below the midpoint the DAC will a4 output Q2 Therefore the DAC output to toggles randomly between Q2 and 2 22S 2 Q3 but the number of times at one level vs the ot
104. ation sisendis ekaks 43 E oA AAE E S 88 VIEWING e aeaiia oni EA aE seia 88 SYS Auto Cil oa o ei 43 SYSTEM Commands ccccccceceeeeeeeeeeeeeeees 140 Table control MOde c0ccccceeeeeees 37 44 66 Temperature iseasi iah haiti COCTICION is snina andiki 47 histOny sine Sea a sie 32 TAM Pisi aa nvidia aA aai 174 207 units SEIECTION ccccececeeesteeeeeeesteeeeeeeeees 31 VEST AEE O A E A E 32 ZONES iann a A A 66 Temperature Sensors eeaeee CDI 2A iii iin aaa 12 213 GCOrnOx A A E T 51 57 58 61 215 D pE iT A O A E E ET 12 213 DT 670 c rrea E 12 213 Gallium Arsenide cccccccccccesesseeeeeeeeeees 57 G rmaniUM isa akea cea ieia Ae 58 NU GC iethn tie cern au esi teva d 57 NTO re SiStOr iieii ao iiaae 58 Platne a aeaa idat aa 58 PTIK ason A 12 213 PTA Keel scans Reson a Manone 12 213 Rhodium lron 12 57 213 RO 600 attenuata ane 12 213 RID iirin 12 57 213 Ruthenium Oxide 12 57 58 213 SOO AEE A E E AE AE TE 12 SI 410 12 213 Silicon Diode 57 213 TNEPMIStOMs 2 ccsedebe swerve chewtial nia 58 thermocouples nivara u 57 Thermocouple 000 92 94 96 114 204 Thermocouple ysn osinaren i Adding new types 92 Calibration Errors ccccccccccccceseesssessseteees 93 User Configurations ccsceeeeeeees 19 39 Cold Junction Compensation 005 92 restore 239 CONNECTION eee eee 12 92 SIV Oii Sea
105. ations Menu To save or restore a setup select the desired configuration number on line 1 Then move the cursor to either Save or Restore and press the Enter key When a configuration has been Configuration saved saved the menu shown here will be Press Home to exit displayed indicating that the current instrument setup has been written to the controller s FLASH memory and may be retrieved by using the Restore function If the user attempts to restore an invalid configuration an error display is shown This is usually caused by attempting to restore a configuration that was 7 never saved Config restored When a configuration is successfully restored the display shown here is shown After a one or two seconds the controller will automatically perform a power up reset with the restored data 39 Model 32 32B User s Manual Front Panel Menu Operation The System Functions Menu This menu is accessed by pressing the Sys key from the Home Status Display It is used to set many of the instrument s parameters including display resolution I O port settings etc System Functions Menu Sets the display time constant in SYS Displa TC 2 osn seconds Selections range from 0 5S to play 64S Sets the resolution Selections are 1 2 Enables or disables Cold Junction 7 i Compensation for Thermocouple SYS CJ Comp Ena ONN sensors Only shown when the thermocouple option is present Offset in C applied to ther
106. ature of the internal heater output stage s heat sink in Celsius Query Example CONFIG 0 NAME Example Response Dewar Two Short Form CONFIG NAM 151 Model 32 32B User s Manual Remote Operation CONFIG SAVE Save User Configuration Saves an the current instrument setup to a user setup Command Syntax CONFIG lt ix gt SAVE Where lt ix gt is the index number of the desired instrument setup Values may be 0 through 5 Command Example CONFIG 1 SAVE Saves the controller s current setup to user setup 1 Short Form CONFIG SAV CONFIG RESTORE Restore User Configuration Restores a previously stored user instrument setup Command Syntax CONFIG lt ix gt RESTORE Where lt ix gt is the index number of the desired instrument setup Values may be 0 through 5 Command Example CONFIG 0 RESTORE Restores the controller s setup from user setup 0 Short Form CONFIG REST 152 Model 32 32B User s Manual Remote Operation INPUT commands The INPUT group of commands are associated with the configuration and status of the four input channels INPUT may also be a stand alone query Parameter references to the input channels may be e Numeric ranging in value from zero to two e Channel ID tags including CHA or CHB e Alphabetic including A or B INPUT Input Channel Temperature Query The INPUT query reports the current temperature reading on any of the input channels Temperature is filte
107. ature should be close to the measurement temperature that requires best accuracy 5 Read the displayed temperature in units of K or C then subtract the known actual temperature from the reading to determine the CJ offset value 6 Enter the CJ offset value into the controller by going to the SYS menu and scrolling down to the CJ offset field This completes the procedure Check the calibration by verifying that the correct temperature is being read Calibration Errors Variation in the manufacture of thermocouple wire and it s annealing over time can cause errors in temperature measurement Instruments that measure temperatures above about 0 C will usually allow the user to correct calibration errors by adjusting an offset in order to zero the error at room temperature Unfortunately in cryogenic applications thermocouples lose sensitivity at low temperatures so a single offset voltage correction is insufficient For example if calibration errors for a Type K thermocouple are zeroed at room temperature a reading near Liquid Nitrogen temperatures may have an error of 5K Correction of Calibration Errors over a wide range of temperature can be made by using the Model 32 s CalGen feature Here the controller should be stabilized at both temperature extremes Then CalGen will generate a new sensor calibration curve that best fits the two points to the actual sensor voltage readings Often CalGen is be done by taking a reading
108. bsolute value of full scale is determined by the selected heater range as shown in this table Note that the read back value is a percent of full Full Scale scale power To compute the output current you Heater Range 50 25 Watt must first compute the square root of the read back value 512 5 Watt 0 333A When using the second control loop of the Model 0 5 0 25 Watt 32B the read back value is always a percentage of 10 Watts Query Syntax LOOP lt no gt HTRREAD Where lt no gt is the loop number 1 or 2 Query Response lt current gt Where lt current gt is the heater output current as a percent of full scale Query Example LOOP 1 HTRR Example Response 33 Indicates that the heater output current has been measured at 33 of full scale by the heater read back circuit If the heater s maximum output power is 50 Watts the output power is 50 0 33 16 5 Watts This corresponds to an output current of 1 0A sqrt 0 33 0 57A Short Form LOOP HTRR 177 Model 32 32B User s Manual Remote Operation LOOP 1 LOAD Heater Load Resistance Select Sets or queries the load resistance setting of the primary heater Loop 1 Selections are 50 for a 50 load and a 50W maximum output power 25 for a 25Q load and a 25W maximum output power Note Loop 2 of the Model 32B controller always assumes a 50Q load Command Syntax LOOP 1 LOAD lt load gt Where lt load gt is the desired resistance of the sel
109. cally begin controlling temperature whenever AC power is applied For a complete description of this function please see the SYS Auto Ctl function in the System Functions menu section Control Loop 2 Secondary Heater Output For a standard Model 32 control loop 2 is a voltage output with a 600 output impedance Range is zero to 10 0 Volts In the Model 32B control loop 2 is a constant current source similar to the Loop 1 heater It has a single output range of zero to 450mA and a compliance of 25V This will result in an output power of 10 Watts into a 50Q load The absolute resolution of Loop 2 is 0 0015 of full scale Sixteen bits However this extended through the use of a dither signal See Appendix C Application Note on Signal Dither for details Connection to the Analog Output is made on the rear panel using the pluggable terminal block provided 65 Model 32 32B User s Manual Specifications Features and Functions Control Types There are four control types available in the Model 32 They are Manual PID PID Table and Ramp All modes are available on both control loops Manual mode operation allows setting the output power manually as a percentage of full scale power PID control allows feedback control using an enhanced PID algorithm that is implemented using 32 bit floating point Digital Signal Processing techniques Enhancements include 1 Implementation of a user settable damping factor that can be
110. cates that no alarm is asserted for input channel A Short Form INP lt channel gt ALAR 159 Model 32 32B User s Manual Remote Operation INPUT ALARM HIGHEST Alarm High Setpoint Sets or queries the temperature setting of the high temperature alarm for the specified input channel When this temperature is exceeded an enabled high temperature alarm condition will be asserted Temperature is assumed to be in the display units of the selected input channel There is a 0 25K hysteresis in the assertion of a high or low temperature alarm condition Command Syntax INPUT lt channel gt ALARM HIGHEST lt temp gt Where lt channel gt is the input channel indicator and lt temp gt is the alarm setpoint temperature Temperature is a floating point string that may be up to 20 characters Query Syntax INPUT lt channel gt ALARM HIGHEST Query Response lt temp gt Where lt channel gt is the input channel indicator and lt temp gt is the temperature setting of the high temperature alarm for lt channel gt Temperature is reported to the full precision of 32 bit floating point Command Example INP A ALARM HIGH 200 5 Sets the high temperature alarm setpoint for input channel A to 200 5 Query Example INP A ALARM HIGHEST Example Response 125 4321 If the display units setting for input channel A are Kelvin this response is also in units of Kelvin Short Form INP lt channel gt ALAR HIGH 160 Model 32
111. ce 250 To change these press the Loop 1 or Loop 2 key and refer to the Control Loop Setup menu section Instrument setup factory defaults are Display Filter Time Constant 2 0 Seconds Display Resolution 3 digits Over Temperature Disconnect Off Remote Interface RS 232 RS 232 Baud Rate 9600 IEEE 488 GPIB Address 12 AC Power Line Frequency 60Hz Cryocooler Filter Off Control on power up OFF To change these press the Sys key and refer to the System Functions Menu section c NOTE Factory defaults may be restored at any time by use of the following sequence 1 Turn power to the Model 32 OFF 2 Press and hold the Enter key while turning power back ON Model 32 32B User s Manual Preparing the controller for use Model Identification The model number of all Cryo con controllers is identified on the front and rear panel of the instrument as well as in various instrument displays Model 32 Basic controller with two standard input channels Outputs are Loop 1 50Watt 3 range linear heater and Loop 2 0 5Volt analog output Model 32B Controller with two standard input channels Outputs are Loop 1 50Watt 3 range linear heater and Loop 2 Ten Watt linear heater The only option that can be ordered with a Model 32 or 32B is a single thermocouple input for sensor B These variations are Model 32B T Model 32B with one standard input plus one universal thermocouple input Model 32 T Model
112. cters then to three since the fourth character is a vowel 145 Model 32 32B User s Manual Remote Operation SYSTEM HTRHST Heater heat sink temperature The temperature of the Model 32 s internal heater circuit heat sink is continuously monitored and used to initiate the automatic shutdown sequence when a heater fault is detected This temperature may be queried using the SYSTEM HTRHST command Query Syntax SYSTEM HTRHST Query Response lt temp gt Where lt temp gt is the temperature of the internal heater output stage s heat sink in Celsius Query Example SYSTEM HTRH Example Response 62C Indicates that the heat sink is at 62 C Short Form SYST HTRH SYSTEM HOME Display Operate Screen Causes the VFD display on the front panel to go to the Operate Screen Command Syntax SYSTEM HOME Command Example SYSTEM HOME Short Form SYST HOME SYSTEM SYNCTAPS Synchronous filter setup Sets or queries the number of taps in the synchronous filter This is an advanced setup function The default is 7 taps Command Syntax SYSTEM SYNCTAPS lt taps gt Where lt taps gt is the number of taps Query Syntax SYSTEM SYNCTAPS Query Response lt taps gt Where lt taps gt is number of taps used by the synchronous filter Query Example SYSTEM SYNCTAPS Example Response 7 Short Form SYST HTRH 146 Model 32 32B User s Manual Remote Operation SYSTEM NAME Unit Name The controller con
113. current excitation To support this the Model 32 has a constant current excitation mode with three selectable outputs of 10uA 100uA and 1 0mA DC The maximum compliance of the constant current source is 2 45V Temperature is measured with diode type sensors by providing a 10uA excitation current and reading the resulting voltage The Model 32 uses a Ratiometric bridge technique to measure resistor sensors Here the measurement is the ratio between the sensor resistance and an internal calibration standard resistance This effectively cancels the DC drift and electronic noise associated with the internal voltage reference and constant current source circuitry Resistor sensors may use any of the three constant current settings Constant Voltage Sensor Excitation A unique feature of the Model 32 is the constant voltage excitation mode where current applied to the sensor is autoranged in order to maintain a constant RMS voltage level across the sensor Aconstant voltage excitation is necessary since the resistance thermometers used below about 10K exhibit a negative temperature coefficient Therefore a constant voltage measurement will reduce the power dissipation in the sensor as temperature decreases By maintaining a low power levels sensor self heating errors that occur at very low temperatures are minimized In the constant voltage mode sensor excitation is a 1 25Hz bipolar square wave This provides DC offset cancellation without
114. d 64 Seconds Calibration Curves Built in curves for industry standard sensors plus four user curves with up to 200 entries each Interpolation is performed using a Cubic Spline CalGen Calibration curve generator fits any diode thermocouple or resistor sensor curve at 1 2 or 3 user specified temperature points Thermocouples Factory installed option on one channel only Input Connector Universal mini spade type thermocouple connector with screw terminals for direct connection to thermocouple wires Input Range 80mV Resolution 0 4yV Electronic Accuracy 1 0u V 0 05 Installed Types K E T and Chromel AuFe 0 07 plus four user supplied curves Cold Junction Compensation Internal enable disable 52 Model 32 32B User s Manual Specifications Features and Functions Control Outputs Number of Loops Two Control Input Either sensor input Loop Update Rate 10Hz per loop Control Type PID table Enhanced PID Ramp or Manual Autotune Minimum bandwidth PID loop design PID Tables Two user PID tables available for storage of Setpoint vs PID and heater range Up to 16 entries table Setpoint Accuracy Six significant digits Fault Monitors Control loops are disconnected upon detection of a control sensor fault or excessive internal temperature Over Temperature Disconnect Heater may be relay disconnected from user equipment when a specified temperature is exceeded on any selected input
115. d its connections Requiring these sensors to be floating and providing a low impedance path to ground is the most effective way to eliminate noise pickup from this antenna effect To ensure that the instrument s grounding scheme is working effectively 1 Make sure that the sensors are floating 2 Make sure that the input cable shields are connected to the connector s metal backshell using the shield clip provided with the connector 3 Make sure that the Third Wire Ground is good quality and not conducting current 101 Model 32 32B User s Manual System Shielding and Grounding Issues Control Loops The circuitry in the Control Loop Area provides power to external heater elements The grounding of this area is identical to the Sensor Area described above Note however that heater elements usually have very low impedance Therefore noise pickup issues are not near the problem that they are in the Sensor Area Digital Circuits The digital circuits of the Model 32 cannot assume that its external connections are floating Therefore it is connected to the Single Point Ground through a Resistor Capacitor network in order to prevent ground loops RS 232 and GPIB connections bring a ground return connection from the host computer This means that the Digital area must be at the same voltage as the host s circuit board ground Otherwise ground loop currents will flow from the host through the instrument and back into the Ear
116. d to the line Format indicators are Numeric entry is required M Enumeration entry using the and 4 keys 8 The line is selected by pressing the Enter key The Setpoint Menu The setpoint menu is accessed by pressing the Set Pt key This gives one key access to the setpoints for both control loops The following 2 line menu will be shown iSetpoint 320 000K Setpoint 100 000K The pound sign character at the end of the top line is the cursor Use the amp and keys to move the cursor between control loop 1 and 2 The location of the cursor is remembered so that it will point to the same loop each time To enter a new setpoint use the numeric keys and then press the Enter key This will update the setpoint on the selected control loop and return the display to the Home display Press the Home key to exit the menu without update 27 Model 32 32B User s Manual Front Panel Menu Operation The Alarm Status Display Menu The current status of the temperature alarms may be viewed by pressing the Alarm key A display like this one will be shown AATarm LO L Alarms are set for each input channel using the Input Channel EAlarm HI Setup menu described below When an alarm is asserted the Alarm LED on the front panel will light Pressing the Alarm key will display all of the alarms Status is shown as follows No alarm LO Low temperature alarm HI High temperature alarm The let
117. defined by the SCPI to identify various standard events and error conditions It is queried using the Common Command ESR This register is often used to generate an interrupt packet or service request when various I O errors occur Bits in the ESR are defined as follows ESR Bit7 Bits Bits Bite Bits Bitz Bitt Bito OPC QE DE EE CE PWR Where Bit7 OPC Indicates Operation Complete Bit5 QE Indicates a Query Error This bit is set when a syntax error has occurred on a remote query It is often used for debugging Bit4 DE Indicates a Device Error Bit3 EE Indicates an Execution Error This bit is set when a valid command was received but could not be executed An example is attempting to edit a factory supplied calibration table Bit2 CE Indicates a Command Error This bit is set when a syntax error was detected in a remote command BitO PWR Indicates power is on 135 Model 32 32B User s Manual Remote Operation The Standard Event Enable Register The Standard Event Enable Register ESE is defined by the SCPI as a mask register for the ESR defined above It is set and queried using the Common Command ESE Bits in this register map to the bits of the ESR The logical AND of the ESR and ESE registers sets the Standard Event register in the Status Byte STB The Status Byte The Status Byte STB is defined by the SCPI and is used to collect individual status bits from th
118. e Diode input sensor type 57 Model 32 32B User s Manual Specifications Features and Functions PTC Resistor Sensor RTDs The Model 32 supports all types of Positive Temperature Coefficient PTC resistive sensors Various combinations of excitation current and full scale input voltage allow the user to trade off accuracy vs sensor self heating The Supported Sensor Configurations table above gives a complete list of combinations that can be selected Standard calibration curves are provided for DIN43760 and IEC751 Platinum sensors While these curves are based on a 100Q sensor they may easily be extended to other resistance values by using the Multiplier field of the sensor setup A table of recommended setups for various types of PTC resistor sensors is shown here Table 20 PTC Resistor Sensor Configuration NTC Resistor Sensor Devices The Model 32 also supports almost all types of Negative Temperature Coefficient NTC resistive sensors Using AC constant voltage excitation these sensors can be used down to extremely low temperatures Examples of NTC resistor sensors include Ruthenium Oxide Cernox Carbon Glass Germanium and Thermistors Calibration tables may be entered either directly in Ohms or in base 10 Log of Ohms A table of recommended setups for various types of NTC resistors sensors is shown here Carbon Glass 1 0 to 10 0mV AC LogOhm Germanium ACR 1 00 10 0mV AC LogOhm
119. e ESE and the ISR as well as to identify that the instrument has a message for the host in it s output queue It is queried using the Common Command STB Bits are defined as follows STB Where Bit6 RQS Request for Service Bit5 SE Standard Event This bit is set as the logical AND of the ESR and ESE registers Bit4 MAV Message Available Bit3 IE Instrument Event This bit is set as the logical AND of the ISR and ISE registers The Status Byte Register The Status Enable Register SRE is defined by the mask register for the STB It is set and queried using the Common Commands SRE The logical AND of the SRE and STB registers is used to generate a service request on the GPIB interface 136 Model 32 32B User s Manual Remote Operation Remote Commands IEEE488 SCPI Common commands The Common Commands are defined by the IEEE 488 2 standard and are supported by the Model 32 on the GPIB port as well as all of the remote interface ports The common commands control some of the basic instrument functions such as instrument identification and reset They also provide an instrument status reporting mechanism CLS Clear Status Clear Status The CLS common command clears the status data structures including the device error queue and the MAV Message Available bit Command Syntax CLS Command Example CLS ESE Event Status Enable Event Status Enable The ESE comm
120. e each Loop Status is a temperature for the controlling input channel In the example here Loop 1 is being controlled by input channel A and Loop 2 is being controlled by input channel B Please note that either loop may be controlled by either input The display will be adjusted to show the control loop directly below the controlling input channel The next example shows the control inputs reversed Loop 1 controlling in the low power range and Loop 2 off Loop 1 and Loop 2 Status Displays These displays show the current status of a selected single control loop Information includes the A17 4567K EF 24 932K controlling input channel 1 15 Low Off 5V temperature setpoint heater status and heater bar chart In the example shown here for Loop 2 the loop is controlling from input E17 4567K 30 10W B with 30 output power and the 2 17 0000K setpoint is 17 0000K Dual Loop Status The Dual Loop Status display is similar to the Dual Input Status display described above However on this display control loop 1 is always on the left side and loop 2 is always on the right Channel A and B Statistics Display The Channel A and B statistics displays show the selected input channel temperature the slope of the temperature history the minimum and maximum EEPE eS E17 4567K M 1 0322 The slope of the temperature history gt 48 Q0022K lt 16 0322K M is given in Display Units per Minute In this example Display Units are
121. eature described in the Autotuning section Most cryogenic systems require significantly different PID parameters at different temperatures To ensure stable control over a wide temperature range use the PID Table feature described in the PID Table Entry section If the heater is controlling with an output power level less than 10 switch to the next lower heater range Symptom Condition _ S Autotune indicates a status Autotune will only abort if the control loops are not engaged or there is of Abort or Fail an invalid temperature reading on the control input channel If it cannot generate a solution because of issues in the system dynamics it will indicate a status of Fail Autotune times out and does Extend the Display Filter time constant to reduce system level noise not generate effective PID and try autotune again The display filter is described in the System parameters Functions Menu section Systems using Diode type sensors above 50K will usually require a 4 or 8 second time constant This setting may be returned to any desired value once tuning is complete Switch to the lowest possible heater range that will control at the target setpoint Try autotuning in the PI mode instead of PID Most cryogenic systems do not benefit from the D term If a Cryo cooler is being used set the controller s cryocooler filter to Input mode This may be returned to Off or Cancel mode once tuning is complete Experiment wi
122. ecommended GPIB Host Setup Parameters 0e8 131 Table 37 Remote Command SUMMary cccecceeeeeeeteeeeeeeeeteeeeeeeeeeaaes 209 Table 38 Factory Installed SeEnSors cceceeeeeeeeeeeeeeeenceeceeeeeeeeeeeeeeeeees 213 Table 39 S700 Cable Color Codes cceeeeceeceeeeeeeeeeeeeeeeeteeeseeeeneaes 232 Model 32 32B User s Manual Index of Figures Figure 1 Rack Mount Kit ec cceeeeeeseeeeeeeeeenneeeeeeeenaeeeeeeseeaeeeeeeeeeeeeaeeaaea 3 Figure 2 Model 32 Front Panel Layout cceeceeeeeeeeeeeneeeeeeeenteeeenee 17 Figure 3 Model 32 Rear Panel Layout ecceececeseeeeteeeeeeeeeeeeeeeeaaaeaaeee 68 Figure 4 Proper Assembly of the Input Connector eres 70 Figure 5 Diode and Resistor Sensor Connections cceeeeeeeeeeees 71 Figure 6 Thermocouple Input Connecto ccceeeeeeeeeeeeeeeeeeeeeeeeeeeeees 72 Figure 7 RS 232 Null Modem Cable ccceccceeceeeeeeeneeeeeeeeeneeeeeeeeaeaaaaa 74 Figure 8 Instrument Calibration SCreen eceeecceeeeeeeeeeeeeeeeeeeeeeteeeeeeeees 125 vi Model 32 32B User s Manual vii Model 32 32B User s Manual Preparing the controller for use Preparing the controller for use The following steps help you verify that the controller is ready for use Supplied Items Verify that you have received the following items with your controller If anything is missing cont
123. ected control loop load from the above list Query Syntax LOOP 1 LOAD Query Response lt LOAD gt Command Example LOOP 1 LOAD 50 Sets the primary heater output for a 50Q load Query Example LOOP 1 LOAD Example Response 25 Short Form LOOP LOAD 178 Model 32 32B User s Manual Remote Operation LOOP MAXPWR Heater Maximum Output Power Sets or queries the maximum output power setting of the selected control loop Please refer to the discussion on maximum output power in the Control Loop Setup Menu section Command Syntax LOOP lt no gt MAXPWR lt MaxPwr gt Where lt no gt is the loop number and lt MaxPwr gt is the desired maximum output power limit expressed as a percentage of full scale Query Syntax LOOP lt no gt MAXPWR Query Response lt MaxPwr gt Command Example LOOP 1 MAXPWR 50 Sets the maximum output power limit on loop 1 to 50 of full scale Query Example LOOP 1 MAXPWR Example Response 25 Short Form LOOP MAXP LOOP MAXSET Control Loop Maximum Setpoint Sets or queries the maximum allowed set point for the selected control loop Please refer to the discussion on Maximum Setpoint in the Control Loop Setup Menu section Setpoint units are the currently selected display units for the controlling input channel Command Syntax LOOP lt no gt MAXSET lt MaxSet gt Where lt no gt is the loop number and lt MaxSet gt is the desired maximum set point Query Syntax
124. ed by rotating the selector cams until the desired voltage shows through the window shown There are two fuses that may be removed by pulling out the fuse modules below the voltage selector Fuses are specified according to the AC power line voltage used Line Voltage Fuse Example _ 100VAC 120VAC 2 0A slow blow Littlefuse 313 002 220VAC 240VAC 1 0A slow blow Littlefuse 313 001 Table 26 AC Power Line Fuses 69 Model 32 32B User s Manual Specifications Features and Functions Sensor Connections All sensor connections are made at the rear panel of the Model 32 using the two DIN 5 receptacles provided Standard Four Wire Sensor Connections Silicon Diode and all resistor type sensors should be connected to the Model 32 using the four wire method It is strongly recommended that sensors be connected using shielded twisted pair wire Wires are connected as shown below and the shield should be connected to the metal backshell of the connector Sense V Sense V Excitation I O O Table 27 Input Connector Pin out Excitation l Caution To ensure proper low noise operation cable shields should be connected to the metal backshell of the connector A metal clip is provided with the connector for this purpose Please refer to the section on shielding and grounding for further information Figure 4 Proper Assembly of the Input Connector cF Note The input connectors on the
125. ed for most systems Sets the autotune timeout in seconds If 4 AT Timeout 180S the process model has not converged within this time tuning is aborted Real time display of the temperature on z 308 112K the input channel being tuned Pressing Enter will initiate the autotune ZAT Idle Autotune status Display only Proportional gain term generated by autotune This field will be blank until a successful autotune is completed Integral gain term generated by autotune This field will be blank until a successful autotune is completed Derivative gain term generated by 10 autotune This field will be blank until a successful autotune is completed the new parameters and exit to the Home Operate Display Pressing Enter cause the controller to transfer the generated PID coefficients 11 ZAT Save amp Exit to the selected loop initiate control with Table 32 Autotune Menu The Delta P field is in percent and is the maximum change in output power that the controller is allowed to apply during the modeling process A value of 100 will allow use full scale power increments A value of 20 will use a maximum power increment of 20 of the current heater output The Mode field tells autotune to generate coefficients for P only PI only or PID Choices are P PI and PID The Timeout field is in units of Seconds and indicates the maximum period of time that the process model will run before aborting This value
126. ed to query the generated D or differentiator gain term Query Syntax lt oc gt AUTOTUNE GAIN Query Response lt value gt Where lt oc gt is the output channel to tune and may be either LOOP 10r LOOP 2 lt value gt is the generated D feedback term in inverse Seconds Query Example LOOP 2 AUTO DGA Example Response 22 0000 Indicates that the generated D gain term is 22 Seconds Short Form AUT DGA 197 Model 32 32B User s Manual Remote Operation AUTOTUNE STATUS Autotune Status Queries the status of the autotune process Return values are Idle Autotune has not started Running Autotune is running Complete Autotune successfully completed Failed Unable to generate PID values Abort Aborted by operator intervention Query Syntax lt oc gt AUTOTUNE STATUS Query Response lt status gt Where lt oc gt is the output channel to tune and may be either LOOP 10r LOOP 2 lt status gt is the current status of the autotune process from the above list Query Example LOOP 1 AUTO STATUS Example Response COMPLETE Indicates that autotune has successfully completed and generated values for PID are available Short Form AUT STAT 198 Model 32 32B User s Manual Remote Operation INSTCAL commands The INSTCAL commands are used to calibrate the Model 32 input sensor measurement circuitry They should only be used in association with the instrument s calibration procedure Instr
127. eeeteeees 22 OUD sa sceteneit see E sere ta ata 42 OTD renine oleae aaa Enable aie irked ese been 40 Setpoint a sevice AA ate 41 TOUET ea alee ad 40 OIDISCONN scan aia cietaw dst 25 output power limit c ceeeeseeeeeeeeeeteeeeees 37 Over Temperature Disconnect a20 Oyvertem pe ken i a a a te 25 OVERTEMP command ccceeeeceeeeees 181 PID Coefficient eean peesi nik Ta 44 193 configuration sessen eenen 35 control 66 171 lOOP sitesinde Eee EEEE A E 66 MOd Cis iiin set tac wank Pears 64 Table 37 44 64 66 103 110 171 172 186 188 189 208 Table index selection ccccceeeeeeeeeeeeees 37 File Format 186 PIDTABLE commands 186 POWER Ke ceeeceeeeeeeeeeeeeseneeeeeeeeeesneeeeeees 11 proportional gain cceeee 35 175 207 Protective Ground ccccccceccssseeeeeessteeeaeaeee 68 Ramping iain nann i Ri ia ae 85 AIQOrth Merete da ea ee 86 OperatiOn eenei a a inaia Gad 85 rate SClECtION cccececceeessteeeeeeeeeeeeeeeeeees 38 SSUDA AN a AEO 86 RatiometiC ae oriee NES RE ELA 55 Readback s seca asain a 25 Real Time Moniitor cc cccccsseceeessseetseenee 110 ReMOte LED Miar seisin iinta aiandi 22 141 remote tranSactiOns ccccceccesseeeeeeeeeeaeaeee VIGWING Shisdesistetiyaes ita ean ee he 43 RS 232 a a a 43 67 144 RS 29 2 tis ccna eL a VA aa EEEo taei CONNECHONS hai wet tdce
128. el 32 it wil be10V and for a Model 32B it will be 10W Control Type Selections are Off Man 8 iType PID PID RampT RampP and Table Power limit as a percent of full scale N iPower Limit 100 On loop 1 this limit only applies to the HI range Table number for control in Table mode iPID Table index OF _ The Model 32 has six PID tables numbered from zero through five 7 Sets the heater load resist 3 Table 10 Control Loop Setup Menus 34 Model 32 32B User s Manual Front Panel Menu Operation Setpoint Numeric Entry The first line of this menu the user can change the setpoint while still viewing the temperature of the controlling source channel This allows the user to view the temperature without leaving the setup menu c Note Entry of a setpoint can be overridden by the Maximum Setpoint field described below The instrument will not accept an entry that exceeds the maximum Control loop setpoints may also be entered by using the Set Pt key Control Loop PID values Numeric Entry The Pgain Igain and Dgain lines correspond to the Proportional Integral and Derivative coefficients of the control loop Pman is the output power that will be applied to the load if the manual control mode is selected Values for the Proportional or P gain term range from zero to 1000 This is a unit less gain term that is applied to the control loop Gain is scaled to reflect the actual heater ran
129. emperature field The first four characters of a Calibration Curve Menu show the two digit sensor index followed by either the sequence gt gt 48 Model 32 32B User s Manual Front Panel Menu Operation Calibration Curve Menu Sets the current index to an entry within the current table Values are 0 to 159 18 gt gt IX 123 When the Enter key is pressed the following lines will display any data corresponding to the selected entry Te ure Uni Iw i 2 18 gt gt T 232 0050 Sensor reading Units are taken from 3 118 gt gt S 14 00002 the Sensor Setup menu described above Pressing Enter will display the next level 4 118 gt gt SaveCurve amp Exit amp menu where the sensor s Calibration Curve data may be viewed and edited Table 16 Calibration Curve Menu The Auto Tune Menu The Model 32 can automatically tune both control loops For a complete description of the autotune process including configuration of the tuning menus refer to the section titled autotuning 49 Model 32 32B User s Manual Specifications Features and Functions Specifications Features and Functions Specification Summary User Interface Display Type 20 x 2 character VFD 9mm character height Number of Inputs Displayed Two Keypad Sealed Silicon Rubber Temperature Display Six significant digits autoranged Display Update Rate 0 5 Seconds Display Units K C F or native sensor units Display
130. emperature ramps on the Loop 1 and Loop 2 channels are independent of each other Command Syntax N A Query Syntax LOOP lt no gt RAMP Where lt no gt is the loop number 1 or 2 Query Response ON or OFF Query Example LOOP 2 RAMP Example Response OFF Short Form LOOP RAMP LOOP RATE Control Loop Ramp Rate Sets and queries the ramp rate used by the selected control loop when performing a temperature ramp Rate is in Units per Minute Command Syntax LOOP lt no gt RATE lt Value gt Where lt no gt is the loop number 1 or 2 and lt Value gt is the ramp rate in Units Minute This may be a value between 0 and 100 Command Example LOOP 1 RATE 0 02 This will set the loop 1 temperature ramp rate to 0 02 If the controlling input channel has units of Kelvin the heater rate will be set to 0 02K min Query Syntax LOOP lt no gt RATE Query Response lt Value gt Query Example LOOP 2 RATE Example Response 0 0100 Short Form LOOP RAMP 174 Model 32 32B User s Manual Remote Operation LOOP PGAIN Control Loop Proportional Gain term Sets or queries the selected control loop s proportional gain term This is the P term in PID and is a unit less numeric field with values between 0 off and 1000 The P gain term is applied to the control loop when controlling in a PID mode Command Syntax LOOP lt no gt PGAIN lt value gt Where lt no gt is the loop number 1 or 2 and lt value gt is
131. enheit or S for primitive sensor units In the case of sensor units the instrument will determine if the actual units are Volts or Ohms based on the actual sensor type selected for the input channel Query Syntax INPUT lt channel gt UNITS Where lt channel gt is the input channel indicator Query Response lt units gt Where lt units gt is the display units indicator which will be K C F V for Volts or O for Ohms Command Example INPUT B UNITS F Query Example INP A UNIT Example Response K Query Example INP A TEMP UNIT Example Response 27 9906K Short Form INP UNIT 154 Model 32 32B User s Manual Remote Operation INPUT SENPR Input Reading in Sensor Units The INPUT SENPR query reports the reading on a selected input channel For diode and thermocouple sensors the reading is in Volts while resistor sensors are reported in Ohms The reading is not filtered by the display time constant filter However the synchronous input filter has been applied Query Syntax INPUT lt channel gt SENPR Where lt channel gt is the input channel parameter of A or B Query Response lt rdg gt Where lt rdg gt is the reading of the specified input channel in Ohms or Volts Query Example INP B SENPR Example Response 124 5933 meaning 124 5933 Ohms Short Form INP lt channel gt SENPR INPUT VBIAS Input channel sensor bias voltage Sets or queries the constant voltage mode voltage used on the specified in
132. ensitivity 1500K 36uV K 1200K 76uV K 600K 60uV K 600K 23 4uV K Measurement 300K 0 6uV 300K 0 6uV 300K 0 5uV 300K 0 5uV Accuracy 1500K 6 7uV 1200K 9 0uV 600K 4 0uV 600K 2 0uV Temperature 300K 15mK 300K 11mK 300K 12mK 300K 17mK Measurement 1500K 190mK 1200K 122mK 600K 75mK 600K 90mK Accuracy Measurement 300K 0 5pV 300K 0 5uV 300K 0 4uV 300K 0 4uV Resolution 1500K 0 5uV 1200K 0 5uV 600K 0O 4uV 600K 0 4uV Temperature 300K 11mK 300K 11mK 300K 12mK Resolution 1500K 13mK 1200K 13mK 600K 73mK 300K 12mK 600K 73mK ae 300K 110mK 300K 56mK 300K 60mK 300K 66mK Control Stability 4500K 100mK 1200K 55mK 600K 56mK 600K 65mK Magneto Very Large Very Large Very Large Very Large Includes error from internal cold junction compensation Table 24 Sensor Performance for Thermocouple Sensors 62 Model 32 32B User s Manual Specifications Features and Functions Factory Installed Sensors For a listing of factory installed sensors refer to Appendix A CalGen Calibration Curve Generator The CalGen feature is used to generate new calibration curves for Silicon Diode Thermocouple or Platinum sensors This provides a method for obtaining higher accuracy temperature measurements without expensive sensor calibrations Curves can be generated from any user selected curve and are written to a specified internal user calibration curve area The CalGen functio
133. ensor setup thermocouple calibration curve 47 92 103 185 188 189 208 CONFIG command6 cee cece eeeeeeeees 151 constant voltage 205 CONTROL command 139 141 CONTROL Key ieisccoruvesesecciefastisedtestestutiesecsesers 11 Control LED 22 control type selection 36 control TY POSs feccacceteceee cesses aurea ap nea ease eee 171 CRV ahne aa arin aneni ate 103 106 GrYyOCOOIG a apa eoa an aenea a aeaee synchronous subtraction 87 thermal Signature ccccesceeeseeeeteeeeeeees 87 Current excitation eee eee eeeeeeeeeeeeeee 55 CUr SAO Pi Meenn erie 103 106 data logging eneee 103 111 CONFIR a a 111 Derivative Qain ecccceeseceeesceceeeeeeeeeeeeeeenaeee 35 differentiator gain term 176 Display eiee ise eee AETA RES iaa brightNeS Sitni ia Aa 42 configuration 22 29 Dual Input Status 0 cece eee 29 Dual Loop Status cccccceceeeeeeseeeeeeeees 29 LOOP Status ies weeklies aenaeelecti 29 FESOIULION ccceeeeeeeeeeeeeeee 23 42 149 204 Stati Stes iiir casei cavee vases irean rira eeeeseeceane 29 time constant 0 eee eee eect eeeeeeeeee 41 DIM ET eave cares Settle dete E E as 65 Electrical Isolation 63 EnG OSU Enn unarna a 74 ENClOSUIC3 tania aren aaa aE aa diMeENSION Sieniniai aiie Weighted arenae asiana aana ady at ENTER KOYcihisictecrevenssnneseteronocnesersuavedugermer abs enumeration fields ESE tar Qin aie iain no
134. ensors by using a software based Cold Junction Compensation scheme as follows 1 The sensor input connection on the rear panel of the instrument is thermally anchored to a temperature sensor that is used for Cold Junction Compensation 2 The Cold Junction Temperature is continuously monitored and converted to a Cold Junction Voltage by a performing a reverse lookup of the sensor s calibration curve 3 When a sensor reading is taken the Cold Junction Voltage is subtracted from the measured voltage The result is used to compute actual sensor temperature by using a forward lookup on the sensor s calibration curve It is important that Thermocouple sensors be connected directly to the input connector as described in the section below For example if the thermocouple wires were first connected to Copper wires then to the Model 32 input the Cold Junction Compensation cannot function properly and measurement errors will result The Cold Junction Compensation function may be turned On or Off for each input channel This is done by using the CJcomp field of the Input Channel Setup Menu Adding New Thermocouple Types New thermocouple types may be added to the Model 32 by adding a new user sensor type and corresponding calibration curve This procedure is described in the section below titled Adding a New Sensor Since the software Cold Junction Compensation technique used by the Model 32 depends on the thermocouple s ca
135. ent documentation Background color Yellow Symbol Frame or Chassis terminal and outline Black On AC Power h Fuse Off AC Power Environmental Conditions Environmental conditions outside of the conditions below may pose a hazard to the operator and surrounding area Indoor use only Altitude to 2000 meters Temperature for safe operation 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 Over voltage category Il Pollution degree 2 Ventilation The instrument has ventilation holes in its side covers Do not block these holes when the instrument is operating Do not operate the instrument in the presence of flammable gases or fumes Operation of any electrical instrument in such an environment is a definite safety hazard 76 Model 32 32B User s Manual Basic Setup and Operating Procedures Basic Setup and Operating Procedures Configuring a sensor Before connecting a new sensor to the Model 32 the instrument should be configured to support it Most common sensors are factory installed others require a simple configuration sequence A complete list of sensors installed at the factory is shown in Appendix A To configure the instrument for one of these sensors proceed as follows 1 To install the sensor on Input Channel A press the ChA key For Ch
136. enu where the sensor s Calibration Curve data may be viewed and edited Table 15 Sensor Setup Menu The first line on this menu is the sensor table index Selecting this field will allow scrolling through all of the sensors configured in the unit including user sensors The index is displayed along with the sensor name Note the sensor name may be entered via any of the Remote I O interfaces but may not be changed from the front panel Sensor Type is an enumeration of all of the basic sensor types supported by the Model 32 Choices are shown in the Supported Sensor Configurations table above The Multiplier field is a floating point numeric entry and is used to specify the sensor s temperature coefficient and to scale the calibration curve Negative multipliers imply that the sensor has a negative temperature coefficient The absolute value of the multiplier scales the calibration curve For example the curve for a Platinum sensor that has 100 of resistance at 0 C may be used with a 10000 47 Model 32 32B User s Manual Front Panel Menu Operation sensor by specifying a multiplier of 10 0 Also note that the temperature coefficient field is only used when the unit is controlling temperature based on the sensor units of Volts or Ohms Units is an enumeration field that identifies the primitive units used by the sensor s calibration curve Choices are Volts Ohms and LogOhm LogOhm selects the base ten logarithm of ohms
137. er may install up to four custom sensors This table shows the sensor index and default name of the user curves index o o Usersensoro a a User sensor OSS 2 2 Tersa OOOO Ce 3 T uersmors OOOO y When using the CALCUR commands only user curves are addressed therefore the user index usenix shown above is used The USENIX remote commands address user installed curves For example CALCUR 2 would address user curve 2 INPUT A USENIX 1 would set input A to use User Sensor 1 214 Model 32 32B User s Manual Appendix A Installed Curves Sensor Curves on CD The following sensors are available on the CD supplied a ee CryocalD3 crv Cryocal D3 Silicon Diode Range 1 5 to 300K CTldiode crv CTI cryo pump silicon diode Range 10K to 325K Scientific Instruments Inc SI 410 Silicon Diode Range 1 5 to 450K Lakeshore Curve 10 Silicon Diode curve for DT 470 series diodes Range 1 4 Curve10 crv to 495K Lakeshore Curve 10 Silicon Diode curve for DT 670 series diodes Range 1 4 to Curve1t crv 500K Cryocon CP 100 DIN43760 or IEC751 standard Platinum RTD 100Q at 0 C PT100385 crv Range 23 to 1023K DIN43760 or IEC751 standard Platinum RTD 1000Q at 0 C Range 23 to PT1K385 crv 1023K Platinum RTD 100Q at 0 C Temperature coefficient 0 003902 Q C Range 73K PT1003902 crv to 833K Platinum RTD 1000Q at 0 C Temperature coefficient 0 00375 Q C Range 73K PT1K375 crv to 833K 215 Model 32 3
138. ess The Model 32 performs autotuning by applying a generated waveform to the heater output and analyzing the resulting changes in process temperature This is used to develop a process model then a PID solution It is important to note that there is a range of PID combinations that will provide accurate control for a given process Further process modeling is a statistical method that is affected by noise and system non linearity As a result multiple autotuning of the same process may yield different results However if the process model has not corrupted any of the generated results will provide equally stable temperature control For further explanation the different PID solutions generated by autotuning will vary only in the resultant closed loop bandwidth Low bandwidth solutions will be slower to respond to changes in setpoint or load disturbances High bandwidth solutions will result be responsive but can exhibit overshoot and damped oscillation The Model 32 attempts to generate minimum overshoot solutions since many cryogenic temperature control applications require this If the process is noisy bandwidth will be minimized as much as possible If the process is very quiet a more aggressive solution will be generated subject to the minimum overshoot requirement The autotune algorithm will produce a heater output waveform in order to force the process model to converge In general a large amplitude waveform will provide the best
139. essing the Enter key resets the accumulation time straight line fit to the input channel temperature Pressing the Enter key resets the accumulation time Selects sensor bias type Applies only to 16 ABias Vol tage 10mV resistor sensors that use constant voltage Displays the offset of the input temperature over the accumulation time The M and b 15 z statistics are the slope and offset of a excitation All others show N A Choices are 10mV 3mV and 1 0mV Table 9 Input Channel Setup Menus Temperature Units Enumeration Default K The Temperature Units field line 1 assigns the units that are used to display temperature for the input channel Options are K for Kelvin C for Celsius F for Fahrenheit and S for sensor units Note that if the S option is selected the actual sensor units will be displayed when the field is deselected Available sensor units are V for Volts and Q for Ohms Use the or 4 key to scroll through all of the options When the desired units are displayed press the Enter key to make the selection The display will now show the current temperature with the new units Sensor Type Selection Enumeration Line 2 selects the Sensor type for the input channel When this field is selected the scroll keys are used to scroll through all of the available sensor types Factory installed sensors appear first and then user sensors For a list of both factory and user sensors refer to Appendix A New use
140. f Range Display If a temperature reading is within the measurement range of the instrument but is not within the specified Sensor Calibration Curve a display of seven dot characters is heek shown cF Note In some cases there will be an erratic temperature display when no sensor is connected This is not an error condition The high input impedance of the controller s input preamplifier causes erratic voltage values when left unconnected 24 Model 32 32B User s Manual Front Panel Operation Loop Status Displays When the Model 32 is not controlling temperature the status of the Loop output is shown The first character of the Loop Status Display is always the loop number which will be either a superscripted 1 or 2 corresponding to Loop 1 or Loop 2 The Loop number will be followed by the heater status as follows 1 OFF Indicates that heater output is functional and the control loop is off or disabled 1 OFF Low For the primary heater Loop 1 the range is also shown Range settings may be either Hi Mid or Low The range is set in the Loop 1 menu For the secondary output or Loop 2 the range will be shown as 10W fora Model 32B or 10V for a Model 32 Overtemp indicates that the controller s Internal Temperature Monitor circuit shut off the heater This fault is usually the result of a shorted heater or use of a heater with significantly less resistance than the selected load resista
141. fic index may be identified using the PIDTABLE query There is a maximum of 16 entries in each PID table Each entry contains a setpoint P and D coefficients and a heater range Either output channel may use any table The heater range field only applies to Loop 1 However it must be specified in each entry The format of an entry is lt setpoint gt lt P gt lt I gt lt D gt lt Heater Range gt Fields are separated by a white space The entry is terminated by a new line n character if the table is transmitted via the RS 232 interface and is not terminated for all others Floating point numbers may be entered with many significant digits They will be converted to 32 bit floating point which supports about six significant digits The heater range is an enumeration field that may have the following values Hi Mid and Low The file format of a PID table is shown below lt name gt lt entry 0 gt lt entry 1 gt lt entry N gt Where lt name gt is the name of the table and is a maximum of 16 ASCII characters lt entry gt is a PID entry Aline that contains only a single semicolon indicates the end of the table 186 Model 32 32B User s Manual Remote Operation An example of a sixteen entry PID Table is as follows PID Test O 300 280 260 240 220 200 180 160 140 120 100 80 60 40 20 10 00 oo oo oo oo oo oo oo oo oo oo oo 00 oo 00 oo
142. g but the remote interfaces are not The Single Point Ground The internal Single Point Ground is the voltage reference point for the instrument s grounding scheme All circuits are designed so that no current will normally flow through the connections to this ground Therefore it provides a good quality low impedance path to ground for any undesired currents that are coupled into the equipment AC Power Entry AC Power enters the instrument directly into a power entry module This provides fusing line voltage selection and RFI filtering The Building Ground often referred to as Earth Ground Shield Ground or Third Wire Ground is connected to the shield of the Power Entry RFI filter then to the instrument s Single Point Ground Since the grounding and shielding scheme depends on having a good quality ground this Earth Ground connection is extremely important Noise and ground loop problems are often traced to how this connection is made If your facility does not provide a building ground it is strongly recommended that one be fabricated Sensor Connection For best performance all sensors connected to the instrument should be electrically isolated floating from any other grounds Sensors used in cryogenic thermometry are often high impedance For example a Silicon Diode temperature sensor will have about 160K ohms of impedance at 5K Because of this a very efficient antenna can develop around the sensor an
143. g device operations have finished RST Reset the controller Control Loop Start Stop commands STOP Disengage all control loops CONTROL Engage all control Loops Query if the loops are engaged CONTROL SYSTEM commands SYSTEM LOCKOUT Sets or queries the remote lockout status indicator SYSTEM LOCKOUT SYSTEM BEEP Asserts the audible alarm SYSTEM REMLED Sets or queries the remote LED status indicator on the front panel SYSTEM REMLED Reports the status of the two temperature control loops Set or query the display filter time constant Available time constants SYSTEM DISTC are 0 5 1 2 4 8 16 32 or 64 Seconds SYSTEM ADRS resulting in faster settling SYSTEM SYNCTAPS Sets the number of taps used by the synchronous filter SYSTEM REMOTE Sets the remote interface port Choices are GPIB and RS232 203 Model 32 32B User s Manual Remote Operation Command st Function S O SYSTEM AMBIENT Query the temperature of the controller s internal voltage reference Example Output 25C SYSTEM AUTOCAL Perform an autocalibrate sequence on both input channels Generally used only to correct for errors caused by significant changes in operating temperature SYSTEM HTRHST Query the temperature of the internal LOOP 1 heatsink Example output 62C SYSTEM HOME Causes the display on the front panel to go to the Operate Screen SYSTEM NAME Set or query the instrument s name string Example SYSTEM NAME SYSTEM NAM
144. g navigation systems and consumer audio CD recordings Perhaps the most common example of a dithering technique is the synthesis of an artificial color on a computer screen by grouping available colors at adjacent pixels When viewed by the user the spatial averaging effect of the eye generates a color that is not available on the computer s color palette In Cryo con s temperature controllers dither is used to extend the dynamic range of a temperature control loop by outputting available power levels in a controlled sequence so that the average power is somewhere between the levels available in the controller s hardware Here the averaging function is performed by the system dynamics Control Accuracy Major error sources in a digital control loop are the input quantizer ADC the Digital Signal Processing mathematical operations and the output quantizer DAC Cryo con controllers use a 24 bit Analog to Digital converter This is the best available with modern components and it establishes the measurement resolution of the controller If all other functions were perfect this ADC would also establish the accuracy of the control loop In order to preserve accuracy the mathematical operations in a digital control loop must be performed to a much higher resolution than the input ADC Therefore Cryo con controllers all use 32 bit floating point arithmetic Finally a high precision loop output value reaches the output quantizer which
145. ge and the load resistance Integrator gain values range from zero to 10 000 The units of this term are Seconds A value of zero turns the integration function off Derivative gain values have units of inverse Seconds and may have values from zero to 1000 A value of zero turns the Derivative control function off The Pman field is only used when the heater output is in manual control mode The value is in percent of full scale output power Watts and may have values from zero to 100 r Note The Model 32 expresses heater output values in terms of percent of full scale output power The actual power in Watts applied to the load is proportional to the square root of output current Control Source Input Channel Enumeration Default Loop 1 ChA Loop 2 ChB The input filed selects the control loop source input Any input channel may be selected 35 Model 32 32B User s Manual Front Panel Menu Operation Control Loop Range Enumeration Default Loop 1 Low The Range field selects the full scale output for the selected control loop For Loop 1 settings are HI MID and LOW The actual full scale output power is determined by this setting along with the load resistance See the Heater Output Ranges Table for more information The full scale output range for Loop 2 is fixed and cannot be changed by using the Range field For a Model 32 the output is a 0 to 10Volt voltage source For the Model 32B the ou
146. gt is the input channel parameter and lt ix gt is the desired sensor index Query Syntax INPUT lt channel gt USENIX Where lt channel gt is the input channel indicator Query Response lt ix gt Where lt ix gt is the sensor index for the selected input channel If the index is outside of the range 0 through 3 a value of 1 will be returned Command Example INPUT B USENIX 0 This command sets the sensor index for input channel B to zero disabled Query Example INP A USENIX Example Response 2 This indicates that sensor 02 is assigned to input channel A Short Form INP SEN 157 Model 32 32B User s Manual Remote Operation INPUT SENIX Sensor index obsolete Sets or queries the sensor index number assigned to an input channel This command is used to assign the sensor type to a channel Sensor types and configurations are accessed using the SENTYPE commands Sensor index zero indicates that there is no sensor connected to the selected input channel This will disable all readings on the channel Refer to Appendix A for a description of sensors indices etc Note To ensure portability of software written for the Model 32 you should use the ISENIX command to assign a factory installed sensor or USENIX to assign a user sensor This way the index will always correspond to the correct sensor regardless of the Model 32 firmware revision Command Syntax INPUT lt channel gt SENIX lt ix gt
147. h input channel statistics have been accumulated TIME is reset by issuing the INPUT RESET command Query Syntax INPUT lt channel gt TIME Where lt channel gt is the input channel indicator Query Response lt time gt Where lt time gt is the time in Seconds that has elapsed since the channel statistics were reset Query Example INPUT A TIME Example Response 232 Indicating 232 seconds have elapsed Short Form INP TIM INPUT RESET Reset Statistics Resets the accumulation of input channel statistical data Command Syntax INPUT lt channel gt RESET Resets the accumulation of input channel statistics Command Example INPUT lt channel gt RESET Short Form INP RES 168 Model 32 32B User s Manual Remote Operation LOOP commands Loop commands are used to configure and monitor Model 32 s control loops Note LOOP 1 may also be referred to as HEATER and LOOP 2 may be referred to as LOOP 2 Loop 1 is the controller s primary heater output channel In the Model 32 and 32B this is a 50 25 Watt three range linear heater Loop 2 is a secondary output In the Model 32 this is a 0 5V voltage output that can drive a strip chart recorder or a booster power supply Loop 2 of the Model 32B is a 10 Watt single range linear heater LOOP SOURCE Control loop Source Input Channel Sets and queries the selected control loop s controlling input channel Command Syntax LOOP lt no gt SOURCE lt chan gt
148. hen a field has been changed a block cursor will flash over the 4 symbol Each time the gt or 4 key is pressed the field value will scroll forward or backward through all of the available choices To select the displayed value press the Enter key To cancel selection without updating the field press the Esc key The cursor will then return to the symbol The Keypad Keys and Numeric Data Fields A numeric data field is indicated by a pound sign in the last column of the display The Keypad Keys are used to enter data into numeric fields These keys are the numerals 0 through 9 the period key and the key When the cursor is positioned to a field that requires numeric data the Keypad Keys become hot and pressing one of them will result in the field being selected and numeric entry initiated This is indicated by a flashing cursor When the Enter key is pressed numeric data in the selected field will be checked for range and the instrument s database will be correspondingly updated If the numeric entry is outside of the required range an error is indicated by the display of the previous value of the field Once the entry of numeric data has started it can be aborted by pressing the Esc or Home key This will cause the field to be de selected and its value will be unchanged c Note Up to 20 digits may be entered in a numeric field When digit entry has exceeded the display field width additional characters wil
149. her is weighted by how O38 eee close the desired output is to the O70 2029 OOO Ao OO nearest quantization level In this example the desired outputis i 25 of the distance from Q3 to Q2 ee ee tore Therefore 75 of the DAC output Q1 samples will be Q3 and the remaining Most importantly the average value of the DAC output converges to the desired output loop value 224 Model 32 32B User s Manual Appendix C Application Note on Signal Dither Using this dither technique the control loop output accuracy will improve as the number of averages increases up to the limits imposed by the other elements of the control loop Fortunately the number of samples averaged in a given system is proportional to its closed loop bandwidth which can be controlled by adjusting PID parameters How much improvement does dither provide Dither causes the average value of the control loop output to converge to the actual desired output How close depends on the number of averages accumulated within the closed loop system The accuracy of an estimate of average value for a fixed number of samples is given by the Chi squared distribution The degrees of freedom used by this function is the number of samples accumulated Using the Cryo con Model 32 the loop output rate is 10 samples per second Therefore if the process being controlled has a time constant on the order of 1 6 seconds a total of 16 samples will be averaged re
150. hort Form SYS RES c Note The RESEED command is very useful in systems where a computer is waiting for a reading to settle Issuing the RESEED command will reduce the required settling time of the reading 144 Model 32 32B User s Manual Remote Operation SYSTEM AMBIENT Query Internal Temperature The Model 32 incorporates a temperature sensor into it s internal voltage reference This temperature is essentially the internal temperature of the instrument and may be queried using the SYSTEM AMBIENT command Query Syntax SYSTEM AMBIENT Query Response lt temp gt Where lt temp gt is the internal temperature of the Model 32 in degrees Celsius Query Example SYSTEM AMB Example Response 25C Indicates that the current temperature of the Model 32 s internal voltage reference is 25 C Short Form SYST AMB Where AMBIENT is truncated to four characters then to three since the fourth character is a vowel SYSTEM AUTOCAL Automatically recalibrate the input channels This command causes the Model 32 to execute an internal recalibration of both input channels It is useful when the operating temperature has changed significantly The process takes about 2 second to complete Autocalibrate should not be executed when the Model 32 is controlling temperature because it may cause the control loops to disengage Command Syntax SYSTEM AUTOCAL Short Form SYST AUT Where AUTOCAL is truncated to four chara
151. ibration Curve Generator e ssssssresssrreressrrrrrerrernnnesrennna 114 The Vapor Pressure Calculatot ceeeececceeeeeeeeeeeceeaeeeeeeeees 117 Downloading Instrument Firmware suicccsssssntcssanscanncersannssenesasesaaretesndaas 118 ner ument Calibration ssni ii a aai 123 Cryo con Calibration ServiCES vcccusessisaccastentisucasusaevininaivartaidauansansasnendes 123 Calibration Merna basri aaa ai 123 Minimum Required Equipment isisisi rendus soinnin didada 124 The Basic Calibration Sequence cecceeeeeeesecceeeceeeeeeeeeeeeeeeeeeees 124 Calibration Of Silicon DIGIES ci cccrcasersvssnnseercncsonancrindecumaatuweniebuedivennsse 129 Calibration of DG RESISTORS oie siininnesrcrxsonansvxeechouiaveaannneawandkaivosabebesiiniesiis 130 Calibration OT AG NOSIS IONS ss csiessarivsiisanenenseuamenatnmniieieaaae 130 Romie Opora toina R A 131 Remote Interface COMmQurationacciiccccccrescncasccenesienscneneeaassassssssormnanadias 131 Introduction to Remote PrOQraMniMING ciscsncceccasirenaviieimineanenzecea 133 SCPI SUS RONTE aoe 134 Remote Command S acnesonnada ana a eaaa 137 Remote Command SUMMATY sssssrsisurrrinssrneninnunnrnesnanunn ninnan 203 EU Declaration of COTTON TD its cretcnsscaoren nieadinoned tenascin iin 211 Appendix A Installed Curves iicsincaocasdancnosoaansananneasannannssncancassernoaacnennnneennn 213 Factoty Installed OUTOS nirien innare TEn EENET 213 Sensor Cumes ON C Derenin a iieii 215
152. ical cooling process it is low frequency and has an irregular shape that is rich in harmonics With most coolers the frequency will be a sub multiple of the AC line frequency around 2Hz and the shape will be a narrow spike followed by a long lull If a conventional PID control loop is connected to a cryocooler the thermal signature will disrupt the loop and degrade the accuracy of control If a fast PID loop is used it will attempt to track the signature which usually results in placing a waveform on the loop output heater that causes control performance to degrade even further In still other systems the thermal signature of the cryocooler will be outside of the PID control loop bandwidth enough to cause a phase reversal that actually amplifies the signature causing the entire system to become unstable These systems will oscillate with a sine wave at a very low frequency Faced with a significant thermal signature users are generally required to de tune the PID loop and live with the resulting inaccurate control Here there is still the possibility of instability The Model 32 uses digital time synchronous filter to actively subtract the cooler s signature resulting in much higher control accuracy and loop responsiveness With the Synchronous Filter enabled the controller will synchronously subtract the thermal signal from the input temperature signal Since synchronous subtraction is used to eliminate the undesired signature there
153. in pane Upon completion the Download Complete dialog box will appear Dismiss this dialog box to complete the download process Cryo con Utility Software dloader 1O x File Comm Firmware Calibration Table PID Table View DataLogging Help 155 449997 163 369995 171 289993 179 210007 187 139999 195 059998 202 979996 210 899994 218 820007 226 740005 234 660004 242 589996 250 509995 258 429993 266 350006 274 269989 282 190002 290 109985 298 040009 305 959991 313 880005 321 799988 Ready 413 149994 433 149994 453 149994 473 149994 493 149994 513 150024 533 150024 553 150024 573 150024 593 150024 613 1500 EEA xj 633 1500 653 1500 673 1500 Downloading to Calibration Curve 1 Please wait 693 1500 ao D e e e e e e e e e e H p e e e p a i i a 713 1 500 0 BERR RRRRRRRRRRR EA 733 1500 753 1500 73150 EEE xl 793 150024 813 150024 AN Download Complete 833 150024 To upload a calibration curve use the same procedure and select Upload This will transfer a curve from the instrument to the PC 109 Model 32 32B User s Manual Cryo con Utility Software Downloading or Uploading a PID Table A PID table may be transferred to the instrument by selecting PID Table gt Download from the main menu toolbar PID tables are transferred from the instrument to the PC by using PID Table gt Upload From this point the sequence is identical to the calibration curve transfer p
154. ine frequency used c Note If you are not using a cryocooler please leave the Sync Filt Taps field set at the default of 7 c Note If you change the setting the Sync Filt Taps setting you will need to re tune the PID control loop Viewing a Cryocooler Thermal Signature In order to view a cryocooler s thermal signature and experiment with the synchronous filter the Cryo con Utility Software may be used In the Data Logging menu set the interval field to the minimum allowed value of 0 1 Seconds and then open a strip chart Use the manual settings on the strip chart to zoom in on the temperature You should be able to see the signature with the chart set to the base temperature plus or minus about 0 5K In order to see the cooler signature you will need to set the Sync Filt Taps field to zero This will disable the removal of the signature From here you can enter various values in order to see the affect of the synchronous filter Shown here is an example of a Cryomech PT403 pulse tube refrigerator with a very low heat capacity load The first part of the graph is with the synchronous filter turned off and the second part shows a setting of 7 taps 88 Model 32 32B User s Manual Basic Setup and Operating Procedures Channel A x 41 Ch 40 In most cases a tap setting may be found that completely eliminates the signature 89 Model 32 32B User s Manual Basic Setup and Operati
155. instrument s front panel by using the Remote I O Setup Menu All configuration information shown on this screen is stored in non volatile memory and once setup will not change when power is turned off or a remote interface is reset IEEE 488 GPIB Configuration The only configuration parameter for the GPIB interface is to set the address This is done by using the System Functions Menu described above Note that each device on the GPIB interface must have a unique address You can set the instrument s address to any value between 1 and 31 The address is set to 12 when the unit is shipped from the factory The controller s GPIB interface does not use a termination character or EOS Rather it uses the EOI hardware handshake method to signal the end of a line Therefore the host must be configured to talk to the instrument using EOI and no EOS Primary Address Secondary Address Terminate Read on EOS Set EOI with EOS on Writes YES EOS byte N A Table 36 Recommended GPIB Host Setup Parameters 131 Model 32 32B User s Manual Remote Operation RS 232 Configuration The user can select RS 232 Baud Rates between 300 and 38 400 The factory default is 9600 The Baud Rate can be changed from the instrument s front panel by using the SYS menu Other RS 232 communications parameters are fixed in the instrument They are set as follows Parity None Bits 8 Stop Bits 1 Mode Half Duplex The RS 232 interface u
156. ion code Query Syntax IDN Query Response lt Instrument Identification String gt OPC Operation Complete The OPC command will cause the instrument to set the operation complete bit in the Standard Event SEV status register when all pending device operations have finished The OPC Query places an ASCII 1 in the output queue when all pending device operations have completed Command Syntax OPC Query Syntax OPC Query Response 1 RST Reset Reset the controller This will cause a hardware reset in the Model 32 The reset sequence will take about 15 seconds to complete During that time the instrument will not be accessible over any remote interface The RST command sets the Model 32 to it s last power up default setting Command Syntax RST 138 Model 32 32B User s Manual Remote Operation Control Loop Start Stop commands STOP Disengage control loops The STOP command will disengage all control loops and disconnect their heaters Command Syntax STOP CONTROL Engage Control Loops The CONTROL command will cause the instrument to enter the control mode by activating enabled control loops To disable an individual loop set its control type to OFF As a query the command will report the status of the loops as ON or OFF Command Syntax CONTROL Command Example CONT Query Syntax CONTROL Query Response lt status gt Where lt status gt is ON or OFF Query Example CON
157. is clicked Once download has started you should not attempt to stop it 120 Model 32 32B User s Manual Cryo con Utility Software When a firmware download has successfully started the VFD display will continuously display the number of records transmitted as shown here There are 1008 records in a complete Record 001 of 502 firmware download The process should Errors 000 take about 15 minutes The PC screen will show a bar graph of progress during download When the download is complete the controller will freeze and the PC will display a Download Complete dialog box Caution When a firmware download is complete the controller should automatically reset within 10 seconds Do not unplug it When the reset process is complete hold down the Enter key and power cycle the instrument from the front panel The new firmware should boot up If a non recoverable communications error occurs during firmware download the controller will power up in an error mode where it is looking for a new firmware transfer on the serial port The VFD screen will display the transfer display shown above In this case repeat the above procedure until the entire firmware transfer sequence works correctly c NOTE Factory defaults may be restored at any time by use of the following sequence 1 Turn power to the Model 32 OFF 2 Press and hold the Enter key while turning power back ON cz NOTE The firmware download
158. is no phase shift or loss of signal energy as would be the case if a classical notch or low pass filter is used Subtraction is performed ahead of the PID control loop Therefore the input to the loop contains only the baseline temperature signal Using the Input Signature Subtraction filter gives much higher temperature measurement accuracy and allows the use of aggressive high precision control It is applicable to virtually any cryocooler system 87 Model 32 32B User s Manual Basic Setup and Operating Procedures Synchronous Filter Setup To use the synchronous filter two parameters must be set e The AC Line Frequency setting must correspond to the actual power input AC frequency The filter uses this to synchronize to the cooler e The Synchronous Filter Taps parameter must be set for the specific cryocooler type This parameter gives the filter a starting point for the number of filter taps required to perform an accurate subtraction Determination of a proper setting may require some experimentation To set the AC Line Frequency go to the Sys menu and scroll down to the field AC Line field Then select Sync Filt Taps O7 60 or 50 Hz as required AC Line 60Hz N To set the Synchronous Filter Taps parameter enter a number between 1 and 25 into the Sync Filt Taps field A setting of 1 turns the filter off For most cryocoolers a setting of 7 is used since this is the most common sub multiple of the AC l
159. isplay as shown here Control Alarm Remote Power Control Home Enter The Green Control LED is illuminated whenever either of the control loops are engaged and actively controlling temperature To disengage the loops press the Stop key The Red Alarm LED is illuminated whenever a user programmed has been triggered To clear the alarm the enabled event that is asserting the alarm must be disabled The Green Remote LED can be turned on or off under program control by the remote interface Use of this LED by a computer connected to the instrument is optional The VFD Display Home Status Displays At the top of the instrument s menu tree are the home status displays They can be selected from anywhere in the instrument s menu tree by pressing the Home key The list of display configurations is accessed by pressing the Display key Dual Input Status default Loop 1 Status Loop 2 Status Dual Loop Status ChA Statistics Ch B Statistics Select the desired configuration and press the Enter to return to the Home display Dual Input Status Display This is the factory default display It shows the status and current input temperature for both control loops OOP ON gt Input channel A is shown on the left and channel B on the right A87 4567K E104 932K 1 15 Hi 28 10W 22 Model 32 32B User s Manual Front Panel Operation The second line of the display shows the Loop Status Display Directly abov
160. l 32 has an automatic control on power up feature If enabled the controller will automatically begin controlling temperature whenever AC power is applied For a complete description of this function please see the SYS Auto Ctl function in the System Functions menu section Model 32 32B User s Manual A Quick Start Guide Configuring the Loop 2 Output The second control loop of a Model 32B controller is a fixed 10 Watt output that is matched to a 500 resistive load Therefore there are no load resistance or range settings to configure On the standard Model 32 the second control loop is a zero to 10 Volt output that is intended to drive a booster supply or other voltage controlled device It is not a heater output All other configuration settings are identical for both Loop 1 and Loop 2 Caution The Model 32 has an automatic control on power up feature If enabled the controller will automatically begin controlling temperature whenever AC power is applied For a complete description of this function please see the SYS Auto Ctl function in the System Functions menu section Restoring Factory Defaults Factory default settings may be restored with the following simple procedure 1 Turn AC power OFF 2 Press and hold the Enter key while turning AC power back ON Keep the key pressed until you see the power up display indicating that defaults have been restored c NOTE Factory defaults may be restored at
161. l cause the display to scroll from right to left When entry is complete the updated display field may not show all of the digits entered because of limited field width however the digits are retained to the full precision of the controller s internal 32 bit floating point format 20 Model 32 32B User s Manual Front Panel Operation Summary of keypad functions Key Function Description O row eenen ee toggle AC power Stop Disengage all controlloops SSCS P Conto Engage all controlioops O oO Home Goto the Home Status Display P Enter Enterdata make aselecion Aa Ee Rimioie tome Siams Depay o o return 19 the Home Status Display W Soroll Display DOWN Cd O gt Scroll to NEXT selection 4 Scroll to PREVIOUS selection Loe Display Go to the Display Setup menu Set Pt___ Change the setpoint value for either control Toop e am CO E a cna Sensor input setup menu 2 cme Sensorinput B setup menu s Loop 1 Primary control loop setup Lop a Config User configuration save and restore s s System functions men e Loop Loop 2setup menu e PibTae PiDtablemenu O o o Auto Tune Autotune menu O O Table 6 Keypad key functions 21 Model 32 32B User s Manual Front Panel Operation The LED indicators and Audible Alarm There are three LED indicators located just below the main d
162. l information refer to the Input Channel Setup Menu Note Pressing the Enter key will reset the statistics Temperature statistics for input channel A Shows current temperature maximum minimum and accumulation time For additional statistical information refer to the Input Channel Setup Menu Note Pressing the Enter key will reset the statistics Table 8 Display Configurations Select the desired configuration and press the Enter to return to the Home display Refer to the section Home Status Displays for more information 29 Model 32 32B User s Manual Front Panel Menu Operation Input Channel Setup Menu The Input Channel Setup menus are selected by pressing the ChA or ChB keys from a Home Status Display These menus contain all of the user configurable parameters for a selected sensor input channel The first character on each line of these menus is always the input identifier which is a superscripted A or B for Input A or Input B Use the amp and keys to move up and down the list A CHBSetupMenu o O ChB ChA ChBSetupMenu o O Menu Input channel units Temperature is displayed on the left and is in the selected A units Selections are K C F or S Here S 77 123 selects primitive sensor units When S is selected the actual sensor units of Volts or Ohms will be displayed gt Sensor type selection Allows selection of A Sen 120 Pt100 385 N any user or factory installed senso
163. libration curve it is important to note that the temperature range of the curve must include room temperature Cold Junction Compensation Errors Cold Junction Compensation is required for any instrument to measure thermocouple sensors accurately The most accurate method for performing this is by using an external Ice Bath setup However this is often impractical Cold Junction Compensation in the Model 32 controller is performed by a circuit that measures the temperature of the input connector pins This reading is then used to look up a compensating voltage from the thermocouple s calibration curve The back shell of the input connector should always be installed This will minimize errors caused by local air currents 92 Model 32 32B User s Manual Basic Setup and Operating Procedures Offset Calibration Offset calibration is used to calibrate the Cold Junction Compensation circuit and is recommended when a thermocouple is first installed or any time a thermocouple is changed An appropriate curve must be selected and Cold Junction Compensation must be enabled before calibration can be started 1 Connect the thermocouple 2 Locate the controller away from drafts as these may affect compensation 3 Allow the instrument to warm up for at least 2 hour without moving or handling the sensor 4 Insert the thermocouple into the ice bath liquid nitrogen liquid helium or other know fixed temperature The temper
164. loop number 1 or 2 and lt number gt is the loop s control PID table number Query Syntax LOOP lt no gt TABLEIX Query Response lt number gt Where lt number gt is the PID table number Command Example LOOP 1 TABLEIX 5 Sets the loop 1 PID table to table number 5 Query Example LOOP 1 TABLE Example Response 3 Which indicates that the Loop 1 is controlling based on PID Table number 3 Short Form LOOP TYPE 172 Model 32 32B User s Manual Remote Operation LOOP 1 RANGE Control Loop 1 Output Range Sets or queries the control loop 1 or the primary heater output range Range determines the maximum output power available and is different for a 50Q load resistance than for a 25Q load Values of heater range are Hi Mid and Low 50Q Load 250 Load These correspond to the output power levels Hi sow 2w shown here C ma w f ew L 0 5W 0 25W Command Syntax LOOP 1 RANGE mew _ lt range gt Where lt range gt is the desired heater output range from the above list Query Syntax LOOP 1 RANGE Query Response lt range gt Command Example LOOP 1 RANGE LOW Sets the heater power output range to Low Query Example LOOP 1 RANGE Example Response Hi Short Form LOOP RANG 173 Model 32 32B User s Manual Remote Operation LOOP RAMP Control Loop Ramp Status Queries the unit to determine if a temperature ramp is in progress on the specified control loop Note that t
165. mK 600K 300K 77K 30K 30K 77K 4mK 4mK 0 5mK 1 0mK 370nW 2 0uW 300K 77K 30K 4mK 0 5mK 1 0mK 30K 77K 37nW 200nW Table 22 Sensor Performance for Diodes and Pt Sensors 60 Model 32 32B User s Manual Specifications Features and Functions Ruthenium A 1 4K 520KQ K 1 4K 240KQ K 1O 160GR 4 2K 422Q K 4 2K 2290Q K Sensor Sensitivity Measurement Accuracy Temperature Measurement Accuracy Measurement Resolution Temperature Resolution Control Stability 4 2K 80 3Q K 20K 3 96Q K 1 0K 1 9 4 2K 1 40 20K 1 092 1 0K 1 9mK 4 2K 17mK 20K 275mK 2 0K 11mQ 4 2K 11mQ 20K 11mQ 2 0K 32uK 4 2K 0 13mMK 20K 2 9mK 2 0K 0 15mK 4 2K 0 15mK 20K 2 9mK 77K 0 1Q K 300K 0 019 K 1 4K 1 4mK 4 2K 1 4mK 77K 150mK 300K 2 1K 4 2K 11mQ 77K 0 2mQ 300K 0 2MQ 4 2K 30uK 77K 1 2mK 300K 12mK 4 2K 0 15mK 77K 35mK 300K 250mK 1 4K 962pW 4 2K 171nW 77K 2 15Q K 300K 0 16Q K 1 4K 6750 4 2K 5 10 77K 161mQ 300K 40MQ 4 2K 0 15mK 77K 0 15mK 300K 35mK 1 4K 1 1nW 4 2K 20nW Power Dissipation TORT TENN 4 2K 73nW Magneto lt 2 for H lt 2T Moderate lt 1 for H lt 2T resistance 2 10mV Constant Voltage bias Table 23 Sensor Performance for NTC sensors 61 Model 32 32B User s Manual Specifications Features and Functions Sensor 300K 41uV K 300K 6luV K 300K 41uV K 300K 22 4uV K S
166. made at the sensor relative to the ground at controller The ground potential at the thermocouple sensor must fall within the 5 volt input range of the controller 94 Model 32 32B User s Manual Basic Setup and Operating Procedures Usually the voltage difference between the sensor ground and the controller s ground is an AC power line signal It can be seen with a battery powered AC voltmeter connected between the controller s chassis and a ground point near the sensor If there is a significant voltage difference a safety hazard may be present Building wiring should be tested before proceeding A voltage difference caused by a loose or non existent ground reference can be corrected by 1 Establishing a good quality ground point that the controller and sensor grounds are both connected to 2 Running a ground strap The preferred connection of the ground strap would be from a ground point near the sensor to the Third Wire ground connection of the controller s AC power cord If this is not available the strap can be connected to the controller s chassis 95 Model 32 32B User s Manual Basic Setup and Operating Procedures CalGen Calibration Curve Generator The CalGen feature is used to generate new calibration curves for Silicon Diode thermocouple or Platinum sensors This provides a method for obtaining higher accuracy temperature measurements without expensive sensor calibrations Most Cry
167. mocouple 4 SYS CJoffset 0 00 Cold Junction Compensation Only shown when the thermocouple option is present 5 SYS Bri g htness o N e H brightness Selections are 0 1 2 Sets the Over Temperature Disconnect 6 OTD Enable Of fn enable Selections are On or Off Sets the Over Temperature Disconnect 7 OTD Source CHAM source input channel Selections are ChA or ChB 40 Model 32 32B User s Manual Front Panel Menu Operation System Functions Menu cont Sets the Over Temperature Disconnect 8 OTD T 300 000 setpoint temperature Selects the port for remote I O 9 RIO Port RS232 cciections are RS232 or GPIB Sets GPIB I O address It is a numeric 10 RIO Address 12 entry with a range of 1 to 31 Default is 12 Sets RS 232 port baud rate Selections RIO RS232 19K N range from 300 to 38K baud Advanced configuration Number of Sync Filt Taps O7 taps in the synchronous filter Normally set to a value of 7 SYS AC Line 60 bq AC line frequency Select 50 or 60Hz Power Up Mode Off for normal 14 SYS Auto Ctl Of fN operation On to engage the control loops 10 seconds after power has been turned on Remote I O Last response Table 12 System Functions Menu Display Time Constant Enumeration Default 2 Seconds The SYS Display TC field is used to set the display time constant This is an enumeration field that sets the time constant used for all temperature displays
168. mode of the Model 32 may be forced by the following sequence 1 Turn power to the Model 32 OFF 2 Press and hold the Stop key while turning power back ON This sequence is intended for use when the controller is not operational and will not accept remote commands to place it in the download mode 121 Model 32 32B User s Manual Instrument Calibration Instrument Calibration Calibration of the Model 32 controller requires the use of various voltage and resistance standards in order to generate calibration factors for the many measurement ranges available Calibration is Closed Case There are no internal mechanical adjustments required The Model 32 cannot be calibrated from the front panel Calibration data is stored in the instrument s non volatile memory and is accessed only via the remote interfaces Calibration of a measurement range is the simple process of generating an offset and gain value However since there are several input ranges available on each sensor input the process can be time consuming Caution Any calibration procedure will require the adjustment of internal data that can significantly affect the accuracy of the instrument Failure to completely follow the instructions in this chapter may result in degraded instrument performance The Cryo con utility software used in this procedure will first read all calibration data out of the instrument before any modifications It is good practice
169. n Calibration of the constant current source is performed by using the SI Diode tab On this screen only an upper target value is required since the current source only requires a gain term The upper target requires connection of a 100KQ resistor The actual value should be within 10 of 100KQ 129 Model 32 32B User s Manual Instrument Calibration Calibration of DC resistors Resistor sensors that use direct current excitation are calibrated by using the 1mA DC 100uA DC and 10uA DC tabs Resistors required for calibration are as follows Oh 1mA DC Upper 1000 Lower 100 100uA DC Upper 1 000 Q Lower 100 Q L 10uA DC Upper 10 000 Q Lower 1 000 Q Calibration of AC resistors Resistor sensors that use auto ranged AC excitation are calibrated by using the 1mA AC 100UA AC and 10UA AC tabs Resistors required for calibration are as follows QO 1mAAC Upper 1000 Lower 100 CL 100uA AC Upper 1 000 Q Lower 100 Q CL 10uA AC Upper 10 000 Q Lower 1 000 Q 130 Model 32 32B User s Manual Remote Operation Remote Operation Remote Interface Configuration The Model 32 has two remote interfaces The GPIB IEEE 488 2 and the RS 232 Connection to these interfaces is made on the rear panel of the instrument For specifics about the connectors and cables required refer to the section above on Rear Panel Connections Configuration of the remote interfaces is done at the
170. n may be performed in the instrument by using the front panel Alternatively the feature is also implemented in the Model 32 utilities software Input Channel Statistics Input temperature statistics are continuously maintained on each input channel This data may be viewed in real time on the Input Channel menu or accessed via any of the remote I O ports Statistics are Minimum Temperature Maximum Temperature Temperature Variance Slope and Offset of the best fit straight line to temperature history Accumulation Time The temperature history may be cleared using a reset command provided Electrical Isolation and Input Protection The input channel measurement circuitry is electrically isolated from other internal circuits However the common mode voltage between an input sensor connection and the instrument s ground should not exceed 40V Sensor inputs and outputs are provided with protection circuits The differential voltage between sensor inputs should not exceed 15V Thermal EMF and AC Bias Issues DC offsets can build up in cryogenic temperature measurement systems due to Thermocouple effects within the sensor wiring Careful wiring can minimize these effects However in a few systems measurement errors induced by thermal EMFs can result in unacceptable measurement errors These cases will require the use of an AC bias or chopped sensor excitation in order to remove DC offsets Sensor Wiring Diode and Platinum RTD type
171. n type from the above list Command Example INST A TYPE R10UA Places the calibration type to R10UA Query Syntax INSTCAL lt chan gt TYPE Where lt chan gt is the input channel indicator Query Response lt type gt Where lt type gt is the calibration type from the above list Query Example INSTCAL lt chan gt TYPE Example Response V10UA Indicates that the calibration type is V10UA Short Form INST lt chan gt TYP 200 Model 32 32B User s Manual Remote Operation INSTCAL GAIN Sets or queries gain calibration factor that is applied to the specified input channel GAIN is a floating point number with a nominal value of 1 000 There is a GAIN factor for each calibration type within a channel Therefore before the INST GAIN is used the INST TYPE command should be used to set the calibration type Command Syntax INSTCAL lt chan gt GAIN lt gain gt Where lt chan gt is the input channel indicator and lt gain gt is the desired gain calibration factor Command Example INST A GAIN 0 999423 Sets the gain calibration factor for input channel A to 0 999423 Query Syntax INSTCAL lt chan gt GAIN Where lt chan gt is the input channel indicator Query Response lt gain gt Where lt gain gt is the gain calibration factor Query Example INSTCAL B GAIN Example Response 0 994321 Indicates that the gain calibration factor for input channel B is 0 994321 Short Form INST lt chan gt GAIN
172. nce 1Overtemp Readback indicates that the Current Readback Monitor circuit has shut down the heater This monitor compares the actual heater output Current with the indicated output Current and asserts a fault condition if there is a difference This fault is usually the result of a broken heater cable or an open heater i1Readback SensorFLT indicates that the heater was shut down by a fault condition on the on the controlling input channel This is usually caused by an error in the sensor or sensor cables None A sensor fault will not shut down the heaters if the loop is in Manual 1SensorFlt output mode OTDisconn indicates that the heater output was disconnected by the Over Temperature Disconnect Monitor This monitor is configured by the user and functions to disable the heater if a specified over temperature condition is exists on a selected input channel See the Sys menu for information on how to configure and 10TDisconn use this important feature 2 oO Model 32 32B User s Manual Front Panel Operation If the Model 32 is controlling temperature loop ON the heater status display shows the loop output as a percentage of full scale This example shows the Heater Status for Loop 2 in a Model 32B controller The unit is in control mode and is 30 10W outputting 30 of full scale output current This means that the output power is 30 2 or 9 of 10 Watts The Loop Bar Chart Display The Loop Bar Chart is a
173. ng Procedures Using an external power booster Some systems require more power than the Model 32 can provide or require a higher power secondary control loop An auxiliary DC power supply or amplifier can be used for this purpose Programmable power supplies that can be programmed by an input voltage or current can be interfaced to either control loop of the Model 32 Both control loops of the Model 32B are unipolar current source outputs This means that they will not have the zero voltage drift problems that bipolar voltage source outputs exhibit Since both loops are current source outputs a programming resistor may be required to develop the voltage needed by the booster supply To use a booster supply with the Loop 1 output setup the controller as follows 1 Set the Loop 1 Load Resistance to 25Q by using the Heater Configuration Menu 2 On the Heater Setup Menu set the Heater Range to Low This will cause the loop to output a full scale programming current of 0 1A 3 If the booster supply requires a voltage input the loop output will need a programming resistor to set the full scale programming voltage This resistor can be installed across the input terminals of the power supply 4 Connect the Loop 1 output to the booster supply to the programming input of the booster supply and set up the supply according to the manufacturer s documentation Example Many programmable power supplies require a zero to
174. nt Status Register ISR Instrument Status Enable Register ISE The Standard Event Register ESRI The Standard Event Enable Register ESE The Status Byte STB The Status Enable Register SRE Name Strings Curve Multiplier Curve Units Sensor Types Input Channel Designators emote Command Reference 113 Model 32 32B User s Manual Cryo con Utility Software CalGen Calibration Curve Generator The CalGen feature is used to generate new calibration curves for Silicon Diode or resistor sensors This provides a method for obtaining higher accuracy temperature measurements without expensive sensor calibrations Most Cryo con temperature controllers support CalGen directly on the instrument However the utility software package implements the same algorithm and can be used with virtually any instrument capable of measuring temperature New Curves can be generated from any user selected sensor calibration curve and are written to a specified file For Diode sensors the user may specify one two or three data points CalGen will generate the new curve based on fitting the input curve to the user specified points Platinum or other resistor calibration curves require one or two data points The generated curve will be a best fit of the input curve to the two specified input points Since CalGen fits a sensor calibration curve to measured data any errors in the instrument s measurement electronics are also
175. o con temperature controllers support CalGen directly on the instrument However the utility software package implements the same algorithm and can be used with virtually any instrument capable of measuring temperature Curves can be generated from any user selected sensor calibration curve and are written to a specified internal user curve location For Diode sensors the user may specify one two or three data points CalGen will generate the new curve based on fitting the input curve to the user specified points Platinum or thermocouple calibration curves require one or two data points The generated curve will be a best fit of the input curve to the two specified input points Since CalGen fits a sensor calibration curve to measured data any errors in the Model 32 s measurement electronics are also effectively cancelled rz Note CalGen is re entrant Therefore the user can enter or exit the CalGen menus at any time without loss of previously captured data points For example a data point may be captured near 300K next the user may exit the CalGen process in order to stabilize the controller near 77K When the CalGen menu is re entered for curve generation the point captured at 300K is still valid CalGen Initial Setup Generation of a calibration curve using CalGen requires the measurement various temperature points Therefore an input channel must be configured with the correct sensor before
176. o download new firmware Firmware must be matched to the product s model number and hardware revision level For that reason please contact Cryo con via e mail or telephone for the most recent firmware Firmware updates include the addition of new features as well as bug fixes Installing a new revision writes to all of the available FLASH type memory in the instrument Therefore existing calibration curves instrument setups and PID tables are reset to factory defaults If user information such as sensor calibration curves has been installed it is recommended that these be uploaded to the computer before new firmware is installed This way they can be re installed after the new firmware Firmware download does NOT erase the instrument s calibration data Note that FLASH memory is inherently non volatile and may be re written in excess of 100 000 times Therefore the user need not be concerned about excessive re writing 118 Model 32 32B User s Manual Cryo con Utility Software c Note Firmware can only be downloading using the RS 232 serial interface It cannot be downloaded via the GPIB Therefore make sure that you have a null modem RS 232 cable attached to the controller and that the Utility Software is configured to use RS 232 at a baud rate of 9600 Do NOT use baud rates above 9600 since the firmware update speed is limited by the programming speed of the flash memories Caution To protect the inst
177. oint 4 Enter a new setpoint The controller will enter ramping mode and ramp to the target setpoint at the specified rate 5 When the new setpoint is reached ramping mode will terminate and temperature regulation will begin at the new setpoint 6 Entry of a different setpoint will initiate another ramp As a variation on the above procedure 1 The controller may be regulating temperature in any available control mode This mode can be changed to a ramping mode without exiting the control loop This will not result in a glitch in heater output power 2 Once a ramp mode is selected ramping is performed as above by changing the setpoint The current status of the ramp function may be seen on the Operate Screen When a ramp is active the word RMP will appear in the control loop status displays It may also be queried via any of the remote ports using the LOOP 1 RAMP Command 85 Model 32 32B User s Manual Basic Setup and Operating Procedures Ramping Algorithm The ramp algorithm uses a basic PID type control loop and continuously varies the setpoint until the specified temperature is reached This means that the PID control loop will continuously track the moving setpoint The result is that there will be small time lag between the target ramp and the actual temperature Although not normally a problem the ramp time lag may be minimized by using aggressive PID values This is accomplished by increasing P dec
178. onfirmed Emissions Immunity Safety EN 55011 1998 EN 50082 1 1997 EN 61010 1 2001 IEC 61010 1 2001 The technical files and other documentation are on file with Mr Guy Covert President and CEO As the manufacturer we declare under our sole responsibility that the above mentioned products comply with the above named directives Laie ra Guy D Covert President Cryogenic Control Systems Inc October 15 2005 211 Model 32 32B User s Manual Appendix A Installed Curves Appendix A Installed Curves Factory Installed Curves The following is a list of factory installed sensors and the corresponding sensor index ISENIX isenix Name Description o O Input disabled None Cryocon 700 Cryo con S700 series Silicon Diode Range 1 4 to 380K 10uA constant current excitation LS DT 670 Lakeshore Silicon Diode Curve 11 for DT 670 series diodes Range 1 4 to 500K 10uA constant current excitation Lakeshore Silicon Diode Curve 10 for DT470 series diodes Range i 1 4 to 495K 104A constant current excitation Cryo Industries CD 12A Silicon Diode Range 1 4 to 325K 104A constant current excitation Scientific Instruments Inc 410 Diode Curve Range 1 5 to 450K 10A excitation Cryo con 800 series Silicon Diode Range 1 4 to 380K 104A constant current excitation 7 Cryocon 900 Cryo con S900 series Silicon Diode Range 1 5 to 500K 10uA constant current excitation CTI Diode CTI Cryopump diode
179. onse FULL Short Form SYST DRES 149 Model 32 32B User s Manual Remote Operation SYSTEM PUCONTROL Power up in control mode Sets or queries the controller s power up in control mode setting Reference the section on power up in control mode Default is OFF Command Syntax SYSTEM PUCONTROL lt mode gt Where lt mode gt is ON or OFF Command Example SYSTEM PUCONTROL OFF Causes the power up in control mode setting to select OFF Query Syntax SYSTEM PUCONTROL Query Response lt mode gt Where lt mode gt is ON or OFF Query Example SYSTEM PUC Example Response OFF Short Form SYST PUC 150 Model 32 32B User s Manual Remote Operation CONFIG commands The CONFIG commands are used to save and restore any of the six available user instrument setups Each setup contains the complete state of the controller CONFIG NAME User Setup Name Instrument setups can be named for user convenience The CONFIG NAME command sets and queries the user configuration names Command Syntax CONFIG lt ix gt NAME lt name gt Where lt ix gt is the index number of the desired instrument setup Values may be 0 through 3 lt name gt is the desired name string and is a maximum of 15 ASCII characters Command Example CONFIG 3 NAME Product Alpha This assigns the name Product Alpha to instrument setup 3 Query Syntax CONFIG lt ix gt NAME Query Response lt name gt Where lt name gt is the temper
180. oooo0oo0o oo 0 0 2B Basses ea a 60 50 40 30 20 10 00 90 80 70 60 50 40 30 20 10 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 oo oo oo oo 00 oo 00 oo 00 oo oo 00 oo 00 oo 00 40 30 30 30 30 20 20 20 20 10 10 oo oo oo oo oo oo oo 00 00 00 00 10 10 O O O oo oo oo oo oo HI HI HI HI HI HI MID MID MID MID MID MID LOW LOW LOW LOW Entries may be sent to the Model 32 in any order The unit will sort the table in ascending order of setpoint before it is copied to Flash RAM Entries containing invalid numeric fields will be deleted 187 Model 32 32B User s Manual Remote Operation PIDTABLE PID Table Name Query Queries the name string of a PID table at a specified index Query Syntax PIDTABLE lt index gt Query Response lt name gt Where lt index gt is the index to the PID table list and lt name gt is the name string associated with the specified table Index may be from zero to five Query Example PIDT 2 Example Response Joe s Cooler Indicates that PID table 2 is named Joe s Cooler Short Form PIDT PIDTABLE NAME PID Table Name Sets or queries the name string of the PID Table at a specified index The name string is used to associate a convenient name with a PID table It may include up to 15 ASCII characters Command Syntax PIDTABLE lt index g
181. oop LOOP MAXPWR Sets and queries the maximum allowed output power LOOP MAXPWR LOOP RAMP Queries the unit to determine if a temperature ramp is in progress on the specified control loop LOOP MAXSET Sets and queries the maximum setpoint LOOP MAXSET LOOP 1 LOAD Sets or queries the load resistance setting of the primary heater Loop 1 LOOP 1 LOAD LOOP PMANUAL Sets and queries the output power level used by the selected control loop LOOP PMANUAL feedback when it is in Manual control mode 207 Model 32 32B User s Manual Remote Operation Command Function S O Over Temperature Disconnect Commands OVERTEMP ENABLE OVERTEMP SOURCE Over Temperature Disconnect feature OVERTEMP TEMP disconnect feature CALCUR Sets or queries sensor calibration curve data CALCUR PID Table Commands PIDTABLE Queries the name string of a PID table at a specified index PIDTABLE PIDTABLE NENTRY Queries the number of entries in a PID Table PIDTABLE NENTRY PIDTABLE TABLE Sets or queries the entries in a PID table PIDTABLE TABLE Command Function S O Relay Commands Model 34 and 62 only RELAYS Relay Status Query RELAYS SOURCE Sets or queries the source input channel for a specified relay RELAYS SOURCE RELAYS HIGHEST Sets or queries the temperature setting of the high temperature RELAYS HIGHEST setpoint for the specified relay RELAYS LOWEST Sets or queries the temperature setting of the low temperature RELAYS
182. or interfacing unauthorized modification or misuse operation outside of the environmental specifications for the product or improper site preparation or maintenance The design and implementation of any circuit on this product is the sole responsibility of the Buyer Cryo con does not warrant the Buyer s circuitry or malfunctions of this product that result from the Buyer s circuitry In addition Cryo con does not warrant any damage that occurs as a result of the Buyer s circuit or any defects that result from Buyer supplied products Notice Information contained in this document is subject to change without notice Cryo con makes no warranty of any kind with regard to this material including but not limited to the implied warranties of merchantability and fitness for a particular purpose Cryo con shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing performance or use of this material No part of this document may be photocopied reproduced electronically transferred or translated to another language without prior written consent Trademark Acknowledgement CalGen and Cryo Con are registered trademarks of Cryogenic Control Systems Inc All other product and company names are trademarks or trade names of their respective companies Safety The Model 32 does not contain any user serviceable parts Do not open the enclosure Do not install
183. ors will use a Multiplier of 1 0 However if a 1000Q sensor is used with a calibration curve for 100Q sensors a Multiplier of 10 0 should be used Units is an enumeration field that identifies the basic units used by the sensor s calibration curve Choices are Volts Ohms and LogOhm LogOhm selects the base ten logarithm of ohms and is useful with sensors whose fundamental resistance vs temperature curve is logarithmic The LogOhm selection is only used with Negative Temperature Coefficient resistor sensors where it acts to improve the accuracy of interpolation The N field is the number of valid points in the calibration curve and is generated from the entries made during the editing process Selecting the EDIT CAL CURVE field will cause the screen to go to the Calibration Curve menu for the selected sensor Here the calibration curve may be entered or edited Calibration Curve Entry Once a sensor type is defined the calibration curve for that sensor may be entered This may be done by using the Calibration Curves Menu described above or using any of the remote I O ports or using the Model 32 Utility Software package One very efficient way to enter a new calibration curve is to use the instrument s CalGen feature to generate a new curve from an existing one Operation of this feature is described below 79 Model 32 32B User s Manual Basic Setup and Operating Procedures Autotuning The Autotune Proc
184. ort Form OVER SOUR OVERTEMP TEMP OTD Maximum Temperature Sets and queries the temperature used by the over temperature disconnect feature Note that this temperature has the same units of the source input channel Command Syntax OVERTEMP TEMP lt temp gt Where lt temp gt is the desired temperature Query Syntax OVERTEMP TEMP Query Response lt temp gt Where lt temp gt is the setpoint temperature in units of the controlling input channel Command Example OVER TEMP 123 4 Sets the over temperature disconnect to trip when a temperature of 123 4 is exceeded Query Example OVERTEMP TEMP Example Response 54 23 Which indicates that the over temperature disconnect is set to a temperature of 54 23 Short Form OVER TEMP 182 Model 32 32B User s Manual Remote Operation CALCUR commands The CALCUR commands are used to transfer sensor calibration curves between the controller and the host controller Curves are referenced by an index number In the Model 32 there are four user curves numbered 1 through 4 In the Model 34 and 62 there are 12 user curves numbered 1 through 12 The CALCUR data block consists of a header multiple curve entries and a terminator character The header consists of four lines as follows Sensor Name Sensor name string 15 characters max Sensor Type Enumeration See Sensor Types table Multiplier Signed numeric Units Units of calibration curve OHMS VOLTS or LOGOHM
185. ple SYSTEM AMBIENT To execute a single function within a subsystem use the following lt subsystem gt lt function gt lt white space gt lt data gt lt terminator gt 133 Model 32 32B User s Manual Remote Operation Command headers control IEEE 488 2 defined functions within the instrument such as Clear status etc Their syntax is lt command header gt lt terminator gt No space or separator is allowed between the asterisk and the command header CLS is an example of a common command header To execute more than one function within the same subsystem a semi colon is used to separate the functions lt subsystem gt lt function gt lt white space gt lt data gt lt function gt lt white space gt lt data gt lt terminator gt Command headers immediately followed by a question mark are queries After receiving a query the instrument interrogates the requested function and places the response in it s output queue The output message remains in the queue until it is read or another command is issued Query commands are used to find out how the instrument is currently configured They are also used to get results of measurements t Note The output queue must be read before the next command is sent For example when you send the query you must follow it with an input statement Truncation of Keywords If a keyword contains more than four characters it may be truncated to four or less
186. pplied to the HI range only For lower power levels on this loop select either the MID or LOW range For Loop 2 the Power Limit is always applied c Note Output Power Limit is an important cryostat protection feature The user is encouraged to apply it Maximum Setpoint Numeric Entry Default 1000K The Maximum Setpoint field is used to prevent the casual user from inadvertently entering a temperature that might damage the cryostat Maximum value is 10 000K and minimum is OK Setpoint values use the temperature units selected for the controlling input channel See the section on Temperature Displays cz Note The Maximum Setpoint selection is an important cryostat protection feature The user is encouraged to apply it PID Table Index Numeric entry Default 0 The PID Table index line is used to identify the number of the user supplied PID Table that will be used when the Table control mode is selected The Model 32 will store up to six PID Tables They are numbered zero through five 37 Model 32 32B User s Manual Front Panel Menu Operation Heater Resistance Enumeration Default 25Q The heater resistance field is an enumeration that sets the value of the heater load resistance Choices are 50Q and 25Q When 500 is selected the heater will output a maximum of 50 Volts at 1 0 Ampere or 50 Watts When 25 Ohms is selected the maximum heater voltage is 25 Volts and the output power is 25 Wa
187. put channel This value only applies to sensors that use constant voltage excitation They are indicated by a sensor type of ACR If this query is used with a sensor type other than ACR it will always return N A for not applicable Command Syntax INPUT lt channel gt VBIAS lt volts gt Where lt channel gt is the input channel parameter and lt volts gt is the bias voltage Choices are 10mV 10milliVolt 3 3mV 3 33milliVolt I1mV 1 0milliVolt Query Syntax INPUT lt channel gt VBIAS Where lt channel gt is the input channel indicator Query Response lt volts gt Command Example INPUT B VBIAS 3 3mV Query Example INP A VBias Example Response 1 0mV Note if the sensor on channel A is not a type ACR the response will always be N A Short Form INP VBIAS 155 Model 32 32B User s Manual Remote Operation INPUT ISENIX Installed Sensor index Sets or queries the sensor index number assigned to an input channel for factory installed sensors Sensor index zero indicates that there is no sensor connected to the selected input channel This will disable all readings on the channel Refer to Appendix A for a description of sensors indices etc Note The use of the ISENIX command to assign a factory installed sensor and the USENIX command to assign a user sensor are preferred to the use of the obsolete SENIX command The SENTYPE command may be used to query the name of a factor
188. query This was common in early IEEE 488 systems Ground loops Some equipment manufacturers improperly connect the IEEE 488 Shield Ground wire to their circuit board ground This can cause ground loops with equipment that is properly connected Debug by disconnecting instruments from the bus Use of unshielded bus cables General problems Symptom Condition __ S O Controller periodically resets Generally caused by low AC line voltage Check the AC voltage and or resets when Control key ensure that it matches the instrument s voltage selection is pressed AC line voltage selection is described in the Fuse Replacement and Voltage Selection section Complete failure Possible cause Blown fuse Check line voltage selection before installing new fuses Review the Fuse Replacement and Voltage Selection section Rack mounted instruments Screws were used in the rack mount shelf that are too long and have penetrated the internal circuit board of the controller 222 Model 32 32B User s Manual Appendix C Application Note on Signal Dither Appendix C Application Note on Signal Dither Using Dither in Digital Control Loops Dither as a signal or image processing technique is a method of extending dynamic range by first perturbing dithering then averaging The technique was first developed to enhance the performance of RADAR target algorithms and is now applied to a wide range of applications includin
189. r The 120 shown indicates that the current sensor is factory installed sensor 20 Selecting this field by pressing the Enter 3 ACalGen key will take the display to the CalGen screen 7 Setpoint for the High Temperature alarm 4 AHi gh Alarm 200 000 uUsethe keypad for numeric entry and then press the Enter key P High temperature alarm enable AHigh Enable NoN Selections are Yes or No 6 Flow Alarm 200 OOO Setpoint for the Low Temperature alarm Enables latching alarms on the selected 3 Enables the internal audio alarm to sound 8 AAudible Ena Yes on any enabled alarm condition Enables or disables latching alarm conditions A latched alarm is cleared by ALatch Enable Yes pressing the Alarm key followed by Home key Continuously displays the Maximum 10 77 5232K temperature on this input channel Pressing the Enter key resets Continuously displays the Minimum 77 0232K temperature on this input channel Pressing the Enter key resets Displays the accumulation time for the 12 input channel statistics Pressing the Enter key resets Model 32 32B User s Manual Front Panel Menu Operation ChA ChB Setup Menu cont Displays the variance of the input channel temperature over the accumulation time 13 1 0543 K Pressing the Enter key resets the accumulation time Displays the slope or rate of change of the input temperature over the 14 1 115 K Min 8 accumulation time Pr
190. r Range gt lt setpoint gt lt P gt lt I gt lt D gt lt Heater Range gt lt setpoint gt lt P gt lt I gt lt D gt lt Heater Range gt e e e lt setpoint gt lt P gt lt I gt lt D gt lt Heater Range gt Where lt index gt is a numeric index of the PID table and lt name gt is the table name 15 characters maximum Table entries are made according to the above description Fields within an entry are separated by one or more white space characters The last entry in a calibration curve must be a single semicolon Query Syntax PIDTABLE lt index gt TABLE Query Response lt Table entries gt Where lt Table entries gt are the entries of the selected PID table 189 Model 32 32B User s Manual Remote Operation CALDATA and SENTYPE Commands The CALDATA commands are used to add delete or edit user installed sensors These commands are the remote equivalent of the front panel Sensor Setup menu SENTYPE commands are used to query the name of a factory installed sensor User installed sensors are indexed from zero to 3 Factory installed sensors are indexed from zero to 60 For additional information refer to Appendix A CALDATA NAME Name for a user installed sensor Sets or queries the name of a user installed sensor Command Syntax CALDATA lt index gt NAME lt val gt Where lt index gt is the index of the user installed sensor and lt val gt the sensor s name string The name string must be s
191. r coded four wire 36 AWG cryogenic ribbon cable Wires may be separated by dipping in Isopropyl Alcohol and then wiping clean Insulation is Formvar and is difficult to strip Techniques include use of a mechanical stripper scrapping and passing the wire over a low level flame Ribbon Cable Color Codes Thermocouple Sensor Connections Thermocouple sensors require the factory installed thermocouple option All thermocouple connections must be made at the sensor input connector since this connector is thermally anchored to an internal sensor that is used for Cold Junction compensation Thermocouple sensors are connected to the Model 32 by use of the special connector provided with the controller Sensor connection is made at the screw terminals Proper polarity of the sensor wires is required Polarity is marked on the input connector and a summary of common thermocouple polarities is given in the table below The input connector should have its backshell and rubber grommet installed in order to prevent local air currents from generating errors in the cold junction circuitry It is recommended that the Thermocouple sensor be electrically isolated or floating from any surrounding circuits or grounds This will ensure the highest possible measurement accuracy Figure 6 Thermocouple Input Connector 72 Model 32 32B User s Manual Specifications Features and Functions Additional discussion on Thermocouple and
192. r sensor types and calibration curves are added using the Sensors menu CalGen Selection of the CalGen field initiates the calibration curve generator feature This feature is described in the section CalGen Calibration Curve Generator 31 Model 32 32B User s Manual Front Panel Menu Operation Setting a Temperature Alarm The Alarm lines are used to setup alarm conditions The Model 32 allows alarm conditions to be assigned independently to any of the input channels High temperature and low temperature alarms may be entered and enabled Note that there is a 0 25K hysteresis in the assertion of high and low temperature alarms Alarm conditions are indicated on the front panel by the Alarm LED and various display fields They are also reported via the remote interfaces When the audible alarm is enabled a high pitched buzzer will sound when an alarm condition is asserted The Model 32 supports latched alarms These are alarms that remain asserted even after the condition that caused the alarm has been cleared To clear a latched alarm first press Alarm to view the Alarm Status Display and then press the Home key to clear Input Channel Statistics The Model 32 continuously tracks temperature history on each input channel The Input Statistics shown in this menu provides a summary of that history The channel history is reset whenever the channel is initialized and can also be reset by pressing the Enter key
193. raise Ba 73 RST COMMANA 0 ccccccessececeessteeeeeeeseeeeeees 138 SOO ict vanhecdiveedrn a ic 8 231 Color CodeS eire re Ne aaas 231 MOUNTING ain aiea iei 232 STOA ad E EA E EN AIEA EE E ENERE EAA AE EENAA AE EEN 67 command headel cccccceeeeeeeeeees 133 134 COMMON COMMANG ceceeceeeeeteeees 133 137 compound Comman6d ccccceeeeeeeeeees 133 keyword truncation 134 simple COMMANG cceceeeeeeeteeeeeeeeees 133 SONS Ol sks ses etdecsasoccdswsziean EE A i deuslwess das aes Calibration CUIVE cccccceceeseteetsteseeeeeeees 183 connection 51 63 70 217 self heating see DD 56 setup 47 table indexi eee e 47 type 191 208 type SeleCtion ccscceeeseeeeeeeeeteeeeeee 31 47 DMS i A S A E 31 154 Sensor Calibration Curve 106 109 185 208 Sensor Calibration Curve ccccccsseeeeeeesnee file fMalta onn cccaecvivegsacereessene acerevane 183 Sensor Setup Menu cceceeeseeeeeeeeeeees 190 SensoOrblt 4 0udciniianiaeiamdlian 25 Single Point Ground ccceeeees 101 102 Standard Event Register ceeee 135 Standard Event Status Enable 137 203 CA NE E E E al Sek 135 136 STOP command 139 141 STOP Key rero ead ara peata an a s E eaa i 11 Supported Sensors cccecceeseeeeeteeeeeeeeeeees 51 Synchronous Filter c ccscceeeseeeeeeeeeeeeees 87 Configur
194. range Note the heater range entry is ignored for Loop 2 To delete a zone from the PID Table enter zero or a negative number in the setpoint field These entries will be rejected when the table is conditioned and stored in Flash memory Save the entire table by scrolling to the last line SaveTable amp Exit then press the Enter key 46 Model 32 32B User s Manual Front Panel Menu Operation Sensor Setup The Sensor Setup menu is used to view and edit user temperature sensor data The Sensor Setup Menu Pressing the Sensor key from the Home Status Display accesses the Sensor Setup Menu Definition of a sensor requires entering configuration data on this screen followed by entering a calibration curve The first three lines of the Sensor Setup Menu show the Sensor Index followed by a greater than gt character This gt character indicates the first level of the Sensor Setup menu Sensor Setup Menu Sets the Sensor Index Scroll through choices until the desired sensor is displayed and press Enter Sets the Sensor Type which includes voltage range and excitation Selections are described in the Sensor Type table above Sets the sensor Temperature 3 18 gt Mult 1 0 Coefficient and Calibration Curve Multiplier T Sets Units of the sensor s Calibration 4 118 gt Units Volts hq Curve Choices are Ohms Volts and LogOhm 7 Pressing Enter will display the next level 5 18 gt Edit Cal Curve m
195. rature alarm enable for the specified input channel An alarm must be enabled before it can be asserted Command Syntax INPUT lt channel gt ALARM HIENA lt status gt Where lt channel gt is the input channel indicator and lt status gt is the status of the high temperature alarm enable lt status gt may be either YES or NO Query Syntax INPUT lt channel gt ALARM HIENA Query Response lt status gt Where lt channel gt is the input channel indicator and lt status gt is the setting of the high temperature alarm enable for lt channel gt lt status gt will be either YES or NO Command Example INPUT A ALARM HIENA NO Disables the high temperature alarm for input channel A Query Example INP B ALARM HIEN Example Response YES Query Command Example INP B ALARM HIGH HIEN NO Example Response 154 2323 The high temperature alarm setpoint for channel B is reported then the high temperature alarm for channel B is disabled Short Form INP lt channel gt ALAR HIEN 162 Model 32 32B User s Manual Remote Operation INPUT ALARM LOENA Alarm Low Enable Sets or queries the low temperature alarm enable for the specified input channel An alarm must be enabled before it can be asserted Command Syntax INPUT lt channel gt ALARM LOENA lt status gt Where lt channel gt is the input channel indicator and lt status gt is the status of the low temperature alarm enable lt status gt may be either YES or NO
196. rce This output is heavily regulated and RFI filtered External filters should not be necessary Automatic shutdown circuitry is provided that will protect the heater output stage from excessive temperature Here the heater output will be turned off until the output stage returns to its Safe Operating Area SOA then the output will be returned to normal operation Load resistance values of either 25Q or 50Q may be selected Using a 25Q load the heater will be automatically configured to have a compliance voltage of 25V With a 50 load the compliance voltage is 50V In either case the maximum output current is 1 0A There are three output ranges which are manually selected in PID mode and automatically selected in the PID Table control mode The ranges are High Medium and Low Range ae Voltage Full Scale Max Output Power Current O a a Medium 25 s osa 25 Watts 5 0 Watts 000a 0 25 Watts 0 50 watts Table 25 Loop 1 Heater output ranges Care must be taken to ensure that the proper load resistance is selected Connection to a 25Q load while a 50Q is selected will result in overheating and eventual automatic heater shutdown Conversely connection to a 50Q load while setting a 25Q load will result in only one half of the indicated heater power being dissipated in the load Load resistance and Full Scale Output Range are selected via the front panel or any of the remote interfaces 64 Model 32 32B
197. reasing and setting D to zero Ramping Parameters and Setup The Ramp Rate is set on the Control Loop Setup menu Note that the ramp rate on Loop 1 is independent of the rate on Loop 2 A ramping control mode must also be set Ramping modes are RampP or RamptT These modes are also selected in the Control Loop Setup menu Summary To perform a temperature ramp proceed as follows 1 Set the control loop P and D parameters to allow stable control at both ends of the desired ramp This is usually done by using slow PID values Low values for P high for and zero for D 2 Set the Ramp Rate in the Heater Configuration Menu Set the setpoint to the starting value for the ramp 3 Press CONTROL Now the controller will begin temperature regulation at the current setpoint 4 Enter a new setpoint The controller will enter ramping mode and ramp to the target setpoint at the specified rate The word RMP will appear in the control loop menu 5 When the new setpoint is reached ramping mode will terminate and temperature regulation will begin at the new setpoint 86 Model 32 32B User s Manual Basic Setup and Operating Procedures Cryocooler Signature Subtraction Cryocoolers often have a thermal signature that is associated with the mechanical cooling process At the low end of their temperature range this signature can have amplitudes of one or more Kelvin Since the thermal signature is related to the mechan
198. red by the display time constant filter and reported in display units Query Syntax INPUT lt channel gt Where lt channel gt is the input channel parameter Query Response lt temp gt Where lt temp gt is the temperature of the specified input channel in display units K F C or S Floating Point string Query Example INPUT B Example Response 123 4567 Alternate Form INPUT lt channel gt TEMP Short Form INP 153 Model 32 32B User s Manual Remote Operation INPUT TEMPER Input Temperature The INPUT TEMPER query is identical to the input query described above It reports the current temperature reading on any of the input channels Temperature is filtered by the display time constant filter and reported in display units Query Syntax INPUT lt channel gt TEMPER Where lt channel gt is the input channel parameter Query Response lt temp gt Where lt temp gt is the temperature of the specified input channel in display units K F C or S Floating Point string Query Example INP B TEMP Example Response 12 45933 Short Form INP lt channel gt TEMP INPUT UNITS Input channel units Sets or reports the display units of temperature used by the specified input channel Command Syntax INPUT lt channel gt UNITS lt units gt Where lt channel gt is the input channel parameter and lt units gt is the display units indicator lt units gt may be K for Kelvin C for Celsius F for Fahr
199. ressure button will take the user to a convenient calculator that will compute the temperature of various cryogens from the current barometric pressure Once the dialog box has been completed click OK to proceed To finish the process you will be prompted to save the modified calibration curve to a file Once complete the file can be transferred to any Cryo con instrument 116 Model 32 32B User s Manual Cryo con Utility Software The Vapor Pressure Calculator The Vapor Pressure Calculator is a convenient aid that computes the actual temperature of most cryogens given the current barometric pressure It can be launched directly off of the utility disk by executing Vapor Pressure Calculator exe or from the CalGen dialog as shown above Atypical calculation is shown here apor Pressure Calculator x Substance Ethyl Alcohol Carbon Dioxide Nitrogen Helium 4 Fa Pressure Temperature Units Calculate Temperature 373 1521 K You must select the Substance from a drop down list and then select the barometric pressure and temperature units 117 Model 32 32B User s Manual Cryo con Utility Software Substance selections are shown here apor Pressure Calculator x Substance Water Pressure 760 Torr Temperature Units K Temperature 373 1521 K Downloading Instrument Firmware A primary feature common to all of Cryo con s instruments is the ability t
200. rocess described above Using the Real Time Strip Charts The real time strip chart feature of the Utility Software lets the user continuously display any combination of input channels on the computer display This function is initiated by selecting the View command on the Utility Software s main toolbar then selecting the desired channels to monitor A strip chart will be displayed for each channel selected The dialog box will show the channel s Input Identifier Name String and a chart of current temperature Channel B 0 0 Ch rel B Manual The update rate of the chart is locked to the program s Data Logging Interval The section below details how to set this value 110 Model 32 32B User s Manual Cryo con Utility Software Data Logging The Utility Software will perform data logging on all of the instruments input and control output channels The result is a disk file in Comma Separated Value or CSV format This format is compatible with any data analysis or charting software including Microsoft Excel To initiate data logging select the Data Logging button from the Utility Software s main menu The Data Logging Setup dialog box will now appear Data Logging Setup Dialog On this dialog box check the desired channels and set an Interval value in Seconds The minimum interval is 0 1 Second 111 Model 32 32B User s Manual Cryo con Utility Software When the Sta
201. rt button is clicked a file selection dialog box will be shown From this dialog box enter a file name and select the directory where data logging Cryo con Utility Software dloader E ioj xj Fie Comm Firmware Calibration Table PID Table View DataLogging Help Save As Save in SJ Customer CD A ex Eee CCUtilty ConsoleUSB Firmware Labview USBdriver UsersManual Save as type MSExcel Comma Separated Value Files css 7 Cancel Z results will be saved As soon as the Save button is clicked the software will begin continuous data logging to the specified file While data logging is in progress a dialog box will be displayed that allows the user to stop logging When this Stop button is clicked logging is stopped and the log file is closed 112 Model 32 32B User s Manual Cryo con Utility Software Remote I O command HELP Help for the remote interfaces and remote commands is available by clicking on the HELP gt Contents button from the Utility Software s main menu Astandard HELP screen will be shown that is indexed and searchable nA Te Cryo con Utility Software dloader Fis Comm Firmware Calibration Table PID Table view Data Logging He Help Topics Cryocon Remote Interface Help Contents Index Find Click a topic and then click Display Or click another tab such as Index Remote Interface Configuration e Remote 0 Data Types 2 e D Instrume
202. rument from casual downloads and possible corruption the Utility software must be executed with a command line argument of f for a firmware download and d for a firmware upload The utility disk contains a shortcut named UtilityFD that contains these command line arguments 119 Model 32 32B User s Manual Cryo con Utility Software To download new firmware select Firmware gt Download from the Utility Software s main menu If the Download item is grayed out you must exit the utility software and re start it with the correct command line switches as noted in the caution above Selecting a firmware download will result in the display of a file selection dialog box as shown below Cryo con Utility Software dloader Zz Ioj xj File Comm Firmware Calibration Table PID Table View DataLogging Help Open 2X Look in Fimwae EK m m343r15a bin fa m623r10 bin File name Files of type BIN Files bin x Cancel Z In this dialog box firmware file names are coded as shown below MmmRev BIN Where mm is the Model Number eg 32 34 62 etc and Rev is the revision code in the format XrXX where the lower case r indicates a period character The file extension is always BIN From the file dialog box find and select the desired firmware file Then click on the Open button in order to initiate the firmware download Firmware download will be initiated immediately after the Open button
203. ry Example INSTCAL lt chan gt MODE Example Response OFF Indicates that the Model 32 is not in calibration mode Short Form INST lt chan gt MOD 199 Model 32 32B User s Manual Remote Operation INSTCAL SAVE This command copies the temporary RAM calibration data table to the actual FLASH memory instrument calibration area It can only be used when the instrument is in calibration mode Otherwise it does nothing Command Syntax INSTCAL lt chan gt SAVE Where lt chan gt is the input channel number required but not used Note that even though a channel indicator is specified the entire RAM table for all four input channels is copied to FLASH memory Therefore this command should only be issued once when the entire procedure is complete Command Example INST A SAVE Short Form INST lt chan gt SAVE INSTCAL TYPE Sets or queries the type of calibration that is being applied to a specified input channel This command is only effective when the unit is in calibration mode Calibration types are shown below V10UA Voltage calibration Full scale is 2 5V 110UA 10UA constant current source calibration R1MaA Resistance calibration Full scale is 2500Q R100UA Resistance calibration Full scale is 25KQ R10UA Resistance calibration Full scale is 250KQ Command Syntax INSTCAL lt chan gt TYPE lt type gt Where lt chan gt is the input channel indicator and lt type gt is the desired calibratio
204. s OFFSET is the offset of the best fit straight line passing through all temperature samples that have been collected since the STATS RESET command was issued STATS TIME Queries the time duration over which input channel statistics have been accumulated STATS RESET Resets the accumulation of input channel statistical data 206 Model 32 32B User s Manual Remote Operation LOOP Commands LOOP SOURCE Sets and queries the selected control loop s controlling input channel LOOP SOURCE LOOP SETPT Sets and queries the selected control loop s setpoint LOOP SETPT LOOP TYPE Sets and queries the selected control loop s control type LOOP TYPE LOOP 1 RANGE Sets or queries the control loop 1 or the primary heater output range LOOP 1 RANGE LOOP TABLEIX Sets or queries the table number that is used with control modes that use LOOP TABLEIX PID tables LOOP RATE Sets and queries the ramp rate used by the selected control loop when LOOP RATE performing a temperature ramp LOOP NAME Sets or queries the name string for the selected control loop LOOP NAME LOOP PGAIN Sets or queries the selected control loop s proportional gain term LOOP PGAIN LOOP IGAIN Sets and queries the integrator feedback term used by the selected control LOOP IGAIN loop LOOP HTRREAD Queries the output current of the selected control loop LOOP DGAIN Sets and queries the differentiator feedback term used by the selected LOOP DGAIN control l
205. s in setpoint or thermal load It does not affect the control accuracy when the system has stabilized However derivative action by it s nature amplifies noise Therefore PID autotuning and control should only be used with very quiet systems PI control should be used with all others Sensor type has a significant impact on measurement noise The Model 32 uses a ratiometric technique to measure resistor sensors such as Thermistors Platinum RTDs Carbon Glass etc This effectively cancels most of the measurement noise and allows effective use of PID control Voltage mode sensors which include diodes and thermocouples cannot benefit from ratiometric measurement Therefore PI control is recommended It is a very common mistake to attempt PID control using a Diode sensor above 70K This is the least sensitive region of the sensor so measurement noise is very high Pl control is recommended Below about 20K the sensitivity of the Diode increases significantly and PID control may be used effectively Pre Tuning and System Stability Before autotuning can be initiated by the controller the system must be stable in terms of both temperature and heater output power This requires the user to perform a basic pre tuning operation before attempting the first autotune The goal of pre tuning is to stabilize the process at a temperature near the desired setpoint so that the tuning algorithm can use this as a baseline to model the process
206. se of a lower voltage limits the maximum resistance range and significantly increases measurement noise Once sensor configuration is complete review the section on Sensor Connections to connect the sensor to the instrument Adding a New Sensor Type This procedure identifies how to add a new sensor type to the controller If the desired sensor is already installed as a factory installed sensor or previously installed user sensor this procedure is not required These sensors can be simply assigned to an 77 Model 32 32B User s Manual Basic Setup and Operating Procedures input channel by using the Input Channel Setup Menu described above Adding a new sensor to the Model 32 is a two step process First the sensor type must be defined using the Sensor Setup Menu Next the sensor s calibration curve must be entered by using the Calibration Curve Menu Note that if the new sensor has a lengthy calibration curve entry from the front panel may be tedious In these cases the user may consider entering the sensor via the remote interfaces using the controller s utility software To add a sensor using one of the remote interfaces please refer to the Remote I O section command syntax etc Sensor Setup 1 18 gt User Sensor 3 XN 2 18 gt Type R39R1MA M 3 18 gt Mult 1 0 18 gt Units Volts K EE s 18 gt Edit Cal Curve Table 31 Sensor Setup Menu The new sensor type is defined using the Sensor
207. sensitivity region below 20K 4 One point near 4 2K This is a two point fit where the 20K point is taken from the existing calibration curve The portion of the curve above 20K is unaffected For a Diode Sensor a sub menu will be displayed that allows the user to select the number of points desired for the CalGen fit First CalGen Menu Diode Sensor Pressing the Enter key will select curve 1 E4 pt CalGen 300K generation with a single point near 300K A Pressing the Enter key will select curve 2 E2 pt CalGen generation at two points where both points must be gt 50K Pressing the Enter key will select curve 3 E3 pt CalGen generation three points Two above 50K and one near 4 2K Pressing the Enter key will select curve E1 pt CalGen 4 2K generation with a single point near 4 2K Table 33 First CalGen Menu Diode Sensor From this screen select the desired number of points For example select 2 point This will take the display to the two point curve generator screen shown here 97 Model 32 32B User s Manual Basic Setup and Operating Procedures CalGen Menu 2 point Diode Sensor The exact temperature at a point near 300K is entered here Note if CalGen E300 000 Captu re has not been used on this channel before the word Capture will appear Otherwise the last captured sensor reading will appear Pressing the Enter key will capture the E Unit 0 98257V
208. ses a New Line or Line Feed character as a line termination In the C programming language this character is n or hexadecimal OxA When sending strings to the controller any combination of the following characters must be sent to terminate the line 1 Carriage Return Hex OxD 2 Line Feed n Hex OXA 3 Null 0 The controller will always return the n character at the end of each line cz Note Some serial port software drivers allow the programmer to set a line termination character This character is then appended to each string sent to the controller and stripped from returned strings In this case the n OxA character should be selected 132 Model 32 32B User s Manual Remote Operation Introduction to Remote Programming Instructions Instructions both commands and queries normally appear as a string embedded in a statement of your host language such as BASIC or C Instructions are composed of two main parts The header which specifies the command or query to be sent and the parameters which provide additional data needed to clarify the meaning of the instruction An instruction header is comprised of one or more keywords separated by colons Queries are indicated by adding a question mark to the end of the header Many instructions can be used as either commands or queries depending on whether or not you have included the question mark The command and query forms of an instruction
209. sponsibility to configure the bus structure with unique addresses for each connected instrument RS232 Rate is an enumeration of the RS 232 baud rate Choices are 300 1200 2400 4800 9600 19k for 19 200 and 38K for 38 400 Synchronous Filter Configuration Numeric Entry Default 7 The Synchronous Filter is used to subtract synchronous noise from the input channel An example of synchronous noise is the thermal signature of a cryocooler The default value of 7 taps is used for a line frequency synchronous cryocooler Values go from 1 off to 25 taps with 25 corresponding to 2 5 seconds of filtering This is an advanced setup function Unless you are familiar with the synchronous noise source that you are trying to remove leave this field at its default value of 7 When the number of taps is changed the control loops will have to be re tuned because this filter affects the PID values AC Line Frequency Selection Enumeration Default 60Hz Select the AC power line frequency Choices are 50 or 60 Hz This function only affects the operation of the Synchronous Filter described above Power up in Control Mode Default Off The SYS Auto Ctl field sets the power up mode of the controller s loops Choose Off for normal operation where the control loops are engaged by pressing the Control key and disengaged by pressing the Stop key When SYS Auto Ctl is ON the controller will power up then after ten seconds will automatically
210. ssigned to an input channel INPUT VBIAS Set or query the sensor voltage excitation used in the constant INPUT VBIAS voltage mode Applies to constant voltage mode sensors only INPUT NAME Sets or queries the name string of the specified input channel INPUT NAME INPUT ALARM HIGHEST alarm for the specified input channel INPUT ALARM LOWEST alarm for the specified input channel INPUT ALARM HIENA specified input channel INPUT ALARM LOENA input channel INPUT ALARM FAULT input channel INPUT ALARM AUDIO channel 205 Model 32 32B User s Manual Remote Operation Command Function S Input Channel Commands INPUT SENPR Queries an input channel reading in basic sensor units Sensor units are Volts for diode and thermocouple sensors and Ohms for resistor sensors Input Channel Statistics INPUT MINIMUM Queries the minimum temperature that has occurred on an input channel since the STATS RESET command was issued INPUT MAXIMUM Queries the Maximum temperature that has occurred on an input channel since the STATS RESET command was issued INPUT VARIANCE Queries the temperature variance that has occurred on an input channel since the STATS RESET command was issued INPUT SLOPE Queries the input channel statistics SLOPE is the slope of the best fit straight line passing through all temperature samples that have been collected since the STATS RESET command was issued INPUT OFFSET Queries the input channel statistic
211. ssociated with the heater s Over Temperature Disconnect feature This feature is used to disconnect the heater if a specified temperature is exceeded on a selected input channel OVERTEMP ENABLE OTD Enable Sets and queries the over temperature disconnect enable Command Syntax OVERTEMP ENABLE lt enab gt Where lt enab gt is the desired enable status which may be ON or OFF Query Syntax OVERTEMP ENABLE Query Response lt enab gt Where lt enab gt is the status of the over temperature disconnect enable Command Example OVERTEMP ENABLE OFF Sets the over temperature disconnect feature to OFF Query Example OVERTEMP ENABLE Example Response YES Indicating that the over temperature disconnect feature is enabled Short Form OVER ENAB 181 Model 32 32B User s Manual Remote Operation OVERTEMP SOURCE OTD Source Input Channel Sets and queries the input channel that is used as the source for the Over Temperature Disconnect feature Command Syntax OVERTEMP SOURCE lt chan gt Where lt chan gt is the designator of the controlling input channel Query Syntax OVERTEMP SOURCE Query Response lt chan gt Where lt chan gt is the designator of the input channel Command Example OVER SOURA Sets the over temperature disconnect to monitor channel ChA Query Example OVERTEMP SOURCE Example Response CHB Which indicates that the over temperature disconnect is set to monitor input channel ChB Sh
212. sulting in a factor of four improvement in control accuracy This is equivalent to adding two bits to the output DAC Since the Model 32 uses a 16 bit output DAC a 1 6 second closed loop time constant will result in the equivalent of an 18 bit DAC Note that 1 6 seconds is an extremely short time constant for a cryogenic temperature process Further Reading Introduction to Signal Processing Sophocles J Orfanidis August 1995 Prentice Hall ISBN 0 13 209172 0 http www ece rutgers edu orfanidi intro2sp 225 Model 32 32B User s Manual Appendix D Tuning Control Loops Appendix D Tuning Control Loops Introduction Tuning PID loops to maintain high accuracy control can be a laborious process since the time constants in cryogenic systems are often long Further some systems must operate over a very wide range of temperature requiring different PID settings at different setpoints The following is a guide to various methods of obtaining PID control loop coefficients Various methods for obtaining PID coefficients The system provider If your controller was received as part of a cryogenic system the PID control loops should already be setup for optimum control If the system operates over a wide range of temperature it will use one of the available Table control modes where PID values are listed for different setpoints If the installed PID values do not provide stable control you should contact the system
213. t NAME lt name gt Where lt index gt is a numeric index 0 3 to the PID table list and lt name gt is an ASCII name string in double quotes Query Syntax PIDTABLE lt index gt NAME Query Response lt name gt Where lt index gt is the index to the calibration curve list lt name gt is the name string associated with the specified curve Command Example PIDTABLE 1 NAME Ed s table This command will assign the name of Ed s table to PID table located at index number 1 Query Example PIDTABLE 3 NAME Example Response Mary s project Indicates that the PID table at index 3 is named Mary s project Short Form PIDT NAM 188 Model 32 32B User s Manual Remote Operation PIDTABLE NENTRY Number of Entries Queries the number of entries in a PID Table This number is generated from the table itself and cannot be changed using this command The maximum number of entries in a table is 16 Query Syntax PIDTABLE lt index gt NENTRY Query Response lt number gt Where lt index gt is the index to the PID table list and lt number gt is the number of entries in the indexed table Query Example PIDTABLE 1 NENTRY Example Response 5 Indicates that there are 5 entries in PID table 1 Short Form PIDT NENT PIDTABLE TABLE PID Table Set Query Sets or queries the entries in a PID table Command Syntax PIDTABLE lt index gt TABLE lt name gt lt setpoint gt lt P gt lt I gt lt D gt lt Heate
214. tains a unit name string that may be set or queried using this command This can be used to assign a descriptive name to the instrument Use the SYSTEM ADRS command to assign a unique address Command Syntax SYSTEM NAME lt name gt Where lt name gt is the desired system name string and is a maximum of 15 ASCII characters Command Example SYSTEM NAME Cryocooler Four This assigns the name Cryocooler Four to the unit so that it may be uniquely identified Query Syntax SYSTEM NAME Query Response lt name gt Where lt name gt is the temperature of the internal heater output stage s heat sink in Celsius Query Example SYSTEM NAME Example Response Model 32 Unit 0 Short Form SYST NAM SYSTEM HWREV Instrument Hardware Revision Level Queries the instrument s hardware revision level Query Syntax SYSTEM HWREV Query Example SYSTEM HWREV Example Response A Indicating that the instrument s hardware is revision level A Short Form SYST HWR 147 Model 32 32B User s Manual Remote Operation SYSTEM FWREV Instrument Firmware Revision Level Queries the instrument s firmware revision level Query Syntax SYSTEM FWREV Query Example SYSTEM FWREV Example Response 3 18 Indicating that the instrument s firmware is revision level 3 18 Short Form SYST FWR SYSTEM LINEFREQ AC Power Line Frequency Sets or queries the AC Power Line frequency setting Command Syntax SYSTEM LINEFREQ
215. teeeeeeeeeeeeeeeeeess 13 Table 5 Control Type SUMMAL cceeeeeeteeeeeeeneeeeeeeeeeneeeeeeseetaeeeeeeeeeaas 14 Table 6 Keypad key fUNCtiONnS cceccceeeeeseeeeeeeeeenneeeeeeeenaeeeeeeeeeeeeeeeeeeetees 21 Table 7 Temperature Units ccccecccccceeeeeeeeeeeeeeseeeeeeccansneeeeeeeeeeeees 24 Table 8 Display Configurations ecceeceeeeeeeeeeeeeeeeeneeeeeeeeeeeteeeeeeeeeeeess 29 Table 9 Input Channel Setup Menus ecseeseeeeeecececeeceeeeeeeeeeeeetesaes 31 Table 10 Control Loop Setup Menus cccccceeeeeeeeeeeeeeeeeeeeetenneaee 34 Table 11 User Configurations Menu ccscceeeeeeeeeeeeeeeeeneeeeeeeeeetneeeeeees 39 Table 12 System Functions Me nu ccccccccceeeeeeeeeeeeeeeeeeeneeeeeeeeeeeeeeees 41 Table 132 PID table Menu ig icf svetseccusts cot se ced tached ereen ana tha phedensdinadceaas 45 Table 14 PID Table Edit M nu cccceeeeeeeeeeeeeeeneeeeceeeeeeeeeeeeaaaeeeeeeeeees 46 Table 15 Sensor Setup MeNnu cccccccceeceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeaea 47 Table 16 Calibration Curve Menu 2 eeeeeceeeeeeeeeeeeeeeeeeeeeeeeeesenneaee 49 Table 17 Voltage Bias Selections ccecceceeeeeeeeeeeeeeesneeeeeeeeenneneeeeeeees 56 Table 18 NTC Resistor Measurement ACCUraC eeeeeeeeeeeeeeeeeeeeeeeee 56 Table 19 Supported Sensor Configurations c ccccceceeeeeeceeeeeeeeeeeeeeee 57
216. ter L at the end of the line indicates that the alarm is latched A latched alarm is asserted when the alarm condition is set It stays asserted until it is manually cleared by the user c Note To clear a latched alarm first press the Alarm key to view the alarms and then press the Home key to clear the latch and return to the Home display 28 Model 32 32B User s Manual Front Panel Menu Operation The Display Configuration Menu The display configuration menu is accessed by pressing the Display key When accessed the menu will appear as a list of possible configurations The cursor indicated by a character will be located at the current configuration Use the amp and keys to move up and down the list Display configurations are Default Input channel status Displays temperature of both input channels and the status of any control loop assigned to the inputs Detailed status of control loop 1 Temperature of controlling input channel set point heater status and bar graph Detailed status of control loop 2 Temperature of controlling input channel set point heater status and bar graph Control loop status Displays the status of both control loops on the second line of the display On the first line the temperature of the controlling input is shown Temperature statistics for input channel A Shows current temperature maximum minimum and accumulation time For additional statistica
217. th Ground An R C network is used to eliminate common mode voltages from the unit s power supply but also has a high enough impedance to reduce ground loop current flow Further since it is isolated from the other areas of the circuit no current carrying paths can flow through the more sensitive analog circuits The RS 232 Connection The RS 232 connection is a three wire serial communication scheme Two wires carry signals and the third carries a ground reference When either of these interfaces is connected to a Cryo con controller the voltage of the digital area is established by the ground reference of the connected interface Because of the internal R C network connection to ground little if any current can flow back through the system grounds The GPIB Connection The GPIB is a 24 wire communications protocol that has six control signal grounds one data signal ground and one shield ground In the Cryo con controller the control and signal grounds are connected together and used to establish the ground reference potential for the digital area The Shield ground connection is connected to the instrument s Single Point Ground through a jumper The jumper is available since some manufacturers connect the GPIB shield ground to their circuit board ground and therefore ground loops are established through the shields Removing the jumper will break this ground 102 Model 32 32B User s Manual Cryo con Utility Software
218. th the DeltaP parameter Increasing it often improves autotune success 219 Model 32 32B User s Manual Appendix B Troubleshooting Guide Temperature Measurement Errors Sane Noise on temperature Possible causes measurements Excessive noise pickup especially AC power line noise Check your wiring and shielding Sensors must be floating so check that there is no continuity between the sensor connection and ground Review the System Shielding and Grounding Issues section Note Cryo con controllers use a shielding scheme that is slightly different than some other controllers If you are using cable sets made for use with other controllers some shield connections may need to change If pin 3 of the input connector is connected to the cable shield disconnect it and either re connect the shield to the backshell contact or leave the shield floating No connection should ever be made to pin 3 of the input connector Check for shielding problems by temporarily removing the input connector s backshell If the noise changes significantly current is being carried by the shields and is being coupled into the controller Use a longer display filter time constant to reduce displayed noise ii DC offset in temperature Possible causes measurements The wrong sensor type or sensor calibration curve is being used Refer to the Input Channel Setup Menu section DC offset in cryostat wiring Review the Thermal EMF and AC Bias
219. the CalGen process can start To initiate the curve generation select the CalGen field on the Input Channel Setup menu This will take the screen to a sub menu for the specific sensor type c Note Before CalGen can be initiated there must be a valid temperature reading on the selected input channel If this is not the case selecting the CalGen field will cause the display of an error message When the input channel has a valid reading CalGen will determine if the sensor is a Diode Platinum or a thermocouple sensor Further the calibration curve of the selected input sensor will be used as the input to the curve generation process 96 Model 32 32B User s Manual Basic Setup and Operating Procedures Using CalGen With Diode Sensors Options for generating Diode calibration curves are 1 One point near 300K The portion of a Diode Sensor curve above 30K will be fit to a user specified point near 300K This is a two point fit where the 30K point is taken from the existing calibration curve The portion of the curve below 30K is unaffected 2 Two points 300K and 77K Here two user specified points are taken to fit the diode curve region above 30K The entire curve is offset to match the 77K point then the gt 30K region is fit to the two points 3 Three points 300K 77K and 4 2K Two points above 30K are fit as in the selection above Then a third point is used to fit a single point in the high
220. the RS 232 port using the terminal mode All command and response strings are displayed This is a good way to establish a connection Intermittent lockup on RS Possible causes 232 interface Long cables Try using a lower baud rate In some cases inserting a 50mS delay between commands will help Noise pickup Try using shielded cables with the shield connected to a metal backshell at both ends Don t send reset RST commands to the controller before reading 221 Model 32 32B User s Manual Appendix B Troubleshooting Guide Symptom Condition __ S y O Can t talk to IEEE 488 Possible causes interface Ensure that the GPIB port is selected Press the Sys key and scroll down to the RIO Port field The IEEE 488 interface does not use terminator characters Rather it uses the hardware EOI handshake Please review the GPIB Configuration section Check that the controller s address matches the host computer s assignment Press the Sys key and scroll down to the RIO Address field Debugging tip Cryo con utility software can be used to talk to the controller over the IEEE 488 port using the terminal mode All command and response strings are displayed Since the software provides the proper interface setup it is a good way to establish initial connection Intermittent lockup on the Possible causes IEEE 488 interface Bus cables too long or too many loads on a single bus Don t send reset commands before each
221. the autotuning process This a numeric field that is expressed as a percent of full scale heater output power The actual power output depends on the range setting of the heater If a value of 100 is used the controller may use any output power within the current range Command Syntax lt oc gt AUTOTUNE DELTAP lt value gt Where lt oc gt is the output channel to tune and may be either LOOP 1or LOOP 2 lt value gt is the maximum allowed change in output power expressed as a percent of full scale Query Syntax lt oc gt AUTOTUNE DELTAP Query Response lt value gt Where lt oc gt is the output channel to tune and may be either LOOP 1 or LOOP 2 lt value gt is the current Delta Power setting Command Example LOOP 1 AUTOTUNE DELTAP 100 This sets the maximum change in output power to 100 of full scale This will allow the tuning process to use any output level Query Example LOOP 2 AUTOTUNE DELTAP Example Response 25 0000 This response says that the maximum change in output power used by autotune will be 25 of the current output power level Short Form AUT DELT 194 Model 32 32B User s Manual Remote Operation AUTOTUNE TIMEOUT Autotune Timeout Sets and queries the timeout value of the autotune process This is a numeric field that specifies the maximum time in seconds that the autotune process model will wait for it s internal error vector to converge without declaring a timeout condition Command
222. the desired P term for the control loop Query Syntax LOOP lt no gt PGAIN Query Response lt value gt Command Example LOOP 1 PGAIN 123 Sets the heater P term to 123 Query Example LOOP 1 PGAIN Example Response 0 49723 Short Form LOOP PGA LOOP IGAIN Control Loop Integral Gain term Sets and queries the integrator gain term used by the selected control loop This is a numeric field with units of seconds Allowed values are 0 off through 1000 seconds The integrator gain term is applied to the selected control loop when controlling in a PID mode Command Syntax LOOP lt no gt IGAIN lt value gt Where lt no gt is the loop number 1 or 2 and lt value gt is the desired Integral Gain term for the control loop in seconds Query Syntax LOOP lt no gt IGAIN Query Response lt value gt Command Example LOOP 1 IGAIN 12 422 Sets the Loop 1 integrator feedback term to 12 422 Seconds Query Example LOOP 2 IGAIN Example Response 18 23 Indicates that the Loop 2 channel feedback term is 18 23 Seconds Short Form LOOP IGA 175 Model 32 32B User s Manual Remote Operation LOOP DGAIN Control Loop Derivative Gain term Sets and queries the differentiator gain term used by the selected control loop This is a numeric field with units of inverse seconds Allowed values are 0 off through 1000 Seconds The D gain term is applied to the selected control loop when controlling in a PID mode
223. this process the controller will freeze operation with an error message display In this case turn the unit off and refer to Appendix B Troubleshooting Guide Model 32 32B User s Manual Preparing the controller for use Caution Do not remove the instrument s cover or attempt to repair the controller There are no user serviceable parts jumpers or switches inside the unit Further there are no software ROM chips trim pots batteries or battery backed memories All firmware installation and instrument calibration functions are performed externally via the remote interfaces After about five seconds the self test will complete and the controller will begin normal operation Model 32 32B User s Manual Preparing the controller for use Installation General The Model 32 can be used as a bench top instrument or mounted in an equipment rack In either case it is important to ensure that adequate ventilation is provided Cooling airflow enters through the side holes and exhausts out the fan on the rear panel It is important to allow at least of clearance on the left and right sides and to ensure that the exhaust path of the fan is not blocked Rack Mounting You can rack mount the controller in a standard 19 inch rack cabinet using the optional rack mount kit Instructions and mounting hardware are included with the kit 4034 032 Single instrument shelf rack mount kit 4034 031 Dual instrument shelf rack
224. tions to minimize coupling include 1 Minimize the length of thermocouple wires For example use a thermocouple Module near the sensor to convert the thermocouple wires to copper as soon as possible 2 Twist the wires Twisted wire for various types of thermocouples is available from several vendors 3 Avoid running sensor wires near or parallel to AC power lines Use the largest diameter sensor wires possible Lowest AWG This will reduce the lead resistance and therefore reduce coupling However in many cryogenic applications wire size must be kept small because thermocouple wire is a good heat conductor Connecting Grounded Thermocouples For best performance thermocouple sensors should be floating This will ensure that no noise currents can flow in the sensor leads and that no common mode noise voltage will be directly coupled into the controller If a thermocouple must be grounded the ground point should be a good earth ground that has the same potential as the earth ground of the instrument If the ground point is floating or only loosely connected to earth ground significant noise pickup can result Since floating thermocouples will always give the best accuracy they should be electrically insulated by using small Sapphire washers Assuming that a grounded thermocouple is properly connected the controller should operate properly If this is not the case the problem can usually be tracked to the ground connection
225. to record these values for future reference and backup Cryo con Calibration Services When the controller is due for calibration contact Cryo con for low cost recalibration The Model 32 is supported on our automated calibration systems which allow Cryo con to provide this service at competitive prices Calibration Interval The Model 32 should be calibrated on a regular interval determined by the measurement accuracy requirements of your application A 90 day interval is recommended for the most demanding applications while a 1 year or 2 year interval may be adequate for less demanding applications Cryo con does not recommend extending calibration intervals beyond 2 years Whatever calibration interval you select Cryo con recommends that complete re adjustment should always be performed at the calibration interval This will increase your confidence that the instrument will remain within specification for the next calibration interval This criterion for re adjustment provides the best measure of the instrument s long term stability Performance data measured using this method can easily be used to extend future calibration intervals 123 Model 32 32B User s Manual Instrument Calibration Minimum Required Equipment All calibrations require a computer with an RS 232 or IEEE 488 connection to the instrument Additionally reference standards are required for each input range as follows e The Silicon Diode input range
226. tput is a 10 Watt linear current source Control Types Enumeration The Type filed selects the actual control algorithm used for the selected loop Selections are Off PID Man Table and RampP Loop control modes are 1 Man for Manual control mode Here a constant heater output power is applied when the unit is controlling temperature The Pman field selects the output as a percentage of full scale 2 Table This is a PID control mode where the PID coefficients are generated from a stored PID table based on setpoint PID for standard PID control Off In this mode the controller will not apply power on this output channel Note that the Model 32 is a dual loop controller The Off control mode is used if regulation is desired only on the other channel 5 RampP This is a temperature ramp mode When a ramp operation is complete the controller will revert to standard PID mode control at the final setpoint For more information on control algorithms refer to the Heater Control Types table above For more information on temperature ramps refer to the section on Temperature Ramping below 36 Model 32 32B User s Manual Front Panel Menu Operation Output Power Limit Numeric entry Default 100 The Power Limit field defines the maximum output power that the controller is allowed to output It is a percent of the maximum allowed output Maximum value is 100 and minimum is 15 For Loop 1 the Power Limit is a
227. tts For additional information please refer to the Heater Ranges table above Warning It is necessary to set the Load resistance field to the actual value of the heater load resistance being used If an incorrect value is selected output power indications will be incorrect and non linear heater operation may result If the actual heater resistance is less than selected the heater may overheat resulting in an automatic over temperature shutdown Ramping Rate Numeric entry Default 0 10 min When performing a temperature ramp the Ramp field defines the ramp rate Units are display units per minute In the default case this means Kelvin per minute For more information on temperature ramps refer to the section on Temperature Ramping below 38 Model 32 32B User s Manual Front Panel Menu Operation User Configurations Menu The User Configurations Menu is displayed by pressing the Config key It is used to save or restore up to four instrument setups Each setup saves the entire state of the Model 32 including setpoints heater configurations input channel data etc User Configurations Menu Selects the user configuration The 1 Confi g UserConfi gO N Model 32 has four configurations available Pressing the Enter key saves the 2 Confi g Save a instrument setup to the selected configuration number 3 Confiaq Restore 8 Pressing the Enter key restores a g saved configuration Table 11 User Configur
228. tune state from complete to idle Command Syntax lt oc gt AUTOTUNE SAVE Where lt oc gt is the output channel to tune and may be either LOOP 10r LOOP 2 Command Example LOOP 2 AUTO SAVE Short Form AUT SAVE AUTOTUNE PGAIN Proportional Gain When an autotune sequence has successfully completed the AUTOTUNE PGAIN command can be used to query the generated P or P gain term Query Syntax lt oc gt AUTOTUNE PGAIN Query Response lt value gt Where lt oc gt is the output channel to tune and may be either LOOP 1 or LOOP 2 lt value gt is the generated P gain feedback coefficient Query Example LOOP 2 AUTO PGA Example Response 125 0000 Indicates that the generated P gain term is 125 Short Form AUT PGA 196 Model 32 32B User s Manual Remote Operation AUTOTUNE IGAIN Integral Gain When an autotune sequence has successfully completed the AUTOTUNE IGAIN command can be used to query the generated I or integrator gain term Query Syntax lt oc gt AUTOTUNE IGAIN Query Response lt value gt Where lt oc gt is the output channel to tune and may be either LOOP 1 or LOOP 2 lt value gt is the generated feedback term in Seconds Query Example LOOP 1 AUTO IGA Example Response 225 0000 Indicates that the generated gain term is 225 Seconds Short Form AUT IGA AUTOTUNE DGAIN Derivative Gain When an autotune sequence has successfully completed the AUTOTUNE DGAIN command can be us
229. ual Specifications Features and Functions Rear Panel Connections The rear panel of the Model 32 is shown here Cryogenic Control Systems Inc amp Model 32 32B Temperature Controller FT noe IEEE 488 2 amp Madein USA azo rr O JO C ai Input B E x 5 Loop2 ro i l l 2 Input A Al CE Figure 3 Model 32 Rear Panel Layout AC Power Connection The Model 32 requires single phase AC power of 50 to 60 Hz Caution Protective Ground To minimize shock hazard the instrument is equipped with a three conductor AC power cable Plug the power cable into an approved three contact electrical outlet or use 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 User replaceable fuses are incorporated in the Power Entry Module 68 Model 32 32B User s Manual Specifications Features and Functions Fuse Replacement and Voltage Selection Access to the Model 32 s fuses and voltage selector switch is made by using a screwdriver to open fuse drawer in the power entry module A slot is provided above the voltage selector window for this purpose The fuse and voltage selection drawer cannot be opened while the AC power cord is connected Voltage selection is perform
230. ues shown on the initial screen before proceeding with actual calibration 125 Model 32 32B User s Manual Instrument Calibration There are two methods available for calibration 1 Automatic The software will recommend voltages and resistances You can set these values on the input channel and capture the instrument s actual readings Then the software will automatically generate offset and gain values for you 2 Manual You can manually enter Offset and Gain values and send them to the instrument Manual Calibration To manually calibrate a range select the desired range from the range type tabs and enter the desired Gain and Offset values in the boxes given and then click the APPLY button Gain is a unit less gain factor that is scaled to a nominal value of 1 0 It is usually computed by gain UT LT UM LM where UT is the upper target and LT is the lower target UM is the upper measurement and LM is the lower measurement Gain values greater than 1 2 or less than 0 8 are rejected as out of range Offset is in units of Volts or Ohms depending on the calibration type Nominal value is 0 0 Positive or negative numbers are accepted It is usually calculated by Offset UT gain UM 126 Model 32 32B User s Manual Instrument Calibration Automatic Calibration Automatic calibration uses the left hand side of the calibration screen and is a four step process 1 Line 1
231. ument calibration requires the use of various transfer standard resistance and voltage references In order to calibrate the Model 32 the calibration mode must first be turned on by using the INST MODE ON command Issuing this command will cause the unit to copy the actual calibration data from flash memory to temporary RAM Further the unit will display raw voltage data that has had the RAM calibration coefficients applied The temporary RAM calibration data is manipulated using the OFFSET and GAIN and TYPE commands for each input channel RAM is copied back to the actual FLASH memory calibration data table using the SAVE command The Model 32 is returned to normal operation by using the INSTCAL MODE OFF command Note that this does not write data to the calibration FLASH memory area INSTCAL MODE Queries or sets the instrument calibration mode Calibration mode must be turned on before most instrument calibration commands are effective Command Syntax INSTCAL lt chan gt MODE lt mode gt Where lt chan gt is the input channel number required but not used and lt mode gt is the desired mode which may be either ON or OFF Command Example INST A MODE ON Places the Model 32 in calibration mode Query Syntax INSTCAL lt chan gt MODE Where lt chan gt is the input channel number required but not used Query Response lt mode gt Where lt mode gt is the calibration mode indicator and will be either ON or OFF Que
232. urrounded with double quotation marks Query Syntax CALDATA lt index gt NAME Query Response lt name gt Where lt index gt is the index of the user installed sensor and lt name gt is the name string for the indexed sensor Query Short Form CALD lt index gt Where lt index gt is the index of the user installed sensor and lt val gt the sensor s name string Query Example CALDATA 3 NAME Example Response User Curve 2 Short Form CALD SENT NAME Name for a factory installed sensor Queries the name of a factory installed sensor Query Syntax SENT lt index gt NAME Or SENT lt index gt Query Response lt name gt Where lt index gt is the index of the factory installed sensor and lt name gt is the name string for the indexed sensor Query Example SENT 1 Example Response Cryocon S700 Short Form SENT 190 Model 32 32B User s Manual Remote Operation CALDATA TYPE Sensor Type Sets or queries the sensor type at a Sensor Table index Supported sensor types are described above in the Supported Sensors section Command Syntax CALDATA lt index gt TYPE lt stype gt Where lt index gt is the index to the user installed sensor and lt stype gt the sensor type selected from the above list Query Syntax CALDATA lt index gt TYPE Query Response lt stype gt Where lt index gt is the index and lt stype gt is the sensor type Command Example SENT 3 TYP
233. usually have different parameters Many queries do not use any parameters The white space is used to separate the instruction header from the instruction parameters If the instruction does not use any parameters you do not need to include any white space White space is defined as one or more spaces ASCII defines a space to be character 32 in decimal Instruction parameters are used to clarify the meaning of the command or query They provide necessary data such as whether a function should be on or off which input channel controls the heater output etc Each instruction s syntax definition shows the parameters as well as the values they accept Headers There are three types of headers Simple Command Compound Command and Common Command Simple command headers contain a single keyword CONTROL and STOP are examples of single command headers The syntax is lt function gt lt terminator gt When parameters indicated by lt data gt must be included with the simple command header for example INPUT CHA the syntax is lt function gt lt white space gt lt data gt lt terminator gt Compound command headers are a combination of two or more keywords The first keyword selects the subsystem and the last keyword selects the function within that subsystem Sometimes you may need to list more than one subsystem before being allowed to specify the function The keywords within the compound header are separated by colons For exam
234. ut Channel B setup menu Display Alam Set Pt Loop 1 Go to the Loop 1 or primary heater output h setup menu Loop 2 Go to the Loop 2 or secondary heater output setup menu Auto Tune Go to the auto tuning menu for either loop Config Go to the User Configurations menu Sensors Go to the Sensors configuration menu including sensor calibration curves PID Table Go to the PID tables setup menu Sys Go to the System Functions menu This includes fields for Remote Input Output Display filters and the Over Temperature Disconnect feature Display Go to the Display setup menu This allows configuration of the front panel display from a list of options Alarm Go to the Alarm Status menu Set Pt Set the setpoint values for both control loops The Selection Keys and Enumeration Fields Enumeration fields are display fields where the value is one of several specific choices For example the Heater Range field in the Loop 1 setup menu may contain one of only three possible values HIGH MID and LOW There are many enumeration fields that contain only the values ON and OFF An enumeration field is always indicated by the character in the last column of the display To edit an enumeration field place the cursor at the desired field by using the Navigation keys Then use the or 4 key to scroll through all of the possible choices in sequence 19 Model 32 32B User s Manual Front Panel Operation W
235. ve been entered the user may select the New Curve field in order to generate the new curve This will cause the display of a menu like the one shown here CalGen New Curve Menu Sets the curve number for the 1 15 User Sensor 1 generated curve Numeric entry Note only the user curves can be written Pressing the Enter key will cause the 2L 2 generation of a new curve The curve Save will be stored at the curve number specified on line 1 Table 35 CalGen New Curve Menu From this screen the user must select the target user curve for the generated curve Finally select the Save field in order to generate the curve and store it in the selected user location Note The CalGen process may be aborted by pressing the Esc or Home key Using CalGen With Platinum and Thermocouple Sensors The calibration curve generation procedure for Platinum or Thermocouple sensors is the same as for the diode sensors described above However Platinum sensor curves are generated using two user specified points Therefore the selection of the number of points is not required 99 Model 32 32B User s Manual System Shielding and Grounding Issues System Shielding and Grounding Issues Grounding Scheme The grounding scheme used in all of Cryo con s instruments is based on a Single Point Ground and is designed to minimize ground loop and noise pickup by assuming that the Sensor and Heater elements are electrically floatin
236. vice please provide a description of the malfunction If possible the original packing material should be retained for reshipment If not available consult factory for packing assistance Cryo con s shipping address is Cryogenic Control Systems Inc 17279 La Brisa Street Rancho Santa Fe CA 92067 Model 32 32B User s Manual A Quick Start Guide A Quick Start Guide A Quick Start Guide to the User Interface Pressing the Power key will toggle the controller s AC power on and off This key must be pressed and held for two seconds before power will toggle Pressing the Stop key will immediately disengage both control loops Pressing the Control key will engage them The Home Status Display Pressing the Home key will return the screen to the Home Display from anywhere in the sub menus The Home Display is the primary display for instrument status information Several Home Displays are available so that the user can see desired information without additional clutter To scroll through the available displays press the amp or key Accessing the heater setpoint To instantly access the setpoint for either control loop press the Set Pt key Configuring a temperature sensor Configuring an input sensor from the front panel is performed by using the Input Channel Setup Menu To access this menu for input A press the ChA key or for input B the ChB key The first line of this menu is used to change the sensor units
237. w the full status of the instrument Generally pressing the Home will take the display up one level in the Setup Menu tree and the Home Status displays are at the root level The Enter key is functional only in the Setup Menus and is used to enter numeric data or make a selection Navigation Keys Navigation through the displays and menus of the Model 32 is accomplished with the cursor keys amp and Esc The and keys are used to scroll the display up or down through all of the lines available on a given menu When the display is showing one of the Home Status displays the amp and keys are used to scroll through the four available display formats When the display is in any of the Setup menus these keys are used to scroll through the various lines of the menu BUG 18 Model 32 32B User s Manual Front Panel Operation The Keypad and Setup Menu Keys The keypad keys on the far right side of the instrument ChB ChA Loop 1 serve a dual function When numeric data is required these keys are used as a standard keypad where the ED numbers are printed on the keys Otherwise they are used to go directly to the Setup Menu printed over the top of the Confi S Loop 2 ey OO PID When used as Setup Menu keys their function is identified Auto by a label printed just above the key and is as follows Sensors Table Tune ChA Go to the Input Channel A setup menu Ce ChB Go to the Inp
238. wer measurements The edit boxes on lines 2 and 4 will contain the measured values At this time you may still change the target values on line 1 and 3 if desired Now you can automatically compute the required gain and offset values by clicking on the Calibrate button in the Calibration Results box This will change the Status field from Current to Calibrated and will update the Offset and Gain values with those calculated At this point to values have been transmitted to the instrument In order to send the offset and gain values to the instrument s calibration memory click the APPLY button You will be required to confirm that you really want to update calibration memory Summary of Calibration Types Calibration data must be generated for each input channel by sequencing through the various calibration types on each channel Asummary of types is given here Calibration Voltage Output Dascriotion Type Range Current p SI DiodeV 0 25V N A Voltage measurement for use with Silicon Diode temperature sensors 10uA constant current source used gt l Diode with Silicon Diode sensors 10mV 1mA range used with constant ULE 1 25Hz Autpranged voltage mode sensors 100uA AC 10mV Autoranged 100uA range used with constant 1 25Hz voltage mode sensors 10uA AC 10mV Autoranged 10uA range used with constant 1 25Hz voltage mode sensors DC measurement of 100 Platinum 1mA DC 0 2 5VDC 1 0mA RTD sensors DC measurement of 1K Ohm 100uA
239. y Module on the rear panel Line voltage selections are 100 120 220 or 240VAC Tolerance on voltages is 10 to 5 for specified accuracy and 10 for reduced full scale heater output in the highest output range Protective Ground To minimize shock hazard the instrument is equipped with a three conductor AC power cable Plug the power cable into an approved three contact electrical outlet or use a three contact adapter with the grounding wire green firmly connected to an electrical ground safety ground at the power outlet 74 Model 32 32B User s Manual Specifications Features and Functions The power jack and mating plug of the power cable meet Underwriters Laboratories UL and International Electrotechnical Commission IEC safety standards Power requirement is 25 Watts plus the power being provided to the heater load The power cord will be a standard detachable 3 prong type User replaceable fuses are incorporated in the Power Entry Module See the section titled Fuse Replacement Voltage Selection cz Note The Model 32 uses a smart power on off scheme When the power button on the front panel is pressed to turn the unit off the instrument s setup is copied to flash memory and restored on the next power up If the front panel button is not used to toggle power to the instrument the user should configure it and cycle power from the front panel button one time This will ensure that the proper setup is restored
240. y installed sensor at a specific index Command Syntax INPUT lt channel gt ISENIX lt ix gt Where lt channel gt is the input channel parameter and lt ix gt is the desired sensor index Query Syntax INPUT lt channel gt ISENIX Where lt channel gt is the input channel indicator Query Response lt ix gt Where lt ix gt is the sensor index for the selected input channel If the index is invalid a value of 1 will be returned Command Example INPUT B SENIX 0 This command sets the sensor index for input channel B to zero disabled Query Example INP A SENIX Example Response 02 This indicates that sensor 02 is assigned to input channel A The name of factory installed sensor 02 may be accessed using the SENTYPE commands Short Form INP SEN 156 Model 32 32B User s Manual Remote Operation INPUT USENIX User Sensor index Sets or queries the sensor index number assigned to an input channel for user installed sensors Refer to Appendix A for a description of sensors indices etc An index number of 0 through 3 indicates user sensor curves 0 through 3 Note The use of the ISENIX command to assign a factory installed sensor and the USENIX command to assign a user sensor are preferred to the use of the obsolete SENIX command The CALD command may be used to query information about the user installed sensor curves Command Syntax INPUT lt channel gt USENIX lt ix gt Where lt channel

User`s Manual - Cryogenic Control Systems, Inc.

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