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1. USER S MANUAL Model 647 Magnet Power Supply akeShore Lake Shore Cryotronics Inc 575 McCorkle Blvd Westerville OH 43082 8888 PH 614 891 2243 FAX 614 891 1392 Internet Addresses sales lakeshore com service lakeshore com Methods and apparatus disclosed and described herein have been developed solely on company funds of Lake Shore Cryotronics Inc No government or other contractual support or relationship whatsoever has existed which in any way affects or mitigates proprietary rights of Lake Shore Cryotronics Inc in these developments Methods and apparatus disclosed herein may be subject to U S Patents existing or applied for Lake Shore Cryotronics Inc reserves the right to add improve modify or withdraw functions design modifications or products at any time without notice Lake Shore shall not be liable for errors contained herein or for incidental or consequential damages in connection with furnishing performance or use of this material Rev 1 0 19 January 1998 Lake Shore Model 647 Magnet Power Supply User s Manual MAGNET POWER SUPPLY CONFIGURATION Sales Order Number MPS Model Number Shipping Date MPS Serial Number Power Settings Below is a checklist of major options installed in your Model 622 633 Magnet Power Supply Read the manual before attempting to operate the equipment C 6224 IEEE 488 Serial Interface L 6476 Gaussmeter Input Card L 6477 High Resolution Display and Programmi
2. Zl Programs Current Zero Value Input Zl current zero where current zero a value between 999 9999 Remarks Enter this setting after enabling ZI Status Control Bus inputs 4 places display rounds to 0 01 or 0 001 place If a ZI value is entered over the Control Bus status automatically turns ON Z1 Current Zero Value Query Input ZI Returned A number between 999 9999 Remarks Returns nine characters plus up to two terminators ZIS Programs Current Zero Status Input ZIS status where status 0 to turn OFF the current zero or 1 to turn it ON Remarks When the current zero is turned off the current zero value resets to 0 ZIS Current Zero Status Query Input ZIS Returned 0 if the current zero is OFF or 1 if it is ON Remarks Returns one character plus up to two terminators A Remote Operation Lake Shore Model 647 Magnet Power Supply User s Manual 4 3 1 5 Current Step Limit Commands Description The following MPS commands configure the various functions of the current step limit features ISTP Programs Output Current Step Limit Input ISTP step limit where step limit a value between 0 and 999 9900 Remarks Truncates the value to the 0 001 place The initial condition is 000 000 A The step limit is forced to a plus Control Bus inputs 4 places display rounds to 0 01 or 0 001 place ISTP Output Current Step Limit Query Input ISTP Returned A number between 0 and 999 9900 A Remarks Re
3. 8 Data and 1 Stop Baud Rate 300 1200 or 9600 Timing Format Asynchronous Parity Type None Connector Two RJ 11 Modular Socket Fixed Terminator CR 0DH LF OAH Transmission Mode Half Duplex Data Interface Levels Transmits amp Receives Using EIA Voltage Levels 4 2 2 Serial Interface Settings To use the Serial Interface set the Baud rate See Paragraph 4 1 1 4 2 3 Sample BASIC Serial Interface Program The QuickBASIC V4 0 program in Table 4 3 is a sample interactive serial poll routine for the MPS Serial Interface Below are typical examples using this BASIC program User input is in bold type ENTER COMMAND IDN Identification Query Returns manufacturer model number 0 and Firmware Date LSCI 622 0 120193 ENTER COMMAND ISET 25 I0UT Output Current Setting and Query Instructs unit to set current to 25 amps and then asks for current reading 24 9975A ENTER COMMAND OVP Overvoltage Quench Protection Circuit Status Query Unit returns setting where 0 Off and 1 On 0 ENTER COMMAND RI Remote Inhibit Status Query Unit returns setting where O Inactive and 1 Active 0 ENTER COMMAND MODE Mode Status Query Instrument returns mode where 0 Local 1 Remote or 2 Remote with Lockout 1 4 24 Notes On Using The Serial Interface e To chain commands together insert a semi colon between them Multiple queries cannot be chained Queries use the same syntax as the associat
4. CMDS TERMS CALL IBWRT DEV12 CMDS Send command to instrument CALL IBRD DEV12 INS Get data back each time DTEST INSTR INS CHRS 13 Test for returned string IF ENDTEST gt 0 THEN String is present if lt CR gt is seen INS MIDS INS 1 ENDTEST 1 Strip off terminators PRINT RESPONSE INS Print return string ELSE PRINT NO RESPONSE No string present if timeout END IF GOTO LOOP2 Get next command Remote Operation Lake Shore Model 647 Magnet Power Supply User s Manual National Instruments GPIBO configuration GPIB PC2 2A Ver 2 1 Primary GPIB Address T Select the primary GPIB address by Secondary GPIB Address using the left and right arrow keys Timeout setting This address is used to compute the Terminate Read on EOS talk and listen addresses which Set EOI with EOS on Writes Yes identify the board or device on the Type of compare on EOS GPIB Valid primary addresses range from 0 to 30 00H to 1EH Send EOI at end of Write Adding 32 to the primary address System Controller forms the Listen Address LA Assert REN whe SC Adding 64 to the primary address Enable Auto Serial Polling forms the Talk Address TA Enable CIC Protocol Bus Timing EXAMPLE Selecting a primary address Parallel Poll Duration of 10 yields the following Use this GPIB board 1032 742 Listen address Board Type 10 64 74 Talk address Base INO Address y F1 Help F6 Reset Value F9 Esc Return to Map Ctl
5. If the OUT terminal is tied to earth ground make certain the OUT cable from the MPS contacts no other earth ground point it forces the MPS output current into this other ground point If the other ground point is a small wire it may melt or catch fire 2 5 3 MPS Remote Inhibit and Fault Indicator Connections The MPS has a Fault Indicator FLT output and a discrete Remote Inhibit RI input which 1 R Remote Inhibit Active low TTL compatible input to are both interface independent 2 RI remotely force the output settings to 0 A and 1 V Also and provide fault indication and activate RI by shorting RI to RI with a relay contact closure or a switch remote output shutdown in the event of catastrophic failure The 3 FLT Fault Indicator A relay contact that closes to indicate a Fault Indicator relay contact is 4 FLT fault Contact rating 0 25 A resistive at 100 VDC 3 W 25 open when the MPS detects no VA faults When the MPS detects an 5 ON ON Indicator A relay contact that closes to indicate when internal fault a remote inhibit or the front panel circuit breaker is in the ON position Contact am output inhibit it lights tha front 6 ON rating 0 25 A resistive at 100 VDC 3 W 25 VA relay contact The contact closure alerts other system components In auto parallel MPS configurations OVP ensures that the of the fault In an auto parallel activation of one MPS Over Voltage Protection circuit z ac
6. Paragraph 4 3 1 2 Ramping Commands Paragraph 4 3 1 3 Current Zero Commands Paragraph 4 3 1 4 Current Step Limit Commands Paragraph 4 3 1 5 and Common Commands Paragraph 4 3 1 6 OPERATIONAL COMMANDS CURRENT ZERO COMMANDS Cmd Function Cmd Function ERR Error Status Summary IMODE Current Programming Mode Query IMAX Upper Current Limit VMODE Voltage Programming Mode Query IMAX Upper Current Limit Query Zl Zero Current Value Status IOUT Output Current Query ZI Zero Current Value Query ISET Output Current Setting ZIS Zero Current Status ISET Output Current Setting Query ZIS Zero Current Status Query IV Output Summary Query OVP Overvoltage Protection Query CURRENT STEP LIMIT COMMANDS RI Remote Inhibit Status Query Cmd Function VOUT Output Voltage Query ISTP Output Current Step Limit VSET Output Voltage Setting ISTP Output Current Step Limit Query VSET Output Voltage Setting Query ISTPS Output Current Step Limit Status ISTPS Output I Step Limit Status Query INTERFACE COMMANDS STEP Output I Step Limit Exceeded Query Cmd Function STEPR1 Output Step Limit Exceeded Reset END EOI Status END EOI Status Query COMMON COMMANDS MODE Interface Status Mode Cmd Function MODE Interface Status Mode Query CLS Interface Clear TERM Terminator ESE Std Event Status Enable Reg TERM Terminator Query ESE Std Event Status Query ESR Std Event Status Enable Query RAMPING COMMANDS IDN Identification Query Cmd Function OPC Operation
7. 1 3 Operating e EE 1 3 1 True Four Quadrant Bidirectional Power Flow r rrrrrarnrrnnrannnnrnnvrnnrannnnrenernnrnnrnnnnanernen 1 3 2 Low Noise High Stability Current Regulated Output 1 3 3 Highly Efficient Air Cooled Compact Unit ccccccccceceeeeeeeeeccceeceeeeeeeteceneaeeeeeeeeeteees 2 INITIAL SETUP AND CONNECTIONS rarennnnnnnnnvnnnnnvnnnnnnnnnvnnnnnnnnnnnnsnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnennnnneen 2 1 Inspecting and Unpackimg canon nn nc nemen 2 2 MPS Mountingi dida Sandane 2 3 Environmental Requirements sssssssssssssse seen emen n enne 24 Connecting the MPS to Power 2 4 1 Power and Ground Requirements sss eene renes 2 4 2 MPS Input Power Ratinga sorur aerei etait tete erect nenne tec ent EE 2 4 3 Input Power Connections eee eeeneaece cess enne nennen streiten nennen 2 5 Power Up ee us dec ete ta po tt its 2 5 1 Magnet Cable Connections nennen menn 2 5 2 Shielding Grounding and Noise oooocconcocococccocococononnononoconnnnnnonnnnonnnnnnnnnnnnnnnnnnnnncnnnnnnnnnes 2 5 3 MPS Remote Inhibit and Fault Indicator Connections ssssss sess 2 5 4 AG Oni seu em 2 5 5 OVP GOMMOCTION EE 2 5 6 MPS Analog Current and Voltage Monitoring Conpnechons 2 5 7 External Current Programming ooooccccnnnccccnnnonccnnononcncno nan cnn nono cnn mener 2 5 8 Remote Sense Connections sse enne 2 6 Multiple Auto Parallel Getup emen 2 7 Post Installation Ins
8. 196 VMAX Digital Programming Repeatability 0 196 VMAX Electronic Resolution Standard High 4 mA 1 mA 1mV 1mV 0 196 IMAX 10 mA 1 mA 0 196 VMAX 10mV 1mV Electronic Accuracy Display Resolution Standard High Stability Drift at 25 1 C Percent of full scale output change over 8 hours under constant line and load after 0 005 IMAX 0 01 VMAX a 30 minute warm up Ripple and Noise 10 Hz to 10 MHz at 1000 VA 40 pA rms Temperature Coefficient Change in output per C 0 1 Imax 0 1 VMAX after 30 minute warm up i 20 mV rms Source Effect Line regulation for any line change within 0 005 IMAX 0 05 VMAX the rated line voltage i Load Effect Load regulation for a load change equal to maximum voltage in Constant Current Mode or maximum 0 196 IMAX 0 196 VMAX current in Constant Voltage Mode Analog Resistance Programming Accuracy 0 to 10 KQ produces negative full scale to positive full scale 10 IMAX current or voltage output 5 KQ is 0 current 10 VMAX Analog Voltage Programming Accuracy Voltage input is 0 01 V A 0 01 V V rm 2 100 mV Monitoring Output Accuracy Voltage output is O 0 01 V A 0 01 V V 1 100 mA 2 100 mV Introduction 1 3 Lake Shore Model 647 Magnet Power Supply User s Manual 1 3 OPERATING CHARACTERISTICS Many Model 647 MPS operating characteristics ideally suit it for charge and discharge cycling of superconducting magnet loads These character
9. 8 to terminate the control bus only if the MPS units are a significant distance from each other Replace the CMP Configure the second MPS as MPS 2 a Locate the CAL AND ID switches on the rear panel Turn ON up position switches 2 and 4 Turn OFF down position switches 1 3 and 5 through 8 Switch 4 ON designates Multiple MPS operation Switches 3 2 and 1 as OFF ON OFF respectively assign the MPS address as 2 b Move the MODE switch to the INTernal up position c On the CMP verify that switches 5 6 and 7 are ON closed and switches 1 through 4 and 8 are OFF OPEN Replace the CMP Connect the control bus Use Lake Shore Model 2001 Modular Cables provided to interconnect the two MPS CMP units Connect the MPS 1 over voltage protection OVP pin 8 to MPS 2 pin 8 Connect the RI and FLT signals Connect the RI terminal 1 to the FLT terminal 3 on MPS 2 Connect the RI terminal 2 to the FLT terminal 4 on MPS 2 Do the same on MPS 1 Connect the RI FLT connection of MPS 2 to the RI FLT connection of MPS 1 Connect the RI FLT connection of MPS 2 to the RI FLT connection of MPS 1 If an external contact closure will remotely inhibit operation connect it across the RI and RI terminals of MPS 1 The FLT and FLT contact closure of MPS 1 indicates a fault Connect the OUT terminal of MPS 1 to the OUT terminal of MPS 2 Connect the OUT terminal of MPS 1 to the OUT terminal of MPS 2 Make these le
10. DVM reading of OV 0 00005V before continuing the calibration 24 Use IMAX and STPS commands to restore IMAX and output current step to Step 7 values 25 Turn off MPS and disconnect calibration loads 26 Restore original Control Bus Serial Interface settings 27 Disable MPS calibration Turn OFF down CAL AND ID switch 8 4 Turn ON MBS Initially the display clears and the alarm sounds tor a Short time Within TWO seconds the Normal Display appears Output Voltage Verification 5 From the MPS front panel select the Instrument Setup INSTR SETUP menu and change com pliance voltage to 5 V Press the Normal Display key to return to the Normal Display screen 6 Set output current to 1 A Use the DVM to read the voltage across the MPS unit s output terminals The reading should be 5 V 0 3 V 7 Set output current to 1 A The DVM should read 5 V 0 3 V 8 Turn OFF MPS Output Current Verification 9 Use AWG 4 wire to connect the current monitor shunt between the MPS OUT and OUT terminals Connect DVM across the shunt monitoring terminals Note DVM offset reading 10 Turn ON MPS Within two seconds the Normal Display appears 11 Select the Instrument Setup INSTR SETUP menu and change compliance voltage to 2 Volts Press the Normal Display key to return to the Normal Display screen 12 Wait 1 minute for MPS output to settle The DVM should read the same as recorded for Step 9 0 01 mV 13 Se
11. Description 4 15 4 3 1 4 Current Zero Commands Description 4 16 4 3 1 5 Current Step Limit Commands Description 4 17 4 3 1 6 Common Commands Description eene 4 18 5 ERROR MESSAGES AND TROUBLESHOOTING nannnvnnnnnnnnnnnnvnnnnnnnnnnnnnnnnnnennnnnnnnnnennnnnnnnnnnnnnnnn 5 1 5 0 E e 5 1 5 1 Software Error Messages dene tatu t e atate arte bebe Reb erga 5 1 5 2 Factory Default Settings iit ir ci o ter ee eb rte 5 3 5 3 Calibration 2 5 i c teet erba et a e le efi to iter M ael e rc Last die 5 4 5 4 Performance l est ee ta b e tl eiie attende dee teat eege 5 5 5 5 Rear Panel Connector Detalls 3 2 Arad ere ute tide rien tasted reta 5 6 5 6 IEEE 488 Interface Connector If Present 5 7 5 7 Serial Interface Cable and Adapters c ccccceceeeeeeeceeeeeeceeeeeeeeeeanaeeeeeeeseesenieeeeeeess 5 7 ii Table of Contents Lake Shore Model 647 Magnet Power Supply User s Manual Chapter Paragraph Title 6 OPTIONS AND ACCESSORIES rnnnnvnnnnnnnnnnnnnnnnennnnnsnnnnnnnnnennnnnnvnnnnnennnnnnnnnvnnnnnnnnnnnnnnnnvnnnnnnnnennnenn 6 0 EE EE 6 1 Model 6224 IEEE 488 Serial Interface 6 2 Model 6476 Gaussmeter Input Card 6 2 1 Hall Sensor Mounting Considerations sss eme 6 2 2 CONNECTIONS EE 6 2 3 Installatiot s iet o RUE ere Reed eee tiene ET 6 2 4 lecum 6 2 5 Remote Operation Commande sss eene nennen 6 3 Model 6477 High Resolution Display and Programming Optio
12. Null Modem Adapter is S 4 8 required to exchange Transmit and Receive lines To customer supplied computer with DE 9 Serial Interface Connector configured as DTE If the interface is DCE a Null Modem Adapter is required to exchange Transmit and Receive lines The Model 2001 2002 and 2003 are options available from Lake Shore Use whichever adapter that matches your computer serial interface connector Pin outs are described in Paragraph 6 5 LSCI Model 2003 RJ 11 to DE 9 Adapter LSCI Model 2001 RJ 11 Cable Assembly Figure 4 2 Serial Interface Adapters Remote Operation Lake Shore Model 647 Magnet Power Supply User s Manual 4 2 1 Serial Interface Hardware Configuration Below is a technical description of the 6224 option card for the Serial Interface configuration Note See Appendix C for Serial Interface on CMP Table 4 2 defines communication parameters Terminators are fixed to Carriage Return CR and Line Feed LF The serial interface connector is a standard 6 wire RJ 11 telephone jack Lake Shore offers the Model 2001 10 foot Cable Assembly Model 2002 RJ 11 to DB 25 Adapter and the Model 2003 RJ 11 to DE 9 Adapter See Chapter 4 Service for Serial I O connector and adapter pin out details and Chapter 5 Options and Accessories for adapter dimensions Table 4 2 Serial Interface Specifications Transmission Three Wire Bits per Character 1 Start
13. Use the procedure below to change or verify the serial interface configuration 1 Turn off the Mainframe and unplug the power cord 2 Loosen the two screws that secure the CMP to the rear panel and slide the CMP out 3 Locate and configure the control bus serial interface DIP switches as defined in the table dicus Unterminated to the right The DIP switches are just inside Configuration the CMP front panel Switches 1 4 define the mile interface as RS 232C Switches 5 8 define the GEES interface as RS 485 multidrop Switch 8 2 Closed Open Open activates 100 O bus termination for long serial 3 Ope Ope interface runs For RS 485 terminate Open Open extremely long main lines at the furthest point 4 Closed Open Open from the host Limit main line length to under 5 Open Closed Closed 4000 feet and multiple short stub lines from 6 Open Closed Closed the main line Mainframe to Mainframe to Ia SEI Closed Closed under 50 feet A typical RS 485 configuration i Closed closed runs the main line from the host to one of the 8 Open Closed Open first Mainframe serial interface jacks a Lake Shore 2001 cable plugs into the other first Mainframe serial interface jack to connect to the second Mainframe and so on Connect up to 32 Mainframes in this way Terminate the last Mainframe only if it is a significant distance from the host Assign unique addresses to multiple Mainframes on a RS 485
14. Zero Screen STATUS lt OFF gt Output Current Zero Status Off I ZERO 0 00 A Output Current Zero Value MODE INTERNAL Output Current Programming Mode Display Only Current Step Limit Screen STATUS lt ON gt Output Current Step Limit Status On I STEP 10 00 A Output Current Step Limit 10 00 Amps Options amp Accessories estsi lt i s lt CO 58 Lake Shore Model 647 Magnet Power Supply User s Manual 5 3 CALIBRATION NOTE Calibration is only as accurate as the current monitor shunt The factory uses a current monitor shunt rated at 0 02 accuracy Shunt manufactur ers typically stock accuracy values of 0 25 or better To use a different value adjust the readings given in the procedure 1 Equipment requirements for MPS calibration a Current monitor shunt 100 mV output at 100A 1 milliohm 0 02 accurate b Load resistor 10V at 100A 0 1 ohm 1 kW c Digital Volt Meter DVM with a resolution of 100 nV 6 1 2 digits 0 0035 accurate HP 3457A or equivalent d Acomputer with a RS 232C serial interface e LSCI Model 2002 RJ 11 to DB 25 adapter or Model 2003 RJ 11 to DE 9 adapter depend ing on the computer serial output connector 2 Turn OFF and unplug the MPS before configuring it for calibration 3 Configure the Control Bus Serial Interface for RS 232C Operation See Paragraph C4 0 Connect output to a computer using a modular cable or if equi
15. and 11 m with positive output currents producing a positive monitor voltage of 10 mV A from Im to m Obtain the Voltage Monitor signal through connections to terminals 10 Vm and 11 m with positive terminal voltages producing a positive monitor voltage of 10 mV V from Vm to m Table 2 4 Analog Monitoring Programming amp Remote Sense Connections TERMINAL LABEL DEFINITION Output Current Monitor Voltage output from Im to GND M is 10 mV A 3 Output voltage monitor Voltage output from Vm to GND M is 10 mV V Monitor and program ground GND m 3 Not Used Not Used Negative voltage supply for programming external current with a potentiometer Current programming input voltage Voltage input from Ip to GND m produces 100 A V Voltage may come from a voltage source or from the center tap of a potentiometer connected from ls to ls m Vp Vs x Positive voltage supply for programming external current with a potentiometer Remote voltage sense correction Correction for load lead drops of up to 0 5 V per lead OVPIm Vm mVp tVs ls lp ls S S 7 8 9 10 11 12 13 14 15 16 17 18 Lad Lane 10K 10K Figure 2 3 Analog Monitoring Programming amp Remote Sense Connections usn EN a E Is S S 2 5 7 External Current Programming Remotely program MPS output current by an external voltage or potentiometer Enable external analog programming via the rear panel I MODE switch When the I M
16. and records evacuation Here is a list of suggested personnel safety considerations e Ground Fault Interrupter GFI AC circuits Fire Extinguisher e Magnetic Field Warnings Emergency Lighting Locate in the immediate vicinity fire extinguisher s that extinguish all three classes of fires A B and C Class A is ordinary combustibles like wood paper rubber many plastics and other common materials that burn easily Class B is flammable liquids like gasoline oil and grease Class C is energized electrical equipment including wiring fuse boxes circuit breakers machinery and appliances Do not use chemical extinguishers even though they are less expensive and cover all classes of fires They may damage electronic equipment Use a Carbon Dioxide or Halon fire extinguisher During the planning stage consult local experts building authorities and insurance underwriters on locating and installing sprinkler heads fire and smoke sensing devices and other fire extinguishing equipment Even where not required by code install some type of automatic battery operated emergency lighting in case of power failure or fire Forward vii Lake Shore Model 647 Magnet Power Supply User s Manual SAFETY SUMMARY Observe the following general safety precautions during all phases of operation service and repair of this instrument Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standa
17. enters Step Limit Mode and forces output settings to O amps and 1 volt On the next update cycle it closes the FLT contacts to indicate the fault and the internal audio indicator beeps about once per second See Chapter 5 for error messages and action to take if the Current Step Limit is exceeded 3 4 Operation Lake Shore Model 647 Magnet Power Supply User s Manual CHAPTER 4 REMOTE OPERATION 4 0 GENERAL Either of two computer interfaces available for the Model 647 permit remote MPS operation the IEEE 488 Interface Paragraph 4 1 and the Serial Interface Paragraph 4 2 Use only one of the interfaces at a time The two interfaces share a common set of commands described in Paragraph 4 3 For further information on RS 485 Mainframe Control Bus Operation see Appendix C 4 1 IEEE 488 INTERFACE The IEEE 488 Interface is an instrumentation bus with hardware and programming standards that simplify instrument interfacing The MPS IEEE 488 Interface complies with the IEEE 488 2 1987 standard and incorporates the functional electrical and mechanical specifications of the standard unless otherwise specified in this manual All instruments on the interface bus perform one or more interface function TALKER LISTENER or BUS CONTROLLER A TALKER transmits data onto the bus to other devices A LISTENER receives data from other devices through the bus The BUS CONTROLLER designates to the devices on the bus which function to perform The MPS p
18. keys toggle the status If the status is ON it must be toggled to OFF to clear the old value before a new value is accepted When the status is toggled ON the output current stores as the current zero and displays as the ZERO value 3 7 2 Current Step Limit Screen When a superconducting magnet quench occurs the magnet becomes resistive The output current forces MPS output to the voltage setting constant voltage mode and output current drops rapidly To avoid excessive cryogen boil off the output current setting should be changed to 0 as quickly as possible The output current step limit feature allows users to enter a current step limit which if exceeded automatically resets the output settings to OA and 1V Press the STEP LIMIT Function Key on Function Menu 3 to display the Current Step Limit screen Use the Cursor keys to move the line indicator up and down The icon indicates parameters that can only be changed using the up or down Numeric Entry keys Change all others using all the numeric entry modes including the cursor See Section 3 for keypad operations Below are valid Output Current Step Limit entries STATUS lt OFF gt or lt ON gt Output Current Step Limit Status Use the Up or down Numeric Entry keys to toggle the status I STEP 0 00 A to 999 99 A Output Current Step Limit Use any numeric entry mode to change the value If the MPS detects a change in output current that exceeds the step limit it
19. mode Z Setup amp Connections Lake Shore Model 647 Magnet Power Supply User s Manual Use the procedure below and see Figure 2 5 to connect multiple MPS units in auto parallel configuration 1 2 Turn off all units and completely disconnect power at the source before changing MPS configuration Determine which MPS to assign as MPS 1 and configure it as follows a Locate the CAL AND ID DIP switches on the rear panel Turn ON up position switches 1 and 4 Turn OFF down position switches 2 3 and 5 through 8 Switch 4 ON designates multiple MPS operation Switches 3 2 and 1 respectively OFF OFF and ON assign the MPS address as 1 Note that the CAL AND ID switch numbers are upside down as viewed from the rear panel Switch 1 is on the right and switch 8 is on the left Take care to use the correct switch numbers b Move the I MODE switch to the INTernal up position c Locate the Communications Microprocessor CMP in the MPS rear panel The CMP is the module with the two RJ 11 telephone jacks Loosen the two screws securing the CMP to the MPS rear panel and slide the CMP out Just inside the CMP front panel there is a set of DIP switches Verify that switches 5 6 and 7 are ON closed and switches 1 through 4 and 8 are OFF OPEN Switches 1 4 define the control bus as Serial RS 232C Switches 5 8 define the control bus as RS 485 multidrop Switch 8 terminates the bus for long communications loop runs Close switch
20. or 0 001 place IMAX Current Limit Query Input IMAX Returned A number between 0 and 72 A Remarks Nine characters plus up to two terminators are returned Value is shown as a but applies to both positive and negative entries IOUT I Output Current Query Input IOUT or I Returned A number between 72 A Remarks Returns nine characters plus up to two terminators ISET I Enter Output Current Input ISET current or current where current a value between 72 A Remarks Value is truncated to the 0 001 place Initial condition is 000 0000 A Setting is limited by IMAX Control Bus inputs 4 places display rounds to 0 01 or 0 001 place ISET Output Current Setting Query Input ISET Returned A number between 72 A Remarks Returns nine characters plus up to two terminators IV Output Summary Query Input IV Returned IOUT VOUT STB I MODE V MODE Remarks Returns twenty seven characters plus up to two terminators OVP Overvoltage Quench Protection Circuit Status Query Input OVP Returned 0 if the circuit is inactive or 1 if it is active Remarks One character plus up to two terminators are returned 2 Remote Operation Lake Shore Model 647 Magnet Power Supply User s Manual RI Remote Inhibit Status Query Input RI Returned 0 if the remote inhibit is inactive or 1 if it is active Remarks One character plus up to two terminators are returned VOUT V Outp
21. 5 for error messages and action to take if IMAX is exceeded VMAX SET 0 00 V to 32 00 V Soft voltage limit A voltage setting cannot exceed this limit Initial condition is 32 00 V Use any numeric entry mode to change the value See Chapter 5 for error messages and action to take if VMAX is exceeded 3 2 Operation Lake Shore Model 647 Magnet Power Supply User s Manual 3 5 2 Output Only Screen Press the OUTPUT ONLY Function key to fill the display screen with the output values 3 5 3 Display Plot Screen Press the DISPLAY PLOT Function key to display a graphic plot of output values on the left side of the display and the current and voltage output values on the right side of the display 3 5 4 Ramp Status Screen Press the RAMP STATUS Function key to display the Ramp Status screen to the right Use the Cursor keys to move the line indicator up or down The icon indicates parameters that can only be changed using the up or down Numeric Entry keys Change all others using all the numeric entry modes including the cursor Below are valid Ramp Status entries SEGMENT OFF or ON gt Ramp status The ramp segment can be put in the Hold Pause mode at any time during the ramp Use the Up or down Numeric Entry keys to toggle the status STATUS HOLDING or RAMPING Indicates the ramp status If the ramp is OFF the status will be HOLDING If the ramp is on it will be RAMPING This line is skipped in the cursor up and d
22. 8 1978 standard document The cable has 24 conductors with an outer shield The connectors at each end are 24 way Amphenol 57 Series or equivalent with piggyback receptacles to daisy chain multiple devices Secure the connectors in the receptacles by a pair of captive locking screws with metric threads The total length of cable allowed in a system is 2 meters for each device on the bus or 20 meters total for a maximum of 15 devices The figure below and the table to the right shows the IEEE 488 Interface connector pin location and signal names Figure 5 3 IEEE 488 Interface Connector SH1 AH1 T5 L4 SR1 RL1 PPO DC1 DTO CO E1 5 7 SERIAL INTERFACE CABLE AND ADAPTERS OO JO Om P ob A Data Input Output Line 1 Data Input Output Line 2 Data Input Output Line 3 Data Input Output Line 4 End Or Identify Data Valid Not Ready For Data Not Data Accepted Interface Clear Service Request Attention Cable Shield Data Input Output Line 5 Data Input Output Line 6 Data Input Output Line 7 Data Input Output Line 8 Remote Enable PIN SYMBOL DESCRIPTION Ground Wire Twisted pair with DAV Ground Wire Twisted pair with NRFD Ground Wire Twisted pair with NDAC Ground Wire Twisted pair with IFC Ground Wire Twisted pair with SRQ Ground Wire Twisted pair with ATN Logic Ground To aid in Serial Interface troubleshooting the figures below provide wiring information for the cable assembly and the two matin
23. BUNI Program Magnetic Field Units Input BUNI units where units kG for kilogauss or T for tesla 10 kilogauss Remarks The initial status is kG Verify there is a space between the command and units parameter Options amp Accessories Lake Shore Model 647 Magnet Power Supply User s Manual BUNI Magnetic Field Units Query Input BUNI Returned Either KG for kilogauss or T for tesla 10 kilogauss Remarks Returns two characters plus up to two terminators IBS Magnetic Field Summary Query Input IBS Returned IOUT BFLD STB Remarks Returns 23 characters plus up to two terminators 6 3 MODEL 6477 HIGH RESOLUTION DISPLAY AND PROGRAMMING OPTION This option increases the current and voltage setting and monitoring resolution to 1 mA and 1 mV respectively The standard display and programming resolution is 10 mA and 10 mV The standard current setting DAC digital to analog converter has a bipolar resolution of 15 bits The smallest step change is 4 mA The Model 6477 High Resolution current setting DAC has a bipolar resolution of 17 bits and improves step change resolution to 1 mA The voltage setting current and voltage monitoring go through the same type of resolution increase The factory must install this option prior to shipment it cannot be field installed With the option installed Setting and Output display resolution automatically expands to the 0 001 place Remote interface operation does not change since rem
24. Basic 4 0 program is for an IBM PC or compatible Enter the Mainframe command at the prompt The Mainframe response then displays END exits the program COUNT 1000 TERMS CHR 13 CHR 10 OPEN com1 9600 0 7 1 RS FOR RANDOM AS 1 LEN 256 INPUT ENTER COMMAND END TO EXIT CMDS CMDS UCASES CMDS IF CMDS END THEN CLOSE 1 END PRINT 1 CMDS TERMS IF INSTR CMD W lt gt O OR INSTR CMD XD lt gt 0 OR INSTR CMD lt gt 0 THI RSS oun N 0 INSTR RS TERMS 0 OR RS 1 N 1 ELSE N 0 WHILE N lt COUNT AND R INPUTS LOC 1 IF R THEN N RSS RSS RS WEND IF RSS lt gt THEN RSS MIDS RS 1 INSTR RS TERMS PRINT RESPONSE RS ELSE PRINT NO RESPONSE END IF END IF GOTO L1 END B 4 Mainframe Remote Operation Lake Shore Model 647 Magnet Power Supply User s Manual Table B 1 MPS Mainframe Control Bus Remote Command Summary ESE ESR IDN SRE STB TST MODE TERM IEEE interface terminator status Terminators fixed at CR LF D ISET VZ VSET IOUT VOUT IMAX RAMP SEG RMP Mainframe digital calibration zn ZIS IMODE VMODE RES ove ERR RI STP STPS Mainframe Remote Operation B 6 Lake Shore Model 647 Magnet Power Supply User s Manual Table B 2 Additional MPS Mainframe Control Bus Remote Commands Input Command Query Mainframe address Multidrop address 0 32
25. Complete RAMP Ramp Segment Parameters OPC Operation Complete Query RAMP Ramp Segment Parameters Query RST Reset Command RMP Ramp Status SRE Service Request RMP Ramp Status Query SRE Service Request Query SEG Active Ramp Segment STB Status Byte Query SEG Active Ramp Segment Query TST Self Test Query WAI Wait To Continue See Chapter 6 for additional IEEE 488 commands for the Model 6476 Gaussmeter Input Card and the Model 6477 High Resolution Display and Programming Option 4 3 1 Commands List Structure Description COMMAND Shortcut Command Short command description Input Syntax of user input Returned Response to command Remarks Further explanation and definition Remote Operation A Lake Shore Model 647 Magnet Power Supply User s Manual 4 3 1 1 Operational Commands Description Below is a list of MPS Operational Commands which configure the various functions ERR Error Status Query Input ERR Returned OVP RI STEP Remarks Returns 0 if the error is inactive or 1 if it is active Returns three characters plus up to two terminators IMAX Programs Upper Current Limit Input IMAX current where current a value between 0 and 72 A Remarks Programs the upper soft current limit of the MPS Truncates the value to the 0 001 place The initial condition is 000 0000 A The current limit is always forced to a plus Setting is limited by product limits Control Bus inputs 4 places display rounds to 0 01
26. ITS FOR MAGNETIC PROPERTIES Conversion from CGS to SI Units Quantit Gaussian Conversion SI amp amp CGS emu Factor C Rationalized mks a weber Wb volt F gilbert Gb 10 47 ampere A oersted Oe Gb cm 107 47 AJ U H M Al 47M 10747 Al M emu g b A m kg 4n x 10 Wbem kg m emu erg G 103 Asm joule per tesla J T Wbem k dimensionless SE S Henry per meter emu cm 47 x 10 H m Wb A m 3 3 intensity of magnetization i u o X 3 3 Permeability Relative permeability Volume energy density Ww Molar susceptibility Xmol 3 Ana 10 m mol Kmol cm mol emu mol 47 x 1073 H m mol u Him Wb A m Ur not defined dimensionless 3 1 3 energy product erg cm 10 Jim Demagnetization factor DN dimensionless NOTES a b C j k Gaussian units and cgs emu are the same for magnetic properties The defining relation is B H 42M Multiply a number in Gaussian units by C to convert it to SI e g 1 G x 10 T G 10 T SI Syst me International d Unit s has been adopted by the National Bureau of Standards Where two conversion factors are given the upper one is recognized under or consistent with SI and is based on the definition B uo H M where to uo 47 x 107H m The lower one is not recognized under SI and is based on the definition B uH J where the symbol is often used in place of J 1 gauss 10 gamma y B
27. M across the current monitoring resistor Send IZER to force output current to 0 amps for output current calibration Verify a DVM reading of OV 0 01V Allow MPS output to settle for 2 minutes Convert the DVM voltage reading to current A reading of 0 000345V equals 0 345A Send the actual current with the command CALZ xxx xxxx If the actual current is 0 345 amps send CALZ 0 3450 The MPS deter mines the zero current calibration constant Send ICAL DOT to inform the MPS of output current calibration and to force output current to 50 amps Verify a DVM reading of 0 05V 10 Allow MPS output to settle for 2 minutes Troubleshooting Lake Shore Model 647 Magnet Power Supply User s Manual 20 Convert DVM voltage reading to current reading of 0 512345V equals 51 2345A Send actual current with CALPL xxx xxxx If actual current is 51 2345A send CALPL 51 2345 The MPS determines the positive current calibration constant 21 After the MPS determines the positive current calibration constant it automatically sets output current to the same value with the opposite sign Verify that the DVM reads 0 05V 10 Allow MPS output to settle for 2 minutes 22 Convert voltage read from the DVM to current A reading of 0 0487655V equals 48 7655A Send actual current with the command CALMN XXX XXXX If actual current is 48 7655A send 5 4 PERFORMANCE TEST Performance tests verify prop
28. Menu 1 Press Next Menu twice to display Function Menu 3 EXIT MENU Returns to the display screen the Function Menu 3 was entered from CURRENT ZERO Enters the Current Zero screen See Paragraph 3 7 1 I STEP LIMIT Enters the Current Step Limit screen See Paragraph 3 7 2 3 7 1 Current Zero Screen Remotely program MPS current and voltage by external voltages or potentiometers in addition to internal digital programming Enable external analog programming via the rear panel MODE switches When the mode switch is in the INT I or V position external current or voltage programming mode is disabled When it is in the EXT I or V position external programming voltage sums with internal programming voltage There may be configurations like multiple auto parallel MPS units that introduce an output current offset from zero This small offset current may translate into a large energy stored in the magnet load The output current zero feature allows users to zero this output current offset from the MPS front panel The current zero feature is enabled when either internal or external programming is used The current zero value stores in non volatile MPS memory Access output current zero from the MPS front panel Enter a current setting of zero and allow the output current to settle to the offset value Press the CURRENT ZERO Function key on Function Menu 3 to display the Current Zero screen with the output values The Up or down Numeric Entry
29. ND Programs MPS Interface EOI End Or Identify Status Input END status where status 0 to enable the EOI or 1 to disable it Remarks When enabled the hardware EOI line becomes active with the last byte of a transfer Not supported by Control Bus END End Of Identify EOI Query Input END Returned 0 if EOI is enabled or 1 if it is disabled Remarks Returns 1 character plus up to 2 terminators Not supported by Control Bus MODE Programs MPS Interface Mode Status Input MODE status where status 0 for local mode 1 for remote mode or 2 for remote mode with local lockout Supported in Control Bus operation MODE Interface Mode Status Query Input MODE Returned 0 for local mode 1 for remote mode or 2 for remote mode with local lockout Remarks Returns 1 character plus up to 2 terminators Supported by Control Bus TERM Programs MPS Interface Terminating Characters Input TERM type where type 0 for a carriage return and line feed CR LF amp 1 for a line feed and carriage return LF CRE9 2 for a line feed EPO 3 for no terminating characters DAB DAB Last Data Byte Remarks Terminating characters are sent when the MPS completes its message on output They also identify the end of an input message Control Bus fixes terminators at CR LF on receipt and transmission TERM Terminator Query Input TERM Returned 0 for a carriage return and line feed CR LFF 1 for a line feed and c
30. ODE switch is in the INT I position external current mode is disabled When the MODE switch is in the EXT I position the external programming voltage is summed with the internal programming voltage Set the internal programming to zero for external programming only Apply an external voltage from Ip to m of 0 to 1 25 volts or use a 10 KQ potentiometer to control the output current over the entire range Make connections to rear panel detachable terminal block defined in Tables 2 3 and 2 4 and Figures 2 2 and 2 3 The MPS produces 100 A of output current for 1 V at the current programming input NOTE MPS protection circuits reduce the effect of open external programming leads An open external programming lead forces external programming voltage to approximately 0 volts Setup amp Connections WW 25 Lake Shore Model 647 Magnet Power Supply User s Manual 2 5 8 Remote Sense Connections The factory configures the MPS to sense but not control remote voltage Call Lake Shore to reconfigure the MPS to control voltage at the load When using remote sense the MPS measures voltage at the magnet instead of at the MPS output terminals allowing a more accurate reading of magnet voltage by eliminating voltage drops in the leads connecting the MPS to the magnet If using remote sense the MPS bases the voltage at the voltage monitor output on the remote sense voltage instead of the MPS terminal voltage Use AWG 24 shielded twisted pair wiring for sens
31. ON and the alarm sounds about once per second If a MPS detects a fault it closes the FLT contacts to initiate Multiple MPS Remote Inhibit Mode 5 1 Lake Shore Model 647 Magnet Power Supply User s Manual No delay is allowed CAL AND ID switch 7 OFF down and multiple MPS operation CAL AND ID switch 4 ON up must be selected After the load discharges turn OFF all units to reset The MPS displays the OVP error message Overvoltage Protection OVP Circuit Activated If the voltage across the MPS output terminals rises above 40 volts the output over voltage protection OVP circuit activates The MPS also may activate the OVP circuit in response to faults Upon activation the OVP circuit uses thyristors to crowbar the output voltage to between 1 and 1 3 volts until magnet current reaches zero If this occurs change the output current setting to zero If the MPS detects OVP activity on power up output current greater than 1 A it turns ON the front panel Fault annunciator closes FLT contacts and sounds the alarm twice per second When the MPS detects the fault it closes the FLT contacts to indicate a fault sounds the alarm once per second and displays When output current falls below 1 A the MPS turns OFF the front panel Fault annunciator and alarm and opens the FLT contacts When the MPS detects no OVP activity the Normal Display appears The MPS continues to display OVP and sounds the alarm until the use
32. PgUp PgDn Next Prev Board National Instruments DEV12 Configuration GPIB PC2 2A Ver 2 1 Primary GPIB Address T Select the primary GPIB address by Secondary GPIB Address gp using the left and right arrow keys Timeout setting This address is used to compute the Terminate Read on EOS talk and listen addresses which Set EOI with EOS on Writes Yes identify the board or device on the Type of compare on EOS 7 Bit GPIB Valid primary addresses range from 0 to 30 OOH to 1EH Send EOI at end of Write Yes Adding 32 to the primary address Enable Repeat Addressing Yes forms the Listen Address LA Adding 64 to the primary address forms the Talk Address TA EXAMPLE Selecting a primary address of 10 yields the following 10 32 42 Listen address 10 64 74 Talk address y F1 Help F6 Reset Value F9 Esc Return to Map Ctl PgUp PgDn Next Prev Board igure 4 1 Typical National Instruments GPIB Configuration from IBCONF Remote Operation Lake Shore Model 647 Magnet Power Supply User s Manual 4 2 SERIAL I O INTERFACE RS 232C is a standard of the Electronics Industries Association EIA and one of the most common interfaces between a computer and electronic equipment The Customer supplied computer must have a Serial Interface port The MPS Serial Interface complies with the electrical format of the RS 232C Interface Standard A Serial Interface between the computer and the MPS permits remote monitoring and control o
33. SPECIFICATIONS The MPS Mainframe control bus SE Serial Interface Configured Configured either for RS 232C or RS 485 RS For Re 2320 For R 485 232C is an unbalanced single ended non terminated line for short distancas typically ess than 50 fee oe thes eee EE SE Dual RJ 11 Modular phone Jacks terminated line for multidrop party ine configurations with up to 32 ee re auntie address and operates in a polled ParityType 04 made Sel he MPS Mainframe to i B3 0 CONTROL BUS SERIAL INTERFACE CONNECTOR The serial interface connectors use dual standard 6 Pin RS 232C Function RS 485 Function dere ie connectors are in parallel and facilitate the RS 485 Q Onneg on EE multidrop configuration Lake Shore Model 2001 data cables which maintain pin 1 polarity simplify Signal Ground multiple Mainframe interconnection Lake Shore 4 offers the Model 2002 RJ 11 to DB 25 adapter and _4 Signal Groun ZE Model 2003 RJ 11 to DE 9 adapter to connect to the Transmit Data ee B O host computer 6 No Connection No Connection Mainframe Remote Operation B4 Lake Shore Model 647 Magnet Power Supply User s Manual B4 0 CONTROL BUS SERIAL INTERFACE CONFIGURATION Configure the control bus serial interface for either RS 232C or RS 485 communications with DIP switches on the Communications Processor Board CMP The CMP plugs into the Mainframe rear panel The standard control bus serial interface configuration is RS 485
34. Shore Model 647 Magnet Power Supply User s Manual 2 7 POST INSTALLATION INSTRUCTIONS The MPS is electrically and mechanically inspected and operationally tested prior to shipment It should be damage free and in perfect working order upon receipt To confirm this visually inspect the instrument for damage and test it electrically to detect any concealed damage upon receipt Study the entire MPS User s Manual before attempting to run the unit See Chapter 3 for any questions on front panel control operation 2 8 SYSTEM SHUTDOWN AND REPACKAGING FOR STORAGE OR SHIPMENT Follow these general guidelines for system shutdown for storage or reshipment If returning something call Lake Shore first to obtain a Return Goods Authorization RGA Number 1 Turn off the power to all instruments Unplug the power cord 2 Remove or disconnect any interface cables and the magnet current output cables 3 Repack the MPS upside down in the original box If returning the MPS to Lake Shore and original box is unavailable please call Lake Shore for a replacement box 4 Label the box for storage or shipment 2 9 RETURNING EQUIPMENT TO LAKE SHORE To return the MPS for repair or replacement obtain a Return Goods Authorization RGA number from a factory representative before returning the instrument to our service department When returning an instrument for service Lake Shore requires the following information before attempting any repair Instrument model a
35. Standard Event Status Enable Register ESR reads the Standard Event Status Register Once this register is read all bits are reset to zero Power On PON Bit 7 This bit is set when the power cycles from OFF to ON Command Error CME Bit 5 Set upon detection of a command error since the last reading This means the instrument could not interpret the command due to a syntax error unrecognized header unrecognized terminators or unsupported command Execution Error EXE Bit 4 Set upon detection of an execution error Occurs when the instrument is instructed to do something outside its capabilities Device Dependent Error DDE Bit 3 Reserved for future use Query Error QYE Bit 2 Indicates a query error Occurs rarely and involves loss of data due to a full output queue Operation Complete OPC Bit 0 Generated in response to the OPC operation complete common command It indicates MPS completion of all selected pending operations 4 1 4 Example IEEE Setup and Program Below is an example of how to setup and run a simple program using the built in MPS IEEE 488 Interface It does not reflect every hardware software configuration found in the field This example uses the National Instruments GPIB PCII IIA card and QuickBasic 4 0 or 4 5 on a PC compatible 4 1 4 1 GPIB Board Installation Use the following procedure to install the GPIB Board Install GPIB PCII IIA card using National Instruments instructions I
36. ads as short as possible to minimize output potential differences between the two MPS units and large enough to handle the maximum MPS current Connect the output terminals to the load using leads large enough to handle the total output current of both MPS units NOTE For proper operation turn on MPS 1 and then MPS 2 within 15 seconds of MPS 1 Setup amp Connections i s i lt SCO 27 Lake Shore Model 647 Magnet Power Supply User s Manual 8 Verify all connections as summarized in Table 2 5 9 To adda third MPS or a fourth MPS in parallel make the RI FLT OVP CMP and output connections in parallel with the connections of MPS 1 and MPS 2 For MPS 3 set the CAL AND ID switches on the rear panel as follows switches 5 through 8 are OFF switches 4 3 2 and 1 are ON OFF ON ON respectively For MPS 4 set the rear panel CAL AND ID switches as follows switches 5 through 8 are OFF switches 4 3 2 and 1 are ON ON OFF OFF respectively Configure the CMP switches for MPS 3 and MPS 4 as those in MPS 1 and MPS 2 NOTE For proper operation turn on MPS 1 and then the remaining MPS units within 15 seconds MPS 2 Rear View Control Bus Control Bus 8 OVP 8 OVP 1 RI 3 FLT 1 RI 3 FLT 2 RI 4 FLT 2 RI 4 FLT OUT OUT OUT OUT Table 2 5 Two MPS Autoparallel Configuration Connections Figure 2 5 Typical Multiple MPS Connections For Two MPS Units 2 8 Setup amp Connections Lake
37. am IEEEEXAM BAS EXAMPLE PROGRAM FOR IEEE 488 INTERFACE This program works with QuickBasic 4 0 4 5 on an IBM PC or compatible The example requires a properly configured National Instruments GPIB PC2 card The REM SINCLUDE statement is necessary along with a correct path to the file QBDECL BAS CONFIG SYS must call GPIB COM created by IBCONF EXE prior to running Basic There must be QBIB QBL library in the QuickBasic Directory and QuickBasic must start with a link to it All instrument settings are assumed to be defaults Address 12 Terminators lt CR gt lt LF gt and EOI active To use type an instrument command or query at the prompt The command transmits to the instrument and the MPS receives and displays the response If no query is sent the instrument responds to the last query received Type EXIT to exit the program NOTE The INPUT instruction accepts no commas as part of an input string If a comma appears in an instrument command replace it with a space REM INCLUDE c gpib pc qbasic qbdecl bas Link to IEEE calls CLS Clear screen PRINT IEEE 488 COMMUNICATION PROGRAM PRINT CALL IBFIND dev12 DEV12 Open communication at address 12 TERMS CHRS 13 CHR 10 Terminators are lt CR gt lt LF gt INS SPACES 2000 Clear for return string INPUT ENTER COMMAND or EXIT CMDS Get command from keyboard CMDS UCASES CMD Change input to upper case IF CMDS EXIT THEN END Get out on Exit CMDS
38. ange the current setting by more than the step limit setting the MPS displays 5 2 FACTORY DEFAULT SETTINGS Below is a list of factory presets To reinitialize the MPS to factory presets hold Esc for about 15 seconds Normal Display Screen I SET 0 00A Current Setting V SET 1 00V Voltage Setting Setup Screen IEEE SIO EEE SIO Option Status lt NP gt if not present CB DEF 9600 0 7 1 Control Bus Definition 9600 Baud Odd Parity 7 Data Bits 1 Stop Bit CB ADD 0 Control Bus Address VW ANGLE 5 Viewing Angle 5 Straight On IMAX SET 72 00 A Maximum Current Setting in Amps VMAX SET 30 00 V Maximum Voltage Setting in Volts IEEE SIO Setup Screen If Present IEEE ADD 12 IEEE Address TERMS CR LF Terminators Status Carriage Return amp Line Feed EOI lt ON gt EOI Status On BAUD 1200 Baud Rate for RS 232 DEF 0 7 1 SIO Definition Odd Parity 7 Data Bits 1 Stop Bit Ramp Status Screen SEGMENT lt OFF gt Ramp Segment Off STATUS HOLDING Ramp Status Holding FROM 0 00 A Ramp From in Amps TO 0 00 A Ramp To in Amps AT 0 00 A Sec Ramp At in Amps per Second Field Measurement Screens If Present READING lt OFF gt Reading Status Off UNITS kG Field Units in Kilogauss mV kG 0 800 Field Probe Sensitivity ZERO RDG lt OFF gt Field Probe Zerio and Status Off Output Current
39. arriage return LF CR 2 for a line feed LFF9 3 for no terminating characters DAB DAB Last Data Byte Remarks Control Bus fixes terminators at CR LF on receipt and transmission 4 Remote Operation Lake Shore Model 647 Magnet Power Supply User s Manual 4 3 1 3 Ramping Commands Description The following MPS Ramping Commands configure the various functions of the ramping features RAMP Programs Ramp Segment Parameters Input RAMP segment initial ramp current final ramp current ramp rate 00 where segment 1 Future updates will allow up to nine segments initial ramp current 0 to 72 A final ramp current 0 to 72 A ramp rate 0 to 99 9999 A S 00 Reserved for future use Operation to perform Need not be present for proper command operation Reserved for future use DWELL time in days hours minutes and seconds Does not need to be present for proper command operation Remarks Truncates value to 0 001 place Enter values with no embedded spaces Undefined parameters are set to 0 Control Bus inputs 4 places display rounds to 0 01 or 0 001 place Example RAMP1 72 0000 72 0000 01 0000 term Indicates Ramp Segment 1 Initial Ramp Current 72 0000 A Final Ramp Current 72 0000 A Ramp Rate 01 0000 A S commas can be replaced by blanks RAMP Ramp Parameter Query Input RAMP Returned Values are the same format as described above for program
40. ative for service and repair to ensure that safety features are maintained Dangerous Procedure Warnings A WARNING heading precedes potentially dangerous procedures throughout this manual Instructions in the warnings must be followed SAFETY SYMBOLS AN Warns to protect the instrument against damage 7 Indicates dangerous voltage appears on terminals fed by voltage exceeding 1000 volts LE or Protective conductor terminal For protection against electrical shock in case of a fault Used with field wiring terminals to indicate the terminal to connect to ground before operating equipment O Low noise or noiseless clean ground earth terminal Provides a signal common as well as protection against electrical shock in case of a fault Connect a terminal marked with this symbol to ground as described in the user manual before operating equipment ER or L Frame or chassis terminal A connection to the frame chassis of the equipment which normally includes all exposed metal structures NY Alternating current power line Direct current power line 4 Alternating or direct current power line viii Forward Lake Shore Model 647 Magnet Power Supply User s Manual CHAPTER 1 INTRODUCTION 1 0 GENERAL This chapter covers Features Paragraph 1 1 Specifications Paragraph 1 2 and Operating Characteristics Paragraph 1 3 1 1 647 MAGNET POWER SUPPLY FEATURES True Four Quadrant Bidirectional Power F
41. available Commands A sent must have the address as the first character Query response will be OO thru 32 D LOC Mainframe Programming Status Query response will be the same LOCK as what is programmed There is no real change in Mainframe CMD status MPS equivalent commands are UNLOCK LOC UNLOCK MODEO MODEO LOCK REM MODE2 MODE 1 Mainframe Operational Status Query response is status byte register contents comma standard event status register contents ERRC equivalent to STB and ESR queries Form of the response is XXX XXX where XXX ranges from 000 to 255 SRE and ESE are forced to 255 to get a status response Mainframe Error Status Query response is equivalent to ERR Output Current Polarity Setting and Status AD1 AD8 Output Current Measurement MPS equivalent command IOUT Output Voltage Measurement MPS equivalent command VOUT required responses are defined R 1 A Output Current Setting MPS equivalent commands are WA R WA ISET ISET RA Mainframe Remote Operation
42. e Adapters TE 4 8 5 1 Rear Panel Connectors date e a Ee ENNEN bee e eae ee und 5 6 5 2 Serial Interface Connector cease e de ae e dre ne da d a d deed 5 6 5 3 EEE 488 Connector manisk ide ideae teni et lead id ve ints bd e edda ea 5 7 5 4 Model 2001 RJ 11 Cable Assembly Wiring ssseeeem emm emnes 5 7 5 5 Model 2002 RJ 11 to DB 9 Adapter Wiring essseeeeene mem emnes 5 7 5 6 Model 2003 RJ 11 to DB 25 Adapter Wiring sse 5 7 LIST OF TABLES Table No Title Page 1 1 Model 647 DC Output Specifications esses emere 1 3 2 1 MPS Line Voltage Limits rei ere eee ea em IEEE Hl b e A IR M DE ER egi 2 2 2 2 Load Wire Lengths and Current Capachty emm 2 3 2 3 RI ET ON and OVP GonnectiOns iced ertet ita tt vua bere dae det 2 4 2 4 Analog Monitoring Programming and Remote Sense Connections oooccconnnccinnnocococoninncccnnnnnnns 2 5 2 5 Connections for a Two MPS Autoparallel Configuration see 2 8 4 1 Sample Basic IEEE 488 Interface Program 4 6 4 2 Serial Interface SpecifiCations 1 ttti trad bat rd ie tus CE e t tope ea iA 4 9 4 3 Sample Basic Serial Interface Program 4 10 5 1 Rear Panel Connector Detfntons nennen 5 6 5 2 Serial Interface Connector Definition sse nennen 5 6 5 3 IEEE 488 Interface Connector Definition emm emm nens 5 7 A 1 Units for Magnetic Propertes enne eee nennen nennen enr nennen nnns A 1 B 1 MPS Mainframe Con
43. e leads to minimize pickup of external noise Any noise on the sense leads may appear at the unit output Ground sense shield to the MPS back panel Make Remote Sense Connections to rear panel detachable terminal block defined in Table 2 4 and Figure 2 3 NOTE The MPS includes a protection circuit which reduces the effect of open sense leads during remote voltage sensing operation If the S lead opens the output voltage changes because it is sensed between OUT and the negative side of the load If the S lead opens the output voltage changes because it is sensed between the positive side of the load and OUT If both leads open the output voltage is sensed internally The procedure below configures the MPS for remote voltage sensing as shown in Figure 2 4 1 Turn off the unit 2 If present disconnect any wires between the OUT and OUT terminals and the S and S connections on the MPS rear panel MPS Rear View 3 Connect the sense leads from the MPS S and S connections to the load Maintain polarity when making these connections CAUTION Maintain polarity between S and OUT and S and OUT The S and S inputs control the output voltage Improper polarity may apply damaging voltages to the load 4 Connect the ground shield to the mounting screw Make sure that the shield does not come into electrical contact with either magnet lead Figure 2 4 Remote Sensing Connections 2 6 MULTIPLE AUTO PARALLEL SETUP Con
44. ect AC line power and all test equipment before proceeding 1 Turn unit OFF and disconnect power cord 2 Remove the two screws of the blank option cover plate to the far left of the MPS rear panel and remove the cover plate If another option exists in this slot remove it The IEEE cable should point down Install the option in the far slot to avoid IEEE cable interference with the power cord 3 Slide the Model 6224 board into the MPS with the board handle towards the bottom of the MPS Tighten the two screws that secure the board to the MPS rear panel If Required Install the option removed from the Model 6224 slot into a different slot 5 Setthe IEEE 488 operating parameters as outlined in Paragraph 4 1 1 and the Serial Interface as outlined in Paragraph 4 2 2 6 2 MODEL 6476 GAUSSMETER INPUT CARD This option provides quantitative magnetic field monitoring Each input has independent excitation Display the field in kilogauss or tesla Field interfacing supports Hall sensors and includes probe zero and entry of probe sensitivity in millivolts per kilogauss Below are specifications for the Model 6476 Gaussmeter Input Card Cryogenic Hall Sensor Type Lake Shore Model HGCT 3020 transverse or Model HGCA 3020 axial Number of Inputs 1 four lead measurement Nominal Excitation Current 100 mA Display Resolution 0 01 kG 0 001 tesla Probe Magnetic Sensitivity 0 8 mV kG 30 Electronic Accuracy 1 of full scale Nominal Field Ran
45. ed setting command followed by a question mark They usually return the same information that is sent Add a query to the end of a command string if the controller must return information For example RMP 0 RMP commands the MPS to pause the ramp then return the ramp status to confirm the change e The MPS returns nothing queries without a and ignores misspelled commands and queries The term free field indicates a floating decimal point that can be placed at any appropriate place in the string of digits Leading zeros and zeros following a decimal point are unneeded in a command string but they are sent in response to a query A leading is not required but a leading is required term indicates where the user places terminating characters or where they appear on a returning character string from the MPS Remote Operation A8 Lake Shore Model 647 Magnet Power Supply User s Manual Table 4 3 Sample BASIC Serial Interface Program SEREXAM BAS EXAMPLE PROGRAM FOR SERIAL INTERFACE This program works with QuickBasic 4 0 4 5 or Qbasic on an IBM PC or compatible with a serial interface It uses the COM1 communication port at 9600 BAUD Enter an instrument command or query at the prompt The command transmits to the instrument which displays any query response Type EXIT to exit the program NOTE The INPUT instruction in this example accepts no commas as part of an input string If a comma appears in an in
46. el identification The Normal Display screen appears with a blinking asterisk indicating each update when the unit is in normal operation CAUTION Set magnet parameters according to manufacturer s specifications Failure to do so may damage the magnet and threaten user safety Operation 3 1 Lake Shore Model 647 Magnet Power Supply User s Manual 3 3 GENERAL DISPLAY DESCRIPTION In general screen displays are split into two sections The left section is the Entry Window where users enter new parameters The right section is the Menu Window where Menus display when Output values do not The Shown to the right is the Normal Display screen It is unique because it allows Settings entry at any time The IMAX SET and VMAX SET values are the soft current and voltage setting limits Settings entered cannot exceed these limits These limits can be changed from the SETUP screen The OUTPUT screen indicates the output values and the interface status The Normal Display key returns the display to this screen at any time 3 4 NUMERIC ENTRY Move the line indicator to the desired line to change a value Use the Up or down Numeric Entry keys not cursor keys to increment or decrement the value Enter accepts the update while Esc returns to the previous value Use the cursor right and left keys to move the cursor to a particular digit or enter numbers with the up or down Numeric Entry keys 3 5 FUNCTION MENU 1 SCREEN Press Function Menu to di
47. er MPS operation into a resistive load without testing all specified parameters The tests include no troubleshooting information but can provide information that may localize faults If any tests fail contact authorized service personnel WARNING For service return the MPS to Lake Shore or a factory representative Lake Shore Cryotronics Inc cannot be held liable for injury or death of personnel attempting unauthorized MPS repairs Test Equipment Required 1 Current monitor shunt 100 mV output rated at 150 A Manufacturers typically stock this shunt value If a different value is used adjust readings given in the procedure 2 Digital Volt Meter DVM capable of reading DC voltage from 100 mV with 0 1 mV accuracy to 35 V with 0 1 V resolution Performance Test Procedure The test procedure includes both front panel and remote operation Execute the performance tests in the order given Note any non compliance Test Setup 1 Connect input power to the MPS as outlined in Sections 2 5 through 2 5 3 of this manual 2 Disconnect any leads from MPS output terminals 3 Set Programming Mode Switches on the MPS rear panel s to the INT up position Set the CAL and ID switch 7 OFF down Options amp Accessories CALMN 48 7655 The MPS determines the negative current calibration constant 23 The MPS stores the zero positive and negative current calibration constants then sets output current to 0 Verify a
48. er device using 1 MO series resistor to protect operator 4 Ground any tools such as soldering equipment that will contact unit Contact with operator s hands provides a sufficient ground for tools that are otherwise electrically isolated 5 Place ESDS devices and assemblies removed from a unit on a conductive work surface or in a conductive container An operator inserting or removing a device or assembly from a container must maintain contact with a conductive portion of the container Use only plastic bags approved for storage of ESD material 6 Donot handle ESDS devices unnecessarily or remove them from their packages until actually used or tested SAFE HANDLING OF LIQUID CRYOGENS Two essential safety aspects of handling LHe are adequate ventilation and eye and skin protection Although helium gas is non toxic it is dangerous because it replaces air in a normal breathing atmosphere Liquid helium is an even greater threat because a small amount of liquid evaporates to create a large amount of gas Store and operate cryogenic dewars in open well ventilated areas WARNING Liquid helium is a potential asphyxiant and can cause rapid suffocation without warning Store and use in an adequately ventilated area DO NOT vent the container in confined spaces DO NOT enter confined spaces where gas may be present unless area is well ventilated If inhaled remove to fresh air If not breathing give artificial respiration If breathing i
49. erforms the functions of TALKER and LISTENER but cannot be a BUS CONTROLLER The BUS CONTROLLER is the digital computer which tells the MPS which functions to perform Below are MPS IEEE 488 interface capabilities SH1 Source handshake capability SR1 Service request capability RL1 Complete remote local capability AH1 Acceptor handshake capability DC1 Full device clear capability e PPO No parallel poll capability DTO No device trigger capability C0 No system controller capability T5 Basic TALKER serial poll capability talk only unaddressed to talk if addressed to listen L4 Basic LISTENER unaddressed to listen if addressed to talk ee o e o o o 4 1 1 Interface Settings To use the IEEE 488 interface the user must set the IEEE Address and Terminators Press Function Menu then press the key corresponding to SETUP to display the Setup screen Use the cursor keys to move the arrow indicator to IEEE SIO then press either of the Up or down Numeric Entry keys to display the IEEE Interface screen IEEE ADD 1 to 30 Use the cursor keys to move arrow indicator to IEEE ADD The Up or down Numeric Entry keys increment or decrement the IEEE Address The default value is 12 The range of choices is from 1 to 30 TERMS CR LF LF CR LF DAB Use the cursor keys to move the arrow indicator to TERM The Up or down Numeric Entry keys cycle through the following choices CR LF LF CR LF DAB The default is Carriage Return a
50. erse voltage generated during the discharge from damaging the unipolar supply output Other conventional supplies dissipate magnet energy in the power supply output transistor pass bank This two quadrant performance requires the output stage to absorb considerable power during the discharge In addition uniform charge and discharge rates are not always ensured Current reversal requires external current reversal switches or manual lead reversal These units provide pseudo four quadrant operation which introduces discontinuities at the current reversal point produced by switching the leads Current reversal switches may incorporate direction detection diodes which reduce available magnet charging voltage and dissipate additional power Current reversal switches must also interlock to prevent lead reversal when current is present Current reversal switches complicate high power cabling requirements increase chances of introducing output current instabilities and require time to reverse leads Manual lead reversal introduces discontinuity at the current reversal point A discontinuous transition through zero current may require a small external supply for near zero current analysis Utility power failure in a conventional supply generally results in a magnet quench 1 4 Introduction Lake Shore Model 647 Magnet Power Supply User s Manual 1 3 2 Model 647 MPS Maintains a high stability low noise current regulated output Digital setting and monitor
51. f MPS control functions which in turn controls MPS operation See Figure 4 2 The Serial Interface can both transmit and receive information In transmit Tx mode the instrument converts parallel information to serial and sends it over a cable up to 50 feet long or longer with proper shielding In receive Rx mode the instrument converts serial information back to parallel for processing See Paragraph 4 2 1 for Serial Interface hardware configuration and adapters Paragraph 4 2 2 for Serial Interface settings and Paragraph 4 2 3 for a sample BASIC program to establish communications between the computer and the MPS The Serial Interface shares Device Specific commands with the IEEE 488 interface listed in Paragraph 4 3 However without the advantage of the IEEE 488 Architecture there are several limitations The OPC and RST Common Commands are not supported The END Bus Control Command is not supported Terminators are fixed to CRLF A query must be added to the end of a command string if the MPS must return information Over IEEE 488 the last query response is sent when addressed to talk For example ISET 10 ISET would set the output current to 10 A and immediately query the output current setting LSCI Model 2002 RJ 11 to DB 25 SERIAL UO To customer supplied Adapter computer with DB 25 Serial Interface Serial Interface Output on rear of Connector configured MPS r as DCE If the interface is DTE a
52. fer until the carriage return CR line feed LF terminator sequence After receiving the terminators the Mainframe responds appropriately to a query if present and stores the new input parameters Queries output requested data immediately following the processing of the command and terminator sequence If more than one query is sent the last query received is acknowledged Commands and queries can be sent in the same command string For example the command string ISET 10 VSET 10 updates the current setting to 10 amps and the voltage setting to 10 volts No query was sent therefore the Mainframe returns no response The command string ISET 10 VSET 10 ISET causes the Mainframe to return the current setting as well The serial interface shares device specific commands with the IEEE 488 interface Tables B 1 and B 2 summarize the commands See Chapter 3 of this manual for detailed command descriptions The END and TERM remote commands are IEEE 488 interface specific commands not supported by the serial interface When programming a Mainframe from the serial interface consider the notes below See Chapter 3 for additional notes on commands The control bus serial interface transmission mode asynchronous half duplex format 10 bits per character 1 start 7 data 1 odd parity and 1 stop and baud rate 9600 are all fixed at the factory as outlined previously in the Serial Interface Specifications The control bus cannot be used for
53. fficient air cooled unit Other conventional MPS s Most use linear regulated outputs The output transistor pass bank internally dissipates power not delivered to the magnet Some units use an off line switching supply to provide the bulk power and add output regulation There is no input power factor correction Low overall efficiency means higher input power and current Without power factor correction a non sinusoidal current with high peaks places tremendous stress on fuses circuit breakers outlets and wiring Dedicated lines may be required because of potential interaction with other equipment These factors result in low overall efficiency large size and considerable weight Introduction 1 5 Lake Shore Model 647 Magnet Power Supply User s Manual This Page Intentionally Left Blank Introduction Lake Shore Model 647 Magnet Power Supply User s Manual CHAPTER 2 INITIAL SETUP AND CONNECTIONS 2 1 INSPECTING AND UNPACKING The MPS ships in a special cardboard box with integrated forklift skid openings Do not stack anything on top of the MPS box Upon receipt set the box on a level surface with the pallet side down Inspect the shipping container for external damage Make all claims for damage apparent or concealed or partial loss of shipment in writing to Lake Shore within five 5 days from receipt of goods If damage or loss is apparent notify the shipping agent immediately Cut off the plastic strapping and lift off t
54. g adapters Figure 5 4 Model 2001 RJ 11 Cable Assembly Wiring TxD Gnd Gnd RxD 654321 Figure 5 5 Model 2002 RJ 11 to DB 9 Adapter Wiring RJ 11 RECEPTACLE OQ Not Used 5 7 YELLOW GREEN BLACK RJ 11 RECEPTACLE Leerso Figure 5 6 Model 2003 RJ 11 to DB 25 Adapter Wiring Troubleshooting Options amp Accessories Lake Shore Model 647 Magnet Power Supply User s Manual This Page Intentionally Left Blank Lake Shore Model 647 Magnet Power Supply User s Manual CHAPTER 6 OPTIONS AND ACCESSORIES 6 0 GENERAL This chapter covers Model 647 MPS options and accessories Model 6224 IEEE 488 Serial Interface Paragraph 6 1 Model 6476 Gaussmeter Input Card Paragraph 6 2 Model 6477 High Resolution Display and Programming Option Paragraph 6 3 and Accessories Paragraph 6 4 6 1 MODEL 6224 IEEE 488 SERIAL INTERFACE This option interfaces with a Customer supplied computer equipped with a compatible IEEE 488 or Serial Interface It accesses operating data and stored parameters and remotely controls front panel operations Only one Model 6224 is required for multiple MPS installations See Chapter 4 for MPS remote operation Installation Procedure WARNING This procedure is intended for trained service personnel who understand electronic circuitry and the hazards involved Do not attempt this procedure unless qualified To prevent shock hazard turn off the instrument and disconn
55. ge Nominal 125 kG 0 8 mV kG Input Voltage Resolution gt 0 01 mV out of 0 1 volts full scale Sample Interval Probe excited continuously amp read when level is not Contact Lake Shore for details on a variety of Hall Probes and Sensors 6 2 1 Hall Sensor Mounting Considerations The Lake Shore Model HGCT 3020 Transverse and Model HGCA 3020 Axial Cryogenic Hall Sensors are four terminal solid state devices that produce output voltage proportional to the product of the input current magnetic flux density and the sine of the angle between the field vector and the plane of the Hall generator The active area of the Model HGCT 3020 Transverse Hall Sensor is approximately 0 04 inch in diameter with the center indicated by a cross on one face of the package When the control current is applied with the red lead positive with respect to the black lead and the magnetic field is perpendicular into the face of the probe with the cross on it the Hall voltage will be positive at the blue lead with respect to the yellow lead A reversal Options amp Accessories 6 Lake Shore Model 647 Magnet Power Supply User s Manual in the mechanical orientation or in the direction of either the magnetic field or the control current will result in a polarity change of the output voltage The active area of the Model HGCA 3020 Axial Hall Sensor is approximately 0 03 inch in diameter in the center of the face opposite the leads When the control current i
56. hazards to personnel CAUTION An operation or maintenance procedure which if not strictly observed may result in equipment damage destruction or loss of effectiveness NOTE Emphasizes an operation or maintenance procedure GENERAL INSTALLATION PRECAUTIONS These recommended general safety precautions are unrelated to any specific procedure and do not appear elsewhere in this manual Personnel should understand and apply these precautions during installation Installation personnel shall observe all safety regulations at all times Keep away from live circuits Turn off system power before making or breaking electrical connections Regard any exposed connector terminal board or circuit board as a possible shock hazard Discharge charged components only when such grounding cannot damage equipment If a test connection to energized equipment is required make the test equipment ground connection before probing the voltage or signal Do not install or service equipment alone Do not under any circumstances reach into or enter any enclosure to service or adjust equipment without the presence or assistance of another person able to render aid Forward Lake Shore Model 647 Magnet Power Supply User s Manual ELECTROSTATIC DISCHARGE Electrostatic Discharge ESD may damage electronic parts assemblies and equipment ESD is a transfer of electrostatic charge between bodies at different electrostatic potentials caused by direct contact or ind
57. he lid Locate the MPS packing list and use it to check for receipt of all components cables accessories and manuals Inspect each item for damage Use two people to lift the MPS Retain internal packing material and box for reshipment Fill out and send the warranty card If there is freight damage to any instruments promptly file proper claims with the carrier and insurance company and notify Lake Shore Cryotronics Notify Lake Shore of any missing parts immediately Lake Shore cannot be responsible for any missing parts unless notified within 60 days of shipment See the standard Lake Shore Cryotronics Inc Warranty on the A Page immediately behind the title page 2 2 MPS MOUNTING After unpacking the MPS and verifying receipt of all packing list items mount the instrument in a suitable location The MPS ships with feet installed and is ready for use as a bench top instrument The MPS also ships with 19 inch rack mounting hardware installed for mounting in a standard 19 inch rack enclosure CAUTION To install the MPS in a 19 inch rack mount enclosure at any position other than the bottom install a slide rail or runner to support the MPS 2 3 ENVIRONMENTAL REQUIREMENTS Operate the MPS in an area with an ambient temperature range of 20 to 30 C 68 to 86 F The unit may be operated within the range of 15 to 35 C 59 to 95 F with reduced accuracy The MPS is intended for laboratory use no specific humidity or altitude specifica
58. here is no digital setting or monitoring integration in the output control circuitry Most achieve computer interfacing by adding computer controlled voltage sources to analog program the output current and voltage Additional inputs must be added to digitize the output current and voltage Setting and monitoring resolution is one to two orders of magnitude poorer than the standard MPS provides External setting and monitoring complicates cabling Degradation of the output current stability due to the addition of external cabling is undefined Output noise specifications are rarely given and sometimes vary with the type of magnet load driven These multiple unit configurations require up to 36 inches of rack space 1 3 3 Highly Efficient Air Cooled Compact Unit Model 647 MPS Quiet switched mode design The output uses a proprietary pulse width modulated technique that incorporates power hybrid circuitry Extremely low conduction loss components minimize internal power dissipation The MPS is not a direct off line switching supply The output is fully floating and isolated from ground Active power factor correction draws a sinusoidal AC current waveform from the utility minimizes AC line harmonics and lowers AC current required Power factor is the ratio of real power measured in watts to the apparent power measured in volt amperes The combination of quiet switched mode design and active power factor correction results in a compact highly e
59. icate a fault condition has occurred Contact rating 0 25 A resistive at 100 VDC 3 W 25 VA ON Indicator Contact closure to indicate when the front panel circuit breaker is in the ON position Contact rating 0 25 A resistive at 100 VDC 3 W 25 VA Overvoltage Protection Enable Analog signal connected in parallel to other MPS Units to remotely activate the output overvoltage protection circuit Output Current Monitor Voltage output from Im to GND M 0 01 V A Table 5 2 Serial Interface Output voltage monitor Voltage output from Vm to GND M lt a Definition 0 01 V V RS 485 FUNCTION Monitor and program ground GND M E Factory Use Only Function MER Factory Use Only 2 Receive Enable external output current programming via MODE switch Data Voltage input from Ip to GND M is 0 01 V A Signal Ground See A 10 KQ potentiometer from Is to Is with center tap to Ip produces the minimum voltage for full scale current output Signal 1 25 V for Model 622 or 1 55 V for Model 623 Voltage applied to Ip sums with internal current programming voltage Ground Goen Remote voltage sense correction Correction for load lead drops 5 Transmit of up to 0 5 V per lead Data ES oU TU 5 6 Troubleshooting Lake Shore Model 647 Magnet Power Supply User s Manual 5 6 IEEE 488 INTERFACE CONNECTOR When Model 6224 Option Is Present Connect to the rear MPS IEEE 488 Interface connector with cables specified in the IEEE 48
60. ignal lines All devices equipped to implement such commands do so simultaneously upon command transmission These commands transmit with the Attention ATN line asserted low There are two Multiline commands recognized by the MPS LLO Local Lockout Prevents the use of instrument front panel controls DCL Device Clear Clears MPS interface activity and puts it into a bus idle state Finally Addressed Bus Control Commands are Multiline commands that must include the MPS listen address before the instrument responds Only the addressed device responds to these commands The MPS recognizes three of the Addressed Bus Control Commands SDC Selective Device Clear The SDC command performs essentially the same function as the DCL command except that only the addressed device responds GTL Go To Local The GTL command is used to remove instruments from the remote mode With some instruments GTL also unlocks front panel controls if they were previously locked out with the LLO command SPE Serial Poll Enable and SPD Serial Poll Disable Serial polling accesses the Service Request SRQ Status Register This status register contains important operational information from the unit requesting service The SPD command ends the polling sequence 4 1 2 2 Common Commands Common Commands are addressed commands which create commonalty between instruments on the bus All instruments that comply with the IEEE 488 1987 standard share
61. ing electronics and computer interfacing integrate into power management and precision analog control circuitry This integration maintains high output stability and repeatability Extensive output filtering and noise cancellation circuitry keep MPS output noise very low The MPS front panel graphic display allows continuous display of output current and voltage while setting parameters from the menu driven keypad In addition to the front panel and remote interface programming the MPS includes analog inputs and outputs for setting and monitoring operating parameters and requires only 7 inches of rack space Other conventional MPS s Some use a compliance limited output with current monitoring to charge the magnet Others require output current to drive against the output current limit to prevent output current drift Most use multi turn potentiometers and Low Noise High Stability Current Regulated Output Analog Analog Current Voltage Programmer Programmer Analog Programmed Power Supply Current Reversal parum Energy Absorber Now Replaced by Lake Shore MPS True Four Quadrant Bi Directional DVM Current Monitor Power Flow FT Magnet Load Figure 1 2 Comparison of Old and New MPS Designs Monitor Magnet Load digital or analog panel meters for front panel current and compliance voltage setting The elegance and repeatability of keypad entry is not available T
62. interface 4 Replace the CMP B5 0 SELECTING THE CONTROL BUS SERIAL INTERFACE ADDRESS Multiple Mainframes on the RS 485 interface each have a unique address and operate in a polled mode Set the MPS Mainframe to respond to one of 32 addresses Prefix all commands sent to a Mainframe with the Mainframe address A Mainframe query response includes the address prefix if the address is not 0 The receipt of the LF OAH terminator resynchronizes communications and alerts all Mainframes that the next character is an address A Mainframe with address 0 responds to all commands on the interface A Mainframe using RS 232C can be given a unique address as well but RS 232C is not suited for multi drop operation Access the Control Bus serial interface address from the Interface Setup screen Press the Function Menu key to display Function Menu 1 Press the key corresponding to INTERFACE SETUP to display the Interface Setup screen CB ADD 0 to 32 Control Bus Address Use the cursor key to move to the line indicating CB ADD Use the Up or down Numeric Entry keys to increment or decrement the Control Bus Address The initial condition is 0 Range is 0 to 32 BR Mainframe Remote Operation Lake Shore Model 647 Magnet Power Supply User s Manual B6 0 CONTROL BUS SERIAL INTERFACE OPERATION The host computer initiates the serial interface link and transmits either a command or a query to the Mainframe The Mainframe stores the characters in a buf
63. istics significantly differentiate the Model 647 from conventional MPS s Consider them when choosing the best MPS for a particular application 1 3 1 True Four Quadrant Bi directional Power Flow Model 647 MPS Sets either positive or V negative current and voltage values This true four quadrant operation significantly simplifies test procedures and system design by eliminating external switching or operator intervention to reverse current polarity The smooth continuous transition through zero current allows the user to readily analyze samples at very small current increments as small as 1 mA about zero Power flow is bi E directional Sink power energy stored in the magnet returns to the AC line instead of dissipating in an energy absorber The MPS either transfers power from the AC line to the magnet or from the magnet back to the AC line The MPS also tolerates AC line faults in the event of utility power failure it draws power from the charged load to maintain operation Figure 1 1 Four Quadrant Power until utility restoration Output Voltage Energy flows from magnet to AC line Energy flows from AC line to magnet Energy flows from AC line to magnet Energy flows from magnet to AC line Output Current Output Voltage Other conventional MPS s Consist of a unipolar power supply with an energy absorber to dissipate magnet energy during discharge The energy absorber prevents rev
64. le carrying the output current Use remote sensing to compensate for any voltage drop in the load leads and obtain a more accurate voltage reading Stranded AWG 4 wire is capable of carrying in excess of 125 amperes Keep conductor temperature under 85 C for a 35 C ambient Table 2 2 lists the ampere capacity and total OUT and OUT lead lengths for load connections 0 1563 85 0 2485 53 0 3951 33 0 6282 21 Table 2 2 Load Wire Lengths and Current Capacity If connecting multiple loads to the unit use separate pairs of wires to connect each load to the output terminals Cut each pair of connecting wires as short as possible Setup amp Connections WW 238 Lake Shore Model 647 Magnet Power Supply User s Manual 2 5 2 Shielding Grounding and Noise For noise reduction tightly twist and shield the leads from the MPS to the magnet Connect the shield to the MPS chassis as shown in figure 2 4 WARNING DO NOT place magnet leads in contact with other MPS system connections or metal parts In some instances the user s measurement leads may pick up noise from the magnet leads Although this common mode noise may affect the user s measurement it rarely affects the current in the magnet If the user s measurement is earth grounded some improvement is almost always possible by tying the OUT terminal of the MPS to earth ground either at the MPS chassis or if the user s system has one the common system earth ground point WARNING
65. lity voltage wave form to draw energy from the utility with a sinusoidal current and return energy to the utility with a sinusoidal current If there is no utility reference signal the MPS disables utility input circuitry and uses the load for energy If utility loss occurs during normal operation in a multiple MPS configuration the MPS detecting the utility loss initiates Multiple MPS Remote Inhibit Mode by closing the FLT contacts and turning off the front panel circuit breaker Then the remaining MPS units enter Multiple MPS Remote Inhibit Mode High AC HI AC Detected Any time the AC line rises above 120 of the nominal line selected the MPS turns off the front panel circuit breaker and enters AC Loss Mode This halts excessive utility voltages to internal circuitry If this occurs on power up the MPS turns off the front panel Overtemperature Detected If the MPS detects internal over temperature or other internal fault it activates the OVP circuit turns off the front panel circuit breaker and then turns itself off OVP stays active until it completely discharges the load If the heat sink temperature exceeds 95 C 203 F the MPS displays Troubleshooting Lake Shore Model 647 Magnet Power Supply User s Manual Rail Fault Detected Excessive DC rail voltage unable to return power to the utility or some other internal fault causes the MPS to display I STEP Limit Exceeded When the user attempts to ch
66. low Operate current or voltage as a source or a sink in either positive or negative polarities Sink power returns to the AC line instead of dissipating through an energy absorber Low Noise High Stability Current Regulation Analog output control uses a precision shunt for current stabilization to better than 50 PPM of full scale current over an 8 hour period 172 A 32 V Output that is Autoranging at up to 2 KVA continuous Standard display and programming resolution is 10 mA and 10 mV 1 mA and 1 mV High Resolution Option is available No current reversal switch is required Output current reversal is smooth and continuous with excellent near zero current performance Remote and local sensing of the output voltage Compensates for voltage drops in the output leads Quiet switched mode design Results in a highly efficient lightweight air cooled unit Front Panel Graphic Display Allows continuous display of output while setting parameters from the menu driven keypad Operating parameters that can be set and monitored are Output current and voltage setting Output current and voltage measurement Output current step limiting Output current zeroing Soft current and voltage setting limits Output ramp programming Status reporting Field monitoring with optional Model 6476 Card Four methods of setting and monitoring all operating parameters 1 From front panel 2 From remote interfaces 3 Through analog inpu
67. lude Output current and voltage setting Output current and voltage measurement Status reporting Output ramp programming Soft current and voltage setting limits Field Monitoring with optional Model 6476 Card Output Current Zeroing Output Current Step Limiting Magnet inductance and maximum charging voltage di dt V L limit the output ramp programming charging current Program output for a constant 0 01 to 99 99 amperes per second as long as dimax dt is not exceeded Energize or de energize the magnet at a pre set voltage limit or ramp rate Pause the ramp at any time during the ramp During a pause the MPS maintains output values until the ramp continues e ee e o o o 1 2 Introduction Lake Shore Model 647 Magnet Power Supply User s Manual Agency Approvals The Model 647 complies with the following requirements UL 1244 Electrical and Electronic Measuring and Testing Equipment VDE 0411 Electronic Measuring Instruments and Automatic Controls FCC 15J Level A RFI Suppression VDE 0871 Level A RFI Suppression Operating Ambient Temperature 15 to 35 C 59 to 95 F Dimensions 483 mm wide x 178 mm high x 508 mm deep 19 x 7 x 20 inches Weight 36 4 kilograms 80 pounds Rack mounting is standard Table 1 1 Model 647 DC Output Specifications SPECIFICATION Digital Programming Resolution Standard High Digital Programming Accuracy CURRENT VOLTAGE 10 mA 1 mA 10 mV 1mV 0 196 IMAX 0 0196 IMAX
68. mark of Emerson amp Cuming Teflon is a trademark of DuPont De Nemours QuickBasic is a trademark of Microsoft Corporation Copyright 1995 1998 by Lake Shore Cryotronics Inc All rights reserved No portion of this manual may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording or otherwise without the express written permission of Lake Shore Lake Shore Model 647 Magnet Power Supply User s Manual TABLE OF CONTENTS Chapter Paragraph Title Berl E e EE Eistof Elei EE eire E ELE Purpose ANG Scope seu n Sereni e ER E OTRA i n Hardware e EE How To Use This Manual iio en ire teret a dan itr te eer PO Beste dataen Warnings Cautions and Notes ooooococococococococccocononononnnnncnnnnnnnnononncnnnnnnnnnnn nn nnrnn rra nnnnnnnnnnnnnnninns General Installation Precautions nn nn cnn nnnnn anar nn nn cnn nnnnnnnnn El ctrostatic DIScCharge eorr Red oer Handling Electrostatic Discharge Sensitive Components oooooccccnnnocccccononcccnonancncnnnanccnnnnnncnnnnnn Safe Handling of Liquid Crvogens sesini aaa aa iaia i a aiaiai Magnet Qlenches euer deet dio Dangerous Voltages iii e of duo dpud rad a patios Before You Operate the Equipment ener ener Ennet Safety SUMMA Y ascii Dar iare er e bere dir et se e te ca nete Safety Syrbols inte RI aeu mee e tup 1 INTRODUCTION PEL 1 0 EE Em 1 1 647 Magnet Power Supply Features 1 2 elle e Ire EE
69. ming in the ramp segments Remarks Returns 48 characters and up to two terminators RMP Programs Ramp Status Input RMP ramp status where ramp status 0 to turn off HOLD the ramp definitely or 1 to turn on the ramp segment or continue a ramp on hold RMP Ramp Status Query Input RMP Returned 0 for holding or 1 for ramping Remarks One character plus up to two terminators are returned SEG Programs Active Ramp Segment Input SEG segment where segment 1 Future updates will allow multiple ramp segments SEG Active Ramp Segment Query Input SEG Returned 1 Future updates will allow multiple ramp segments Remarks Returns one character plus up to two terminator Remote Operation 445 Lake Shore Model 647 Magnet Power Supply User s Manual 4 3 1 4 Current Zero Commands Description The following MPS commands configure the various functions of the current zero features IMODE Current Programming Mode Query Input IMODE Returned 0 if I MODE switch is set to EXT or 1 if set to INT Remarks Returns one character plus up to two terminators When multiple MPS units are present the current programming mode of MPS No 1 is reported VMODE Voltage Programming Mode Query Input VMODE Returned 0 if the V MODE switch is set to EXT or 1 if set to INT Remarks Returns one character plus up to two terminators When multiple MPS units are present the voltage programming mode of MPS No 1 is reported
70. mmand string Returns one character plus up to two terminators Not supported by Control Bus RST Instrument Reset Command Input RST Returned Nothing Remarks Restores MPS to power up settings just like the DCL and SDC bus commands The MPS reverts to the Normal Display Screen forces ramp status to the Hold mode and clears any latched error along with the Status Byte and the Standard Event Status Registers Not supported by Control Bus Remote Operation eeeseses itits 449 Lake Shore Model 647 Magnet Power Supply User s Manual SRE Enables Status Reports In The Service Request Enable Register Input SRE bit weighting where bit weighting the sum 000 to 255 of bit weighting of each bit to be set See the discussion on registers and below Remarks Each bit is assigned a bit weighting See the format of the Status Byte Register given below to see weighting and register placement of bits See the register section following the Common Command Table See Paragraph 4 1 3 1 for a complete description of status bits Lus s las 3e 8 4 2 3 Weighting SDR SRQ ESB OVP ERR RSC LIM ODR Bit Name Example If a bit in the Service Request Enable Register is set 1 its function is enabled and reported in the Status Byte Register For example to enable bits 1 2 4 and 6 send the command SRE86 86 is the sum of the bit weighting for each bit Bit Weighting 2 4 16 64 86 DAN A SRE Ser
71. n ss 6 4 ACCOSSOLFIOS x a imi enar ird te eesti ec TEE APPENDIX A UNITS FOR MAGNETIC PROPERTIES rrrnnnnnnvovvvvnnnnnnnnnnnnnvnnnnnnnnnrnnnnnnnnnennnnnnvnnnnn APPENDIX B MAINFRAME REMOTE OPERATION anonvnnnnnnvnnnnnvnnnnnnnnnvnnnnnvnnnnnnnnnnennnnnnnnnnnnnnnvnnnnn B1 0 Generali ction te ER B2 0 Control Bus Serial Interface Gpechhcations senten rseesrtenrrrnernesreerrnnreneseene B3 0 Control Bus Serial Interface Connector sssssssssssssseeeeeeeenee B4 0 Control Bus Serial Interface Configuration eseeeeenn ee B5 0 Selecting the Control Bus Serial Interface Address B6 0 Control Bus Serial Interface Operation B7 0 Control Bus Serial Interface Sample Program Table of Contents eonmnahhhkA oooooooooo 7 E 6 5 Lake Shore Model 647 Magnet Power Supply User s Manual LIST OF ILLUSTRATIONS Figure No Title Page 1 1 Four Quadrant Power 1 4 1 2 Comparison of Old and New MPS Desons nan c cnn nn nn cnn narran 1 5 2 2 Rk FLT ON and e dulde kandidater atre c ueri dim ePi ena 2 4 2 3 Analog Monitoring Programming amp Remote Sense Connechons 2 5 2 4 Remote Sensing Bel Le 2 6 2 5 Typical Multiple MPS Connections for Two MPS Units ccccccccececeeeeeeeeeeeceeeeeeeseeeennieeeeeeeeeeees 2 8 3 1 Front Panel Numeric Entry Keys 3 1 4 1 Typical National Instruments GPIB Configuration from IBCONF EXE seem 4 7 4 2 Serial Interfac
72. n a serial poll of the Status Byte Register The Service Request Enable Register inhibits or enables any of the status reports in the Status Byte Register The SRE command sets the bits A bit that is set enables its function Inhibit these reports by turning OFF their corresponding bits in the Service Request Enable Register Refer to the SRE discussion Setting Data Ready SDR Bit 7 When set the MPS resets current and voltage to 0 A and 1 V because of OVP or RI activity Service Request SRQ Bit 6 Determines whether the MPS is to report via the SRQ line and five bits determine which status reports to make If bits 0 1 2 3 4 and or 5 are set then the corresponding bit in the Status Byte Register is set The MPS produces a service request only if bit 6 of the Service Request Enable Register is set If disabled the Status Byte Register can still be read by the BUS CONTROLLER by means of a serial poll SPE to examine the status reports but the Service Request does not interrupt the BUS CONTROLLER The STB common command reads the Status Byte Register but does not clear the bits Certain bits in the Status Byte Register continually change Above are bit assignments in the Status Byte Register These reports occur only if the bits are enabled in the Service Request Enable Register Event Status ESB Bit 5 When set it indicates if one of the bits from the Standard Event Status Register has been set Refer to Paragraph 4 1 4 2 O
73. nd Line Feed CR LF EOI ON or OFF Use the cursor keys to move the arrow indicator to EOI The Up or down Numeric Entry keys toggle EOI On or Off The default is On If turned on End Or Identify is asserted during the last byte of a multibyte transfer BAUD 300 1200 9600 Use the cursor keys to move the arrow indicator to BAUD The Up or down Numeric Entry keys cycle through the following baud rates for the RS 232 interface 300 1200 9600 Remote Operation A Lake Shore Model 647 Magnet Power Supply User s Manual 4 1 2 IEEE 488 Command Structure The Model 647 supports several command types There are three groups of commands 1 Bus Control see Paragraph 4 1 2 1 a Universal 1 Uniline 2 Multiline b Addressed Bus Control 2 Common see Paragraph 4 1 2 2 3 Interface and Device Specific see Paragraph 4 1 2 3 4 1 2 1 Bus Control Commands A Universal Command addresses all devices on the bus Universal Commands include Uniline and Multiline Commands A Uniline Command Message asserts only a single signal line The MPS recognizes two of these messages from the BUS CONTROLLER Remote REN and Interface Clear IFC The MPS sends one Uniline Command Service Request SRQ REN Remote Puts the MPS into remote mode IFC Interface Clear Stops current operation on the bus SRQ Service Request Tells the bus controller that the MPS needs interface service A Multiline Command asserts a group of s
74. nd serial number User s name company address and phone number Malfunction symptoms Description of system Returned Goods Authorization number OUR ON Consult the factory for shipping instructions Ship the MPS upside down in the original shipping box Setup amp Connections e Z Lake Shore Model 647 Magnet Power Supply User s Manual This Page Intentionally Left Blank Setup amp Connections Lake Shore Model 647 Magnet Power Supply User s Manual CHAPTER 3 OPERATION 3 0 GENERAL This chapter covers seven areas MPS Front Panel Paragraph 3 1 Power Up Paragraph 3 2 Setting Current on an MPS with Manual PSH Control Paragraph 3 3 Setting Current with Automatic PSH Control Paragraph 3 4 Instrument Setup Screens Paragraph 3 5 Function Menus Paragraph 3 6 and an Automatic Persistence Control Example Paragraph 3 7 Setup the MPS software with the MPS output terminals shorted together as in section 3 2 This ensures that while the user learns MPS operation an inadvertent keystroke causes no damage to the magnet 3 1 THE MPS FRONT PANEL Figure 3 1 below shows the MPS Front Panel The up or down Display Cursor Control keys move the line indicator to the line containing a value to be changed Use either the Data Entry Keypad to enter the desired value or the up or down Numeric Entry keys to increment or decrement the value The Enter key accepts the update while the Esc key discards the change and returns to the p
75. nect up to four MPS units in an auto parallel configuration for increased output current capability The maximum total current allowed is the sum of the maximum currents of the individual units For example four 623 MPS units provide 4 155 620 amps total current The maximum total power is the sum of the maximum power ratings of the individual units Assign each unit a unique address 1 for MPS 1 2 for MPS 2 etc The MPS at address 1 polls the control bus to determine if an auto parallel configuration is present and how many MPS units are involved When multiple MPS units are present MPS 1 sends the output current and voltage limits ramp status output current step limit and other operating parameters to the other MPS units so all units operate identically For two MPS configuration each MPS is programmed for half of the total output current This is true for the ramp destination current and ramp rate Each MPS contributes half the output current required MPS 1 software polls MPS 2 to determine the total output current The output voltage current settings during a ramp and instrument status from MPS 1 are reported since the values are the same for both units An analog signal is also provided for remote activation of the output over voltage protection OVP circuit The signals connect in parallel so that the output OVP circuits of each MPS activate in unison CAUTION Consult Lake Shore prior to operating multiple MPS units in auto parallel
76. ng Special Configurations LIMITED WARRANTY Lake Shore Cryotronics Inc henceforth Lake Shore the manufacturer warrants the instrument to be free from defects in material and workmanship for a period of twelve months from the date of shipment During the warranty period under authorized return of instruments or component parts to Lake Shore freight prepaid the company will repair or at its option replace any part found to be defective in material or workmanship without charge to the Owner for parts service labor or associated customary shipping cost Replacement or repaired parts will be warranted for only the unexpired portion of the original warranty All products are thoroughly tested and calibrated to published specifications prior to shipment Calibration Certifications are offered for six month periods only Where such documentation must be updated a re certification service is offered by Lake Shore at a reasonable cost LIMITATION OF WARRANTY This warranty is limited to Lake Shore products purchased and installed in the United States or Internationally through our approved distribution agents This same protection will extend to any subsequent owner during the warranty period It does not apply to damage resulting from improper or inadequate maintenance unauthorized modification or misuse operation outside of the environmental specifications or from buyer supplied software interfacing It does not apply to damage caused b
77. ng voltage across the OUT and OUT terminals Send the command VZER to inform the MPS of output voltage calibration and force output voltage to OV Verify a DVM reading of OV 0 1V Allow MPS output to settle for 2 minutes Read actual output voltage from the DVM Send the MPS the actual voltage using the command CALZ Xxxx xxxx If actual voltage is 0 0123 volts send CALZ 0 0123 The MPS deter mines the zero voltage calibration constant Send VCALS to force output voltage to 5 volts Verify that the DVM reads 5V 10 Allow MPS output to settle for 2 minutes Read actual output voltage from the DVM Send the actual voltage with the command CALPL xxx xxxx If actual voltage is 5 1234V send CALPL 5 1234 The MPS determines the positive voltage calibration constant After the MPS determines the positive voltage calibration constant it automatically sets output voltage to the same value with the opposite sign Verify a DVM reading of 5V 10 Allow MPS output to settle for 2 minutes Read actual output voltage from the DVM Send the actual voltage with the command CALMN XXX XXXx If actual voltage is 4 8766V send CALMN 4 8766 The MPS determines the negative voltage calibration constant The MPS stores the zero positive and negative voltage calibration constants then sets the output voltage to 0 Verify a DVM reading of OV 0 1V before continuing the calibration Connect the DV
78. normally closed contacts when the unit is OFF When the unit is ON and no fault is present the contacts are open If the MPS detects a fault or an RI input assertion from an external contact closure it enters Remote Inhibit Mode forces output settings to 0 amps and 1 volt and turns ON the front panel Fault annunciator The MPS closes the FLT contacts to indicate a fault sounds the alarm once per second and displays The alarm stops sounding when RI is removed but the MPS continues to display RI until the user enters new output settings then turns them OFF This latching action informs the user of RI activity When the MPS detects no RI input activity it turns OFF the front panel Fault annunciator and internal alarm and opens the FLT contacts When the MPS software detects open FLT contacts RI is inactive it displays the Normal Display To insert a 2 to 3 second delay between RI activation and the initial fault operation turn CAL AND ID switch 7 ON up the MPS polls for RI activity after the delay If Rl is still active the fault operation continues if not it is ignored In multiple MPS configuration if an external contact closure activates the MPS RI indicators the MPS units enter Multiple MPS Remote Inhibit Mode They activate their output over voltage protection OVP circuits and turn off their output circuits If a charged load is present the OVP circuits discharge it the front panel Fault annunciators turn
79. nsider using a constant voltage transformer For power outages consider using an Uninterruptible Power Supply UPS CAUTION Do not attempt to apply electrical power until the MPS is checked for proper line voltage settings Factory preset MPS line voltage requirements allow proper operation at the shipping destination The line voltage setting is indicated on the rear panel Before applying power to the main input power cable check for correct input power settings for the power source voltage Ground the instrument panels and cabinets The safety ground provides a true ground path for electrical circuitry and in the event of internal electrical faults such as shorts carries the entire fault current to ground to protect users from electrical shock The MPS has a three conductor power input connector which grounds the MPS chassis when plugged into a 3 wire receptacle EMI is both a natural and man made electromagnetic phenomena which either directly or indirectly may degrade electronic system performance Natural EMI includes thunderstorms solar disturbances cosmic rays etc Man made EMI includes fixed and mobile transmitters high voltage power lines power tools and appliances florescent lights and other equipment containing motors heaters etc Protect the AC source from EMI Consider transient surge protectors for lightning protection Nominal Line Line Voltage Maximum Input source 50 to 60 Hz Table 2 1 lists the input voltage
80. nstall NI 488 2 software for DOS Version 2 1 1 was used for the example Verify that config sys contains the command device C GPIB COM Reboot the computer Run IBTEST to test software configuration Do not install the instrument before running IBTEST Run IBCONF to configure the GPIB PCII IIA board and dev 12 Set the EOS byte to OAH See setup in Fig 4 1 IBCONF modifies gpib com 7 Connect the instrument to the interface board and power up the instrument Verify the address as 12 and the terminators as CR LF O 9 moo dq c Remote Operation Lake Shore Model 647 Magnet Power Supply User s Manual 4 1 4 2 Run The Example QuickBasic Program Use the following procedure to run the QuickBasic Program 1 2 Copy c gpib pc Qbasic qbib obj to the QuickBasic directory QB4 Change to the QuickBasic directory and type link q qbib obj bqlb4x lib where x 0 for QB4 0 and 5 for QB4 5 This one time only command produces the library file qbib qlb The procedure is found in the National Instruments QuickBasic readme file Readme qb Start QuickBasic Type qb 1 qbib qlb Start QuickBasic in this way each time the IEEE interface is used to link in the library file Create the IEEE example interface program in QuickBasic See Table 4 1 Name the file ieeeexam bas and save Run the program 4 1 5 Notes On Using the IEEE Interface The term free field indicates a floating decimal point that may be placed any appr
81. nt related command is RST ESE Enables Status Reports In The Standard Event Status Enable Register Input ESE bit weighting where bit weighting the sum of the bit weighting of each bit to be set The value can be 000 to 255 See the discussion on registers and below Remarks Each bit is assigned a bit weighting See the format of the Standard Event Status Register given below to see bit weighting and register placement Further explanation of each bit is discussed in the register section following the Common Command Table See Paragraph 4 1 3 2 for a complete description of status bits 7 6 5 4 3 2 1710 Bi 128 64 32 16 8 4 2 1 Weighting PON CME EXE DDE QYE OPC Bit Name Example To set a bit send the command ESE with the sum of the bit weighting for each bit desired For example to set bits 0 3 4 and 5 send the command ESE57 57 is the sum of the bit weighting for each bit Bit Weighting 1 0 3 8 4 16 5 32 57 ESE Standard Event Status Enable Query Input ESE Returned An integer between 000 and 255 Remarks Reads the Standard Event Status Enable Register The integer returned represents the bits set in the Standard Event Status Enable Register It is a sum of the bit weighting of each bit set Returns three digits plus up to two terminators ESR Standard Event Status Register Query Input ESE Returned An integer between 000 and 255 Rema
82. nterface Settings 12 rec eerte deett dediti 4 1 4 1 2 IEEE 488 Command Structure sse eene erret 4 2 4 1 2 1 Bus Control Commande sess nnne 4 2 4 1 2 2 Common Be el EE 4 2 4 1 2 3 Interface and Device Specific Commande 4 2 4 1 3 Status Registers 4 5 0 eire Lb nc Adare d de ae EE ENNEN Ee et 4 2 4 1 3 1 Status Byte and Service Request Enable Register 4 3 4 1 3 2 Standard Event and Standard Event Status Registers ssssssssesss 4 4 4 1 4 Example IEEE Setup and Program 4 4 4 1 4 1 GPIB Board Installation sssssssssssseeeeeemeneeenenmemen enne 4 4 4 1 4 2 Run the Example QuickBasic Program 4 5 4 1 5 Notes On Using the IEEE Interface 7 scutes ich ecient dit eerte reda 4 5 4 2 Serial O Interface ire Ue ed eene ees Le d i ace i ee tut eee e acca but 4 8 4 2 1 Serial Interface Hardware Configuration sss 4 9 4 2 2 Serial Interface Settings iiid eut eai va derer it bade eet e dari ee etas 4 9 4 2 3 Sample BASIC Serial Interface Program ooococcnnnccccnnnocccccononcccnnnoncccnnnnnnncnnn nn nnc nana ncncnnnns 4 9 4 2 4 Notes on Using the Serial Interface 4 9 4 3 Summary of IEEE 488 Serial Interface Commands AA 4 11 4 3 1 Commands Description List Structure 4 11 4 3 1 1 Operational Commands Description cece ee seeeeeaeceeeeeeesecetaeeeeeeeeeneees 4 12 4 3 1 2 Interface Commands Description sssssssssssesseeeem tenn nennen 4 14 4 3 1 3 Ramping Commands
83. on Procedure Paragraph 5 3 Performance Test Paragraph 5 4 Rear Panel Connectors Definition Paragraph 5 5 IEEE 488 Connector Definition Paragraph 5 6 and Serial Interface Cable and Adapters Paragraph 5 7 5 1 SOFTWARE ERROR MESSAGES The MPS constantly monitors its circuits for faults like low or high line voltage line loss or internal temperature and rail faults Upon detection the error and a brief description display Below are error messages that may display during normal operation Error 01 Unwriteable NOVRAM Error Error 02 NOVRAM Data Verification Error Error 06 Calibration Data NOVRAM Error Output Current Step Limit Exceeded If the MPS detects an output current change that exceeds the step limit it enters Step Limit Mode and forces MPS output to 0 amps and 1 volt On the next display update cycle the MPS closes the FLT contacts to indicate the fault sounds an alarm about once per second and displays Options amp Accessories The MPS sounds the alarm and halts operation until the user presses a Data Entry up a or down v key to clear the fault When the fault clears the MPS opens the FLT contacts silences the alarm and displays the normal display Remote Inhibit RI Detected The Remote Inhibit RI and Fault FLT indicators provide hardware fault indication and remote shutdown in addition to internal protection features The FLT indicator is a set of
84. ontinue normal operation enter new output settings Output Inhibit Ol Press the front panel Ol key to force output settings to 0 A and 1 V To continue normal operation enter new output settings Output Current Step Limit The output current settings are forced to 0 A and 1 V if a preset current step limit is exceeded A key entry is required to continue operation Utility Low Line or Loss Maintains operation until load is discharged or utility is restored Utility High Line Turns off input and maintains operation until load is discharged Overvoltage Crowbars output when output terminal voltage induced by the load exceeds 40 VDC Overtemperature Crowbars output and turns off input when internal heat sink temperature exceeds 95 C AC Input Factory set for operation from 200 208 220 or 240 VAC 10 5 50 to 60 Hz single phase Input Protection A front panel 20 A two pole circuit breaker protects the AC input The MPS turns off the breaker in the event of a fault Remote Interfaces RS 232C is standard IEEE 488 is optional All front panel functions can be controlled over the interfaces In addition interfaces output displayed quantities Input Current Nominal Line Line Voltage Maximum Input Voltage VAC Range VAC Current A rms Front Panel Contains a menu driven keyboard and graphic display for entry and display of results Operating parameters to set and monitor from the front panel and remote interface inc
85. opriate place in the string of digits term indicates where the user places terminating characters or where they appear on a returning character string from the MPS To chain commands together insert a semi colon comma or blank space between them Some programming languages allow only blank spaces to chain Multiple queries cannot be chained The MPS responds to the last query entered when addressed as a talker Queries generally use the same syntax as an associated setting command followed by a question mark They most often return the same information that is sent Some queries have no command form Leading zeros and zeros following a decimal point are unneeded in a command string but they are sent in response to a query A leading is not required but a leading is required As characters are received over the interface they store in a buffer with a length of 95 characters After receiving the terminators any new parameters are stored The Mainframe requires about 100 msec to store new parameters before receiving any new commands The Mainframe implements new parameters and updates measurement data once per 500 msec operation cycle noted by the blinking asterisk to the left of the mode status Sending new parameters or requesting data at a rate faster than 2 Hz is not recommended Remote Operation A8 4 6 Lake Shore Model 647 Magnet Power Supply User s Manual Table 4 1 Sample BASIC IEEE 488 Interface Progr
86. or identifying utility supply conductors is green yellow for earth GND blue for neutral N and brown for line L The US and Canadian codes are green for earth GND white for neutral N and black for line L PB Setup amp Connections Lake Shore Model 647 Magnet Power Supply User s Manual Use this procedure to connect input power to the MPS 1 Loosen the two connector cover screws and open the cover 2 Slip the strain relief over the power cable with the flanged end at the end to be terminated 3 Attach the wires to the connector in accordance with prevailing color codes green or green yellow to the GND terminal white or blue to the N terminal and black or brown to the L terminal 4 Position the strain relief close the cover and then tighten the cover screws 5 Connect the other end of the power cord to an appropriate AC power source 6 Plug the power cord into the detachable power connector plug on the MPS rear panel 2 5 POWER UP Read and follow instructions in Paragraphs 2 1 2 4 3 and safety recommendations in the Forward before applying power to the MPS Do not connect the MPS to the magnet at this point Short the output terminals together with a 44 gauge or larger cable This protects the magnet against incorrect configurations Turn on the MPS It requires approximately 2 seconds for initialization Initially all front panel annunciators come on and the alarm sounds for a short
87. ote resolution is already to the 0 0001 place The increased resolution does not increase MPS stability or accuracy over the standard resolution Specifications for the Model 6477 are Current Display and Programming Resolution 1 mA Voltage Display and Programming Resolution 1 mV RES Resolution Query Input RES Returned Either 0 for low resolution or 1 for high resolution Remarks Returns two characters plus up to two terminators GA Options amp Accessories Lake Shore Model 647 Magnet Power Supply User s Manual 6 4 ACCESSORIES Accessories are devices that perform a secondary duty as an aid or refinement to the primary unit Below are accessories for the Model 647 MPS RJ 11 Cable Assembly Four Wire Cable Assembly with RJ 11 plugs on each end Used with RS 232C Interface Cable is 14 feet 4 6 meters long See Figure 7 1 RJ 11 to DB 25 Adapter Adapts RJ 11 receptacle to female DB 25 connector Used to connect Model 647 to Serial Port on rear of Customer s computer See Figure 7 2 RJ 11 to DE 9 Adapter Adapts RJ 11 receptacle to female DE 9 connector Used to connect Model 647 to Serial Port on rear of Customer s computer See Figure 7 3 8072 IEEE 488 Interface Cable Cable is 3 4 feet 1 meter in length MST 410 Transverse Probe Used in electromagnetic fields This probe is the same as used with the Lake Shore Model 410 Gaussmeter Axial Probe Used in electromagnetic fields This probe is the same as used with
88. oth oersted and gauss are expressed as cm geg in terms of base units A m was often expressed as ampere turn per meter when used for magnetic field strength Magnetic moment per unit volume The designation emu is not a unit Recognized uder SI even thoug based on the definition B ue J See footnote c Ur uuo 1 x all in SI u is equal to Gaussian p B Hand uM H have SI units J m M H and B H 4x have Gaussian units erg cm R B Goldfarb and F R Fickett U S Department of Commerce National Bureau of Standards Bolder Colorado 80303 March 1985 NBS Special Publication 696 For sale by the Superintendent of Documents U S Government Printing Office Washington D C 20402 Magnetic Units A 1 A 2 Lake Shore Model 647 Magnet Power Supply User s Manual This Page Intentionally Left Blank Magnetic Units Lake Shore Model 647 Magnet Power Supply User s Manual APPENDIX B MAINFRAME CONTROL BUS OPERATION B1 0 GENERAL There are seven elements to the Model 647 Mainframe Control Bus operating instructions Control Bus Serial Interface Specifications Paragraph B2 0 Control Bus Serial Interface Connector Paragraph B3 0 Control Bus Serial Interface Configuration Paragraph B4 0 Selecting the Control Bus Serial Interface Address Paragraph B5 0 Control Bus Serial Interface Operation Paragraph B6 0 and a sample control bus serial interface program Paragraph B7 0 B2 0 CONTROL BUS SERIAL INTERFACE
89. own line selection FROM 72 00 A to 72 00 A Initial ramp current This value is the present current setting or the current setting when the ramp was put in hold mode If the ramp is put in the hold mode the value will be whatever the current output setting is When the ramp is complete this value is changed to the present current setting TO 72 00 A to 72 00 A Destination ramp current Use any numeric entry mode to change the value AT 0 00 A SEC to 99 99 A SEC Ramp rate Use any numeric entry mode to change the value While ramping the message RAMPING TO HOLD appears to the left of the interface status This allows the ramp segment to be put in the hold mode using the Up or down Numeric Entry keys from any screen 3 6 FUNCTION MENU 2 SCREEN To determine available secondary functions available press Function Menu to display Function Menu 1 Press Next Menu to display Function Menu 2 NP indicates the function is Not Present and the associated function key is ignored EXIT MENU Returns to the display screen the Function Menu 2 was entered from LHe LEVEL Liquid Helium Level is not used with the Model 647 and shows NP FIELD Enters the Field screen See Paragraph 6 2 SWITCH HTR Persistent Switch Heater is not used with the Model 647 and shows NP Operation 3 3 Lake Shore Model 647 Magnet Power Supply User s Manual 3 7 FUNCTION MENU 3 SCREEN Press Function Menu to display Function
90. pped use the IEEE 6224 card 4 Connect current monitoring shunt and load resistor in series to OUT and OUT terminals 5 Enable MPS calibration Locate rear panel CAL AND ID switches and turn ON up switch 8 Verify that both MODE switches in the INTernal up position 6 Plug the MPS in turn it ON and allow it to warm up for one hour NOTE To terminate calibration at any time send the CALDN command Cycle MPS power to recover calibration constants present prior to calibration initiation Calibration determines a zero positive span and negative span digital calibration constant for both current and voltage Enter calibration constants with extreme caution If a constant is entered incorrectly terminate the calibration procedure with the CALDN command and re start the sequence 7 When calibrating current the MPS forces ISET to the calibration current When calibrating voltage the MPS forces VSET to the calibration voltage and ISET to IMAX Set IMAX to equal or greater than the calibration current Input and note the IMAX value using the IMAX command For this calibration procedure send IMAX 50 to set IMAX to 50 Turn OFF the output current step feature during calibration Input and note the output current step status using the ISTPS command Send the ISTPSO command to turn OFF output current step limiting 5 4 8 10 11 12 13 14 15 16 17 18 19 Connect the DVM readi
91. r enters new output settings then turns them OFF This latching action informs the user of OVP activity The MPS opens the FLT contacts upon detecting OVP inactivity Low AC LO AC Detected If the AC line falls below 80 of the nominal line selected the MPS enters AC Loss Mode If this occurs on power up the MPS turns off the front panel circuit breaker and displays This indicates that the AC source does not match the line voltage listed on the rear panel Upon utility loss during normal operation of a single MPS with a charged load the MPS disables utility input circuitry and uses the load as an energy source It turns OFF the front panel Power annunciator and turns ON the front panel Fault annunciator It closes the FLT contacts to indicate 5 2 a fault and sounds the alarm about once per second The MPS sets output voltage compliance to the level required to maintain operation and continuously monitors output current If the utility recovers the MPS enters Remote Inhibit Mode and forces output settings to 0 amps and 1 volt If the utility does not recover the MPS activates the output OVP circuit and turns OFF the front panel circuit breaker when the output current drops below 10 amps Upon power down the MPS enters AC Loss Mode NOTE A utility loss while the MPS returns energy from a charged load to the utility presents no hazard to personnel working on the utility circuit The MPS is not a UPS It uses the uti
92. range and maximum current required for each nominal 180 to 210 input A rear panel label indicates MPS factory preset 2 42 MPS Input Power Ratings Operate the MPS from a nominal 200 208 220 or NE MES Seon pe 188 to 218 nominal line voltage Normally the line voltage setting is not changed in the field Consult the factory to 198 to 231 Table 2 1 MPS Line Voltage Limits 2 4 3 Input Power Connections The MPS uses a three prong detachable input power connector supplied to mate with the UL CSA IEC approved rear panel AC input connector The user supplies a three conductor power cord rated for at least 85 C operation Each conductor must be AWG 16 or larger Larger wires may be required to prevent excessive voltage drop in AC power lines if unit is located an extended distance from the main AC distribution terminals WARNING For proper circuit breaker protection mate the wire connected to the L terminal of the connector to the L hot side of the line and mate the wire connected to the N terminal to the N neutral side of the line Mate the wire connected to the GND terminal to earth ground Do not operate this instrument without an adequate ground connection CAUTION Before applying power to the MPS verify that the AC source matches the line voltage listed on the rear panel NOTE Make connections to the AC power line in accordance with applicable electrical codes The international color code f
93. rds of design manufacture and intended use of the instrument Lake Shore Cryotronics Inc assumes no liability for the customer s failure to comply with these requirements Ground the Instrument To minimize shock hazard connect the instrument chassis and cabinet to an electrical ground The instrument is equipped with a three conductor AC power cable Plug this cable into either an approved three contact electrical outlet or a three contact adapter with the grounding wire green firmly connected to an electrical ground safety ground at the power outlet The power jack and mating plug of the power cable meet Underwriters Laboratories UL and International Electrotechnical Commission IEC safety standards Do Not Operate in an Explosive Atmosphere Do not operate the instrument in the presence of flammable gases or fumes Operating any electrical instrument in such an environment constitutes a definite safety hazard Keep Away from Live Circuits Operating personnel must not remove instrument covers Refer component replacement and internal adjustments to qualified maintenance personnel Do not replace components with power cable connected To avoid injuries always disconnect power and discharge circuits before touching them Do Not Substitute Parts or Modify Instrument Do not install substitute parts or perform any unauthorized modification to the instrument Return the instrument to an authorized Lake Shore Cryotronics Inc represent
94. remote interfacing if a Multiple Mainframe MMF configuration is used In MMF mode the Control Bus is used for Mainframe to Mainframe communications End of string terminators are fixed at CR LF Add a query to the end of a command string if the Mainframe is required to return information Chain commands together with a semi colon a comma or a blank Some programming languages do not allow separators other than a blank At 9600 baud each character takes about 1 millisecond to transmit Some host computers DMA serial interface access The program must allow for the transmission time delay before looking for a query response Characters received by the Mainframe store in a buffer After receiving the terminators the Mainframe stores any new parameters and responds to the query if requested The Mainframe requires about 100 milliseconds to store new parameters before receiving any more new commands The Mainframe implements new parameters and updates measurement data once per 500 millisecond operation cycle Do not send new parameters or request data at a rate faster than 2 Hz Mainframe Remote Operation B3 Lake Shore Model 647 Magnet Power Supply User s Manual B7 0 CONTROL BUS SERIAL INTERFACE SAMPLE PROGRAM The following PC program is an interactive program that prompts the user for a Mainframe command and displays the Mainframe response The command must include a query for the Mainframe to respond This Quick
95. rior value Move the cursor to a particular digit with the right and left Display Cursor Control keys and change it with the Numeric Entry keys Esc Key returns to prior value Display Menu Select Keys Data Entry Keypad nterface Keys l Function Mod Function Next Normal Menu Menu Display Local EZ Remote Output Inhibi Dv E Display Function Keys Numeric Entry Increment and Decrement Keys Enter Key Output Display US accepts a change Inhibit Key Figure 3 1 Front Panel Numeric Entry Keys 3 2 POWER UP Read and follow instructions in Paragraphs 2 1 2 4 3 and the Forward safety recommendations before applying power to the MPS Do not connect the MPS to the magnet yet Short the output terminals together with a 44 gauge or larger cable to protect the magnet against incorrect configurations Turn on the MPS It requires approximately 2 seconds for initialization Initially all front panel annunciators come on and the alarm sounds for a short time Within 1 second the Fault and Persistent Switch Heater On annunciators and the alarm turn off If the MPS detects a high or low AC line fault it blinks the front panel Fault annunciator and turns off the input circuit breaker If this occurs verify that the AC source matches the line voltage listed on the MPS rear panel Initially the entire display clears and the alarm sounds for a short time The MPS initializes itself and displays the mod
96. rks Reads the Standard Event Status Register The integer returned represents bits set in the Service Request Enable Register It is a sum of the bit weighting of each bit set This Query supplies various error conditions and whether the MPS has been powered off and on since the last query Returns three digits plus up to two terminators 4 18 Remote Operation Lake Shore Model 647 Magnet Power Supply User s Manual IDN Identification Query Input IDN Returned Manufacturer Model Number Model Serial Number Firmware Date Remarks Returns seventeen characters plus up to two terminators Example LSCI 622 0 120193 term OPC Operation Complete Status Input OPC Returned Nothing Remarks Causes the MPS to set an update cycle counter to 2 Each time through an update cycle parameters entered by device dependent commands update and the cycle count decrements Two update cycles complete all pending device dependent commands When this occurs the MPS sets the operation complete bit in the Standard Event Status Register not the IEEE 488 2 defined operation Not supported by Control Bus OPC Operation Complete Status Query Input OPC Returned 0 or 1 where 0 indicates incomplete 1 indicates complete Remarks Places 1 in the instrument output queue and sets the Operation Complete Bit in the Standard Event Status Register upon completion of all pending selected device operations This must be sent as the last command in a co
97. s applied with the red lead positive with respect to the black lead and the magnetic field is perpendicular into the face of the probe opposite the leads the Hall voltage is positive at the blue lead with respect to the yellow lead Again a reversal in mechanical orientation or in the direction of either the magnetic field or control current results in a output voltage polarity change Handle the Hall sensor with care The ceramic substrate is brittle and very sensitive to bending stress Mount the sensor to minimize mechanical strains as the sensor cools Failure rates approaching 10 occur on initial cool down with improperly installed sensors sensors surviving initial cool down generally experience no problems on subsequent cycles Avoid applying tension to the leads Bend the leads at any angle so long as the bend is at least 0 125 inch away from the substrate connection Mount the device to a non flexible smooth surface with a coefficient of thermal expansion no greater than a factor of three different from that of the ceramic substrate about 7 x 10 in in per K Locate the probe in a cavity that is 0 003 inch wider and 0 01 inch longer than the substrate and with a depth the same or slightly greater than the thickness of the package Tack the leads outside the slot with GE 7031 varnish or other similar substance Sparingly apply the mounting substance to the corners or a dot on each side of the sensor to hold it in place Avoid applying moun
98. s difficult give oxygen Get medical attention e Liquid helium can cause severe frostbite to exposed body parts DO NOT touch frosted pipes or valves For frostbite consult a physician immediately If a physician is unavailable warm the affected parts with water that is near body temperature vi Forward Lake Shore Model 647 Magnet Power Supply User s Manual MAGNET QUENCHES For protection during a magnet quench fit the dewar with pressure relief valves of sufficient size and pressure rating to allow the helium gas to escape and to prevent excessive pressure in the dewar Operating a magnet in a dewar without proper pressure relief is dangerous and possibly life threatening The magnet may transfer tremendous energy to the cryogen during a quench Consult both the magnet and dewar manufacturers to check pressure relief valve sufficiency DANGEROUS VOLTAGES High voltages are present inside the MPS Never attempt to service the MPS Refer all service to qualified personnel There are no user serviceable parts inside the MPS The MPS current output terminals may be dangerous Although MPS output voltage is limited to 40 VDC a catastrophic failure inside the MPS could pass lethal voltages to the output terminals Do not touch the terminals during MPS operation BEFORE YOU OPERATE THE EQUIPMENT Train personnel in proper emergency measures such as electrical power shut off fire department notification fire extinguishing and personnel
99. splay Function Menu 1 The 1 3 in the upper right corner indicates Menu 1 of 3 To exit Menu 1 press Function Menu again 3 5 1 Setup Screen To verify setup press the SETUP Function key The Setup screen to the right displays with Output values Use the Cursor keys to move the line indicator up or down The up and down arrow icon indicates parameters that can only be changed with the up or down Numeric Entry keys All others can be changed using all the numeric entry modes including the cursor Below are valid Setup entries IEEE SIO See Paragraph 4 1 1 to set the optional IEEE SIO Interface lt NP gt indicates the IEEE SIO option is Not Present CB DEF 9600 0 7 1 The Control Bus Definition is fixed at 9600 Baud odd parity 7 data bits and 1 stop bit See Appendix B CB ADD 0 to 32 Control Bus Address in the range of 0 to 32 See Appendix B VW ANGLE 2 to 9 Display viewing angle 9 view from above 5 view in the middle 2 view from below Initial condition is 5 Use the up or down Numeric Entry keys to increment or decrement the value MF ID 647 1 MPS ID 1 single MPS 2 multiple MPS configuration The MPS and quantity are determined from polling done at power up This line is skipped in the cursor up and down line selection IMAX SET 0 00 A to 72 00 A Soft current limit A current setting cannot exceed this limit Initial condition is 72 00 A Use any numeric entry mode to change the value See Chapter
100. strument command replace it with a space CLS Clear screen PRINT SERIAL COMMUNICATION PROGRAM PRINT TIMEOUT 2000 Read timeout may need more BAUDS 9600 TERMS CHR 13 CHR 10 Terminators are lt CR gt lt LF gt OPEN COM1 BAUDS N 8 1 RS FOR RANDOM AS 1 LEN 256 INPUT ENTER COMMAND or EXIT CMDS Get command from keyboard CMD UCASES CMDS Change input to upper case IF CMDS EXIT THEN CLOSE 1 END Get out on Exit CMDS CMDS TERMS PRINT 1 CMDS Send command to instrument IF INSTR CMD lt gt 0 THEN Test for query RSS um If query read response N 0 Clr return string and count WHILE N lt TIMEOUT AND INSTR RS TERMS 0 Wait for response INS INPUTS LOC 1 1 Get one character at a time IF INS THEN N N 1 ELSE N 0 Add 1 to timeout if no chr RSS RS INS Add next chr to string WEND Get chrs until terminators IF RSS lt gt THEN See if return string is empty RS MIDS RSS 1 INSTR RS TERMS 1 Strip off terminators PRINT RESPONSE RS Print response to query ELSE PRINT NO RESPONSE No response to query END IF END IF Get next command GOTO LOOP1 440 Remote Operation Lake Shore Model 647 Magnet Power Supply User s Manual 4 3 SUMMARY OF IEEE 488 SERIAL INTERFACE COMMANDS Below is an alphabetical list of IEEE 488 Serial Interface commands consisting of Operational Commands Paragraph 4 3 1 1 Interface Commands
101. t The up and down arrow icon indicates parameters that can only be changed using the Data Entry up and down arrows When there are lt ON gt or lt OFF gt indicators the Data Entry up and down arrows change the status The following are valid Field Probe Setting entries UNITS T or kG Field Units The Up or down Numeric Entry keys scroll between the units T tesla or KG kilogauss The default is KG SETTING CHANGE DONE Field Probe Setting Change Done The Up or down Numeric Entry keys exit the Field Probe Setting screen and return to the Field Measurement screen NOTE The entries below change probe calibration Do not change unless probe is actually being calibrated CALIBRATE PROBE mV kG XXX XXX Field Probe Sensitivity Each Hall Probe comes with a mV kG sensitivity Use any numeric entry mode to change the value from 0 to 999 999 ZERO RDG lt OFF gt or lt ON gt Field Probe Zero Reading Connect the Hall Probe and place it in zero magnetic field Press a Data Entry up or down arrow key to zero the probe The display changes to ON to indicate an active field probe zero reading When the field probe zero is complete the display returns to lt OFF gt 6 2 5 Remote Operation Commands Below is a list of IEEE 488 commands that control Model 6476 remote operation BFLD Magnetic Field Query Input BFLD Returned A number between 999 9999 Remarks Returns nine characters plus up to two terminators
102. t a later date For field installation use the procedure below WARNING This procedure is intended for trained service personnel who understand electronic circuitry and the hazards involved Do not attempt this procedure unless qualified To prevent shock hazard turn off the instrument and disconnect Table 6 1 Model 6476 Connections AC line power and all test equipment before removing cover 1 2 3 4 5 6 7 8 9 1 Turn off the MPS and disconnect the power cord Locate the Optional Plug In Board Slots on the MPS rear panel Loosen the two screws that secure one of the blank cover plates and remove the cover plate 3 Slide the Model 6476 board into the MPS with the board handle towards the bottom of the MPS Tighten the two screws that secure the board to the MPS rear panel 6 20 Options amp Accessories Lake Shore Model 647 Magnet Power Supply User s Manual 6 2 4 Operation To access field monitoring press Function Menu then Next Menu Function Menu 2 displays Press the FIELD Function key to display the Field Measurement screen The Menu window returns to displaying the Output values The following are valid Field Measurement entries READING lt OFF gt or lt ON gt Field Reading Status CHANGE PROBE SETTING Change Field Probe Settings Press either of the Data Entry up or down keys to display the Field Probe Setting screen to the right The cursor up and down keys move the line indicator g
103. t output current to 50 Amps The DVM should read about 33 mV After about 1 minute the DVM should read 33 333 mV 0 117 mV not including offset from Step 9 5 5 Lake Shore Model 647 Magnet Power Supply User s Manual 14 Set output current to 100 Amps The DVM 17 Set output current to 0 A should read about 66 mV After about 1 minute the DVM should read 66 666 mV Fant R Operation Verification 0 233 mV not including offset from Step 9 18 Short the MPS RI input with a shorting jumper MPS output current should drop to 0 A and the 15 Set output current to 50 Amps The DVM alarm should sound about once per second should read about 33 mV After about 1 minute Verify the MPS displays the RI screen shown in the DVM should read 33 333 mV 0 117 mV Paragraph 3 7 1 not including the offset from Step 9 19 With the unit ON disconnect AC power 16 Set output current to 100 A mps The DVM connector The front panel circuit breaker should should read about 66 mV After 1 minute the trip DVM should read 66 666 mV 0 233 mV not including the offset from Step 9 20 The performance verification is complete Figure 5 1 MPS Rear Panel Connectors Table 5 1 Rear Panel Connector Definitions Remote Inhibit Active low TTL compatible input to remotely Figure 5 2 Serial disable the output force the output settings to 0 A and 1 V Interface Connector Fault Indicator Normally open contact closure to ind
104. the Lake MSA 410 Shore Model 410 Gaussmeter MPEC 410 3 Extension Cable Used with the Model MST 410 and MSA 410 listed above Hall Sensor Magnetic Field Cryogenic Transverse This is an individual transverse Hall HGCT 3020 sensor meant for use in cryogenic magnet applications Refer to Paragraph 7 4 1 for mounting considerations Hall Sensor Magnetic Field Cryogenic Axial This is an individual axial Hall sensor HGCA 3020 meant for use in cryogenic magnet applications Refer to Paragraph 7 4 1 for mounting considerations MCT 3160 WN Probe Magnetic Field Cryogenic Transverse This is a complete 60 inch long Probe Assembly using a Model HGCT 3020 Transverse Hall Sensor Probe Magnetic Field Cryogenic Axial This is a complete 60 inch long Probe Assembly using a Model HGCA 3020 Axial Hall Sensor Output Cable Set Output cables are 4 AWG Each cable is 12 feet 3 meters long MCA 2560 WN Options amp Accessories ss i i lt CO 65 Lake Shore Model 647 Magnet Power Supply User s Manual This Page Intentionally Left Blank Options amp Accessories Magnetic flux density Magnetic induction Magnetic Flux magnetomotive force Magnetic field strength magnetizing force Volume magnetization Volume magnetization Magnetic polarization Mass magnetization Magnetic moment Magnetic dipole moment Volume susceptibility Lake Shore Model 647 Magnet Power Supply User s Manual APPENDIX A UN
105. these commands and their format Common commands all begin with an asterisk They generally relate to bus and instrument status and identification Common query commands end with a question mark See Paragraph 4 3 for a complete listing of all MPS common commands 4 1 2 3 Interface and Device Specific Commands Device Specific Commands are addressed commands The MPS supports a variety of Device Specific commands to program instruments remotely from a digital computer and to transfer measurements to the computer Most Device Specific Commands perform functions also performed from the front panel This section discusses Common and Device Specific commands Device Specific Commands consist of Interface Display Channel Control Process and Curve commands See Paragraph 4 3 for a complete listing of all MPS interface and device specific commands 4 1 3 Status Registers There are two status registers the Status Byte Register Paragraph 4 1 3 1 and the Standard Event Status Register Paragraph 4 1 3 2 4 1 3 1 Status Byte and Service Request Enable Registers 2 Remote Operation Lake Shore Model 647 Magnet Power Supply User s Manual The Status Byte Register consists of a single data byte containing seven bits of MPS status information STATUS BYTE REGISTER FORMAT If the Service Request is enabled any bits that are set cause the MPS to pull the SRQ management low to signal the BUS CONTROLLER These bits reset to zero upo
106. time Within 1 second the Fault and Persistent Switch Heater On annunciators and the alarm turn off If the MPS detects a high or low AC line fault it blinks the front panel Fault annunciator and turns off the input circuit breaker If this occurs verify that the AC source matches the line voltage listed on the MPS rear panel The MPS front panel AC On LED lights any time the MPS is connected to the AC line and the MPS power switch is ON Initially the entire display clears and the alarm sounds for a short time The MPS initializes itself and displays the model identification The Normal Display screen appears with a blinking asterisk indicating each update when the unit is in normal operation 2 5 1 Magnet Cable Connections WARNING Turn off the AC power before changing any rear panel connections and verify that all connections are securely tightened before reapplying power CAUTION Initially setup the MPS without connecting it to the magnet This lessens the chance for inadvertent damage to the load while the user learns MPS operation Make MPS Dad connections dine Area Capacity Resistivity Total Lead Length feet OUT and OUT terminals on the rear 2 panel These plated copper bus bars AWG mm Amperes 9 1000 feet 100A 125A accommodate 1 4 inch mounting 0 09827 135 hardware Use load wires heavy enough to limit the voltage drop to less than 0 5 volts per lead This ensures proper regulation and prevents overheating whi
107. ting substance on top of the sensor Alternately use Kapton tape or a mechanical cover over the top of the sensor to keep it in place The tape or cover should apply only light pressure to the sensor If epoxy is the mounting substance use it sparingly and use the same type as is used in the sensor Stycast 2850 FT epoxy Never pot the probe A room temperature calibration over the range of 30 kG comes with each probe The calibration specifies the terminating resistor not included required to maintain an accuracy of 1 of reading up to 30 kG and 2 of reading up to 150 kG over the entire temperature range For a terminating resistor use a metal film resistor with 1 or better accuracy mounted across the output voltage leads as close to the probe as is practical To extend the leads use AWG 34 stranded copper with Teflon insulation the same wire used on the probe Any impedance in the output leads acts as a voltage divider with the terminating resistor Probe reading reproducibility is within 1 over repeated thermal cycling between 4 2 K and room temperature 6 2 2 Connections The Model 6476 has one rear panel 9 pin connector to interface with the mE level and field probes See Table 6 1 SC right Field Current Field Voltage Field Voltage Field Current Shield Not Used Not Used Not Used Not Used 6 2 3 Installation The 6476 Gaussmeter Input Option is factory installed if ordered with a MPS or may be field installed a
108. tions have been determined However relative humidity of 20 to 80 percent no condensation and altitudes from sea level to 2 4 km 8 000 feet are generally acceptable WARNING To prevent electrical fire or shock hazards do not expose this instrument to moisture Provide adequate ventilation The fan cooled MPS draws air in from the sides and exhausts it from the rear install it with sufficient space at the rear and sides for air flow Filter dust and other particulate matter at the site to a reasonable level For salt air corrosive gases or other air pollutants consult an air conditioning expert for special filtering arrangements Setup amp Connections ZA Lake Shore Model 647 Magnet Power Supply User s Manual 2 4 CONNECTING THE MPS TO POWER Read and thoroughly understand sections 2 4 1 through 2 4 3 and the safety recommendations in the Forward before connecting the MPS to power Failure to do so may expose operating personnel to lethal voltages or damage the magnet and or MPS 2 4 1 Power and Ground Requirements The AC power source for the MPS should be frequency and voltage regulated and isolated from sources that may generate Electromagnetic Interference EMI The MPS is designed for single phase 3 wire alternating current AC power do not use two wire without ground AC power Lake Shore recommends Ground Fault Interrupter GFI and Transient Surge Protection circuitry at the AC source In areas where AC voltage varies co
109. tivates all the other parallel MPS units protection circuits system up to four MPS units connected in parallel these Table 2 3 RI FLT ON and OVP Connections signals connect in parallel between each of the MPS units MODE See Paragraph 2 6 for details on INT connections between two auto V I parallel units Make connections to a rear panel detachable terminal block defined in Table 2 3 and Figure 2 2 V I EXT Figure 2 2 RI FLT ON and OVP Connections 2 5 4 AC On Indicator The MPS provides a discrete ON indicator Terminals 5 and 6 on the terminal block connector shown in Figure 2 2 above connect to relay contacts that close when the front panel circuit breaker is in the ON position There is also a front panel LED that lights when the MPS is ON and connected to AC power 2 5 5 OVP Connection In auto parallel MPS configurations this connection synchronizes the firing of the Over Voltage Protection OVP circuits of each MPS see Chapter 5 See Paragraph 2 6 and Figure 2 5 for auto parallel connections Setup amp Connections Lake Shore Model 647 Magnet Power Supply User s Manual 2 5 6 MPS Analog Current And Voltage Monitoring Connections The MPS provides amplified and buffered current and voltage monitor output signals at the terminal block on the back panel Connect these signals to external meters to indicate output current and voltage Obtain the Current Monitor signal through connections to terminals 9 Im
110. trol Bus Remote Command Summary sss B 5 B 2 Additional MPS Mainframe Control Bus Remote Commande sess B 6 iv Table of Contents Lake Shore Model 647 Magnet Power Supply User s Manual FOREWORD PURPOSE AND SCOPE This manual contains user instructions for the Model 647 Superconducting Magnet Power Supply Lake Shore Cryotronics Inc designed manufactures and assembles the MPS in the United States of America We welcome your comments concerning this manual Although every effort has been made to keep it free of errors some may occur To report a specific problem please describe it briefly and include the manual title and revision number the paragraph figure table number and the page number Send comments to Lake Shore Cryotronics Inc Attn Technical Publications 575 McCorkle Blvd Westerville Ohio 43082 8888 HARDWARE COVERED The MPS is available in the following configuration Model 647 Electromagnet Power Supply 72 A 32 V 2 kVA Page A of this manual following the title page details the options installed in your unit See chapter 6 for detailed definitions of hardware configurations WARNINGS CAUTIONS AND NOTES Warnings cautions and notes appear throughout this manual and always precede the step to which they pertain Multiple warnings cautions or notes are bulleted WARNING An operation or maintenance procedure which if not strictly observed may result in injury death or long term health
111. tructions sssssssssssssssseeenennmeenen enne 2 8 System Shutdown and Repackaging for Storage or Shipment ocicocccnnnociccnocacinincnnnnos 2 9 Returning Equipment to Lake Ghore conc cnnnnnnnannnnnnnnnnn Table of Contents LI wech sen ge enkt ech I I LI I L I L LI D I MAKAN Se QOAONNNN sch N A 2 4 Lake Shore Model 647 Magnet Power Supply User s Manual Chapter Paragraph Title Page 3 OPERATION pee 3 1 3 0 iere 3 1 3 1 he MPS Front Panel oit edere ede a EE Arsene 3 1 3 2 Power UP iii tents imet reete dnne 3 1 3 3 General Display Description eene 3 2 3 4 N metic ENUY ss ceto titre t pe tadas 3 2 3 5 Function TV M 3 2 3 5 1 SOUP Sree Menhan ee a re ar aiaa io iaa a e eren aa e 3 2 3 5 2 Output Only Screen cia eoe De tur DIO GE 3 3 3 5 3 Display Plot Screen unnsette edit ee HO Gardens 3 3 3 5 4 Ramp Status Screen EE 3 3 3 6 Function Menu Zi ir auke fatuus e de eek hee es Ade REA 3 3 3 7 Function Men g eterne tren LH eo ib del era ru MEET erba de RR 3 4 3 7 1 Vi Ee Be EE 3 4 3 7 2 Current Step Limit Screen 2 0 2 2 ee ce cececcecce cece eeeeeccee cece eee eeeaeaeceeeeeseeensaeaeceeeeesnesnsiaeeeeeess 3 4 4 REMOTIEORERATION ees renidet nce eee eee ee eee nat eee Eege 4 1 4 0 General nc oa aient ta ae ities o oed Hee tee Dedi ee eh eee el 4 1 4 1 IEEE 488 Interface eerte tec cb ee terrent PUER ae ee cU egre d 4 1 4 1 1 IEEE 486 I
112. ts and outputs IEEE 488 Interface available Gaussmeter Input Option available 0 cd Om P AM Protection Overvoltage Quench protection circuits protect against internal overtemperature AC line fault and unit fault Also includes a Remote Inhibit RI and a discrete Fault Indicator FLT Introduction 1 1 Lake Shore Model 647 Magnet Power Supply User s Manual 1 2 SPECIFICATIONS Below are performance specifications for current with a 1 Henry load and voltage with a resistive load DC Output True Four Quadrant Bidirectional Power Flow output Autoranging current and voltage operate as a source or a sink in either polarity in current or voltage mode Program current and voltage via the front panel remote interfaces or analog input See Table 1 1 for DC Output Specifications Current 0 to 72 A Voltage 0 to 32 V Maximum Power 2 KVA continuous Remote Sensing Corrects for load lead drop of up to 0 5 V per lead Operation with more drop per load lead is possible with a degradation of the load effect specification Output Terminals The two rear panel output bus bars are isolated from the chassis earth ground Multiple Unit Operation Connect up to four units in an auto parallel configuration for increased output current Protection Front panel annunciators an audio indicator and a contact closure indicate faults Remote Inhibit RI An active RI forces output settings to 0 A and 1 V until the RI is no longer active To c
113. turns nine characters plus up to two terminators Value is shown as a but applies to both positive and negative step changes ISTPS Programs Output Current Step Limit Status Input ISTPS status where status 0 to turn OFF output current step limit or 1 to turn it ON Remarks The initial condition is 0 ISTPS Output Current Step Limit Status Query Input ISTPS Returned 0 for OFF or 1 for ON Remarks Returns one character plus up to two terminators STEP Output Current Step Limit Exceeded Query Input STEP Returned 0 if the step limit has not been exceeded or 1 if it has been exceeded Remarks Returns one character plus up to two terminators STEPR1 Output Current Step Limit Status Reset Input STEPR1 Returned Nothing Remarks When the output current step limit has been exceeded this command must be issued before normal operation can be resumed Remote Operation AT Lake Shore Model 647 Magnet Power Supply User s Manual 4 3 1 6 Common Commands Description The MPS Common Commands below are input output commands defined by the IEEE 488 standard and shared with other instruments complying with the standard Common commands begin with CLS Clear Status Register Command Input CLS Returned Nothing Remarks Clears the Status Register but not the instrument It clears the bits in the Status Byte Register and the Standard Event Status Register and terminates all pending operations The instrume
114. uced by an electrostatic field The low energy source that most commonly destroys Electrostatic Discharge Sensitive ESDS devices is the human body which generates and retains static electricity Simply walking across a carpet in low humidity may generate up to 35 000 volts of static electricity Current technology trends toward greater complexity increased packaging density and thinner dielectrics between active elements which results in electronic devices with even more ESD sensitivity Some electronic parts are more ESDS than others ESD levels of only a few hundred volts may damage electronic components such as semiconductors thick and thin film resistors and piezoelectric crystals during testing handling repair or assembly Discharge voltages below 4000 volts cannot be seen felt or heard Identification of Electrostatic Discharge Sensitive Components Below are various industry symbols used to label components as ESDS HANDLING ELECTROSTATIC DISCHARGE SENSITIVE COMPONENTS Observe all precautions necessary to prevent damage to ESDS components before attempting installation Bring the device and everything that contacts it to ground potential by providing a conductive surface and discharge paths As a minimum observe these precautions 1 De energize or disconnect all power and signal sources and loads used with unit 2 Place unit on a grounded conductive work surface 3 Ground technician through a conductive wrist strap or oth
115. ut Voltage Query Input VOUT or V Returned A number between 0 and 32 0000 V Remarks Returns nine characters plus up to two terminators VMAX Programs an upper soft voltage limit that the unit will accept Input VMAX voltage where voltage 0 to 32 0000 V Remarks Normal resolution truncates the value to 0 01 place High resolution truncates the value to the 0 001 place The initial condition is 000 0000 V The voltage limit is always forced to a plus VMAX Voltage Limit Query Input VMAX Returned A value between 0 and 32 0000 V Remarks Returns a nine character value with up to two terminators VSET V Programs the output voltage in the voltage mode Input VSET voltage or V voltage where voltage 0 to 32 0000 V Remarks Normal resolution truncates the value to 0 01 place High resolution truncates the value to the 0 001 place The initial condition is 00 0000 V The voltage setting is always forced to a Setting is limited by VMAX Control Bus inputs 4 places display rounds to 0 01 or 0 001 place VSET Output Voltage Setting Query Input VSET Returned A value between 0 and 432 0000 V Remarks Returns a nine character value with up to two terminators Remote Operation AS Lake Shore Model 647 Magnet Power Supply User s Manual 4 3 1 2 Interface Commands Description The MPS Interface Commands below help configure IEEE 488 interface compatibility for a variety of computer equipment E
116. vervoltage Protection OVP Bit 4 Indicates overvoltage quench protection circuit activation Error ERR Bit 3 Indicates operation error The error displays on the front panel and can be read using the TST Command Ramp Segment Complete RSC Bit 2 Indicates active ramp segment completion Limit Exceeded LIM Bit 1 Indicates a new current or voltage exceeds the current or compliance voltage limit Read the new setting with the ISET or VSET commands Output Data Ready ODR Bit 0 When set makes current and voltage readings available Remote Operation AA Lake Shore Model 647 Magnet Power Supply User s Manual 4 1 3 2 Standard Event Status and Standard Event Status Enable Registers The Standard Event Status Register supplies various conditions of the instrument STANDARD EVENT STATUS REGISTER FORMAT Bits 2 and 6 are not used The reports of this register occur only if the bits are enabled in the Standard Event Status Enable Register along with bit 5 of the Service Request Enable Register The Standard Event Status Enable Register enables any of the Standard Event Status Register reports The Standard Event Status Enable command ESE sets the Standard Event Status Enable Register bits Set a bit to enable its function To set a bit send the ESE command with the bit weighting for each bit to set added together See the ESE command for further details The Standard Event Status Enable Query ESE reads the
117. vice Request Enable Query Input SRE Returned An integer from 000 255 Remarks Reads the Service Request Enable Register The integer returned represents the sum of the bit weighting of each bit set Returns three digits plus up to two terminators STB Status Byte Query Input STB Returned An integer from 000 255 Remarks Reads the Status Byte Register The integer returned represents the sum of the bit weighting of each bit set Although this query acts like a serial poll it does not reset the register to all zeros Returns three digits plus up to two terminators TST Self Test Query Input TST Returned 0 No errors 3 Reserved 6 AC High 9 0I Active 1 Remote Inhibit Active 4 STP Error 7 Rail High 2 OVP Active 5 AC Low 8 Overtemperature Error Remarks Causes instrument to report any failures Returns 1 character plus up to 2 terminators WAI Wait to Continue Command Input WAI Returned Nothing Remarks The command prevents the instrument from executing any further commands or queries until all previous ones have been serviced This command is accepted but not supported not the IEEE 488 2 defined operation Not supported by the Control Bus mn Remote Operation Lake Shore Model 647 Magnet Power Supply User s Manual CHAPTER 5 ERROR MESSAGES AND TROUBLESHOOTING 5 0 GENERAL This chapter covers Software Error Messages Paragraph 5 1 Factory Default Settings Para graph 5 2 Calibrati
118. y accident misuse fire flood or Acts of God or from failure to properly install operate or maintain the product in accordance with the printed instruction provided This warranty is in lieu of any other warranties expressed or implied including merchantability or fitness for a particular purpose which are expressly excluded the owner agrees that Lake Shore s liability with respect to this product shall be set forth in this warranty and incidental or consequential damages are expressly excluded CERTIFICATION Lake Shore certifies that this product has been inspected and tested in accordance with its published specifications and that this product met its published specifications at the time of shipment The accuracy and calibration of this product at the time of shipment are traceable to the United States National Institute of Standards and Technology NIST formerly known as the National Bureau of Standards NBS or to a recognized natural standard TRADEMARK ACKNOWLEDGMENT Many manufacturers and sellers claim designations as trademarks to distinguish their products Where those designations appear in this manual and Lake Shore was aware of a trademark claim they appear with initial capital letters and a proceeding or symbol CalCurve Carbon Glass Cernox Duo Twist IDEA Gamma Probe Quad Lead and Quad Twist are trademarks of Lake Shore Cryotronics Inc Kapton is a trademark of 3M Stycast is a trade

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