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1. lt curve number gt Format nn term Returns the input curve number See the INCRV command for parameter descriptions lt input gt Specifies which input to query 1 8 lt curve number gt Specifies which curve the input uses 0 none 1 5 Standard Diode Curves 6 9 Standard Platinum Curves 21 28 User Curves Note Curve locations 10 20 not used Remote Operation INPUT Input Returned Remarks Example INPUT Input Returned Remarks INTYPE Input Returned Remarks Example INTYPE Input Returned Remarks KEYST Input Returned Remarks KRDG Input Returned Remarks Remote Operation Lake Shore Model 218 Temperature Monitor User s Manual Configure Input Control Parameter INPUT lt input gt lt off on gt Nothing Turns selected input on or off lt input gt Specifies which input to configure 1 8 lt off on gt Disables Enables input 0 Off 1 On INPUT 4 0 Input 4 is turned off and not scanned Query Input Control Parameter INPUT lt input gt lt offlon gt Format n term Returns selected input status lt input gt specifies which input to query 1 8 Configure Input Type Parameters INTYPE lt input group gt lt sensor type gt Nothing Configures input type parameters for a group of inputs lt input group gt Specifies input group to configure A inputs 1 4 B inputs 5 8 lt sensor type gt Specifies input sensor type Vali
2. 7 4 Service Lake Shore Model 218 Temperature Monitor User s Manual 7 8 IEEE 488 INTERFACE CONNECTOR MODEL 218S ONLY Connect to the IEEE 488 Interface connector on the Model 218 rear with cables specified in the IEEE 488 1978 standard document The cable has 24 conductors with an outer shield The connectors are 24 way Amphenol 57 Series or equivalent with piggyback receptacles to allow daisy chaining in multiple device systems The connectors are secured in the receptacles by two captive locking screws with metric threads The total length of cable allowed in a system is 2 meters for each device on the bus or 20 meters maximum A system may be composed of up to 15 devices Figure 7 5 shows the IEEE 488 Interface connector pin location and signal names as viewed from the Model 460 rear panel IEEE 488 INTERFACE SH1 AH1 T5 L4 SR1 RL1 PPO DC1 DTO CO E1 12 11 10 9 8 T 6 5 4 3 2 1 24 23 22 21 20 9 18 17 16 15 14 13 C 218 7 5 eps PIN SYMBOL DESCRIPTION DIO1 Data Input Output Line 1 DIO2 Data Input Output Line 2 DIO3 Data Input Output Line 3 DIO4 Data Input Output Line 4 EOI End Or Identify DAV Data Valid NRFD Not Ready For Data NDAC Not Data Accepted IFC Interface Clear SRQ Service Request ATN Attention SHIELD Cable Shield DIO5 Data Input Output Line 5 DIO6 Data Input Output Line 6 DIO7 Data Input Output Line 7 DIO8 Data Input Output Line 8 REN Remote Enable GND 6 Ground Wire
3. LOCK 1 123 term Enables keypad lock out and sets the code to 123 Query Lock out and Lock out Code LOCK lt off on gt lt code gt Format n nnn term Returns lock out status and lock out code See LOCK command for parameter descriptions Turns Logging On and Off LOG lt off on gt Nothing Turns logging on and off lt offfon gt 0 Off 1 On Query Logging Status LOG lt off on gt Format n term Returns logging status See LOG command for parameter descriptions Query Number of Last Data Log Record Stored LOGNUM lt last record number gt Format nnnn term Returns number of last data log record stored Remote Operation LOGREAD Input Returned Remarks LOGREAD Input Returned Remarks LOGSET Input Returned Remarks LOGSET Input Returned Remarks LOGVIEW Input Returned Remarks Lake Shore Model 218 Temperature Monitor User s Manual Configure Log Records LOGREAD lt reading number gt lt input gt lt source gt Nothing Configures log records lt reading number gt The individual reading number 1 8 within a log record to configure lt input gt The input number to log 1 8 lt source gt Specifies data source to log 1 Kelvin 2 Celsius 3 sensor units 4 linear data Query Log Record Parameters LOGREAD lt reading number gt lt input gt lt source gt Format n n term Returns log record parameters See LOGREAD command desc
4. Twisted pair with DAV GND 7 Ground Wire Twisted pair with NRFD GND 8 Ground Wire Twisted pair with NDAC GND 9 Ground Wire Twisted pair with IFC GND 10 Ground Wire Twisted pair with SRQ GND11 Ground Wire Twisted pair with ATN GND Logic Ground CON OO PS ON Figure 7 5 IEEE 488 Rear Panel Connector Details Service 7 5 Lake Shore Model 218 Temperature Monitor User s Manual 7 9 SERIAL INTERFACE CABLE AND ADAPTERS 7 6 218 DE 9P 5 GND 2 RD in 3 TD out 4 DTR out 6 DSR in 1 NC 7 DTR tied to 8 NC 218 DE 9P 5 GND 2 RD in 3 TD out 1 NC 7 DTR tied to 8 NC 6 DSR in 4 DTR out 218 DE 9P 5 GND 2 RD in 3 TD out 1 NC 6 DSR in 4 DTR out 218 to PC Serial Interface PC with DE 9P Standard Null Modem Cable DE 9S to DE 9S 29 A _ AA p gt lt a 4 E 218 to PC Serial Interface PC with DB 25P Standard Null Modem Cable DE 9S to DB 25S Ml D a o cc S an ooo y 218 to PC Interface using Null Modem Adapter Null Modem Adapter ec Iy ooo RR i e A 7 DTR tied to 4 E 8 NC 9 NC s PC DE 9P 5 GND 3 TD out 2 RD in 6 DSR in 4 DTR out 7 RTS out 8 CTS in 1 DCD in PC DB 25P 7 GND 2 TD out 3 RD in 4 RTS out 5 CTS in 8 DCD in 20 DTR out 6 DSR in PC D
5. term 6 16 A parameter with enable in the name uses these values 0 disabled or 1 enable A parameter with status in the name uses these values 0 disabled off or 1 enabled on A parameter with value in the name is specified in floating point format A number between 0 and 255 derived from the sum of all the weighted bit values Indicates which sensor input to use Valid values 1 8 Indicates whether an item is turned off or turned on 0 is off and 1 is on Indicates which analog output to use Valid values 1 2 Used when examples are given and indicates where terminating characters should be placed by the user or where they appear on a returning character string from the Model 218 Remote Operation Lake Shore Model 218 Temperature Monitor User s Manual Table 6 5 Model 218 Interface Commands by Function Command Function Page Command Function CLS Clear Interface FILTER Query Filter ESE Set Std Event Status Enable IEEE Set IEEE Interface ESE Query Std Event Status Enable IEEE Query IEEE Interface ESR Query Std Event Status Register INCRV Set Input Curve IDN Query Identification INCRV Query Input Curve OPC Set Operation Complete INPUT Set Input Control OPC Query Operation Complete INPUT Query Input Control RST Reset Instrument INTYPE Set Input Type SRE Set Service Request Enable INTYPE Query Input Type SRE Query Service Request Enable KEYST Query Keypad Status STB Query
6. Apiezon is a trademark of Biddle Instruments CalCurve Carbon Glass Cernox Duo Twist Quad Lead Quad Twist Rox SoftCal and Thermox are trademarks of Lake Shore Cryotronics Inc Chromel and Alumel are trademarks of Hoskins Manufacturing Company Formvar is a trademark of Monsanto Chemical Company MS DOS and Windows are trademarks of Microsoft Corp NI 488 2 is a trademark of National Instruments PC XT AT and PS 2 are trademarks of IBM Stycast is a trademark of Emerson amp Cuming Teflon is a trademark of DuPont De Nemours Copyright 1998 2002 and 2004 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 218 Temperature Monitor User s Manual CE DECLARATION OF CONFORMITY We Lake Shore Cryotronics Inc 575 McCorkle Blvd Westerville OH 43082 8888 USA hereby declare that the equipment specified conforms to the following Directives and Standards Application of Council Directives oocoocconn o o 73 23 EEC 89 336 EEC Standard to which Conformity is declared EN 61010 1 2001 Overvoltage II Pollution Degree 2 EN 61326 A2 2001 Class A Annex B EL ei Ed Maloof Printe
7. 1 10580 1 11160 1 11900 1 13080 1 14860 1 17200 1 25070 1 35050 1 63590 1 76100 1 90660 2 11720 2 53660 2 59840 0 090570 0 110239 0 136555 0 179181 0 265393 0 349522 0 452797 0 513393 0 563128 0 607845 0 648723 0 686936 0 722511 0 755487 0 786992 0 817025 0 844538 0 869583 0 893230 0 914469 0 934356 0 952903 0 970134 0 986073 0 998925 Lake Shore Model 218 Temperature Monitor User s Manual Table A 2 Other Standard Diode and Platinum Curves DT 500 D DIODE CTI DIODE PLATINUM 100 OHM PLATINUM 1000 OHM 500 0 491 0 479 5 461 5 425 5 390 0 346 0 320 0 298 5 279 0 261 0 244 0 228 0 213 0 198 5 184 5 171 5 159 5 148 0 137 5 127 5 118 0 109 0 100 5 93 5 0 29680 0 33820 0 36400 0 39110 0 40500 0 43410 0 48960 0 64080 0 72550 0 79710 0 82450 0 83760 0 86250 0 87690 0 90490 0 91840 0 93140 0 94400 0 96260 0 99580 1 01000 1 07470 1 11620 1 12900 1 15000 1 31610 1 36560 1 38500 1 40000 1 01064 1 02125 1 03167 1 04189 1 05192 1 06277 1 07472 1 1 1 1 Ne 1 1 1 1 1 1 1 1 1 1 1 3 82000 4 23500 5 14600 5 65000 6 17000 6 72600 7 90900 9 92400 12 1800 15 0150 19 2230 23 5250 32 0810 46 6480 62 9800 75 0440 98 7840 116 270 131 616 148 652 165 466 182 035 198 386 216 256 232 106 247 712 261 391 276 566 289 830 Table A 3 Standard DT 670 Diode Curve emp reaKpoin emp reakpoin emp Tv Temp Breakpoint v
8. 6 5 ii Table of Contents Lake Shore Model 218 Temperature Monitor User s Manual TABLE OF CONTENTS Continued Chapter Paragraph Title Page 6 2 SERIAL reet 6 8 6 2 1 PAV SIGAll CONNECCION strain sae anes see ane es tee cease aac 6 8 6 2 2 HardWare ee e 6 8 6 2 3 AAC lel ot alerta eiii 6 9 6 2 4 MESS ee E 6 9 6 2 5 Message Flow Control EEN 6 10 6 2 6 Changing Baud EE 6 10 6 2 7 Serial Interface Basic brogorams 6 11 6 2 7 TrOuUDlESNOOUNG NEE 6 16 6 3 IEEE 488 Serial Interface COMMANAS oocccccncccccncccccnccnocnnonononononnnoncnnonnnnnnnnnnnnonnnnnnnnnonononos 6 16 k SERVICE EE 7 1 7 0 GENE Alsa ct ed at e a e tio ed EN tee 7 1 7 1 GENERAL MAINTENANCE PRECAUTIONS cocccocccccnccncnoccnccncnncnccncnncnncnncnonononononononononononos 7 1 7 2 ELECTROSTATIC DISCHARGE E 7 1 7 2 1 Identification of Electrostatic Discharge Sensitive Components nsnsnnnnsennensnnesenennn 7 1 7 2 2 Handling Electrostatic Discharge Sensitive Components nsannsnennesnnnnnennnesernesrnrennne 1 2 7 3 Fee i ende cto ce Saco mans ane arene te epee 7 2 7 4 LINE VOELTAGESELECHON EE 7 2 7 5 FUSE REPLACEMENT sensata 7 3 7 6 SENSOR INPUT CONNECTOR AND PINOUT ooocccoccnccnccncnnconcnccnonoconcnncncconcnonononconononononos 7 3 1 7 TERMINAL BLOCK MODEL 218S ONT 7 4 7 8 IEEE 488 INTERFACE CONNECTION 7 5 7 9 SERIAL INTERFACE CABLE AND ADAPTERS cu eon ee 7 6 7 10 TOP OF ENCLOSURE REMOVE AND REPLACE DROCEDURE 7 7 7 11 EPROM AND NOVRAM REPLACEMENT co ooccco
9. Data Eu gt DTR out tied to 4 8 NoConnection NC 9 No Connection NC NOTE A P at the end of a connector description indicates a male connector an S indicates a female connector 218 to Serial Printer Printer with DB 25S P PC to Printer Cable using hardware flow control Printer DB 25S P 3 RD in 2 TD out Goo 20 DTR l OND Figure 5 3 Serial Port Pinouts To print with the Model 218 first connect the serial port to a serial printer then press Printer The screen shown below displays The Model 218 printer function has three operating modes Printer function can also be turned off freeing the port for serial interface operation Printer modes are Off Print Stored Log Special Features No printer operation serial I O enabled Prints the contents of data log memory to the printer The data log feature is described in section 5 3 Once the data log sequence completes all stored records can print Printing the entire contents of memory may take up to 40 pages Normal sensor reading operation suspends during printing 9 13 Lake Shore Model 218 Temperature Monitor User s Manual Printer Operation Continued Print Continuous Directs log records to the printer instead of internal memory Setup the data log feature as described in paragraph 5 3 1 The log period must be greater than 10 seconds when printing If log period is set to a value below 10 the instrument prin
10. Lead Soldering When additional wire is soldered to short sensor leads care must be taken not to overheat the sensor A heat sink such as a metal wire clamp or alligator clip will heat sink the leads and protect the sensor Leads should be tinned before bonding to reduce the time that heat is applied to the sensor lead Solder flux should be cleaned after soldering to prevent corrosion Heat Sinking Leads Sensor leads can be a significant source of error if they are not properly heat sinked Heat will transfer down even small leads and alter the sensor reading The goal of heat sinking is to cool the leads to a temperature as close to the sensor as possible This can be accomplished by putting a significant length of lead wire in thermal contact with every cooled surface between room temperature and the sensor Lead wires can be adhered to cold surfaces with varnish over a thin electrical insulator like cigarette paper They can also be wound onto a bobbin that is firmly attached to the cold surface Some sensor packages include a heat sink bobbin and wrapped lead wires to simplify heat sinking Thermal Radiation Thermal black body radiation is one of the ways heat is transferred Warm surfaces radiate heat to cold surfaces even through a vacuum The difference in temperature between the surfaces is one thing that determines how much heat is transferred Thermal radiation causes thermal gradients and reduces measurement accuracy Many cooling s
11. The Model 218 does not have three lead measurement capability Lowering Measurement Noise Good instrument hardware setup technique is one of the least expensive ways to reduce measurement noise The suggestions fall into two categories 1 Do not let noise from the outside enter into the measurement and 2 Let the instrument isolation and other hardware features work to their best advantage e Use four lead measurement whenever possible e Do not connect sensor leads to chassis or earth ground e Use twisted shielded cable outside the cooling system e Attach the shield pin on the sensor connector to the cable shield e Do not attach the cable shield at the other end of the cable not even to ground e Run different inputs and outputs in their own shielded cable e Use twisted wire inside the cooling system e Use a grounded receptacle for the instrument power cord e Consider ground strapping the instrument chassis to other instruments or computers Installation Lake Shore Model 218 Temperature Monitor User s Manual 3 3 3 Terminal Block Model 218S only The terminal block on the Model 218S rear panel contains signals for analog outputs and alarm relays The terminal block connectors are detachable remove the top or bottom half from the instrument for convenient wire installation Use up to 12 AWG stranded copper wire with the terminals Smaller wire is suitable for most applications See Figure 3 4 O RELAYS 30 VDC 5 A k
12. it is representative of the overall procedure This example uses the National Instruments GPIB PCII IIA card and QuickBasic 4 0 or 4 5 on a PC compatible 6 1 4 1 GPIB Board Installation 1 OV es IY Install GPIB PCII IIA card using National Instruments instructions Install Nl 488 2 software for DOS Version 2 1 1 was used for the example Verify that config sys contains the command device gpib pc gpib com Reboot the computer Run IBTEST to test software configuration Do not install the instrument before running IBTEST Run IBCONF to configure the GPIB PCII IIA board and dev 12 Set the EOS byte to OAH See Figure 6 1 IBCONF modifies gpib com Connect the instrument to the interface board and power up the instrument Verify address is 12 and terminators are CR LF 6 1 4 2 Running The Example QuickBasic Program 1 2 5 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 O 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 l qbib qlb Start QuickBasic in this way each time the IEEE interface is used to link in the library file Create the IEEE example interface program in QuickBasic Refer to Table 6 1 Name the file jeeeexam bas and save Run the pro
13. lt value gt Nothing Provides the gain calibration constant for the selected input The calibration constant is calculated using the raw A D data and is multiplied by the necessary constant to supply the corrected value for the input type lt input gt Specifies which input to provide zero calibration constant for Valid entries are 1 8 lt type gt Specifies the input groups sensor type Valid entries are O Silicon Diode 1 GaAlAs Diode 2 Platinum 100 250 Q lt value gt Gain Calibration Constant 3 Platinum 100 500 Q 4 Platinum 1000 5 NTC Resistor Service GCAL Input Returned Remarks RAWAD Input Returned Remarks CALCLEAR Input Returned Remarks CALSAVE Input Returned Remarks Service Lake Shore Model 218 Temperature Monitor User s Manual Returns the Gain Calibration Constant for the Selected Input GCAL lt input gt lt type gt Value of gain calibration constant for the selected input See GCAL command for description of returned data lt input gt Specifies which input to query gain calibration constant for Valid entries are 1 8 lt type gt Specifies the input groups sensor type Valid entries are O Silicon Diode 1 GaAlAs Diode 2 Platinum 100 250 Q 3 Platinum 100 500 Q 4 Platinum 1000 5 NTC Resistor Querys Raw A D Value for the Selected Input RAWAD lt input gt Raw A D value Format n nnnnnn term Returns 7 digit value of sele
14. must take full responsibility for flow control and timing as described in Paragraph 6 2 5 Remote Operation Lake Shore Model 218 Temperature Monitor User s Manual 6 2 3 Character Format 6 2 4 A character is the smallest piece of information that can be transmitted by the interface Each character is 10 bits long and contains data bits bits for character timing and an error detection bit The instrument uses 7 bits for data in the ASCII format One start bit and one stop bit are necessary to synchronize consecutive characters Parity is a method of error detection One parity bit configured for odd parity is included in each character ASCII letter and number characters are used most often as character data Punctuation characters are used as delimiters to separate different commands or pieces of data Two special ASCII characters carriage return CR ODH and line feed LF OAH are used to indicate the end of a message string Table 6 2 Serial Interface Specifications Connector Type DE 9 D Style Connector Connector Wiring DTE Voltage Levels EIA RS 232C Specified Transmission Distance 50 feet maximum Timing Format Asynchronous Transmission Mode Half Duplex Baud Rate 300 1200 9600 Handshake Software timing Character Bits 1 Start 7 Data 1 Parity 1 Stop Parity Odd Terminators CR ODH LF OAH Command Rate 20 commands per second maximum Message Strings A message string is a group of characters assembled
15. sequence appears Use the Data Selection keys to turn Bipolar Mode On or Off then press Enter Bipolar allows the analog output to set a negative voltage On Allows a range from 10V to 10V Off Allows a range from O V to 10V The fourth display in the Input mode setting sequence appears Use the number keys to input a value corresponding to the lowest setting of the analog output then press Enter For bipolar operation this value corresponds to 10 V out for unipolar operation it corresponds to O V out Resolution is 5 digits The fifth display in the Input mode setting sequence appears Use the number keys to input a value corresponding to the highest setting of the analog output 10 V then press Enter Resolution is 5 digits Press Escape at any time to return to the normal display The instrument retains values changed prior to pressing Escape After setting all Input mode parameters the normal display appears 4 12 Operation 4 8 1 4 9 Lake Shore Model 218 Temperature Monitor User s Manual Example of Low and High Analog Parameter Setting With the analog output set to input mode the temperature input data and voltage output data can be related as shown in the top diagram This setup results in a wide temperature range but sensitivity is poor The resulting sensitivity is 0 01 V K or 10 mV K If the application does not require a wide temperature range the user can change the value of the low and h
16. Alarm Reset in Paragraph 4 10 Relay Setup in Paragraph 4 11 Locking The Keypad in Paragraph 4 12 and Model 218 Reset in Paragraph 4 13 Display Screen Keypad SI Ea E read all akeShore Key Data gt Selection K 218 Temperature Monitor Enter Key F 218 4 1 eps Figure 4 1 Model 218 Front Panel DISPLAY SCREEN DESCRIPTION The Model 218 has a 4 line by 20 character backlit LCD During normal operation it is divided into eight reading locations Each of the eight reading locations can be configured by the user with the Display Format feature Data from a sensor input can be displayed in any location Sensor readings can be displayed in temperature or sensor units Results of the math feature can be displayed at the same time as live readings The reading location indicates the number of the sensor input to the left of the reading value The character to the right of the reading value indicates units for live readings or shows an annunciator for one of the math values The column of characters on the far right side of the display are used for system annunciators See Figure 4 2 During keypad operation display format changes to prompt for data entry Operation 4 1 Lake Shore Model 218 Temperature Monitor User s Manual Display Screen Description Continued Sensor Input Reading Source Number Value Annunciator System Y Annunciators F 218 4 2 eps Figure 4 2 Model 218 Normal Display Screen Format Source Annunciat
17. Model 218 Remote Operation 6 19 ALARM Input Returned Remarks Example ALARM Input Returned Remarks ALARMST Input Returned Remarks ALMB Input Returned Remarks ALMB Input Returned Remarks ALMRST Input Returned Remarks 6 20 Lake Shore Model 218 Temperature Monitor User s Manual Configure Input Alarm Parameters ALARM lt input gt lt off on gt lt source gt lt high value gt lt low value gt lt deadband gt lt latch enable gt Nothing Configures the alarm parameters for an input lt input gt Specifies which input to configure 1 8 lt off on gt Determines whether the instrument checks the alarm for this input lt source gt Specifies input data to check 1 Kelvin 2 Celsius 3 sensor units 4 linear data Sets the value the source is checked against to activate the high alarm Sets the value the source is checked against to activate low alarm Sets the value that the source must change outside of an alarm condition to deactivate an unlatched alarm lt latch enable gt Specifies a latched alarm remains active after alarm condition correction ALARM 3 1 1 320 5 250 0 1 0 O term Turns on alarm checking for input 3 activates high alarm if Kelvin reading is over 320 5 and deactivates the alarm when reading falls below 320 5 K minus the deadband or 319 5 K Activates low alarm if Kelvin reading falls below 250 0 K and deactivates the alarm when the
18. Panel o sil 3 2 Line Input EE 3 3 Model 218 Input Connector Pinouts cccocccccoccnccccnnococononocononacnnoncnononnnonanonenanos 3 4 Terminal Block Connechors 4 1 Model 219 Front Panel iii 4 2 Model 218 Normal Display Screen Fommat 4 3 Example of Low and High Analog Parameter Setting 00nnn00nnnnennnnnennnnennnnennnn 5 1 softCal Temperature Ranges for Silicon Diode Gensors 5 2 softCal Temperature Ranges for Platinum Sensors cocoooccncccccccnconoccnconnncnnnnnos 5 3 senal POM RT EE 6 1 Typical National Instruments GPIB Configuration from IBCONF EXE IEN FUSS DW o ida 1 2 Power ee 1 3 Model 213 Input Connector PInouts siosan ee ee 7 4 Terminal Block Connect Sarita id 7 5 IEEE 488 Rear Panel Connector Details 7 6 SenaliPOr PINOS a o li 2 7 Location of Internal Components eer 8 1 Model RM 1 2 Rack Mount Kio id eas 8 2 Model RM 2 Dual Rack Mount hm LIST OF TABLES Table No Title 1 1 Supported Lake Shore Gensors 1 2 Model 218 Sensor Input Performance Chart 3 1 AGUINALDO dia 4 1 Sensor Input Type Display Messages cccccococccccconccnconocononnnonnonnnnonconanenonnnnnannnnos 4 2 Sensor Configuration Update Rates nnnnaannnnennnnennnnnrnnnesrrnnnrnrrrrnrrnsnrrrsrnrenne 4 3 Standard Curves Included in the Model 219 4 4 Model 218 Parameter Defaults oocccconccccccnccconnnococonoconnnnanonononnnnonononanonenanos 9 1 Recommended Curve Parameters occccccocncccc
19. R5 HS uig C e gt R2 1 J3 R4 al za 2 DE C2 C47 C1 Si U2 U27 U1 Default Jumper Positions JMP1 Run Test Run Position JMP2 218S 218E Position depends on Model number JMP4 IEEE Shield No jumper installed NOTE There is no JMP3 F 218 7 7 eps Figure 7 7 Location Of Internal Components 7 9 Lake Shore Model 218 Temperature Monitor User s Manual 7 13 CALIBRATION PROCEDURE Both groups of sensor inputs require calibration Sensor Input groups consist of 4 separate current sources which can supply 10 yA or 1 mA of current They are calibrated by adjusting pots on the Model 218 main board The Sensor Input groups consist of 4 inputs each with multiple gain configurations to accommodate the various sensors the Model 218 supports The input circuitry is not adjusted during calibration Instead precision voltages and resistors are attached to each input and mathematical calibration constants are calculated and programmed into the Model 218 to use to compensate for input offset and gain errors Refer to Paragraph 7 13 15 for details on calibration specific interface commands 7 13 1 7 13 2 7 13 3 7 13 4 7 10 Required Equipment List 1 PC with software loaded which provides serial command line communication 2 DE 9 to DE 9 cable Pin to pin connections on all 9 pins Female connectors on both ends There is a 3 foot minimum DE 9 null modem adapter DVM with minimum 5 digits resolution Precision refer
20. Send EOI at end of Write ii Adding 32 to the primary address H forms the Listen Address LA Enable Repeat Addressing i Adding 64 to the primary address Hi 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 F1 Help F6 Reset Value F9 Esc Return to Map Ctl PgUp PgDn Next Prev Board C 218 6 1 eps Figure 6 1 Typical National Instruments GPIB Configuration from IBCONF EXE Remote Operation Lake Shore Model 218 Temperature Monitor User s Manual 6 2 6 2 1 6 2 2 6 8 SERIAL INTERFACE OVERVIEW The serial interface used in the Model 218 is commonly referred to as an RS 232C interface RS 232C is a standard of the Electronics Industries Association ElA that describes one of the most common interfaces between computers and electronic equipment The RS 232C standard is quite flexible and allows many different configurations However any two devices claiming RS 232C compatibility cannot necessarily be plugged together without interface setup The remainder of this paragraph briefly describes the key features of a serial interface that are supported by the instrument A customer supplied computer with similarly configured interface port is required to enable communication Physical Connection The Model 218 has a 9 pin D Subminiature plug on the rear panel for serial communication The original RS 232C standard
21. Sensors The platinum sensor is a well accepted temperature standard because of its consistent and repeatable temperature response above 30 K SoftCal gives platinum sensors better accuracy than their nominal matching to the DIN 43760 curve One two or three calibration data points can be used If using one point the algorithm shifts the entire curve up or down to meet the single point If using two points the algorithm has enough information to tilt the curve achieving good accuracy between the data points The third point extends the improved accuracy across all three points Point 1 Calibration data point at or near the boiling point of nitrogen 77 35 K Temperatures outside 50 K to 100 K are not allowed Point 2 Calibration data point near room temperature 305 K Temperatures outside 200 K to 350 K are not allowed Point 3 Calibration data point at a higher temperature 480 K Temperatures outside 400 K to 600 K are not allowed SoftCal Point 1 SoftCal Point 2 SoftCal Point 3 Liquid Nitrogen Room Temperature High Temperature Boiling Point Point Point 77 35 K 305 K 480 K Vi ue D A 0 50 100 150 200 250 300 350 400 450 500 550 600 650 KC Deeg 50 100 K 200 325 K 400 600 K Acceptable Temperature Range for Platinum SoftCal Inputs C 218 5 2 eps Figure 5 2 SoftCal Temperature Ranges for Platinum Sensors Special Features 5 7 9 2 4 5 2 5 5 8 Lake Shore Model 218 Temperature Monitor User
22. SoftCal calibration is only as good as the accuracy of the calibration points The accuracies listed for SoftCal assume 0 05 K for 77 35 K liquid nitrogen and 305 K room temperature points and 0 01 K for 4 2 K liquid helium Users performing the SoftCal with silicon diodes and Lake Shore instruments should note that liquefied nitrogen and ice point temperatures can vary as much as 20 5 K Use a calibrated standard sensor if possible The boiling point of liquid helium though quite accurate is affected by atmospheric pressure One point SoftCal calibrations for applications under 30 K are performed at liquid helium 4 2 K Resultant accuracy for the DT 470 SD 13 diode is 0 5 K from 2 K to lt 30 K no change above 30 K Two point SoftCal calibrations for applications above 30 K are performed at liquid nitrogen 77 35 K and room temperature 305 K Resultant accuracy for the DT 470 SD 13 diode sensor is 1 0 K from 2 K to lt 30 K no change below 30 K 0 25 K from 30 K to lt 60 K 0 15 K from 60 K to lt 345 K 0 25 K from 345 K to lt 375 K 1 0 K from 375 to 475 K Three point SoftCal calibrations are performed at liquid helium 4 2 K liquid nitrogen 77 35 K and room temperature 305 K Resultant accuracy for the DT 470 SD 13 diode sensor is 0 5 K from 2 K to lt 30 0 25 K from 30 K to lt 60 K 0 15 K from 60 K to lt 345 K 0 25 K from 345 K to lt 375 K 1 0 K from 375 to 475 K 5 2 3 SoftCal and Platinum
23. Tempshield Cryo Gloves or equivalent when handling anything that is or may have been in contact with the liquid or cold gas or with cold pipes or equipment Wear long sleeve shirts and cuffless trousers long enough to prevent liquid from entering shoes Recommended First Aid Post an appropriate Material Safety Data Sheet MSDS obtained from the manufacturer distributor at every site that stores and uses LHe and LN The MSDS specifies symptoms of overexposure and first aid If a person exhibits symptoms of asphyxia such as headache drowsiness dizziness excitation excessive salivation vomiting or unconsciousness remove to fresh air If breathing is difficult give oxygen If breathing stops give artificial respiration Call a physician immediately If exposure to cryogenic liquids or cold gases occurs restore tissue to normal body temperature 98 6 F by bathing it in warm water not exceeding 105 F 40 C DO NOT rub the frozen part either before or after rewarming Protect the injured tissue from further damage and infection and call a physician immediately Flush exposed eyes thoroughly with warm water for at least 15 minutes In case of massive exposure remove clothing while showering with warm water The patient should not drink alcohol or smoke Keep warm and rest Call a physician immediately Introduction 1 5 1 3 2 1 3 3 1 6 Lake Shore Model 218 Temperature Monitor User s Manual Safety Summary Obser
24. Use the Data Selection keys to turn the audible alarm On or Off then press Enter This is a global parameter that controls beeper operation for all input alarms On Beeper sounds for any active alarm on any input Off Beeper will not sound for any active alarm on any input After setting all alarm parameters a list of the previous alarm status of all inputs momentarily displays before returning to the normal display Press Escape at any time to return to the normal display The instrument retains values changed prior to pressing Escape Operation Lake Shore Model 218 Temperature Monitor User s Manual 4 10 ALARM RESET 4 11 Alarm Reset resets a latched active alarm after the alarm condition has been cleared If the alarm condition is not cleared the alarm activates again during the next sensor input update cycle Alarm Reset does not affect a non latching alarm After pressing Alarm Reset the following message displays momentarily to confirm the reset RELAY SETUP MODEL 218S ONLY There are eight relays on the Model 218S numbered 1 to 8 They are most commonly thought of as alarm relays but may be manually controlled also Relay assignments are configurable A relay can be used with any input it is not necessary for example to use relay one with input one One relay can be assigned to activate when either alarm from a sensor input is active or two relays can be used with one sensor input for independent high and low
25. be read from the instrument with either the IEEE 488 or serial interface The display update rate remains at twice per second Table 4 2 Sensor Configuration Update Rates Group 1 4 Group 5 8 Readings Second On Inputs On Individual Input CURVE SELECT Each sensor input of the Model 218 must be assigned a temperature response curve if it is used to read temperature If no temperature response curve is assigned to an input it will read in sensor units only During curve selection only curves appropriate for the sensor type will be displayed so sensor type must be selected before curves Standard curves are included in the instrument and can be assigned to sensor inputs that match them Standard curves included in the Model 218 are listed in Table 4 3 Users may store a unique 200 point user curve for each of the eight inputs if standard curves are inadequate CalCurves for Lake Shore calibrated sensors store as user curves User curves can be entered from the front panel or with a computer interface The built in SoftCal algorithm can also generate improved curves for DT 470 diodes and platinum sensors stored as user curves Refer to Chapter 5 for details about user curves User curves must be stored in the same location number as the sensor input Once an appropriate user curve stores for a sensor input it can be selected just like standard curves but it can be used for only one input Table 4 3 Standard Curves Included in the Model 2
26. can be displayed at the same time as live readings The reading location indicates the number of the sensor input to the left of the reading value The character to the right of the reading value indicates units for live readings or shows an annunciator for one of the math values The column of characters on the far right side of the display are used for system annunciators See Figure 4 2 During keypad operation the display format changes to prompt for data entry Reading locations numbered 1 8 correlate to the sensor input numbers shown in Figure 4 2 To configure the display press Display Format The first display of the setting sequence shown to the right appears Use the Data Selection keys to cycle through display locations 1 8 Press Enter when the desired location appears The second display in the setting sequence appears Operation Lake Shore Model 218 Temperature Monitor User s Manual Display Setup Continued 4 5 Use the Data Selection keys to cycle through input selections 1 8 or none for the selected display location Select None to blank the display location Press Enter when the desired input appears The same input may display in different locations simultaneously The third display in the setting sequence appears Use the Data Selection keys to cycle through the source selections for the selected display location K Kelvin temperature reading from input C Celsius temperature reading from input Sensor
27. configured for the 7 5 V range and the process repeated Continue changing ranges and repeating the above process until ZCAL constants have been supplied for all input ranges The ranges should be zero calibrated in the following order 2 5V 7 5V 250 Q 500 Q 5 kQ and 7 5 kQ Once zero offset constants for all ranges have been determined and provided back to the Model 218 the CALSAVE command is issued to save the constants in the E prom 2 5 Volt Input Gain Calibration PURPOSE CONFIG PROCESS To determine the input gain errors when the input is configured for the 2 5 V input and provide gain calibration constants back to the Model 218 Same as Paragraph 7 13 4 above Via the interface obtain the RAWAD reading of the 1 input To determine the calibration constant add the 2 5 V range zero offset constant to the value read and then divide 2 5 by that value or 2 5 RAWAD reading zero offset constant For example if the value read was 2 49940 and the zero offset constant was 0 00005 the gain calibration constant is 2 5 2 49945 1 00022 This gain calibration constant is provided back to the Model 218 using the GCAL command This constant is valid for all inputs of the group therefore GCAL must be sent 4 times assigning the constant to each input Once gain calibration constants for all ranges have been determined and provided back to the Model 218 the CALSAVE command is issued to save the constants in the E prom 7 5 Volt In
28. minimized Larger conductor 22 to 28 AWG stranded copper wire is recommended because it has low resistance yet remains flexible when several wires are bundled in a cable The arrangement of wires in a cable is also important For best results twist voltage leads V and V together and twist current leads I and together Cover the twisted pairs of voltage and current leads with a braided or foil shield connected to the shield pin of the instrument This type of cable is available through local electronics suppliers Instrument specifications are given assuming 10 feet of sensor cable Longer cables 100 feet or more can be used but environmental conditions may degrade accuracy and noise specifications Grounding and Shielding Sensor Leads The sensor input measurements are NOT isolated from earth ground Do not ground sensor leads outside of the instrument Shielding the sensor lead cable is important to keep external noise from entering the measurement A shield is most effective when it is near the measurement potential so the Model 218 offers a shield that stays close to the measurement Connect the sensor cable shield to the input connector shield pin Do not terminate the shield at the opposite end Do not connect the shield to earth ground on the instrument chassis or in the cooling system Please note the shell of the connector is in contact with the chassis so the cable shield should never touch the outer shell of the connector If a c
29. operation When using relays with alarm operation set up alarms first Paragraph 4 9 The relays are rated for 30 VDC and 5A Their terminals are in the detachable terminal block on the Model 218S rear panel To begin relay setup press Relay Setup The first display appears Use the Data Selection keys to cycle through the relays 1 8 Press Enter when the desired relay appears The second display in the setting sequence appears Use the Data Selection keys to cycle through the relay modes There are three relay modes Off Relay manually set to the normal state On Relay manually set to the active state Alarms Relay tied to alarm operation When the desired mode appears press Enter Select On or Off to manually set the relay state and return to the normal display Select Alarm to tie the relay to an alarm The third display in the setting sequence appears Use the Data Selection keys to cycle the sensor inputs 1 8 to which the relay applies Press Enter when the desired input appears The fourth display in the setting sequence appears Use the Data Selection keys to cycle through alarms There are three alarms Low Relay active only when low alarm is active High Relay active only when high alarm is active Both Relay active when high or low alarm is active Press Enter when the desired alarm appears The normal display appears Press Escape at any time to return to the normal display The instrument retains val
30. selected input There are four source options K Kelvin temperature reading from input C Celsius temperature reading from input Sensor Sensor units reading from input Linear Linear equation data from input Press Enter when the desired source appears The next three displays involve data entry Press Escape once to clear the entry twice to return to the Normal display The instrument retains values changed prior to pressing Escape twice The fourth display in the setting sequence appears Use the number keys to input a high alarm setpoint in the specified units then press Enter Resolution is five digits The fifth display in the setting sequence appears Use the number keys to input a low alarm setpoint with the specified source then press Enter Resolution is five digits The sixth display in the setting sequence appears Use the number keys to input a dead band value with the specified source then press Enter Used only with non latching alarm Set to 0 if not used Resolution is five digits The seventh display in the setting sequence appears Use the Data Selection keys to turn alarm latching On or Off then press Enter Latching determines whether the alarm remains active after removing the cause On Alarm active state is latched and remains active until Alarm Reset is pressed Off Alarm active state is not latched and clears when the alarm condition is removed The eighth display in the setting sequence appears
31. short and direct as possible e Do not tightly bundle cables that carry different types of signals e Add the clamp on ferrite filters Part Number 9009 020 included with the connector kit to the sensor input cables near the instrument rear panel Lake Shore Model 218 Temperature Monitor User s Manual TABLE OF CONTENTS Chapter Paragraph Title Page 1 INTRODUCTION cursar dai liada A a a dd ca N 1 1 1 0 GENE RA Cernere eeh eege 1 1 1 1 MODEL 2 O RE EE 1 2 1 2 ler BE ee en e e LEE 1 3 1 3 EE Ee 1 5 1 3 1 Handling Liquid Helium and Liquid Nitrogen oocccoccccocnccccnccncnccncnoncncnncnnoncnnnnnnnnnnonanoss 1 5 1 3 2 SIS ty SUMA eeh 1 6 1 3 3 EE 1 6 2 SENSOR CONSIDERATIONS susuranssnsne rea 2 1 2 0 CENERAL ni ir 2 1 2 1 TEMPERATURE SENSOR SELECTION osa 2 1 2 1 1 Temperature Range ici 2 1 2 1 2 Sensor SEMSIMIVILY dado losa lees 2 1 2 1 3 Environmental Ee Le ren amaia N A tea eate 2 1 2 1 4 Vie asSureMmentCACCulaCy nation a nasi aa ee awa anand 2 2 2 1 5 Sensor Package ai Aen denuded anew il do ao 2 2 2 2 e ENEE Ee 2 2 2 2 1 Traditional ele Ur Le DEE 2 2 2 2 2 SE een E ee ee ee eee ee 2 2 2 2 3 SEL eebe e 2 3 2 2 4 A a She ae i ed EE 2 4 2 3 SENSOR INSTALLATION ese a 2 4 2 3 1 Mounting Mate a Scsi ias 2 4 2 3 2 EE Ee 2 4 2 3 3 Baton 2 4 2 3 4 Tele WEE 2 5 2 3 5 Contact eS SUIS arc ata oe ee toate ce nat ean E oe eee 2 5 2 3 6 E A elena Mester 2 6 2 3 1 Erin A 2 6 2 3 8 Feat SINKING LEE 2 6 2 3 9 Thema Radial Mireia li o ll
32. specifies 25 pins but both 9 and 25 pin connectors are commonly used in the computer industry Many third party cables exist for connecting the instrument to computers with either 9 or 25 pin connectors Paragraph 6 5 gives the most common pin assignments for 9 and 25 pin connectors Please note that not all pins or functions are supported by the Model 218 The instrument serial connector is the plug half of a mating pair and must be matched with a socket on the cable If a cable has the correct wiring configuration but also has a plug end a gender changer can be used to mate two plug ends together The letters DTE near the interface connector stand for Data Terminal Equipment and indicate the pin connection of the directional pins such as transmit data TD and receive data RD Equipment with Data Communications Equipment DCE wiring can be connected to the instrument with a straight through cable As an example pin 3 of the DTE connector holds the transmit line and pin 3 of the DCE connector holds the receive line so the functions complement It is likely both pieces of equipment are wired in the DTE configuration In this case pin 3 on one DTE connector used for transmit must be wired to pin 2 on the other used for receive Cables that swap the complementing lines are called null modem cables and must be used between two DTE wired devices Null modem adapters are also available for use with straight through cables Paragraph 7 9 ill
33. the published tolerance band Below are Standard Curve 10 Tolerance Accuracy Bands for DT 470 Precision Calibration Lake Shore can calibrate most sensors with up to 200 separate data points and concentrate data taking in specific areas interest 305 K 305 K Typical Precision Cal Accuracy Band 375 K Typical 2 Point Accuracy Temp Typical Maximum A1 120 25 K 40 5 K 10K 1 0K_ 2K to lt 30 K lt 10K 12mK 20mK 0 25 K 1 of Temp 0 25K 30K to lt 60 K 10K 12mK 20mK 2 0 K 0 15K 60K to lt 345 K 20K 15mK 25mK 1 of Temp 0 25K 345 K to lt 375 K 320K 2mK 45 mK 1 of Temp 10K 375K to 475K Te 7 TEN El H 50 K 30mK 55 mK emperatures aown to 1 on i H with n Calibrated Ge Vis E 7 i p ON d OR A me l SE 300K 25mK DO mb To increase accuracy Perform a 0 25K 30K to lt 60 K 340K 100 mK SoftCal with the controller and 0 15K 60K to lt 345 K 480K 100 mK sensor After sensor calibration 0 25 K 345 K to lt 375 K raken hoet eraci the custom curve for that sensor 1 0 K 375 K to 475 K oe g replaces Standard Curve 10 these points and sends a detailed report with the sensor that includes Raw Temperature Data Polynomial Fits and Interpolation Tables User manually enters data Or into the instrument Breakpoint pairs are Breakpoint pairs loaded on a Floppy Disk are loaded in a in ACSII format for NOVRAM for Customer downloading field installation Enter the voltage at 2 or 3 data points S
34. to perform an interface function There are three types of message strings commands queries and responses The computer issues command and query strings through user programs the instrument issues responses Two or more command strings can be chained together in one communication but they must be separated by a semi colon Only one query is permitted per communication but it can be chained to the end of a command The total communication string must not exceed 64 characters in length A command string is issued by the computer and instructs the instrument to perform a function or change a parameter setting The format is lt command mnemonic gt lt space gt lt parameter data gt lt terminators gt Command mnemonics and parameter data necessary for each one is described in Paragraph 4 3 Terminators must be sent with every message string A query string is issued by the computer and instructs the instrument to send a response The query format is lt query mnemonic gt lt gt lt space gt lt parameter data gt lt terminators gt Query mnemonics are often the same as commands with the addition of a question mark Parameter data is often unnecessary when sending queries Query mnemonics and parameter data if necessary is described in Paragraph 6 3 Terminators must be sent with every message string The computer should expect a response very soon after a query is sent A response string is the instruments response or answer to a quer
35. when the instrument is turned off or parameters related to the input change 4 7 2 Linear The Model 218 will process a simple linear equation MX B for each sensor input M slope of a line X reading data from a sensor input and B offset of a line The result can be displayed or directed to one of the analog voltage outputs To set up the linear equation press Math select an input then press Enter until the fourth display in the Math setting sequence appears Use the Data Selection keys to select an appropriate source for the selected sensor input X K Kelvin temperature reading from input C Celsius temperature reading from input Sensor Sensor units reading from input Operation 4 9 Lake Shore Model 218 Temperature Monitor User s Manual Linear Continued 4 7 3 4 10 Press Enter when the desired source appears In the fifth display of the Math setting sequence specify the M variable then press Enter Resolution is 5 digits 0 0001 to 9999 9 In the sixth display of the Math setting sequence specify the B variable then press Enter Resolution is 5 digits 0 0001 to 9999 9 Press Escape at any time to return to the normal display The instrument retains values changed prior to pressing Escape Filter The reading filter applies exponential smoothing to the sensor input readings If the filter is turned on for a sensor input all reading values for that input are filtered The filter does not chan
36. window gt Format n nn nn term Returns input filter configuration See FILTER command for returned parameter descriptions lt input gt specifies which input to query 1 8 Configure IEEE 488 Interface Parameters IEEE lt terminator gt lt EOI enable gt lt address gt Nothing Configures parameters of the IEEE interface lt terminator gt Specifies the terminator 0 lt CR gt lt LF gt 1 lt LF gt lt CR gt 2 lt LF gt 3 no terminator lt EOl enable gt Disables enables the EOI mode 0 Enabled 1 Disabled lt address gt Specifies the IEEE address IEEE 1 0 4 term After receipt of the current terminator the instrument responds to address 4 uses lt CR gt lt LF gt as the new terminator and uses EOI mode Query IEEE 488 Interface Parameters IEEE lt terminator gt lt EOI enable gt lt address gt Format n n nn term Returns IEEE interface parameters See IEEE command for returned parameter descriptions Configure Input Curve Number INCRV lt input gt lt curve number gt Nothing Specifies the curve an input uses for temperature conversion lt input gt Specifies which input to configure 1 8 lt curve number gt Specifies which curve the input uses 0 none 1 5 Standard Diode Curves 6 9 Standard Platinum Curves 21 28 User curves Note Curve locations 10 20 not used INCRV 5 6 term Input 5 standard curve 6 PT 100 Query Input Curve Number INCRV lt input gt
37. workmanship for the Warranty Period specified above the Warranty Period If Lake Shore receives notice of any such defects during the Warranty Period and the Product is shipped freight prepaid Lake Shore will at its option either repair or replace the Product if it is so defective without charge to the owner for parts service labor or associated customary return shipping cost Any such replacement for the Product may be either new or equivalent in performance to new Replacement or repaired parts will be warranted for only the unexpired portion of the original warranty or 90 days whichever is greater 2 Lake Shore warrants the Product only if it has been sold by an authorized Lake Shore employee sales representative dealer or original equipment manufacturer OEM 3 The Product may contain remanufactured parts equivalent to new in performance or may have been subject to incidental use 4 The Warranty Period begins on the date of delivery of the Product or later on the date of installation of the Product if the Product is installed by Lake Shore provided that if you schedule or delay the Lake Shore installation for more than 30 days after delivery the Warranty Period begins on the 31st day after delivery 5 This limited warranty does not apply to defects in the Product resulting from a improper or inadequate maintenance repair or calibration b fuses software and non rechargeable batteries c software interfacing p
38. zero offset constant to the value read and divide 5000 by that value or 5000 RAWAD reading zero offset constant For example if the value read was 2 49870 and the zero offset constant was 0 00005 the gain calibration constant is 5000 2 49875 2001 00 This gain calibration constant is provided back to the Model 218 using the GCAL command for the 1 input of the group only The above process must be repeated for the remaining 3 inputs of the group Once gain calibration constants for all ranges have been determined and provided back to the Model 218 the CALSAVE command is issued to save the constants in the E prom 7 13 13 Calibrate Input Group B Repeat steps in Paragraphs 7 13 4 thru 7 13 12 for input Group B Inputs 5 8 7 13 14 Analog Output Calibration And Test Model 218s Only The Model 218S has two analog outputs which require calibration Zero offset and gain are adjusted for each input via pots on the Model 218 main board NOTE Analog output calibration must be performed on both analog outputs 7 13 14 1 Analog Output Zero Adjust PURPOSE To adjust the zero offset error of the analog output amplifier to 0 V CONFIG The positive lead of the DVM is connected to the analog output positive terminal the negative lead is connected to the analog output negative terminal The DVM should be set to read DC VOLTS Via the front panel manually set the analog output to O V TOLERANCE 2 5 mV PROCESS Adjust the offset adjus
39. 18 Curve Display Lake Shore Temperature DT 470 Silicon Diode DT 470 1 4 475 K DT 500 Silicon Diode DT 500 DRC D 1 4 365 K DT 670 Silicon Diode DT 670 DT 670 1 4500 K 6 PT 100 1002 Platinum RTD PT 100 DIN 43760 30 800 K PT 1000 1000 Q Platinum RTD PT 1000 DIN 43760 30 800 K Operation 4 7 Lake Shore Model 218 Temperature Monitor User s Manual Curve Select Continued 4 7 4 7 1 4 8 To select a temperature response curve press Curve Select The display below appears Use the Data Selection keys to cycle through the inputs 1 8 for which to select a temperature response curve Press Enter when the desired input appears The second display in the setting sequence appears Use the Data Selection keys to cycle through the temperature response curves When the desired curve appears press Enter to assign that curve to the selected input and return to the normal display Press Escape at any time to return to the normal display The instrument retains values changed prior to pressing Escape MATH Simple math features are included for convenience and aid in setting up experiments Readings can be filtered to quiet effects of a noisy environment Max and Min readings can be captured A linear equation can be applied to input data to correct system errors or improve performance of the analog outputs Math features can be performed on all eight sensor inputs Each input must be configured seperately Max Min Th
40. 218 is Y2K compliant 5 10 Special Features 9 3 2 9 3 3 9 3 4 Lake Shore Model 218 Temperature Monitor User s Manual Starting and Stopping Data Log The Log On Off key is used to start and stop data logging The start and overwrite parameters set with Log Setup determine the operation of Log On Off key If start is set to clear the Log On Off key will first clear the data buffer of old records and then begin the log sequence Pressing Log On Off again will stop the log sequence so data can be viewed or printed If overwrite is set to no the log sequence will stop automatically at the end of the data buffer If overwrite is set to yes new records will continue to overwrite old ones until the sequence is stopped Whichever method stops the log sequence all logged data will be lost when the a new log sequence is begun If start is set to continue the Log On Off key will begin the log sequence at the end of the old records Pressing Log On Off again will stop the sequence If overwrite is set to no the log sequence will stop automatically at the end of the data buffer If overwrite is set to yes new records will continue to overwrite old ones until the sequence is stopped With logging active the Data Log D annunciator displays If overwrite is set to No the D annunciator will turn off when the end of the data buffer is reached Viewing Logged Data To view logged records first turn off logging with the Log On Off key
41. 8 to a 482 6 mm 19 inch rack mount space See Figure 8 1 Dual Mounting Shelf for Two Model 218 Temperature Monitor Mounting shelf to attach two Model 321 Temperature Controllers side by side on a 482 6 mm 19 inch rack mount shelf See Figure 8 2 9009 020 Clamp On Ferrite Noise Filter Add the clamp on ferrite filter to the sensor input cables Accessories included with a new Model 218 8 2 Accessories Lake Shore Model 218 Temperature Monitor User s Manual Refer to 13 N ote NOTE Customer must use 5 64 2 mm hex key to remove four existing screws from sides of instrument Unit on right side mounting shown Unit on left side also possible Rack Mount Ear 107 440 Rack Mount Support 107 442 Rack Mount Panel 107 432 Rack Mount Handle 107 051 01 Screw 6 32 x 1 2 Inch 0 035 FHMS Phillips Screw 8 32 x 3 8 Inch FHMS Phillips C 218 8 1 eps Figure 8 1 Model RM 1 2 Rack Mount Kit Accessories 8 3 8 4 Lake Shore Model 218 Temperature Monitor User s Manual Refer to Installation Procedure Installation Procedure 1 Use 5 64 inch 2 mm hex key to remove two 6 32 x 1 4 black button head screws from side of Model 218 2 Place Instrument on shelf 3 Use 5 64 inch 2 mm hex key to reinstall two 6 32 x 1 4 black button head screws through side of rack into corresponding holes in the side of the Model 218 C 218 8 2 eps Figure 8 2 Mode
42. 88 Command Structure The Model 218 supports several command types These commands are divided into three groups 1 Bus Control refer to Paragraph 6 1 2 1 a Universal 1 Uniline 2 Multiline b Addressed Bus Control 2 Common refer to Paragraph 6 1 2 2 3 Interface and Device Specific refer to Paragraph 6 1 2 3 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 Model 218 recognizes two of these messages from the BUS CONTROLLER Remote REN and Interface Clear IFC The Model 218 sends one Uniline Command Service Request SRQ REN Remote Puts the Model 218 into remote mode IFC Interface Clear Stops current operation on the bus SRQ Service Request Tells the bus controller that the Model 218 needs interface service A Multiline Command asserts a group of signal lines All devices equipped to implement such commands do so simultaneously upon command transmission These commands transmit with the Attention ATN line asserted low The Model 218 recognizes two Multiline commands LLO Local Lockout Prevents the use of instrument front panel controls DCL Device Clear Clears Model 218 interface activity and puts it into a bus idle state Remote Operation Lake Shore Model 218 Temperature Monitor User s Manual Bus Control Commands Continue
43. 88 interface capabilities e SH1 Source handshake capability e RL1 Complete remote local capability e DC1 Full device clear capability e DTO No device trigger capability e CO No system controller capability e T5 Basic TALKER serial poll capability talk only unaddressed to talk if addressed to listen e L4 Basic LISTENER unaddressed to listen if addressed to talk e SR1 Service request capability e AH1 Acceptor handshake capability e PPO No parallel poll capability e El Open collector electronics Remote Operation 6 1 6 1 2 1 6 2 Lake Shore Model 218 Temperature Monitor User s Manual IEEE 488 Interface Settings If using the IEEE 488 interface you must set the IEEE Address and Terminators Press the Interface key The first screen selects Serial Interface Baud Rate and therefore is skipped by pressing the Enter key The Address screen is then displayed Press the A or Y keys to increment or decrement the IEEE Address to the desired number Press Enter to accept new number or Escape to retain the existing number Pressing Enter displays the Terminators screen Press the A or Y keys to cycle through the following Terminator choices CR LF LF CR LF and EOI To accept changes or the currently displayed setting push Enter To cancel changes push Escape Power down the Model 218 then back up again to allow other devices on the IEEE 488 bus to recognize a new Address or Terminator setting IEEE 4
44. A 008 18 MW OL 4 929 MW OL A 00 18 MW OL A OL ve MW Lt A GLY MW OLL A 00 IP MW Ott A Z2 e MW OOE 51 OL e MW oi CO c0 0 AN 091 A GZ e MW OL A 00 IP MW OL A Cy ye MW LEF A GLY 18 MU A 00 IP MW 88F MLL ye MU SEL Acy ye MW LF 90g 10 0 AN 091 4 GLY 18 MW OL A 00 IP MW OL Aoeinooy ainjesodwoay a9usajermby aunjyesodwe SIUM JOSU8S A 9e In99Y 21U0 1399 3 MLZ ye MU ZZ ve MU OL ZZ ye MW OL A ZZ ye MW QI y ZL ye MW LL Acy ye Mw L gt Of e MW 9 0L gt OE JE MW QOL z OL IP MW y Z ye MW esuejeamby almejadus OW 0S OW Oc gu AN OC AN OC sHun JOSUSS UOIANJOSIY JUSUIIINSEIIA gt 008 1 Y O CEO 5141291 Y O GEO A 00 IB Y O 680 A LNO Cv A Z2 NO cvo 51 008 IP 1 0 z 00 1 1 0 6 A GLY e A AU GI z 00 18 4 AU GI A LL Ie Y AU GL A ZZ e 4 AU 6 ACV e W O OLL z 0E e Y O 61 A 0E e 1 0 6L 0 51 OL 18 Y AW O8L A CY Ie AAW OE uoyeJqies Saba 0 9 p NIG Woy pajeos 09 b NIC uopesqieog seuinboy OL anno 1987 A 0Ov S E A 008 0 A 008 0 doitb PL doitb FL 1e9 Hr e IM e IM 2 e IM e IM ID Tp UUM GS OSOL XO 180 fY UNM LOOL Ld 120 FYL WIM E0L Ld IEO Hel YIM GSOZL OL WH z GLY 1 A AU dc A 00 Je MIAU P AuAtlsuge A 00 1E Y O L O JOSU9S Je91d 1 1122 W O 9 l 8AIND JOSUSS DIEDUEIe 2Buey sinjyesodwo J0SU9S 1987 3 duex3 gu 001 gu 001 mun An 001 AN 001 od GER das S eh SS K ua
45. B 9P 5 GND 3 TD out 2 RD in 4 DTR out 1 DCD in 6 DSR in NOTE Same as null modem cable design except PC CTS is provided from 218 on DTR 218 DE 9P 3 TD out 2 RD in 8 NC 6 DSR in 1 NC 5 GND 218 to Serial Printer Printer with DB 25S P PC to Printer Cable using hardware flow control ooo MO Printer DB 25S P o 3 RD in 2 TD out 20 DTR 7 GND Service Lake Shore Model 218 Temperature Monitor User s Manual F 218 7 6 eps Model 218 Computers and Printers 218 DE 9P DB 25P Description Pin Description Pin Description Gmn A ERE 72 Receive Data Rom a Roo 2 Rom 3 tremendo fa fersen fo foem Data Terminal een DTR out E CS Data Sn Se DSR mi 7 GN S out KR No Connection NC DTR out EM EA Data Terminal Ready DTR out tied to 4 ECH EC 8 9 R Figure 7 6 Serial Port Pinouts 7 10 TOP OF ENCLOSURE REMOVE AND REPLACE PROCEDURE WARNING To avoid potentially lethal shocks turn off controller and disconnect it from AC power line before performing this procedure Only qualified personnel should perform this procedure REMOVAL GE aS NS Set power switch to off O and disconnect power cord from rear of unit If attached remove 19 inch rack mounting brackets Use 5 64 hex key to remove four screws attaching top panel to unit Use 5 64 hex key to loosen four screws attaching bottom panel to unit Carefully remove t
46. Cal curve stores Press Enter when the desired input appears CAUTION If a user curve already exists at the input location the instrument overwrites it with the new SoftCal user curve The third display in the setting sequence appears Use the number keys to input up to a ten digit serial number then press Enter The fourth display in the setting sequence appears Use the number keys to input the voltage or resistance of the first calibration data point then press Enter Use the number keys to input the temperature in Kelvin that corresponds to the voltage or resistance of the first calibration data point then press Enter Points outside acceptable range will not be allowed If the first point is not used press Enter twice without entering any data The fifth display in the setting sequence appears Use the number keys to input the voltage or resistance of the second calibration data point then press Enter Use the number keys to input the temperature in Kelvin that corresponds to the voltage or resistance of the second calibration data point then press Enter If the second point is not used press Enter twice without entering any data Special Features Lake Shore Model 218 Temperature Monitor User s Manual SoftCal Calibration Curve Creation Continued The sixth display in the setting sequence appears Use the number keys to input the voltage or resistance of the third calibration data point then press Enter Use the nu
47. Configuration GPIB PC2 2A Ver 2 1 Primary GPIB Address Select the primary GPIB address by Secondary GPIB Address using the left and right arrow keys Timeout setting ii This address is used to compute the Terminate Read on EOS a talk and listen addresses which Set EOI with EOS on Writes ff identify the board or device on the Type of compare on EOS j i GPIB Valid primary addresses range EOS byte from 0 to 30 00H to 1EH Send EOI at end of Write dE i Adding 32 to the primary address System Controller i forms the Listen Address LA Assert REN when SC i Adding 64 to the primary address Enable Auto Serial Polling it forms the Talk Address TA Enable CIC Protocol i 500nsec EXAMPLE Selecting a primary address Parallel Poll Duration Default ii of 10 yields the following Use this GPIB board ie 10 32 42 Listen address NY 10 64 74 Talk address Base I O Address Fl Help F6 Reset Value F9 Esc Return to Map Ctl PgUp PgDn Next Prev Board National Instruments DEV12 Configuration GPIB PC2 2A Ver 2 1 Primary GPIB Address A Select the primary GPIB address by Secondary GPIB Address using the left and right arrow keys Timeout setting S Serial Poll Timeout This address is used to compute the Hi talk and listen addresses which Terminate Read on EOS ii identify the board or device on the Set EOI with EOS on Writes ji GPIB Valid primary addresses range Type of compare on EOS i i from 0 to 30 00H to 1EH
48. MOVAL procedure in Paragraph 7 10 2 Locate EPROM U17 M218 HEX or NOVRAM U24 on the main circuit board Note orientation of existing IC See Figure 7 7 3 Use IC puller to remove existing EPROM NOVRAM from socket 4 Noting orientation of new EPROM NOVRAM use an IC insertion tool to place new device into socket 5 Follow the top of enclosure INSTALLATION procedure in Paragraph 7 10 Si akeShore M218 HEX qe DALLAS A 113 535 XXXXXXXXX Match notch on 02 03 99 Match notch on O EPROM to notch NOVRAM to notch in socket 1 Typical EPROM in socket Typical NOVRAM ERROR MESSAGES Model 218 error messages during normal operation Disabled Input is turned off No Curve Input has no curve S Over Input is at over full scale S Under Input is at under negative full scale T Over Temperature conversion went off the high end of the curve T Under Temperature conversion went off the low end of the curve Error 1 Defective NOVRAM Error 2 Invalid NOVRAM Press and hold Escape for approximately 20 seconds to initialize NOVRAM Refer to Paragraph 4 13 Service Service Lake Shore Model 218 Temperature Monitor User s Manual 1 J7 J9 JMP4 IEEE SHIELD BACK c40 Z S L U29 C41 2 U28 st foe N lt Ke lt lt C39 U25 C51 R3 C32 U21 U22 Z C35 3 C124 Q S O U63 U17 LO y 3 C38 O N lt lt O U19 co U16 C48 B gt U20 U23 C33 u C49 J U15 S 5 U30 K u54 2 5 TI RN5
49. MQ 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 Do not handle ESDS devices unnecessarily or remove from the packages until actually used or tested 7 3 FUSE DRAWER The fuse drawer supplied with the Model 218 Fuse O holds the instrument line fuses and line voltage selection module The drawer holds two 5 x 20 mm time delay fuses lt requires two good fuses of the same rating to operate safely a Fuse ratings are different for different line voltages Refer to Paragraph 7 5 Front View Side View Rear View European Dual Fuse Configuration EU_Fuse eps 7 4 LINE VOLTAGE SELECTION Figure 7 1 Fuse Drawer Use the following procedure to change the instrument line voltage selector Verify the fuse value whenever line voltage is changed WARNING To avoid potentially lethal shocks turn off controller and disconnect it from AC power before performing these procedures Identify the line input assembly on the instrument rear panel See Figure 7 2 Turn th
50. Sensor units reading from input Linear Linear equation data from input Min Results of Minimum Math function Max Results of Maximum Math function Press Enter when the desired source appears The normal display appears with the selected sensor input and source displayed in the selected location Press Escape at any time to return to the normal display The instrument retains values changed prior to pressing Escape Repeat the sequence for other display locations INPUT TYPE The Model 218 supports a variety of temperature sensors sold by Lake Shore and other manufactures An appropriate sensor type must be selected for each group of inputs Refer to Table 4 1 for a list of display messages and common sensor types If a particular sensor is not listed in the Input Type selection look at Table 1 2 to find a sensor with similar range and excitation Sensor type is selected for all sensors in a group 1 4 or 5 8 All sensors in a group must share the same excitation and range The two groups can be set to a different type It is recommended that all unused inputs are turned off To select sensor type press Input Type The display below appears Use the Data Selection keys to cycle through the different sensor types for Input group 1 4 When the desired type appears press Enter The second display in the setting sequence appears Operation 4 5 Lake Shore Model 218 Temperature Monitor User s Manual Input Type Continued Use the Da
51. Status Byte KRDG Query Kelvin Reading TST Query Self Test LINEAR Set Linear Equation WAI Wait To Continue LINEAR Query Linear Equation ALARM Set Alarm LOCK Set Lock out and Code ALARM Query Alarm LOCK Query Lock out and Code ALARMST Query Alarm Status LOG Turns Logging On and Off ALMB Set Audible Alarm LOG Query Logging Status ALMB Query Audible Alarm Parameters LOGNUM Query Last Log Record Stored ALMRST Reset Alarms LOGREAD Set Log Records ANALOG Set Analog Outputs LOGREAD Query Log Record Parameters ANALOG Query Analog Outputs LOGSET Configure Logging Parameters AOUT Query Analog Output Data LOGSET Query Logging Parameters BAUD Set Serial Interface Baud Rate LOGVIEW Query Logged Data Record BAUD Query Serial Interface Baud Rate LRDG Query Linear Equation Input Data CRDG Query Celsius Reading MNMX Set Max Min CRVDEL Erase a Curve MNMX Query Max Min CRVHDR Set Curve Header MNMXRDG Query Max Min Data CRVHDR Query Curve Header MNMXRST Reser Min Max Function CRVPT Set Curve Point MODE Set Local Remote Mode CRVPT Query Curve Point MODE Query Local Remote Mode DATETIME Set Date and Time RDGST Query Reading Status DATETIME Query Date and Time RELAY Set Relay DFLT Set To Factory Defaults RELAY Query Relay DISPFLD Set Display Field RELAYST Query Relay Status DISPFLD Query Display Field SCAL Generate SoftCal Curve FILTER Set Filter SRDG Query Sensor Units Reading Remote Operation 6 17 Lake Shore Model 218 Tempe
52. Status Register ESR lt ESR bit weighting gt Format nnn term Queries for various Model 218 error conditions and status The integer returned represents the sum of the bit weighting of the event flag bits in the Standard Event Status Register Bit Bit Weighting Event Name Bit Bit Weighting Event Name 0 1 OPC 4 16 EXE 2 4 QYE 5 32 CME 3 8 DDE 7 128 PON Query Identification IDN lt manufacturer gt lt model number gt lt serial number gt lt firmware date gt Format LSCI LMODEL218S aaaaaa nnnnnn term Identifies the instrument model and software level Operation Complete Command OPC Nothing Generates an Operation Complete event in the Standard Event Status Register upon completion of all pending selected device operations Remote Operation Lake Shore Model 218 Temperature Monitor User s Manual OPC Query Operation Complete Input OPC Returned 1 Format n term Remarks Places a 1 in the controller output queue upon completion of all pending selected device operations Send this as the last command in a command string This is not the same function as the OPC command RST Reset Instrument Input RST Returned Nothing Remarks Sets controller parameters to power up settings SRE Configure Status Reports in the Service Request Enable Register Input SRE lt bit weighting gt Returned Nothing Remarks Each bit has a bit weighting and represents the enable disable status of the correspo
53. Switch Drawer e ECS 100 120 220 240 V 10 6 Voltage _ 100 120V 0 25 AT 250V_5x20mm 50 60 Hz 18 VA MAX 220 240V 0 20 AT 250V 520mm F 218 3 2 eps Figure 3 2 Line Input Assembly 3 2 Installation 3 3 1 1 3 3 1 2 3 3 1 3 3 3 1 4 Installation Lake Shore Model 218 Temperature Monitor User s Manual Line Voltage The Model 218 has four different AC line voltages configurations so that it can be operated from line power anywhere in the world The nominal voltage and voltage range of each configuration is shown in Table 3 1 The recommended setting for 230 V operation is 240 V Table 3 1 AC Line Input Definitions C Nominal Minimum Maximum 120 V 108 V 127 V 220 V 198 V 233 V 240 V 216 V 254 V Verify that the AC line voltage indicator in the fuse drawer window shows the appropriate AC line voltage before turning the instrument on The instrument may be damaged if turned on with the wrong voltage selected Instructions for changing the line voltage configuration are given in Paragraph 7 4 Line Fuse and Fuse Holder The line fuse is an important safety feature of the Model 218 If a fuse ever fails it is important to replace it with the value and type indicated on the rear panel for the line voltage setting The letter T on the fuse rating indicates that the instrument requires a time delay or slow blow fuse Fuse values should be verified any time line voltage configuration is changed Instruct
54. T RESPONSE RS Print response to query ELSE PRINT NO RESPONSE No response to query END IF END IF Get next command GOTO LOOP1 6 14 Remote Operation Lake Shore Model 218 Temperature Monitor User s Manual 6 2 7 3 Program Operation Once either program is running try the following commands and observe the response of the instrument Input from the user is shown in bold and terminators are added by the program The word term indicates the required terminators included with the response ENTER COMMAND KRDG 1 Query Kelvin Reading for Input 1 Monitor will return a temperature reading in Kelvin RESPONSE 77 350 term ENTER COMMAND AOUT 1 Query Analog Output for data output 1 Monitor will return output reading in percent RESPONSE 10 122 term ENTER COMMAND DISPFLD 3 1 3 Configures display field 3 to display input 1 in sensor units ENTER COMMAND FILTER 5 Query filter parameters for input 5 Monitor returns filter settings RESPONSE 1 08 Do term ENTER COMMAND INCRV 7 2 INCRV 7 Combination command Selects curve 2 for input 7 and then requests input 7 curve number RESPONSE 02 term The following are additional notes on using either Serial Interface program e If you enter a correctly spelled query without a nothing will be returned Incorrectly spelled commands and queries are ignored Commands and queries and should have a space separating the command and associated parameters e Leadin
55. Temperature Coefficient The unit derives the temperature coefficient from the first two breakpoints The user does not enter this setting If it is not correct check for proper entry of those points A positive coefficient P indicates that the sensor signal increases with increasing temperature A negative coefficient N indicates that the sensor signal decreases with increasing temperature Table 5 1 Recommended Curve Parameters Lake Shore eer ee Recommended te Matar Umts nmn Limit coeticent EN Silicon Diode DT 470 0 00001 V GaAlAs Diode TG 120 0 00001 V Platinum 100 PT 100 0 001 2 Ruthenium Oxide TU Ohms Loga K 300 Negative 0 0000t Loge GR 200A 1000 Log Q K 0 00001 Log 2 Special Features 5 1 9 2 Lake Shore Model 218 Temperature Monitor User s Manual Curve Breakpoints Reduce the temperature response data of a calibrated sensor to a table of breakpoints before entering it into the instrument Each breakpoint consists of a value in sensor units and a corresponding temperature value in Kelvin Linear interpolation is used by the instrument to calculate temperature between breakpoints Enter from 2 to 200 breakpoints as a user curve No special endpoints are required Setting resolution is six digits in sensor units The sensor type determines the practical range of values The input resolution of the instrument determines the practical resolution Additional resolution is ignored Setting res
56. Tome Breakpoint v Temp 26 51 38 2000 42 3500 51 4600 56 5000 61 7000 67 2600 79 0900 99 2400 121 800 150 150 192 230 235 250 320 810 466 480 629 800 750 440 987 840 1162 70 1316 16 1486 52 1654 66 1820 35 1983 86 2162 56 2321 06 2477 12 2613 91 2 65 66 2898 30 1 19475 1 24208 1 26122 1 27811 1 29430 1 31070 1 32727 1 34506 1 36423 1 38361 1 40454 1 42732 1 45206 1 48578 1 53523 1 56684 1 58358 1 59690 1 60756 1 62125 1 62945 1 63516 1 63943 1 64261 1 64430 Appendix A
57. User s Manual Model 218 Temperature Monitor all akeShore wo Hd 3 3 Ei D Q II EJ Sr O ES 218 Temperature Monitor Includes Coverage For Model 218S and Model 218E LakeShore Lake Shore Cryotronics Inc 575 McCorkle Blvd Westerville Ohio 43082 8888 USA Internet Addresses sales lakeshore com service lakeshore com Visit Our Website www lakeshore com Fax 614 891 1392 Telephone 614 891 2243 Methods and apparatus disclosed and described herein have been developed solely on company funds of Lake Shore Cryotronics Inc No government or other contractual support or relationship whatsoever has existed which in any way affects or mitigates proprietary rights of Lake Shore Cryotronics Inc in these developments Methods and apparatus disclosed herein may be subject to U S Patents existing or applied for Lake Shore Cryotronics Inc reserves the right to add improve modify or withdraw functions design modifications or products at any time without notice Lake Shore shall not be liable for errors contained herein or for incidental or consequential damages in connection with furnishing performance or use of this material Revision 2 0 P N 119 007 15 October 2004 Lake Shore Model 218 Temperature Monitor User s Manual LIMITED WARRANTY STATEMENT WARRANTY PERIOD ONE 1 YEAR 1 Lake Shore warrants that this Lake Shore product the Product will be free from defects in materials and
58. al Features 6 0 6 1 Lake Shore Model 218 Temperature Monitor User s Manual CHAPTER 6 REMOTE OPERATION GENERAL This chapter provides operational instructions for the computer interface for the Lake Shore Model 218 Temperature Monitor Either of the two computer interfaces provided with the Model 218 permit remote operation The first is the IEEE 488 Interface described in Paragraph 6 1 The second is the Serial Interface described in Paragraph 6 2 The two interfaces share a common set of commands detailed in Paragraph 6 3 Only one of the interfaces can be used at a time IEEE 488 INTERFACE The IEEE 488 Interface is an instrumentation bus with hardware and programming standards that simplify instrument interfacing The Model 218 IEEE 488 Interface complies with the IEEE 488 2 1987 standard and incorporates its functional electrical and mechanical specifications unless otherwise specified in this manual All instruments on the interface bus perform one or more of the interface functions of TALKER LISTENER or BUS CONTROLLER A TALKER transmits data onto the bus to other devices A LISTENER receives data from other devices through the bus The BUS CONTROLLER designates to the devices on the bus which function to perform The Model 218 performs the functions of TALKER and LISTENER but cannot be a BUS CONTROLLER The BUS CONTROLLER is the digital computer which tells the Model 218 which functions to perform Below are Model 218 IEEE 4
59. always smaller than error contributed by the Model 218 The Lake Shore Temperature Measurement and Control Catalog has complete accuracy specs for calibrated sensors Calibrated sensors include measured test data printed and plotted coefficients of a Chebychev polynomial fitted to the data and two tables of data points used as interpolation tables optimized for accurate temperature conversion The smaller table called a breakpoint interpolation table fits into instruments like the Model 218 where it is called a temperature response curve Install a curve into a Model 218 through a CalCurve Paragraph 2 2 4 or manually through the instrument front panel Note instrument specifications before ordering calibrated sensors A calibrated sensor is required when a sensor does not follow a standard curve if the user wishes to display in temperature Otherwise the Model 218 operates in sensor units like ohms or volts The Model 218 may not work over the full temperature range of some sensors The Model 218 is limited to operation above 1 K or more even with sensors that can be calibrated to 50 mK SoftCal SoftCal is a good solution for applications that do not require the accuracy of a traditional calibration The SoftCal algorithm uses the predictability of sensors that follow a standard curve to improve individual sensor accuracy A few known temperature points are required to perform SoftCal Lake Shore sells SoftCal calibrated sensors that incl
60. am Public gSend As Boolean Global used for Send button state Private Sub cmdSend Click Routine to handle Send button press gSend True Set Flag to True End Sub Private Sub Form _Load Main code section Dim strReturn As String Used to return response Dim strHold As String Temporary character space Dim Term As String Terminators Dim ZeroCount As Integer Counter used for Timing out Dim strCommand As String Data string sent to instrument frmSerial Show Show main window Term Chr 13 amp Chr 10 Terminators are lt CR gt lt LF gt ZeroCount 0 Initialize counter strReturn Clear return string strHold Clear holding string If frmSerial MSComm1 PortOpen True Then Close serial port to change settings frmSerial MSComml PortOpen False End If frmSerial MSComm1 CommPort 1 Example of Comm 1 frmSerial MSComml Settings 9600 0 7 1 Example of 9600 Baud Parity Data Stop frmSerial MSComml Inputlen 1 Read one character at a time frmSerial MSComml PortOpen True Open port Do Do Wait loop DoEvents Give up processor to other events Loop Until gSend True Loop until Send button pressed gSend False Set Flag as false strCommand frmSerial txtCommand Text Get Command strReturn Clear response display strCommand UCase strCommand Set all characters to upper case If strCommand EXIT Then Get out on EXIT End End If frmSerial MSComm1 Output strCommand amp Term Send command to instrume
61. and results of the math function Input number and data source are always displayed for convenience Introduction Lake Shore Model 218 Temperature Monitor User s Manual 1 2 MODEL 218 SPECIFICATIONS Thermometry Number of Inputs Input Configuration Measurement Type Excitation Supported Sensors temp range Accuracy Resolution Maximum Update Rate Standard Curves User Curves SoftCal Math Filter Front Panel Display Number of input displays Display Units Display Update Rate Temperature Display Resolution Sensor Units Display Resolution Display Annunciators Keypad Front Panel Curve Entry Interface IEEE 488 2 Interface 218S Only Serial Interface Printer Capability Alarms Number Data Source Settings Actuators Relays 218S Only Number Contacts Contact Rating Operation Corrected Analog Output 218S Scale Range Resolution Accuracy Minimum Load Data Logging Readings Operation Data memory General Ambient Temperature Power Requirement Size Weight Approval Introduction 8 Two groups of four Each group must contain same input type Four lead differential Eight constant current sources Silicon Diode GaAlAs Diode RTDs 100 Q Platinum 1000 Q Platinum Germanium Carbon Glass Cernox ROX Thermox Refer to Table 1 2 16 readings per second total DT 470 DT 670 CTI C DT 500D PT 100 PT 1000 Room for eight one per inpu
62. appropriate for the accuracy requirement Sensor Package There are many types of sensor packages which generally determine sensor size thermal and electrical contact to the outside and sometimes limit temperature range Some sensors may be purchased as bare chips without a package When different packages are available for a sensor consider the sensor mounting surface and how to heat sink the leads CALIBRATED SENSORS It can be difficult to choose the right sensor calibrate it translate calibration data into a temperature response curve understandable to the Model 218 and load the curve into the instrument Lake Shore offers a variety of calibration and curve loading services to fit different accuracy requirements and budgets Traditional Calibration in Paragraph 2 2 1 SoftCal in Paragraph 2 2 2 Standard Curves in Paragraph 2 2 3 and the Lake Shore CalCurve Service in Paragraph 2 2 4 Traditional Calibration Calibration compares a sensor with an unknown temperature response to an accepted standard Lake Shore temperature standards are traceable to the U S National Institute of Standards and Testing NIST or the National Physical Laboratory in Great Britain These standards allow Lake Shore to calibrate sensors from 50 mK to above room temperature Calibrated sensors are more expensive than uncalibrated sensors Calibrated temperature sensors are the most accurate available from Lake Shore Errors from sensor calibration are almost
63. arge Never try to permanently bond materials with linear expansion coefficients that differ by more than three Use a flexible mounting scheme or the parts will break apart potentially damaging them The thermal expansion or contraction of rigid clamps or holders could crush fragile samples or sensors that do not have the same coefficient Sensor Location Positioning a sensor is less problematic if the entire load and sample holder are at the same temperature Unfortunately this not the case in many systems Temperature gradients differences in temperature exist because there is seldom perfect balance between the cooling source and heat sources Even in a well controlled system unwanted heat sources like thermal radiation and heat conduction through mounting structures can cause gradients For best accuracy position sensors near the sample so that little or no heat flows between the sample and sensor Thermal Conductivity Thermal conductivity is the ability of heat to flow through a material Copper and aluminum have good thermal conductivity while stainless steel does not Non metallic electrically insulating materials like alumina oxide and similar ceramics have good thermal conductivity while G 10 epoxy impregnated fiberglass does not Sensor packages cooling loads and sample holders should have good thermal conductivity to reduce temperature gradients Surprisingly connections between thermally conductive mounting surfaces often hav
64. arts or other supplies not furnished by Lake Shore d unauthorized modification or misuse e operation outside of the published specifications or f improper site preparation or maintenance 6 TO THE EXTENT ALLOWED BY APPLICABLE LAW THE ABOVE WARRANTIES ARE EXCLUSIVE AND NO OTHER WARRANTY OR CONDITION WHETHER WRITTEN OR ORAL IS EXPRESSED OR IMPLIED LAKE SHORE SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OR CONDITIONS OF MERCHANTABILITY SATISFACTORY QUALITY AND OR FITNESS FOR A PARTICULAR PURPOSE WITH RESPECT TO THE PRODUCT Some countries states or provinces do not allow limitations on an implied warranty so the above limitation or exclusion might not apply to you This warranty gives you specific legal rights and you might also have other rights that vary from country to country state to state or province to province 7 TO THE EXTENT ALLOWED BY APPLICABLE LAW THE REMEDIES IN THIS WARRANTY STATEMENT ARE YOUR SOLE AND EXCLUSIVE REMEDIES 8 EXCEPT TO THE EXTENT PROHIBITED BY APPLICABLE LAW IN NO EVENT WILL LAKE SHORE OR ANY OF ITS SUBSIDIARIES AFFILIATES OR SUPPLIERS BE LIABLE FOR DIRECT SPECIAL INCIDENTAL CONSEQUENTIAL OR OTHER DAMAGES INCLUDING LOST PROFIT LOST DATA OR DOWNTIME COSTS ARISING OUT OF THE USE INABILITY TO USE OR RESULT OF USE OF THE PRODUCT WHETHER BASED IN WARRANTY CONTRACT TORT OR OTHER LEGAL THEORY AND WHETHER OR NOT LAKE SHORE HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES Your use of th
65. asic Directory and QuickBasic must start with a link to it All instrument settings are assumed to be defaults Address 12 Terminators lt CR gt lt LF gt and EOI active To use type an instrument command or query at the prompt The computer transmits to the instrument and displays any response If no query is sent the instrument responds to the last query received Type EXIT to exit the program REM SINCLUDE c gpib pc qbasic qbdecl bas CLS PRINT IEEE 488 COMMUNICATION PROGRAM PRINT CALL IBFIND dev12 DEV123 TERMS CHR 13 CHR 10 INS SPACES 2000 LINE INPUT ENTER COMMAND or EXIT CMDS CMD UCASES CMDS IF CMDS EXIT THEN END CMD CMDS TERMS CALL IBWRT DEV12 CMDS CALL IBRD DEV12 INS ENDTEST INSTR INS CHRS 13 IF ENDTEST gt 0 THEN INS MIDS INS 1 ENDTEST 1 PRINT RESPONSE INS ELSE PRINT NO RESPONSE END IF GOTO LOOP2 Link to IEEE calls Clear screen Open communication at address 12 Terminators are lt CR gt lt LF gt Clear for return string Get command from keyboard Change input to upper case Get out on Exit Send command to instrument Get data back each time Test for returned string String is present if lt CR gt is seen Strip off terminators Print return string No string present if timeout Get next command Remote Operation Lake Shore Model 218 Temperature Monitor User s Manual National Instruments GPIBO
66. attaches to the positive terminal Connect the ground of the voltage reference to the negative input terminals of both inputs Short the positive current source terminal to the negative current source terminal on the 1 and ge inputs On the 3 and 4 inputs short all 4 terminals together Do not tie the 4 terminals to ground Input group configured for 2 5 V input all inputs of the group are enabled PROCESS Via the interface send the ADCAL command specifying the input group to be calibrated The CALSAVE command must then be issued to save the A D calibration in the E prom Finally the XRST command is issued to reload both A Ds with the calibration data stored in the E prom to both A Ds Service Lake Shore Model 218 Temperature Monitor User s Manual 7 13 5 Zero Calibration 7 13 6 7 13 7 7 13 8 Service PURPOSE CONFIG PROCESS To determine the zero offset of the input stage and provide an offset constant back to the Model 218 Same as Paragraph 7 13 4 above except that only the 3 input of the group is enabled All other inputs of the group are disabled Via the interface obtain the RAWAD reading of the 3 input To obtain the zero offset constant determine the inverse of the value read Write this number down The inverse of the value read is provided back to the Model 218 using the ZCAL command and should be sent as the ZCAL constant to all inputs of the group for the 2 5 V range The input group should then be
67. below When the desired mode appears press Enter Off Disables Log functions Log On Off will not initiate logging and current logging stops Selecting Off displays the Set Time screen next see below Log Continuous Logs data to internal memory at regular intervals Log Event Logs to internal memory only when an input configured for logging goes into or comes out of an alarm or error condition Print Continuous Sends data to printer using data log setup parameters Sends one record at a time with a minimum of 10 seconds between records Print Event Similar to Log Event The instrument sends data to the printer instead of logging it to internal memory The second display in the setting sequence appears Use the Data Selection keys to specify the Overwrite status listed below When the desired status appears press Enter Special Features 5 9 Lake Shore Model 218 Temperature Monitor User s Manual Log Setup Continued Yes Data logging continues beyond the maximum number of records specified and overwrites old records with new No Data logging stops at the maximum number of records specified The third display in the setting sequence appears Use the Data Selection keys to specify the Start Mode listed below When the desired mode appears press Enter Clear Log On command clears old records before new data is logged Continue Log On command continues data logging and adds new records to existing data The fourth display i
68. ccncnccncnnccnononononocononncncnoncnnoncnnnonnnonononononenonos 7 8 7 12 ERROME OAOE er a o ndo el eaten eee 7 8 7 13 CALIBRATON PROCEDURE ais cos copie arsine ceed aces mance academe iia 7 10 7 13 1 Required Equipment LIST o cates 7 10 7 13 2 Sensor Input Calibration Getup 7 10 7 13 3 Clear Calibration A ee ele eee 7 10 7 13 4 AD Linearity Calilorallon EE 7 10 7 13 5 Ee Balen EE 7 11 7 13 6 2 5 Volt Input Gain Calibration aici ees oie a ee ee A 7 11 7 13 7 ES VOM Input Gall Callao srt did 7 11 7 13 8 1 0 DA Current Source e lee Lee EE 7 11 7 13 9 290 0 Input Gait EH Me E te Moca dla 7 12 7 13 10 500 0 Input Gal CaliDRatOM seiko disnei da a 7 12 7 13 11 O KO INPutGaln Calla MON EE 7 12 7 13 12 5 KO Input Gain Calibration ia ee ee es 7 13 7 13 13 Calibrate Input Group Di EE 7 13 7 13 14 Analog Output Calibration and Test Model 218S Only oococcccocccncococcncconcononnancnnnnonoss 7 13 7 13 15 Calibration Specific Interface Commande cocccccoccnccoccnccocnnononnnoncnnnoncnnnnnnnononnnononenonanonos 7 14 6 ACCESSORIES d pd ole 8 1 8 0 GENERA Le ed ean aed cia 8 1 8 1 lei RE 8 1 8 2 OPTIONS rs tic 8 1 8 3 ee 8 1 APPENDIXA CURVE TABLES ai dl dra ae A 1 Table of Contents Lake Shore Model 218 Temperature Monitor User s Manual LIST OF ILLUSTRATIONS Figure No Title 1 1 Cryogenic Storage RE 2 1 Silicone Diode Sensor Calibrations and Cal une 2 2 Typical Sensor Installation in a Mechanical Hetgerator 3 1 Model 218 Rear
69. ce loss of use of the product or property damage caused by this product or its failure to work or any other incidental or consequential damages Use of our product implies that you understand the Lake Shore license agreement and statement of limited warranty FIRMWARE LICENSE AGREEMENT The firmware in this instrument is protected by United States copyright law and international treaty provisions To maintain the warranty the code contained in the firmware must not be modified Any changes made to the code is at the user s risk Lake Shore will assume no responsibility for damage or errors incurred as result of any changes made to the firmware Under the terms of this agreement you may only use the Model 218 firmware as physically installed in the instrument Archival copies are strictly forbidden You may not decompile disassemble or reverse engineer the firmware If you suspect there are problems with the firmware return the instrument to Lake Shore for repair under the terms of the Limited Warranty specified above Any unauthorized duplication or use of the Model 218 firmware in whole or in part in print or in any other storage and retrieval system is forbidden TRADEMARK ACKNOWLEDGMENT Many manufacturers claim designations used to distinguish their products as trademarks Where those designations appear in this manual and Lake Shore was aware of a trademark claim they appear with initial capital letters and the TM or symbol
70. ces 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 4 000 volts cannot be seen felt or heard Identification of Electrostatic Discharge Sensitive Components Below are various industry symbols used to label components as ESDS ar y CAUTION d O ge Bi Service 7 1 Lake Shore Model 218 Temperature Monitor User s Manual 7 2 2 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 other device using 1
71. cted input reading Used for ZCAL and GCAL functions lt input gt Specifies which input to query Valid entries are 1 8 Returns All Calibration Constants to Their Default Value CALCLEAR Nothing Returns all A D Linearity ZCAL and GCAL calibration constants to their default value Saves all Calibration Constants CALSAVE Nothing Saves all A D Linearity ZCAL and GCAL calibration constants 7 15 Lake Shore Model 218 Temperature Monitor User s Manual This Page Intentionally Left Blank Service Lake Shore Model 218 Temperature Monitor User s Manual CHAPTER 8 ACCESSORIES 8 0 GENERAL This chapter provides information on the model numbers options and accessories available for the Model 218 Temperature Monitor Model numbers are detailed in Paragraph 5 1 options in Paragraph 8 2 and accessories in Paragraph 5 3 8 1 MODELS The list of Model 218 Model numbers is provided as follows Model Description of Model Numbers Standard Model 218 Temperature Monitor Includes 8 inputs IEEE 488 and serial interface alarms relays analog output data logging and printer support Economy Model 218 Temperature Monitor Includes 8 inputs serial interface alarms data logging and printer support 8 2 OPTIONS A list of Model 218 options is provided as follows Model Description of Options Precision Option Floppy Disk The Model 8000 Precision Option consists of breakpoint pairs 8000 from a Se
72. d 6 1 2 2 6 1 2 3 6 1 3 1 Finally Addressed Bus Control Commands are Multiline commands that must include the Model 218 listen address before the instrument responds Only the addressed device responds to these commands The Model 218 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 Status Byte Register This status register contains important operational information from the unit requesting service The SPD command ends the polling sequence 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 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 Model 218 common commands are detailed in Paragraph 6 3 and summarized in Table 6 5 Interface and Device Specific Commands Device specific command
73. d discussion Data Log Done Bit 7 This bit is set when data log is completed Remote Operation 6 3 Lake Shore Model 218 Temperature Monitor User s Manual Status Byte Register and Service Request Enable Register Continued 6 1 3 2 6 4 Service Request SRQ Bit 6 Determines whether the Model 218 is to report via the SRQ line and six bits determine which status reports to make If bits 0 2 3 4 5 or 7 are set then the corresponding bit in the Status Byte Register is set The Model 218 produces a service request only if bit 6 of the Service Request Enable Register is set If disabled the Status Byte Register can still be read by the BUS CONTROLLER by means of a serial poll SPE to examine the status reports but the BUS CONTROLLER will not be interrupted by the Service Request The STB common command reads the Status Byte Register but will not clear the bits It must be understood that certain bits in the Status Byte Register continually change Bits 0 5 and 7 remain latched until the Status Byte Register is read The bit assignments are discussed below as they pertain to the Status Byte Register These reports can only be made if they have been enabled in the Service Request Enable Register Standard Event Status ESB Bit 5 When bit 5 is set it indicates if one the bits from the Standard Event Status Register has been set Refer to Paragraph 6 1 3 2 Error Bit 4 This bit is set when there is an instr
74. d input appears press Enter The final display in the sequence appears Press Enter to delete the specified curve and return to the normal display Press Escape to cancel the deletion and return to the normal display Viewing Standard Curves View standard curves using the curve entry procedure Standard curves are read only uneditable Copying Curves Temperature curves can be copied from one location inside the Model 218 to another This is a good way to make small changes to an existing curve Curve copy may also be necessary if the user needs the same curve with two different temperature limits or needs to extend the range of a standard curve The curve that is copied from is always preserved NOTE The copy routine allows you to overwrite an existing user curve Please ensure the curve number you are writing to is correct before proceeding with curve copy To copy a curve press the Curve Entry key Press the A or Y key until you see the following display Press the Enter key You can press the Escape key anytime during this routine to return to the normal display Special Features Lake Shore Model 218 Temperature Monitor User s Manual Copying Curves Continued 9 2 Use the A or Y key to select the curve number to copy from Once the curve number is selected press the Enter key You will see the following message Use the A or Y key to select the input number 1 thru 8 of the curve to copy to Press the Ent
75. d Name Vice President of Engineering Position Lake Shore Model 218 Temperature Monitor User s Manual Electromagnetic Compatibility EMC for the Model 218 Temperature Monitor Electromagnetic Compatibility EMC of electronic equipment is a growing concern worldwide Emissions of and immunity to electromagnetic interference is now part of the design and manufacture of most electronics To qualify for the CE Mark the Model 218 meets or exceeds the generic requirements of the European EMC Directive 89 336 EEC as a CLASS A product A Class A product is allowed to radiate more RF than a Class B product and must include the following warning WARNING This is a Class A product In a domestic environment this product may cause radio interference in which case the user may be required to take adequate measures The instrument was tested under normal operating conditions with sensor and interface cables attached If the installation and operating instructions in the User s Manual are followed there should be no degradation in EMC performance Pay special attention to instrument cabling Improperly installed cabling may defeat even the best EMC protection For the best performance from any precision instrument follow the grounding and shielding instructions in the User s Manual In addition the installer of the Model 218 should consider the following e Leave no unused or unterminated cables attached to the instrument e Make cable runs as
76. d entries 0 2 5V Diode 2 250Q Platinum 1 7 5V Diode 3 500Q Platinum INTYPE A O term Sets Inputs 1 4 sensor type to silicon diode 4 5kQ Platinum 5 Cernox Query Input Type Parameters INTYPE lt input group gt lt sensor type gt Format n term Returns input type parameters lt input group gt Specifies input group to query A inputs 1 4 B inputs 5 8 lt sensor type gt Specifies input sensor type Valid entries 0 2 5V Diode 2 250Q Platinum 1 7 5V Diode 3 500Q Platinum 4 5kQ Platinum 5 Cernox Query Keypad Status KEYST lt keypad status gt Format n term Returns keypad status since the last KEYST 1 key pressed 0 no key pressed KEYST returns 1 after initial power up Query Kelvin Reading for a Single Input or All Inputs KRDG lt input gt lt Kelvin value gt Format nn nnn term Or if all inputs are queried lt input 1 Kelvin Value gt lt Input 2 Kelvin Value gt lt Input 3 Kelvin Value gt lt Input 4 Kelvin Value gt lt Input 5 Kelvin Value gt lt Input 6 Kelvin Value gt lt Input 7 Kelvin Value gt lt Input 8 Kelvin Value gt Format nn nnn t nn nnn tnn nnn nn nnn nn nnn t nn nnn tnn nnn tnn nnn Returns the Kelvin reading for a single input or all inputs lt input gt specifies which input s to query 0 all inputs 1 8 individual input NOTE Use 0 all inputs when reading two or more inputs at the maximum update rate of 16 redgs sec 6 25 LINEAR I
77. e RELAY 1 RELAY 2 RELAY4 1 A alolalolalolalolal lal lale AAA alal l l l l l l l l l E S RELAY5 RELAY 6 RELAY8 2 E F 218 3 4 eps PIN DESCRIPTION DESCRIPTION Relay 1 NC Relay 5 NC Relay 1 COM Relay 5 COM Relay 1 NO Relay 5 NO Relay 2 NC Relay 6 NC Relay 2 COM Relay 6 COM 6 Relay2NO Relay 6 NO Relay 3 NC Relay 7 NC 8 Relay 3 COM Relay 7 COM 9 Relay3NO Relay 7 NO Relay 4 NC Relay 8 NC Relay 4 COM Relay 8 COM Relay 4 NO Relay 8 NO Analog 1 Signal Analog 2 Signal Analog 1 Gnd Analog 2 Gnd Figure 3 4 Terminal Block Connectors Installation 3 3 3 3 1 3 3 3 2 Lake Shore Model 218 Temperature Monitor User s Manual RELAYS MODEL 2188 only The Model 218 has eight relays most commonly associated with the alarm feature If a relay is inactive Off it is in its normal state of open or closed When the relay is active On it is in the opposite state The relay contacts are isolated from the instrument ground Connect to the relay contacts through the terminal block refer to Paragraph 3 3 3 Analog Outputs MODEL 218S only Analog Output 1 and 2 on the Model 218S rear panel are voltage outputs that can be used for monitor applications Figure 3 4 Their most basic function is a temperature monitor where they put out a voltage proportional to temperature Both analog outputs are variable DC voltage sources that can vary from 10 V to 10 V The resolution of the analog output is 1 25 mV or 0 0125 of ful
78. e 2 6 2 3 10 Thermal EMF Compensation with Voltage Excitation ccccoonccccococcnncooconconanononnnnons 2 6 3 MINS PRED TIN ere 3 1 3 0 GENERAL e e dl 3 1 3 1 INSPECTION AND UNPACKING eebe ege gegierft ege getest eg an eege aia 3 1 3 2 REPACKAGING ee e VE 3 1 3 3 REAR PANEL DEFINITION o eto 3 2 3 3 1 Line IMPUCASSEMDI Y etica sillin a dd 3 2 3 9 2 SR El gleef 3 4 3 3 3 Terminal Block Model 218S ON 3 7 3 3 4 BE elauter 3 8 A OPERATION o o eco eco Lord 4 1 4 0 A E Cee Oe eee ee ee ee a 4 1 4 1 DISPLAY SCREEN DESCRIPTION suscit ati 4 1 4 2 Ee Ee 4 3 4 2 1 General Keypad Operation 4 4 4 3 TURNING POWER ON arc Shee osha oe caer a a E 4 4 4 4 DISPLAY SETUR EE 4 4 Table of Contents Lake Shore Model 218 Temperature Monitor User s Manual TABLE OF CONTENTS Continued Chapter Paragraph Title Page 4 5 IR Ee d tete edu 4 5 4 5 1 Optimizing the Update EE 4 7 4 6 CURVE SELLO oe caes atte aid 4 7 4 7 MATE E OO oO AQ O 4 8 4 7 1 KEN O E 4 8 4 7 2 Eelere 4 9 4 7 3 POY ee EE 4 10 4 8 ANALOG OUTPUTS MODEL 218S ONLY 4 11 4 8 1 Example of Low and High Analog Parameter Gettnmg 4 13 4 9 ALARMS SETUP AND OPERA TION srta id verte 4 13 4 10 ALARM RESET tt ci 4 15 4 11 RELAY SETUP MODEL 2163 ONLY WEE 4 15 4 12 LOCKING THE KE VRAD EE 4 16 4 13 RESETTING MODEL 218 TO DEFAULTS urnida aaia 4 16 9 SFECGIAL FEATURES unida nta arena ccoo oct 5 1 5 0 GENERA Lt de aa ed an EOS 5 1 5 1 FRONT PANELCURVE ENTR rasca adan 5 1 dal Cu
79. e 6 3 works with Visual Basic 6 0 VB6 on an IBM PC or compatible with a Pentium class processor A Pentium 90 or higher is recommended running Windows 95 or better with a serial interface It uses the COM1 communications port at 9600 Baud Use the following procedure to develop the Serial Interface Program in Visual Basic 1 Start VB6 2 Choose Standard EXE and select Open 3 Resize form window to desired size 4 On the Project Menu click Components to bring up a list of additional controls available in VB6 5 Scroll through the controls and select Microsoft Comm Control 6 0 Select OK In the toolbar at the left of the screen the Comm Control will have appeared as a telephone icon 6 Select the Comm control and add it to the form 7 Add controls to form a Add three Label controls to the form b Add two TextBox controls to the form c Add one CommandButton control to the form d Add one Timer control to the form 8 On the View Menu select Properties Window 9 Inthe Properties window use the dropdown list to select between the different controls of the current project Label Command w Serial Interface Program CC A Rp a A Ep a A AA RR RR Label3 Label2 10 Set the properties of the controls as defined in Table 6 3 11 Save the program Remote Operation 6 11 Lake Shore Model 218 Temperature Monitor User s Manual Table 6 3 Serial Interface Program Control Properties Caption Type exit
80. e Max Min feature simply captures and stores the highest Max and lowest Min reading taken since the last reset The feature will only capture from one reading source so it is important to select a source Max and min can be manually reset as described below They are also reset when the instrument is turned off or parameters related to the input are changed To select a source for Max Min press Math The display below appears Press Enter to select an input for Max Min The second display in the Math setting sequence appears Operation Lake Shore Model 218 Temperature Monitor User s Manual Max Min Continued Use the Data Selection keys to select the sensor input 1 8 from which to capture and store the highest Max and lowest Min reading Press Enter when the desired input appears The third display in the Math setting sequence appears Use the Data Selection keys to select the appropriate source for the selected sensor input K Kelvin temperature reading from input C Celsius temperature reading from input Sensor Sensor units reading from input Linear Linear equation data from input Press Enter when the desired source appears Press Escape at any time to return to the normal display The instrument retains values changed prior to pressing Escape 4 7 1 1 Resetting Max Min To manually reset Max Min press Math The display to the right appears Press Math again to reset Max Min Max Min automatically resets
81. e Product is entirely at your own risk Some countries states and provinces do not allow the exclusion of liability for incidental or consequential damages so the above limitation may not apply to you LIMITED WARRANTY STATEMENT Continued 9 EXCEPT TO THE EXTENT ALLOWED BY APPLICABLE LAW THE TERMS OF THIS LIMITED WARRANTY STATEMENT DO NOT EXCLUDE RESTRICT OR MODIFY AND ARE IN ADDITION TO THE MANDATORY STATUTORY RIGHTS APPLICABLE TO THE SALE OF THE PRODUCT TO YOU CERTIFICATION Lake Shore certifies that this product has been inspected and tested in accordance with its published specifications and that this product met its published specifications at the time of shipment The accuracy and calibration of this product at the time of shipment are traceable to the United States National Institute of Standards and Technology NIST formerly known as the National Bureau of Standards NBS FIRMWARE LIMITATIONS Lake Shore has worked to ensure that the Model 218 firmware is as free of errors as possible and that the results you obtain from the instrument are accurate and reliable However as with any computer based software the possibility of errors exists In any important research as when using any laboratory equipment results should be carefully examined and rechecked before final conclusions are drawn Neither Lake Shore nor anyone else involved in the creation or production of this firmware can pay for loss of time inconvenien
82. e line power switch OFF 0 Remove the instrument power cord With a small screwdriver release the drawer holding the line voltage selector Line Cord Power Switch Screwdriver Fuse and fuse Input Oz Off On Slot Drawer 5 Slide out the removable plastic fuse holder from the drawer 6 Rotate the fuse holder until the proper voltage indicator shows through the window 7 Verify the proper fuse value 8 Re assemble the line input assembly in the reverse order er ee e e 9 Verify the voltage indicator in the window Ee Y 100 120V 0 25 AT250V_ 5x20mm e 10 6 Voltage of the line input assembly 50 60 Hz 18 VA MAX 220 240V 0 20A T 250V 5x20mm 10 Connect the instrument power cord F 218 7 2 eps 11 Turn the line power switch On I Figure 7 2 Power Fuse Access 7 2 Service Lake Shore Model 218 Temperature Monitor User s Manual 7 5 FUSE REPLACEMENT Use the following procedure to remove and replace a line fuse WARNING To avoid potentially lethal shocks turn off controller and disconnect it from AC power before performing these procedures CAUTION For continued protection against fire hazard replace only with the same fuse type and rating specified for the line for the line voltage selected NOTE Test fuse with an onmmeter Do not rely on visual inspection of fuse oS INES IN SN Locate line input assembly on the instrument rear panel See Figure 7 2 Turn power switch Off O Remove i
83. e shared between multiple inputs Collect and format all necessary information on paper before beginning the entry process Curve header information cannot be overlooked it is as important to proper operation as the data breakpoints Enter curve data breakpoints in increasing sensor units order Other instruments use this curve data format and curve breakpoints may be entered that are beyond the Model 218 reading capability Curve Header Parameters Curve Number User curves accessed from the front panel are numbered by sensor input 1 8 When accessed over the computer interface they are numbered from 21 to 28 Name Defaults to the name User Curve for front panel entry When entering a user curve over the computer interface a curve name of up to 15 characters can be entered Serial Number Up to a 10 character sensor serial number Both numbers and letters can be entered over computer interface only numbers can be entered from the front panel Format The format parameter tells the instrument what breakpoint data format to expect Different sensor types require different formats Formats for Lake Shore sensors are V K Volts vs Kelvin for Diode sensors Q K Resistance vs Kelvin for platinum RTD sensors Log Q K Log Resistance vs Kelvin for NTC resistive sensors Limit Enter a temperature limit in Kelvin for the curve Default is 375 K Enter a setting of 9999 9 K if no limit is needed This parameter is not used by the Model 218
84. e the ANALOG command for parameter descriptions Query Analog Output Data AOUT lt output gt lt analog output gt Format nn nnn term Returns the percentage of output lt output gt specifies analog output to query Configure Serial Interface Baud Rate BAUD lt bps gt Nothing Configures to serial interface baud rate lt bps gt specifies bits per second bps rate 0 300 1 1200 2 9600 Query Serial Interface Baud Rate BAUD lt bps gt Format n term Returns serial interface baud rate See BAUD command for parameter descriptions 6 21 CRDG Input Returned Remarks CRVDEL Input Returned Remarks Example CRVHDR Input Returned Remarks Example CRVHDR Input Returned Remarks CRVPT Input Returned Remarks Example 6 22 Lake Shore Model 218 Temperature Monitor User s Manual Query Celsius Reading for a single Input or All Inputs CRDG lt input gt lt Celsius value gt Format nn nnn term Or if all inputs are queried lt Input 1 Celsius Value gt lt Input 2 Celsius Value gt lt Input 3 Celsius Value gt lt Input 4 Celsius Value gt lt Input 5 Celsius Value gt lt Input 6 Celsius Value gt lt Input 7 Celsius Value gt lt Input 8 Celsius Value gt Format nn nnn nn nnn nn nnn nn nnn nn nnn nn nnn nn nnn nn nnn Returns the Celsius reading for a single input or all inputs lt input gt specifies which inpu
85. e very poor thermal conductivity Thermal conductivity can change with temperature Do not assume a heat sink grease that works well at room temperature and above will do the same job at low temperatures Sensor Considerations Lake Shore Model 218 Temperature Monitor User s Manual 2 3 4 Contact Area Thermal contact area greatly affect thermal conductivity because a larger area has more opportunity to transfer heat Even when the size of a sensor package is fixed thermal contact area can be improved with the use of a gasket material A soft gasket material forms into the rough surface being mated to increase the area of the two surfaces that is in contact Good gasket materials are soft thin and have good thermal conductivity themselves They must also withstand the environmental extremes Indium foil and cryogenic grease are examples 2 3 5 Contact Pressure When sensors are permanently mounted the solder or epoxy used to hold the sensor acts as both gasket and adhesive Permanent mounting is not a good solution for everyone because it limits flexibility and can potentially damage sensors Much care should be taken not to over heat or mechanically stress sensor packages Less permanent mountings require some pressure to hold the sensor to its mounting surface Pressure will greatly improve the action of gasket material to increase thermal conductivity and reduce thermal gradients A spring clamp is recommended so that different rates of therma
86. echnical Commission IEC safety standards Ventilation The instrument has ventilation holes in its top and bottom covers Do not block these holes when the intrument is turned on Do Not Operate In An Explosive Atmosphere Do not operate the instrument in the presence of flammable gases or fumes Operation of any electrical instrument in such an environment constitutes a definite safety hazard Keep Away From Live Circuits Operating personnel must not remove instrument covers Refer component replacement and internal adjustments to qualified maintenance personnel Do not replace components with power cable connected 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 representative for service and repair to ensure that safety features are maintained Cleaning Do not submerge instrument Clean only with a damp cloth and mild detergent Exterior only Safety Symbols Direct current power line Equipment protected throughout by Ol double insulation or reinforced insulation equivalent to Class II of Alternating or direct current power line IEC 536 see Annex H Three phase alternating current power line Caution High voltages danger of electric shock Background color Earth ground terminal Yellow Sy
87. ed Remarks RELAYST Input Returned Remarks Remote Operation Lake Shore Model 218 Temperature Monitor User s Manual Query Input Status RDGST lt input gt lt reading bit weighting gt Format nnn term The integer returned represents the sum of the bit weighting of the input status flag bits lt input gt specifies which input to query Bit Bit Weighting Status Indicator Bit Bit Weighting Status Indicator 4 16 temp under range 6 64 units under range 5 32 temp over range 7 128 units over range Configure Relay Control Parameters RELAY lt relay number gt lt mode gt lt input alarm gt lt alarm type gt Nothing Configures relay control lt relay number gt Specifies which relay to configure 1 8 lt mode gt Specifies relay mode 0 Off 1 On 2 Alarms lt input alarm gt Specifies which input alarm activates the relay when the relay is in alarm mode 1 8 Specifies the input alarm type that activates the relay when the relay is in alarm mode 0 Low alarm 1 High Alarm 2 Both Alarms RELAY 3 2 3 O term Relay 3 activates when Input 3 low alarm activates lt alarm type gt Query Relay Control Parameters RELAY lt relay number gt lt mode gt lt input gt lt alarm type gt Returns relay control parameters See the RELAY command for returned parameter descriptions lt relay number gt specifies which relay to query Query Relay Status RELAYST lt relay status bit w
88. eighting gt Format nnn term The integer returned represents the sum of the bit weighting of the relay status Bit Bit Weighting Active Relay 0 1 Relay 1 1 2 Relay 2 2 4 Relay 3 3 8 Relay 4 4 16 Relay 5 5 32 Relay 6 6 64 Relay 7 T 128 Relay 8 6 29 SCAL Input Returned Remarks Example SRDG 6 30 Input Returned Remarks Lake Shore Model 218 Temperature Monitor User s Manual Generate SoftCal Curve SCAL lt std gt lt dest gt lt SN gt lt T1 value gt lt U1 value gt lt T2 value gt lt U2 value gt lt T3 value gt lt U3 value gt Nothing lt std gt Specifies the standard curve to generate a SoftCal from 1 6 7 lt dest gt Specifies the user curve to store the SoftCal curve 21 28 lt SN gt Specifies the curve serial number Limited to 10 characters lt T1 value gt Specifies first temperature point lt U1 value gt Specifies first sensor units point lt T2 value gt Specifies second temperature point lt U2 value gt Specifies second sensor units point lt T3 value gt Specifies third temperature point lt U3 value gt Specifies third sensor units point SCAL 1 21 SC12345 4 2 1 6260 77 32 1 0205 300 0 0 5189 term Generates a 3 point SoftCal curve from DT 470 and saves it in user curve 21 with serial number SC12345 Query Sensor Units Reading for a Single Input or all Inputs SRDG lt input gt lt sensor units value gt Format nn nnn ter
89. ence providing 2 5 0 00001 V and 2 5 0 00001 V Four 200 KQ resistor calibrated to 2 0 Q Four 250 Q resistors calibrated to 0 001 Q Four 5 kQ resistors calibrated to 0 025 Q Eight 100 KQ resistor calibrated to 0 5 Q Oe A E SENSOR INPUT CALIBRATION SETUP Allow the Model 218 to warm up for at least one hour with 100 kQ resistors attached to all eight input Configure both input groups to the 2 5 V Diode range Connect the Model 218 to the PC via the serial port Verify operational serial communication by sending the IDN command and receiving the proper response from the Model 218 During the calibration process leave four 100 kQ resistors attached to the input group not currently being calibrated Calibrate input group A first then repeat the process for input group B Clear Calibration Send the CALCLEAR command to return all calibration constants to their default value Once cleared send the CALSAVE command to save the constants in the E Prom CAUTION Once this step is complete the Model 218 sensor inputs must be completely calibrated for proper operation A D Linearity Calibration PURPOSE To provide ground positive and negative full scale voltages to the input of the A D to allow it to self calibrate linearity CONFIG Attach the precision 2 5 V to the 1 inputs voltage terminals the positive side attaches to the positive terminal Attach the precision 2 5 V to the St inputs voltage terminals the negative side
90. ent file proper claims promptly with the carrier and insurance company and notify Lake Shore Notify Lake Shore immediately of any missing parts Lake Shore cannot be responsible for any missing parts unless notified within 60 days of shipment Refer to the standard Lake Shore Warranty on the A Page behind the title page REPACKAGING FOR SHIPMENT To return the Model 218 sensor or accessories for repair or replacement obtain a Return Goods Authorization RGA number from Technical Service in the United States or from the authorized sales service representative from which the product was purchased Instruments may not be accepted without a RGA number When returning an instrument for service Lake Shore must have the following information before attempting any repair Instrument model and serial number User name company address and phone number Malfunction symptoms Description of system 5 Returned Goods Authorization RGA number E Wrap instrument in a protective bag and use original spacers to protect controls Repack the system in the LSCI shipping carton if available and seal it with strong paper or nylon tape Affix shipping labels and FRAGILE warnings Write the RGA number on the outside of the shipping container or on the packing slip Installation 3 1 Lake Shore Model 218 Temperature Monitor User s Manual 3 3 REAR PANEL DEFINITION CAUTION Verify that the AC Line Voltage shown in the window on the fuse holder
91. er key to copy the curve You now return to the normal display SOFTCAL The Model 218 performs inexpensive sensor calibrations with two algorithms called SoftCal These algorithms work with DT 400 Series Silicon Diode sensors and Platinum Sensors They create a new temperature response curve from the standard curve and known data points entered by the user The new curve loads into one of the eight user curve locations These paragraphs describe the data points needed from the user and the expected accuracy of the resulting curves Both DT 400 and Platinum SoftCal algorithms use an existing standard curve in the Model 218 The new curve will be named SCAL DT or SCAL PT When calibration is complete the user must select the new curve for the input the Model 218 does not automatically choose the newly generated curve for any input Each algorithm operates with one two or three calibration points The range of improved accuracy increases with more points The calibration points are normally measured at easily reached temperatures like the boiling point of cryogens There are two ways to get SoftCal calibration data points The user records the response of an unknown sensor at well controlled temperatures or the user buys a Lake Shore SoftCal calibrated sensor There are advantages to both methods e User When the user can provide stable calibration temperatures with the sensor installed SoftCal calibration eliminates errors in the sen
92. er value after setting sequence Also used to lock the keypad Enter numeric data during a setting sequence 4 3 4 2 1 4 3 4 4 4 4 Lake Shore Model 218 Temperature Monitor User s Manual General Keypad Operation There are three basic keypad operations Direct Operation Setting Selection and Data Entry Direct Operation is where the key function occurs as soon as the key is pressed Log On Off Local and Alarm Reset operate directly when the key is pressed Setting Selection allows the user to select from a list of values During a selection sequence the Data Selection keys are used to select a parameter value After a selection is made the Enter key is pressed to make the change and advance to the next setting Escape is pressed to return to the Normal display The instrument retains values changed prior to pressing Escape Some selections are made immediately after pressing a function key like Interface Most are part of a string of settings that often begins by entering an input number Data Entry expects the user to enter number data using the data entry keys Data entry keys include the numbers 0 9 and decimal point Alarm setpoints are an example of parameters that require data entry During a data entry sequence use the data entry keys to enter the number value press the Enter key to accept the new data and advance to the next setting Press Escape once to clear the entry twice to return to the Normal display The ins
93. ero Power On PON Bit 7 Set to indicate an instrument off on transition Command Error CME Bit 5 If bit 5 is set a command error has been detected since the last reading This means that the instrument could not interpret the command due to a syntax error an unrecognized header unrecognized terminators or an unsupported command Execution Error EXE Bit 4 If bit 4 the EXE bit is set an execution error has been detected This occurs when the instrument is instructed to do something not within its capabilities Device Dependent Error DDE Bit 3 A device dependent error has been detected if the DDE bit is set The actual device dependent error can be found by executing the various device dependent queries Remote Operation Lake Shore Model 218 Temperature Monitor User s Manual Standard Event Status Register and Standard Event Status Enable Register Continued Query Error QYE Bit 2 The QYE bit indicates a query error It occurs rarely and involves loss of data because the output queue is full Operation Complete OPC Bit 0 This bit is generated in response to the OPC common command It indicates when the Model 218 has completed all selected pending operations 6 1 4 Example IEEE Setup and Program Below is an example of how to setup and run a simple program using the built in Model 218 IEEE 488 Interface While it does not reflect every hardware software configuration found in the field
94. fore issuing command the input group must be configured as follows A precision 2 5 V attached to input 1 a precision 2 5 V attached to input 2 and a precision ground at input 3 lt input group gt Specifies which group of inputs to calibrate Valid entries are A inputs 1 4 and B inputs 5 8 Provides the Zero Calibration Constant for each Input ZCAL lt input gt lt type gt lt value gt Nothing Provides the zero calibration constant for the selected input The calibration constant is calculated using the raw A D data lt input gt Specifies which input to provide zero calibration constant for Valid entries are 1 8 lt type gt Specifies the input groups sensor type Valid entries are O Silicon Diode 1 GaAlAs Diode 2 Platinum 100 250 Q lt value gt Zero Calibration Constant 3 Platinum 100 500 Q 4 Platinum 1000 5 NTC Resistor Returns Value of Zero Calibration Constant for the Selected Input ZCAL lt input gt lt value gt Returns value of zero calibration constant for the selected input and input configuration lt input gt Specifies which input to query zero calibration constant for Valid entries are 1 8 lt type gt Specifies the input groups sensor type Valid entries are O Silicon Diode 1 GaAlAs Diode 2 Platinum 100 250 Q 3 Platinum 100 500 Q 4 Platinum 1000 5 NTC Resistor Provides the Gain Calibration Constant for each Input GCAL lt input gt lt type gt
95. g Sensor Leads in Paragraph 3 3 2 3 Sensor Polarity in Paragraph 3 3 2 4 Four Lead Sensor Measurement in Paragraph 3 3 2 5 Two Lead Sensor Measurement in Paragraph 3 3 2 6 and Lowering Measurement Noise in Paragraph 3 3 2 7 Sensor Input Connector and Pinout This paragraph details how to connect sensors to the Model 218 inputs The sensor inputs operate with most resistive and diode sensors Refer to Paragraph 4 5 to configure inputs for a sensor type with software Disable unused sensor inputs with the Input Type key Paragraph 4 5 It is possible for an overload condition on one sensor to affect the reading on another in the same connector Wire redundant sensors in separate connectors for best reliability Split fewer than eight sensors evenly between connectors for best reading efficiency F218 3 3 eps PIN DESC PIN DESC PIN DESC PIN DESC e t no 2f s u s s ul s es a pao s oe ra fave a paa Js 6l refs fal s s s als of m paja fe pm fal ref m a a lisa foe Figure 3 3 Model 218 Input Connector Pinouts S Shield NC No Connect Installation 3 3 2 2 3 3 2 3 3 3 2 4 3 3 2 5 Installation Lake Shore Model 218 Temperature Monitor User s Manual Sensor Lead Cable The sensor lead cable used outside the cooling system can be much different form what is used inside Between the instrument and vacuum shroud heat leak is not a problem but error and noise pick up need to be
96. g the response or for 50 ms after it completes e Not initiate communication more than 20 times per second Failure to follow these simple rules will result in inability to establish communication with the instrument or intermittent failures in communication 6 2 6 Changing Baud Rate To use the Serial Interface you must first set the Baud rate Press Interface key to display the following screen Press the A or Y keys to cycle through the choices of 300 1200 or 9600 Baud Press Enter to accept the new number 6 10 Remote Operation Lake Shore Model 218 Temperature Monitor User s Manual 6 2 7 Serial Interface Basic Programs Two BASIC programs are included to illustrate the serial communication functions of the instrument The first program was written in Visual Basic Refer to Paragraph 6 2 7 1 for instructions on how to setup the program The Visual Basic code is provided in Table 6 4 The second program was written in Quick Basic Refer to Paragraph 6 2 7 2 for instructions on how to setup the program The Quick Basic code is provided in Table 6 5 Finally a description of operation common to both programs is provided in Paragraph 6 2 7 3 While the hardware and software required to produce and implement these programs not included with the instrument the concepts illustrated apply to almost any application where these tools are available 6 2 7 1 Visual Basic Serial Interface Program Setup The serial interface program Tabl
97. g zeros and zeros following a decimal point are not needed in a command string but they will be sent in response to a query A leading is not required but a leading is required Remote Operation 6 15 Lake Shore Model 218 Temperature Monitor User s Manual 6 2 8 Trouble Shooting New Installation 1 Check instrument baud rate 2 Make sure transmit TD signal line from the instrument is routed to receive RD on the computer and vice versa Use a null modem adapter if not 3 Always send terminators 4 Send entire message string at one time including terminators Many terminal emulation programs do not 5 Send only one simple command at a time until communication is established 6 Be sure to spell commands correctly and use proper syntax Old Installation No Longer Working 1 Power instrument off then on again to see if it is a soft failure 2 Power computer off then on again to see if communication port is locked up 3 Verify that baud rate has not been changed on the instrument during a memory reset 4 Check all cable connections Intermittent Lockups 1 Check cable connections and length 2 Increase delay between all commands to 100 ms to make sure instrument is not being over loaded 6 3 IEEE 488 SERIAL INTERFACE COMMANDS Parameter conventions in the command list are lt enable gt lt status gt lt value gt lt bit weighting gt lt input gt lt offlon gt lt output gt
98. ge the update rate on an input Filtered readings are available as often as non filtered readings The number of filter points determines how much smoothing is done One filter point corresponds to one new reading on that input A larger number of points does more smoothing but also slows the instruments response to real changes in temperature If the measured temperature changes quickly the reading will settle at the new value in about 6 times the number of filter points The filter window is a limit for restarting the filter If a single reading is different from the filter value by more than the limit the instrument will assume the change was intentional and restart the filter Filter window is set in percent of full scale range To set up the filter press Math select an input then press Enter until the seventh display of the Math setting Sequence appears Use the Data Selection keys to turn the filter On or Off On Filters all reading values for the specified input Off No filtering for the specified input Operation Lake Shore Model 218 Temperature Monitor User s Manual Filter Continued 4 8 Press Enter to continue The eighth display of the Math setting sequence appears Use the Data Selection keys to select the number of filter points from 2 to 64 Press Enter The ninth display of the Math setting sequence appears Use the Data Selection keys to select the filter window from 1 to 10 then press Enter to retu
99. gram 6 1 5 Notes On Using the IEEE Interface Remote Operation To chain commands or queries together insert a semi colon between them Multiple queries cannot be chained The Model 218 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 The term free field indicates that the decimal point is a floating entity and 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 Model 218 6 5 6 6 Lake Shore Model 218 Temperature Monitor User s Manual Table 6 1 Sample BASIC IEEE 488 Interface Program IEEEEXAM BAS EXAMPLE PROGRAM FOR IEEE 488 INTERFACE This program works with QuickBasic 4 0 4 5 on an IBM PC or compatible The example requires a 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 QuickB
100. he back bezel by sliding it straight back away from the unit Slide the top panel back and remove it from the unit INSTALLATION ot S a I A Service Slide the top panel forward in the track provided on each side of the unit Carefully replace the back bezel by sliding it straight into the unit Use 5 64 hex key to install four screws attaching top panel to unit Use 5 64 hex key to tighten four screws attaching bottom panel to unit If required reattach 19 inch rack mounting brackets Connect power cord to rear of unit and set power switch to on I 1 1 7 11 7 12 7 8 Lake Shore Model 218 Temperature Monitor User s Manual EPROM AND NOVRAM REPLACEMENT The operating software for the Model 218 is contained on one Erasable Programmable Read Only Memory EPROM Integrated Circuit IC The reference designator for the EPROM is U17 See Figure 7 7 The EPROM has a sticker on top labeled with M218 HEX and the date The reference designator for the Non Volatile Random Access Memory NOVRAM IC is U24 Use the procedure below to replace either the EPROM or the NOVRAM NOTE The factory may provide the CalCurves to users in U24 NOVRAM CAUTION The EPROM and NOVRAM are Electrostatic Discharge Sensitive ESDS devices Wear shock proof wrist straps resistor limited to lt 5 mA to prevent injury to service personnel and to avoid inducing an Electrostatic Discharge ESD into the device 1 Follow the top of enclosure RE
101. igh parameters to improve sensitivity The bottom diagram shows how sensitivity improves when working at liquid nitrogen temperature 77 K This setup has a narrow range with much improved sensitivity of 0 2 V K or 200 mV K Please note that in any application the resolution of the analog output voltage is always 1 25 mV as specified Low High Input Temperature K 0 500 1000 Unipolar Output V 0 5 10 Low High Input Temperature K 50 75 100 Unipolar Output V 0 5 10 C 218 4 3 eps Figure 4 3 Example of Low and High Analog Parameter Setting ALARMS SETUP AND OPERATION Each input of the Model 218 has high and low alarm capability Input reading data from any source can be compared to the alarm setpoint values A reading higher than the high setpoint triggers the high alarm for that input A reading lower than the low alarm setpoint triggers the low alarm for that input If an alarm activates for a particular input the display location for that input flashes The beeper inside the instrument can also be programmed to sound if any alarms activate The eight relays on a 218S can also be tied to alarm functions as described in Paragraph 4 11 The system Alarm annunciator steadily displays when any alarm is enabled it flashes when any alarm activates An input need not display for the system Alarm annunciator to indicate input alarm status Latching Alarms Often used to detect faults in a system or experiment that require operator i
102. iling Point Boiling Point Point 4 2K 77 35 K 305 K LS US IS UI a 0 25 50 15 100 125 150 175 200 225 250 275 300 325 350 Ki E 2 10 K 50 100 K 200 325 K Acceptable Temperature Range for Silicon Diode SoftCal Inputs C 218 5 1 eps Figure 5 1 SoftCal Temperature Ranges for Silicon Diode Sensors A unique characteristic of DT 400 Series diodes is that their temperature responses pass through 28 K at almost exactly the same voltage This knowledge improves SoftCal operation by providing an extra calibration data point It also explains why SoftCal calibration specifications are divided into two temperature ranges above and below 28 K See Figure 5 1 Point 1 Calibration data point at or near the boiling point of helium 4 2 K Temperatures outside 2 K to 10 K are not allowed This data point improves accuracy between the calibration data point and 28K Points 2 and 3 improve temperatures above 28 K Point 2 Calibration data point at or near the boiling point of nitrogen 77 35 K Temperatures outside 50 K to 100 K are not allowed This data point improves accuracy between 28 K and 100 K Points 2 and 3 together improve accuracy to room temperature and above Point 3 Calibration data point near room temperature 305 K Temperatures outside the range of 200 K to 350 K are not allowed 5 6 Special Features Lake Shore Model 218 Temperature Monitor User s Manual 5 2 2 SoftCal Accuracy with Silicon Diode Sensors NOTE A
103. ing Configures date and time using 24 hour format lt MM gt Specifies month Valid entries are 1 12 lt DD gt Specifies day Valid entries are 1 31 lt YY gt Specifies year Valid entries are 00 99 lt HH gt Specifies hour Valid entries are 0 23 lt mm gt Specifies minutes Valid entries are 0 59 lt SS gt Specifies seconds Valid entries are 0 59 DATETIME 2 3 99 15 30 O term Sets date to February 3 1999 time to 3 30pm DATETIME Query Date and Time Input Returned Remarks DFLT Input Returned Remarks DISPFLD Input Returned Remarks Example DISPFLD Input DATETIME lt MM gt lt DD gt lt YY gt lt HH gt lt mm gt lt SS gt Format nn nn nn nn nn nn term Returns date and time See the DATETIME command for parameter descriptions Set to Factory Defaults DFLT 99 Nothing Sets all configuration values to factory defaults and resets the instrument The 99 is required to prevent accidentally setting the unit to defaults Does not clear user curves or instrument calibration Configure Display Parameters DSPFLD lt location gt lt input gt lt source gt Nothing Configures the display parameters lt location gt Specifies display location to configure 1 8 lt input gt Specifies input to display in the display location 0 8 D none lt source gt Specifies input data to display 1 Kelvin 2 Celsius 3 sensor units 4 li
104. ion 7 13 11 7 12 PURPOSE CONFIG PROCESS To determine the input gain errors when the input is configured for 500 Q input and provide gain calibration constants back to the Model 218 Attach the precision 250 Q resistors to each input of the group Be sure to connect the resistors using proper 4 lead connection techniques Input group configured for 500 Q input all inputs of the group are enabled Via the interface obtain the RAWAD value of the 1 input To determine the calibration constant add the 500 Q range zero offset constant to the value read and divide 250 by that value or 250 RAWAD reading zero offset constant For example if the value read was 1 24887 and the zero offset constant was 0 00009 the gain calibration constant is 250 1 24896 200 166 This gain calibration constant is provided back to the Model 218 using the GCAL command for the 1 input of the group only The above process must be repeated for the remaining 3 inputs of the group Once gain calibration constants for all ranges have been determined and provided back to the Model 218 the CALSAVE command is issued to save the constants in the E prom 7 5 kQ Input Gain Calibration PURPOSE CONFIG PROCESS To determine the input gain errors when the input is configured for 7 5 KQ input and provide gain calibration constants back to the Model 218 Attach the precision 5 kQ resistors to each input of the group Be sure to connect the resistor
105. ions for changing and verifying a line fuse are given in Paragraph 7 5 Power Cord The Model 218 includes a 3 conductor power cord that mates with the IEC 320 C14 line cord receptacle Line voltage is present on the two outside conductors and the center conductor is a safety ground The safety ground attaches to the instrument chassis and protects the user in case of a component failure ACE approved power cord is included with instruments shipped to Europe a domestic power cord is included with all other instruments unless otherwise specified when ordered Always plug the power cord into a properly grounded receptacle to ensure safe instrument operation The delicate nature of measurement being taken with this instrument may necessitate additional grounding including ground strapping of the instrument chassis In these cases the operators safety should remain the highest priority and low impedance from the instrument chassis to safety ground should always be maintained Power Switch The power switch is part of the line input assembly on the rear panel of the Model 218 and turns line power to the instrument On and Off When the circle is depressed power is Off When the line is depressed power is On 3 3 Lake Shore Model 218 Temperature Monitor User s Manual 3 3 2 Sensor Inputs 3 3 2 1 3 4 This section covers Sensor Input Connector and Pinout in Paragraph 3 3 2 1 Sensor Lead Cable in Paragraph 3 3 2 2 Grounding and Shieldin
106. is appropriate for the intended AC power input If the voltage setting is changed remove and verify the proper fuse is installed before inserting the power cord and turning on the instrument Always turn off the instrument before making any rear panel connections This is especially critical when making sensor to instrument connections WARNING NO USER SERVICEABLE PARTS INSIDE REFER SERVICING TO TRAINED SERVICE PERSONNEL INPUTS 1 4 ANALOG PY lo BR RELAYS 30VDC 5A OUTPUTS Gei 1 100 120 220 240 V RELAY 1 RELAY 2 RELAY 3 RELAY A 1 5 0 HE IB VA MAK S S IEEE 488 INTERFACE ae re ee a RRRRRRARARAREA SIT AH1 T5 L4 SR1 RL1 PPO DC1 DTO CO El RELAY5 RELAY6 RELAY7 RELAY8 2 F 218 3 1 eps 1 Line Input Assembly kk Paragraph 3 3 1 2 Serial l O and Printer Connector oocccconccncococcnnconconccnonnnnononcnnnnnas Paragraph 6 2 3 Sensor Input Connector for Inputs 1 4 Paragraph 3 3 2 1 4 Sensor Input Connector for Inputs 5 8 oocccccccncccnncccnnncnono Paragraph 3 3 2 1 5 Terminal Block for Relays and Analog Outputs 218S Only Paragraph 3 3 3 6 IEEE 488 INTERFACE Connector 218S Only Paragraph 6 1 Figure 3 1 Model 218 Rear Panel 3 3 1 Line Input Assembly This section describes how to properly connect the Model 218 to line power Please follow these instructions carefully to ensure proper operation of the instrument and the safety of operators Line Cord Power On Off Fuse Input
107. ivity The Model 218 can read Platinum RTDs to achieve temperature readings greater than 1000 K 727 C Platinum RTDs sold by Lake Shore are limited to 800 K 527 C Diode Measurements The Model 218 can read up to eight Lake Shore DT 470 or any other diode temperature sensor Diode sensors are easily interchangeable and provide a wide measurement range from 1 4 to 475 K Many diodes like the DT 470 follow a standard temperature response curve that may eliminate the need for costly or time consuming individual calibration The convenient SoftCal feature can be used to improve the accuracy of less expensive DT 470 sensors NTC Resistor Measurements The Model 218 can read up to eight NTC negative temperature coefficient resistor sensors using their standard curves or individual calibrations NTC resistor sensors are typically used in specialized applications such as magnetic and radiation environments In some applications the constant current excitation of the 218 may limit the useful range of NTC resistor sensors refer to Table 1 2 Configurable Sensor Inputs The Model 218 has eight constant current sources one for each input that can be configured for a variety of sensors The inputs can be configured from the front panel or via computer interface and are grouped in two sets of four Each set of four inputs are configured for the same sensor type i e all 100 Q Platinum or all Silicon Diodes etc Sensor Input Reading Capabi
108. keys to scroll to the breakpoint then set both sensor units and temperature values to zero The instrument erases the point and moves following points up To erase an entire curve refer to Paragraph 5 1 5 Special Features Lake Shore Model 218 Temperature Monitor User s Manual 5 1 4 Entering a New Curve To begin entering a user curve press Curve Entry The first screen appears Use the Data Selection keys to select Edit Curve then press Enter The second display in the setting sequence appears Use the Data Selection keys to cycle through the different inputs to which the curve applies 1 8 and standard curves If a standard curve is selected the curve view screen appears Standard curves are read only users cannot change their parameters When the desired input or standard curve appears press Enter The third display in the setting sequence appears Use the number keys to input up to a ten digit serial number for the curve to be entered then press Enter The fourth display in the setting sequence appears Use the Data Selection keys to select the appropriate sensor format for the installed sensor There are three formats VIK Volts vs Kelvin for Diode sensors QIK Resistance vs Kelvin for platinum RTD sensors Log Q K Log Resistance vs Kelvin for NTC resistive sensors When the desired format appears press Enter Refer to Table 5 1 for recommended formats for specific sensors The fifth display in the
109. l RM 2 Dual Rack Mount Shelf Accessories Lake Shore Model 218 Temperature Monitor User s Manual APPENDIX A CURVE TABLES A1 0 GENERAL The following are curve tables applicable to the Model 218 Temperature Monitor Table A 1 Standard DT 470 Diode Curve Breakpoint Pov Temp K Breakpoint EN Temp K Breakpoint wv Oo Temp K OO OO JO Om PS GO A Appendix A 0 09062 0 10191 0 11356 0 12547 0 13759 0 14985 0 16221 0 17464 0 18710 0 19961 0 22463 0 24964 0 27456 0 28701 0 32417 0 36111 0 41005 0 44647 0 45860 0 50691 0 51892 0 55494 0 60275 0 63842 0 67389 0 70909 0 74400 0 77857 0 80139 0 82405 0 84651 0 86874 0 87976 0 89072 0 90161 0 91243 0 92317 0 93383 0 94440 0 95487 0 96524 0 97550 0 98564 0 99565 1 00552 1 01525 1 02482 1 03425 1 04353 1 05630 1 06702 1 07750 1 08781 1 08953 1 09489 1 09864 1 10060 1 10263 10476 10702 10945 11212 11517 11896 12463 13598 15558 17705 19645 1 22321 1 26685 1 30404 1 33438 1 35642 1 38012 1 40605 1 43474 1 46684 1 50258 1 59075 1 62622 1 65156 1 67398 1 68585 1 69367 1 69818 zech zc sesch vs sesch sesch vc zech ve wesch Breakpoint Number OONDOAARWDNDN Breakpoint 1 y Temp v Temp k Ohms Temp mi Ohms 0 19083 0 24739 0 36397 0 42019 0 47403 0 53960 0 59455 0 73582 0 84606 0 95327 1 00460 1 04070 1 07460 1 09020 1 09700
110. l expansion don t increase or decrease pressure with temperature change 1 To Room Temperature Vacuum Shroud eu Refrigerator Expander Vacuum Space Radiation Shield Dental Floss Tie Down or Cryogenic Tape Thermal Anchor Bobbin Refrigerator Second Stage Thermal Anchor Bobbin Cryogenic Wire small diameter large AWG Sensor Cold Stage and Heater Sample Holder wiring not shown for clarity Drawing Not To Scale Optical Window If required C 218 2 2 eps Figure 2 2 Typical Sensor Installation in a Mechanical Refrigerator Sensor Considerations 2 5 2 3 6 2 3 7 2 3 8 2 3 9 2 3 10 2 6 Lake Shore Model 218 Temperature Monitor User s Manual Lead Wire Different types of sensors come with different types and lengths of electrical leads In general a significant length of lead wire must be added to the sensor for proper heat sinking and connecting to a bulk head connector at the vacuum boundary The lead wire must be a good electrical conductor but a poor thermal conductor or heat will transfer down the leads and change the temperature reading of the sensor Small 30 to 40 AWG wire made of an alloy like phosphor bronze is much better than copper wire Thin wire insulation is preferred and twisted wire should be used to reduce the effect of RF noise if it is present The wire used on the room temperature side of the vacuum boundary is not critical so copper cable is normally used
111. l scale They can drive a resistive load of no less than 1 kQ The output is short protected so the instrument is not harmed if resistance is too small It is not recommended because the additional load on instrument power supplies causes noise on internal circuits It is not recommended to attach the analog output ground to a ground outside the instrument The output should be read by an instrument with an isolated or differential input wherever possible Connecting to an external ground can cause noise in the analog output voltage or the sensor input measurement If this cannot be avoided try to keep the chassis of the two instruments at the same potential with a ground strap Connect to the analog out contacts through the terminal block refer to Paragraph 3 3 3 3 3 4 Computer Interfaces 3 8 Refer to Chapter 6 for details about the IEEE 488 Model 218S ONLY and serial computer interfaces Refer to also Chapter 5 for details on connecting the serial port to a printer Installation 4 0 4 1 Lake Shore Model 218 Temperature Monitor User s Manual CHAPTER 4 OPERATION GENERAL This chapter covers Model 218 front panel operation Display Screen Description in Paragraph 4 1 Keypad Description in Paragraph 4 2 Turning Power On in Paragraph 4 3 Display Setup in Paragraph 4 4 Input Type in Paragraph 4 5 Curve Select in Paragraph 4 6 Math in Paragraph 4 7 Analog Outputs in Paragraph 4 8 Alarm Setup and Operation in Paragraph 4 9
112. lity The Model 218 has two high resolution A D converters to increase its update rate It can read sensor inputs more quickly than other scanning monitors because it does not have to wait for current Source switching The result is 16 new readings per second allowing all inputs to be read twice each second Inputs can be turned off to obtain a higher reading rate on fewer sensors All readings can be read out of the instrument with the IEEE 488 interface The serial interface can also be used to read all readings if it is operated efficiently The display is updated twice each second Temperature Response Curves The Model 218 has standard temperature sensor response curves for silicon diodes and platinum RTDs It can support a wide variety of temperature sensors that do not have a standard curve because a unique 200 point user curve can be stored for each of the eight inputs CalCurves for Lake Shore calibrated sensors can be stored as user curves User curves can be entered from the front panel or with a computer interface The built in SoftCal algorithm can also be used to generate improved curves for DT 470 diodes and platinum RTDs that are stored as user curves Configurable Display The eight display locations on the Model 218 are user configurable These locations can be used to display a single readout for each of the eight inputs or for more than one readout for fewer inputs Sources for readout data are temperature units sensor units
113. m Or if all units are queried lt input 1 Sensor Units Value gt lt Input 2 Sensor Units Value gt lt Input 3 Sensor Units Value gt lt input 4 Sensor Units Value gt lt Input 5 Sensor Units Value gt lt Input 6 Sensor Units Value gt lt Input 7 Sensor Units Value gt lt Input 8 Sensor Units Value gt Format nn nnn nn nnn nn nnn tnn nnn tnn nnn nn nnn tnn nnn t tnn nnn Returns the Sensor Units reading for a single input or all inputs lt input gt Specifies which input s to query 0 all inputs 1 8 individual input NOTE Use 0 all inputs when reading two or more inputs at the maximum update rate of 16 rdgs sec Remote Operation 7 0 7 1 7 2 7 2 1 Lake Shore Model 218 Temperature Monitor User s Manual CHAPTER 7 SERVICE GENERAL This chapter provides general service information for the Model 218 Temperature Monitor There is no calibration procedure for the Model 218 There are no serviceable parts inside the Model 218 Contact Lake Shore about specific problems with the Model 218 GENERAL MAINTENANCE PRECAUTIONS Below are general safety precautions unrelated to any other procedure in this publication These are recommended precautions that personnel should understand and apply during the maintenance phase Keep away from live circuits Installation personnel shall observe all safety regulations at all times Turn off system power before making or breaking electrical connections Regard any exposed con
114. m 1 2 High Alarm 2 4 Temperature Over or Under Range 3 8 Sensor Over or Under Range lt source gt Returns data source recorded 1 Kelvin 2 Celsius 3 sensor units 4 linear data Remote Operation 6 27 LRDG Input Returned Remarks MNMX Input Returned Remarks Example MNMX Input Returned Remarks Lake Shore Model 218 Temperature Monitor User s Manual Query Linear Equation Data for a Single Input or All Inputs LRDG lt input gt lt Linear value gt Format nn nnn term Or if all inputs are queried lt Input 1 Linear Value gt lt Input 2 Linear Value gt lt Input 3 Linear Value gt lt Input 4 Linear Value gt lt Input 5 Linear Value gt lt Input 6 Linear Value gt lt Input 7 Linear Value gt lt Input 8 Linear Value gt Format nn nnn nn nnn nn nnn nn nnn nn nnn nn nnnt nn nnn nn nnn Returns the linear equation data for an input lt input gt specifies which input to query 0 all inputs 1 8 individual input NOTE Use 0 all inputs when reading two or more inputs at the maximum update rate of 16 redgs sec Configure Minimum and Maximum Input Function Parameters MNMX lt input gt lt source gt Nothing Configures the minimum and maximum input functions lt input gt Specifies input to configure 1 8 lt source gt Specifies input data to process through max min 1 Kelvin 2 Celsius 3 sensor units 4 linear data MNMX 1 3 term Inpu
115. mber keys to input the temperature in Kelvin that corresponds to the voltage or resistance of the third calibration data point then press Enter The Model 218 creates and stores the SoftCal curve but users must select the curve for the appropriate input before it is used If the third point is not used press Enter twice without entering any data Press Escape at anytime to cancel the SoftCal creation sequence and return to the normal display 5 3 DATA LOGGING The Model 218 has internal memory reserved for data logging Reading data can be stored in the instrument to be printed or read over computer interface at a later time Data log setup parameters can also be used to control printer operation Active data logging and active printing cannot occur at the same time Data is taken in groups called records Up to eight readings can be logged or printed as one record Readings can be from any input and any source Each record includes a time stamp The Model 218 dedicates 12 Kbytes of memory to data logging Table 5 2 indicates the maximum number of records that can be stored based on the number of readings in a record Table 5 2 Storage Capability Based on Readings per Record 00 as o e Cw e 5 3 1 Log Setup NOTE Changing Log Setup will erase stored records To setup the data log function press Log Setup The first screen in the setting sequence appears Use the Data Selection keys to cycle through the different log modes listed
116. mbol and outline Black Alternating current power line Protective conductor terminal instrument documentation Background color Yellow Symbol and outline Black Caution or Warning See Frame or chassis terminal On supply Off supply Fuse O Or 2 de Introduction 2 0 2 1 2 1 1 Lake Shore Model 218 Temperature Monitor User s Manual CHAPTER 2 SENSOR CONSIDERATIONS GENERAL Selecting the proper sensor is vital to good temperature monitoring This chapter covers Temperature Sensor Selection in Paragraph 2 1 Calibrated Sensors in Paragraph 2 2 and Sensor Installation in Paragraph 2 3 This chapter describes cryogenic applications but many ideas apply to other temperature measurements TEMPERATURE SENSOR SELECTION This section covers general information about sensor selection Find additional information on temperature sensor characteristics and selection in the Lake Shore Temperature Measurement and Control Catalog Temperature Range The experimental temperature range must be known when choosing a sensor Some sensors can be damaged by temperatures that are too high or too low Manufactures recommendations should always be followed Sensor sensitivity is also dependent on temperature and can limit a sensors useful range It is important not to specify a range larger than necessary If an experiment is being done at liquid helium temperature and a very high sensitivity is needed for good meas
117. n Refer to Paragraph 4 4 Configures relays and associates them with the alarm feature 2185 Refer to Paragraph 4 11 Sets up alarms Refer to Paragraph 4 9 Resets latched alarm state Refer to Paragraph 4 10 Configures an input set for sensor type Also disables unused inputs Refer to Paragraph 4 5 Selects a temperature response curve for an input Refer to Paragraph 4 6 Manually enters a temperature response curve and copies curve data Refer to Paragraph 5 1 Configures analog voltage outputs 2185 Refer to Paragraph 4 8 Initiates SoftCal feature Refer to Paragraph 5 2 Sets up data log feature Refer to Paragraph 5 3 1 Views logged data Refer to Paragraph 5 3 3 Turns data logging on or off Refer to Paragraph 5 3 2 Returns instrument to local operation after remote IEEE 488 operation 2185 Refer to Chapter 6 Sets up the IEEE 488 218S or serial computer interface Refer to Chapter 6 Sets up math feature Max Min Linear and Filter Also resets Max Min Refer to Paragraph 4 7 Sets up or initiates printer operation Refer to Paragraph 5 4 Exits from a parameter setting sequence and returns to the normal display During entry of numerical settings press Escape once to clear the entry twice to return to the normal display Also resets memory Increments parameter values or selections during setting sequence Decrements parameter values or selections during setting sequence Accepts a new paramet
118. n the setting sequence appears Use the number keys to input the period in seconds 1 to 3600 between data log records then press Enter Ten second minimum if logging operates in print mode NOTE Continuous polling of the instrument over the computer interface can affect the log period The fifth display in the setting sequence appears Use the Data Selection keys to select the number of readings per record 1 8 The sixth display in the setting sequence appears Use the Data Selection keys to specify the input from which to take readings 1 8 When the desired input appears press Enter The next display in the setting sequence appears Use the Data Selection keys to select the appropriate source for the selected sensor input K Kelvin temperature reading from input C Celsius temperature reading from input Sensor Sensor units reading from input Linear Linear equation data from input Press Enter when the desired source appears The number of source selection screens that follow depends on the number of readings selected The eighth display in the setting sequence appears Use the number keys to input the time of day in hours 01 24 minutes 01 60 and seconds 01 60 After inputting the correct time press Enter The final display in the setting sequence appears Use the number keys to input the date in month 01 12 day 01 31 year 00 99 format After inputting the date press Enter NOTE The Model
119. nding status flag bit in the Status Byte Register To enable a status flag bit send the command SRE with the sum of the bit weighting for each desired bit See the STB command for a list of status flags Example To enable status flags 0 3 4 and 6 send SRE 89 term 89 is the bit weighting sum for each bit Bit Bit Weighting Event Name 0 1 New Reading 3 8 Alarm 4 16 Error 6 64 SRQ 89 SRE Query the Configuration of Status Reports in the Service Request Enable Register Input SRE Returned lt SRE bit weighting gt Format nnn term Remarks The integer returned represents the sum of the bit weighting of the enabled bits in the Service Request Enable Register See the STB command for a list of status flags STB Query Status Byte Input STB Returned lt STB bit weighting gt Format nnn term Remarks Acts like a serial poll but does not reset the register to all zeros The integer returned represents the sum of the bit weighting of the status flag bits that are set in the Status Byte Register Bit Bit Weighting Event Name Bit Bit Weighting Event Name 0 1 New Reading 4 16 Error 1 2 Unused 5 32 ESB 2 4 Overload 6 64 SRQ 3 8 Alarm 7 128 Datalog Done TST Query Self Test Input TST Returned 0 or 1 Format n term Remarks The Model 218 performs a self test at power up 0 no errors found 1 errors found KWAI Wait to Continue Input KWAI Returned Nothing Remarks This command is not supported in the
120. near data 5 minimum data 6 maximum data DSPFLD 2 4 1 term Displays Kelvin reading for Input 4 in display location 2 Query Displayed Field DISPFLD lt location gt Returned lt input gt lt source gt Format n n n term Remarks Remote Operation Returns the parameters for a displayed field See DISPFLD command for returned parameter descriptions lt location gt specifies display location to query 1 8 6 23 FILTER Input Returned Remarks Example FILTER Input Returned Remarks IEEE Input Returned Remarks Example IEEE Input Returned Remarks INCRV Input Returned Remarks Example INCRV Input Returned Remarks 6 24 Lake Shore Model 218 Temperature Monitor User s Manual Configure Input Filter Parameters FILTER lt input gt lt off on gt lt points gt lt window gt Nothing lt input gt Specifies input to configure 1 8 lt offion gt Specifies whether the filter function is off or on 0 Off 1 On lt points gt Specifies how many data points the filtering function uses 2 64 lt window gt Specifies what percent of full scale reading limits the filtering function 1 10 Reading changes greater than this percentage reset the filter FILTER 1 1 10 2 term Filter input 1 data through 10 readings with 2 of full scale window Query Input Filter Parameters FILTER lt input gt lt off on gt lt points gt lt
121. nector terminal board or circuit board as a possible shock hazard Discharge charged components only when such grounding results in no equipment damage If a test connection to energized equipment is required make the test equipment ground connection before probing the voltage or signal to be tested Do not install or service equipment alone Do not reach into or enter any enclosure to service or adjust the equipment without another person capable of rendering aid If there is no power verify the power cord is plugged into a live outlet and that both ends are securely plugged in Next check the fuse refer to Paragraph 3 3 1 1 Clean the Model 218 periodically to remove dust grease and other contaminants as follows 1 Clean front back panels and case with soft cloth dampened with mild detergent and water solution NOTE Do not clean with aromatic hydrocarbons or chlorinated solvents They may react with the plastic materials used in the controller or the silk screen printing on the back panel 2 Clean surface of printed circuit boards PCBs with clean dry air at low pressure 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 induced by an electrostatic field The low energy source that most commonly destroys Electrostatic Discharge Sensitive ESDS devi
122. nfiguration DTE Connector DE 9P Baud Rate 9600 Timing Format Asynchronous Data Bits 8 Start Stop Bits 1 Parity None Data Interface Levels Transmits and receives using EIA voltage levels Printer Support Serial printers connected directly to the Model 218 must have a serial interface port and should be Epson or HP compatible and support ASCII text mode Continuous feed printers are recommended for all print modes Single sheet feed printers are recommended for printing stored logs only A minimum print speed of 15 characters per second is required For typical serial printer operation DTR is the preferred method of handshaking Under DTR the printer maintains a HIGH signal when ready to receive Model 218 data The signal drops to LOW when the printer suspends the flow of data If a printer uses a different lead for flow control 4 11 19 or 25 connect that lead to pin 6 DSR in of the 218 serial connector Check printer users manual for more information Special Features Lake Shore Model 218 Temperature Monitor User s Manual 5 4 2 Printer Connector amp Cable For most serial printers a standard PC to printer cable may be used 218 DE 9P 3 TD out 2 RD in 8 NC 6 DSR in 1 NC 5 GND 5 4 3 Printer Operation F 218 5 3 eps Pin Description No Connection NC Receive Data RD in Transmit Data TD out Data Terminal Ready DTR out Ground GND 6 Data Set Ready DSR in
123. no juejsuo y0 0F WA OL ZE OT WU E OF YUI L0 0F WN OL y0 0F WA OL UO JOSUOS Y 0092 0 Y 0009 0 Y 00S 0 AGL 0 AGZ 0 ebuey indu 75 suyo 75 swyo 75 suyo A SHOA A SHOA spun osuas OAIUGDON 9AINSOJ 9AIHSOJ SAITEDON OAIEDON JUSIDIZJOOD 3 IN e19QUIS SEN aan eN d GLY n XOUI9Q GLY wnuneld 250001 91895 11 3 O00S spoiq SYIVED SPOIG VOS ad sosues aLY wnueld 70004 yeys a9ueuloJ1ag indu JOSUSS 8LZ I PON Z 3108 1 jenuey sasn JOUUOIN SINJEJSALWA YLZ apon SJOYS 3427 Lake Shore Model 218 Temperature Monitor User s Manual 1 3 SAFETY 1 3 1 1 3 1 1 1 3 1 2 1 3 1 3 Handling Liquid Helium and Liquid Nitrogen Liquid Helium LHe and liquid nitrogen LN2 may be used in conjunction with the Model 218 Although LHe and LN are not explosive there are certain safety considerations when handling them NON MAGNETIC Handling Cryogenic Storage Dewars Operate all cryogenic containers dewars in accordance with manufacturer instructions Safety instructions are normally posted on the side of each dewar Keep cryogenic dewars in a well ventilated place protected from the weather and away from heat sources Figure 1 1 shows a typical cryogenic dewar Liquid Helium and Nitrogen Safety Precautions Transfer LHe and LN and operate storage dewar controls in accordance Figure 1 1 Cryogenic with manufacturer supplier instructions During transfer foll
124. nput Returned Remarks Example LINEAR Input Returned Remarks LOCK Input Returned Remarks Example LOCK Input Returned Remarks LOG Input Returned Remarks LOG Input Returned Remarks LOGNUM Input Returned Remarks 6 26 Lake Shore Model 218 Temperature Monitor User s Manual Configure Input Linear Equation Parameters LINEAR lt input gt lt varM value gt lt X source gt lt varB value gt Nothing Configures the linear equation for an input lt input gt Specifies input to configure 1 8 lt varM value gt Specifies a value for m in the equation lt X source gt Specifies input data 1 Kelvin 2 Celsius 3 sensor units lt varB value gt Specifies a value for b in the equation LINEAR 6 1 0 2 3 2 term The linear data for Input 6 is calculated from the Celsius reading of the input using the equation y 1 0 x 3 2 Query Input Linear Equation Parameters LINEAR lt input gt lt varM value gt lt X source gt lt varB value gt Format nn nnn n nn nnn Returns input linear equation configuration See LINEAR command for returned parameter descriptions lt input gt specifies input to query 1 8 Configure Lock out and Lock out Code LOCK lt offlon gt lt code gt Nothing Configures keypad lock out and lock out code lt offlon gt Disables enables the keypad lock out lt code gt Specifies lock out code 000 999
125. nsor Precision Calibration being loaded on a floppy disk in ASCII format for Customer downloading Precision Option Factory Installed The Precision Option provides custom programming of specific sensor calibration curve at the factory The Precision Option improves combined 8001 sensor instrument accuracy to within 0 1 K or better over the calibrated temperature range of the sensor The Precision Option data is stored in a memory chip NOVRAM Requires the use of a calibrated sensor Precision Option Field Installation For field installation of the precision option for users who 8002 218 already own a Model 218 When ordering please specify your instrument serial number and calibrated sensor model and serial number A new NOVRAM will be sent for Customer installation 8 2 ACCESSORIES Accessories are devices that perform a secondary duty as an aid or refinement to the primary unit Model Description of Accessories SSCS 106 253 Sensor Mating Connector Two DB 25 D Style plugs for sensor input connector 106 255 Sensor Mating Connector Shell Two DB 25 D Style shells for sensor input connector 106 772 Terminal Block Mating Connector For Model 218S Only Two 14 pin terminal blocks for relays and analog outputs 115 006 Detachable 120 VAC line cord Model 218 IEEE 488 Cable Kit One meter 3 feet long IEEE 488 GPIB computer interface cable assembly Includes extender which is required to use both IEEE cable and relay
126. nstrument power cord With a small screwdriver release the drawer holding the line voltage selector and fuses Remove and discard both existing fuses Replace with proper Slow Blow time delay fuse ratings as follows 100 120 V 025AT250V 5x20 mm 220 240 V 0 20AT250V 5x20 mm Re assemble line input assembly in reverse order Verify voltage indicator in the line input assembly window Connect instrument power cord Turn power switch On I 7 6 SENSOR INPUT CONNECTOR AND PINOUT Service Tri DESC PIN DESC PIN DESC PIN DESC 12 Figure 7 3 Model 218 Input Connector Pinouts S Shield NC No Connect 1 3 Lake Shore Model 218 Temperature Monitor User s Manual 7 7 TERMINAL BLOCK MODEL 218S ONLY ANALOG RELAYS 30 VDC5A Malos RELAY 1 RELAY 2 RELAY3 RELAY4 1 2l l l l l l l l l l l l l l l l l l l l l l l l RELAY5 RELAY6 RELAY7 RELAY8 2 F 218 7 4 eps FIN DESCRIPTION PIN DESCRIPTION Ca relay 1n0 15 Reyne 2 Relay 1com 16 Relays COM a Relay1No 17 RelaysNO__ Ca Reay2nc 18 Relay6nc 75 Relay2com 19 Retay 6 COM e Relay2No 20 Relay NO Cr Retayano 21 Retay7 NC e Relaya com 22 Relay7 COM o Reay3No 23 Relay 7 NO 710 Relay Nc 24 Relayenc 711 Retay4con 25 Relays COM 712 Relay4no 26 Relay 8 NO 713 Analog 1 Signal 2 Analog 2 Signal 714 Analog 1 Gnd 28 Analog 2 Gna Figure 7 4 Terminal Block Connectors
127. nt If InStr strCommand lt gt 0 Then Check to see if query While ZeroCount lt 20 And strHold lt gt Chr 10 Wait for response If frmSerial MSComml InBufferCount 0 Then Add 1 to timeout if no character frmSerial Timerl Enabled True Do DoEvents Wait for 10 millisecond timer Loop Until frmSerial Timerl Enabled False ZeroCount ZeroCount 1 Timeout at 2 seconds Else ZeroCount 0 Reset timeout for each character strHold frmSerial MSComml Input Read in one character strReturn strReturn strHold Add next character to string End If Wend Get characters until terminators If strReturn lt gt Then Check if string empty strReturn Mid strReturn 1 InStr strReturn Term 1 Strip terminators Else strReturn No Response Send No Response End If frmSerial txtResponse Text strReturn Put response in textbox on main form strHold Reset holding string ZeroCount 0 Reset timeout counter End If Loop End Sub Private Sub Timerl Timer Routine to handle Timer interrupt frmSerial Timerl Enabled False Turn off timer End Sub Remote Operation 6 13 Lake Shore Model 218 Temperature Monitor User s Manual 6 2 7 2 Quick Basic Serial Interface Program Setup The serial interface program Table 6 5 works with QuickBasic 4 0 4 5 or Qbasic on an IBM PC or compatible running DOS or in a DOS window with a serial interface It uses the COM1 communication port at 9600 Baud Use the following proced
128. ntervention The alarm state remains visible to the operator for diagnostics even if the alarm condition is removed Relays often signal remote monitors or for added safety take critical equipment off line Alarm Reset clears latched alarms Non Latching Alarms Often tied to relay operation to control part of a system or experiment The dead band parameter can prevent relays from turning on and off repeatedly when the sensor input reading is near an alarm setpoint Example If the high alarm setpoint 100 K and the dead band 1 K the high alarm triggers when sensor input temperature increases to 100 K and it will not deactivate until temperature drops to 99 K To begin alarm setup press Alarm Setup The first display appears Use the Data Selection keys to cycle through the inputs 1 8 to set up for alarms Press Enter when the desired input appears The second display in the setting sequence appears Use the Data Selection keys to turn alarm operation On or Off for the selected input Off Disables alarm operation for the selected input The instrument skips to the eighth display screen below On Enables alarm operation for the selected input and displays the third display in the setting sequence Operation 4 13 Lake Shore Model 218 Temperature Monitor User s Manual Alarms Setup and Operation Continued 4 14 The third display of the setting sequence appears use the Data Selection keys to cycle through source selections for the
129. oconcccncnncononnnnnnnannnnonnnnnonannnnnnnanannss 5 2 Storage Capability Based on Readings per Record 5 3 Serial Printer Interface Gpoecfcatons 6 1 Sample BASIC IEEE 488 Interface Drogram 6 2 Serial Interface Gpecfcatons 6 3 Serial Interface Program Control bropertes nn000nnnnennensennenrnnnnsrnrnnnnrnsrnnnnne 6 4 Visual Basic Serial Interface Program cccooocccccoccncoconcnnconanoncononenonnncnnonoanonconanenoos 6 5 Quick Basic Serial Interface rogram 6 5 Model 218 Interface Commands by Function coocccccccccnccccncnnccnnccnononencnnoncnnnnnos A 1 Standard DT 470 Diode Curve ooccooccnccococccocnccoccnnoncnoconnnononononnnnnonnnnononnnnnnnnnenanenes A 2 Other Standard Diode and Platinum Curves occcccoccccccnccnnononcnnononconconanoncnnoncnnnnnos A 3 Standard DT 670 Diode Curve E IV Table of Contents Lake Shore Model 218 Temperature Monitor User s Manual CHAPTER 1 INTRODUCTION 1 0 GENERAL The Model 218 is an eight input temperature monitor that can be used with diode or resistive temperature sensors The measurement input was designed for the demands of cryogenic temperature measurement The monitor s low noise high resolution and wide operating range make it ideal for noncryogenic applications as well There are two versions of the Model 218 the Model 218S and Model 218E Both versions have the same sensor measurement and display capabilities but include different interfaces The Model 218S has many inte
130. oftCal capable instrument A calibration report ships with the sensor Generate a Precision Option for either SoftCal or Precision Calibration Breakpoint pairs are loaded in a NOVRAM and factory installed Precision Option C 218 2 1 eps Figure 2 1 Silicon Diode Sensor Calibrations and CalCurve Sensor Considerations 2 3 2 2 4 2 3 2 3 1 2 3 2 2 3 3 2 4 Lake Shore Model 218 Temperature Monitor User s Manual CalCurve The CalCurve service provides the user with a convenient way get the temperature response curve from Lake Shore s calibrated sensors into instruments like the Model 218 It can be performed at the factory when calibrated sensors and instruments are ordered together The factory installed CalCurve option is Model 8001 and should be ordered with the calibrated sensor A CalCurve can be done in the field when additional or replacement sensors are installed Curve data is loaded into some type of non volatile memory that is installed into the instrument by the user In the case of the Model 218 the curve is loaded into a non volatile memory chip which can be installed into the instrument The field installed version is a Model 8002 and it should be ordered with the calibrated sensor Customers that have an RS 232C or IEEE 488 interface have another option in loading curves from calibrated sensors A Model 8000 includes the curve and a download program on a 3 5 inch floppy disk The d
131. olatile 15 35 C at rated accuracy 10 40 C at reduced accuracy 100 120 220 240VAC 6 10 50 or 60Hz 18 VA 217 mm W x 90 mm H x 317 5 mm D 8 5 x 3 5 x 12 5 in half rack 3 kilograms 6 6 pounds CE Mark contact Lake Shore for availability uononpou aJoys ye7 wouy jqejere JaBuo ON AN OL uey ssa aq pinoys eyon JUN ewy suwa s s peubisap jam uj 9SBEJOA JN ewy jo AN yoes woy synsal 75w JO 10119 UY SEebeYJOA JW ewy jo Steg OU s pnjou Aoeinose paloads 16l1 gt 98MZ lt l1 JO papuauuuogay A00 18 A 787 LF ALL 18 MU SELF 1SZ gt g38mMm0v lt _l JO p2puauuuogay 1GzZ gt aRyor lt l JO pepusWULWWODEyY A 008 IP MW Ob A 00 IP YU OLL A 221 MU EGF A 008 IP MW 8c A GLY MW COC A 00 IP MW GOLF LL ye MW Ber LG gt gReyzr lt l JO p2puauuuogay A GLY e MW OLC A 00 IP MW OVL A 2118 MW 06EF LE gt ageyNoga lt l JO p23puauuogay GLY MU ZIL A 00 IP MW SELF LZ ye MW C6L gen PI91J 9H9UBEIA JOSU9S pajzeiqijed pue woeAINgjey A9e mo99e 9140 1393 9 Buipn 9u1 A C y e MW Gr MOOE 18 Y VL b M ZZ ye MW 88F A Cy e MU Li 904 v0 0F U 1 0 A 00 IP MW 00G A OE JE MW 09F A 008 IP MW OLE A 00 Je MW GELF A LZ ye MU EEF A OE JE MW Ob 903 wb 0F Y 90 0 OGY A 008 IP MU OL gt A 00 fe MW OL A OE JE MW Gy A 008 IP MW 81 4 GLY ye MU COL A 00 Je MW 0 MLL ye MW 8LF A OE JE MW GEF Cc0 0 Y v00 0
132. olution is six digits in temperature Enter most breakpoints with 0 001 K resolution Enter temperatures above 1000 K with lower resolution Enter temperatures below 10 K with 0 0001 K resolution Increased low temperature resolution can improve the curve accuracy of NTC resistors that have increased sensitivity at low temperatures Enter breakpoints with the sensor units increasing with breakpoint number Leave all unused breakpoints at zero Leave no zero breakpoints in the middle of a user curve they are interpreted as the end of the curve Editing an Existing Curve Curve editing functions work for existing user curves as well as new curves Enter the curve entry mode as described for a new curve add or erase points as needed then press Enter on the zero breakpoint to exit curve entry mode and save the changes To edit a breakpoint use the Data Selection keys to scroll to the breakpoint input the new value then press Enter If the new breakpoint is out of order the instrument flashes a message similar to the one shown below and moves the breakpoint to the appropriate location To add a breakpoint to the table use the Data Selection keys to scroll to the end of the curve data and add the new point on the first line displayed as zero If the new breakpoint is out of order the instrument flashes a message similar to the one shown above and moves the breakpoint to the appropriate location To erase a breakpoint use the Data Selection
133. ommercial cable is used in which the outer shield is tied to the connector shell do not terminate the shield at the sensor end or connect it to a shield pin in the connector Sensor Polarity Lake Shore sensors ship with instructions that indicate which sensor leads are which It is important to follow these instructions for plus and minus leads polarity as well as voltage and current when applicable Diode sensors do not operate in the wrong polarity They look like an open circuit to the instrument Two lead resistors can operate with any lead arrangement and the sensor instructions may not specify Four lead resistors may depend more on lead arrangement Follow any specified lead assignment for four lead resistors Mixing leads could give a reading that appears correct but is not the most accurate DT 470 SD Diode Sensor Leads Cathode A A Anode Four Lead Sensor Measurement All sensors including both two lead and four lead can be measured with a four lead technique Four lead measurement eliminates the effect of lead resistance on the measurement If it is not taken out lead resistance is a direct error when measuring a sensor Four Lead Platinum Four Lead 3 5 Lake Shore Model 218 Temperature Monitor User s Manual Four Lead Sensor Measurement Continued 3 3 2 6 3 3 2 7 3 6 In a four lead measurement current leads and voltage leads run separately to the sensor With separate leads there is lit
134. on Lake Shore Model 218 Temperature Monitor User s Manual Configure Analog Output Parameters ANALOG lt output gt lt bipolar enable gt lt mode gt lt input gt lt source gt lt high value gt lt low value gt lt manual value gt Nothing lt output gt Specifies which analog output to configure 1 or 2 lt bipolar enable gt Specifies analog output O positive only or 1 bipolar lt mode gt Specifies data the analog output monitors 0 off 1 input 2 manual lt input gt Specifies which input to monitor if lt mode gt 1 1 8 lt source gt Specifies input data 1 Kelvin 2 Celsius 3 sensor units 4 linear equation If lt mode gt 1 this parameter represents the data at which the analog output reaches 100 output If lt mode gt 1 this parameter represents the data at which the analog output reaches 100 output if bipolar or 0 output if positive only lt manual value gt If lt mode gt 2 this parameter is the output of the analog output ANALOG 2 0 1 5 1 100 0 0 0 term Sets analog output 2 to monitor Input 5 Kelvin reading with 100 0 K at 100 output 10 0 V and 0 0 K at 0 output 0 0 V lt high value gt lt low value gt Query Analog Output Parameters ANALOG lt output gt lt bipolar enable gt lt mode gt lt input gt lt source gt lt high value gt lt low value gt lt manual value gt Format n n n n nn nnn nn nnn nn nnn term Se
135. ors A ee eee Sensor input data in Kelvin Oe ee ee eee Sensor input data in Celsius VOP iii brea loe Sensor input data in sensor units dos Result of maximum hold function a CONE PO o Result of minimum hold function EE Result of linear equation output KA Remote IEEE 488 operation Ee Alarm Enabled RE Data Log Enabled Other Displays Dank Display location off DISGARI EI Input for this location disabled ALM HIGH o cocccccncccncnno oo High alarm triggered for input at this location ALM LO Low alarm triggered for input at this location NO CURVE E No curve selected for input at this location Ee Temperature over curve capability T UNDER scores Temperature under curve capability S OVER comia Voltage or resistance over input capability S UNDER o0ocooccccccccccncconoo Voltage or resistance under input capability 4 2 Operation 4 2 Lake Shore Model 218 Temperature Monitor User s Manual KEYPAD DESCRIPTION The Model 218 has a 4 row by 5 column sealed membrane keypad Keys are used for both beginning a setting change sequence and numeric data entry The function of each key is described below followed by general operation Display Format Relay Setup Alarm Setup Alarm Reset Input Type Curve Select Curve Entry Analog Outputs SoftCal Log Setup Log View Log On Off Local Interface Math Printer Escape Up Arrow Down Arrow Enter Numbers 0 9 Operation Formats the reading display including units selectio
136. ow all safety Storage Dewar precautions written on the storage dewar and recommended by the manufacturer 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 is difficult give oxygen Get medical attention WARNING 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 Two essential safety aspects of handling LHe are adequate ventilation and eye and skin protection Although helium and nitrogen gases are non toxic they are dangerous because they replace 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 When transferring LHe and LN protect eyes and skin from accidental contact with liquid or the cold gas issuing from it Protect eyes with full face shield or chemical splash goggles safety glasses even with side shields are inadequate Always wear special cryogenic gloves
137. own load program is a good idea if sensors are changed often The Model 8000 should also be ordered with the calibrated sensor SENSOR INSTALLATION This section covers Mounting Materials in Paragraph 2 3 1 Sensor Location in Paragraph 2 3 2 Thermal Conductivity in Paragraph 2 3 3 Contact Area in Paragraph 2 3 4 Contact Pressure in Paragraph 2 3 5 Lead Wire in Paragraph 2 3 6 Lead Soldering in Paragraph 2 3 7 Heat Sinking Leads in Paragraph 2 3 8 Thermal Radiation in Paragraph 2 3 9 and Thermal EMF Compensation with Voltage Excitation in Paragraph 2 3 10 For more detailed information Lake Shore sensors ship with installation instructions that cover that specific sensor type and package The Lake Shore Temperature Measurement and Control Catalog includes an installation section as well Lake Shore also offers a line of Cryogenic Accessories Many of the materials discussed are available through Lake Shore and can be ordered with sensors or instruments Mounting Materials The high vacuum used to insulate cryostats is one consideration in choosing sensor mounting materials Choose materials with a low vapor pressure so they do not evaporate or out gas and spoil the vacuum insulation Metals and ceramics do not have this problem but greases and varnishes must be checked Another consideration is temperature extremes most sensors are exposed to The linear expansion coefficient of a material becomes important when temperature changes are so l
138. put Gain Calibration PURPOSE CONFIG PROCESS To determine the input gain errors when the input is configured for 7 5 V input and provide gain calibration constants back to the Model 218 Same as Paragraph 7 13 4 above except the input group is configured for 7 5 V input Via the interface obtain the RAWAD reading of the 1 input To determine the calibration constant add the 7 5 V range zero offset constant to the value read and then divide 2 5 by that value or 2 5 RAWAD reading zero offset constant For example if the value read was 0 832248 and the zero offset constant was 0 00007 the gain calibration constant is 2 5 0 832241 3 00394 This gain calibration constant is provided back to the Model 218 using the GCAL command This constant is valid for all inputs of the group therefore GCAL must be sent 4 times assigning the constant to each input Once gain calibration constants for all ranges have been determined and provided back to the Model 218 the CALSAVE command is issued to save the constants in the E prom 10 pA Current Source Calibration PURPOSE TOLERANCE CONFIG To calibrate all 4 of the 10 yA current sources to within the specified tolerance 10 yA 0 01 Attach the precision 200 KQ resistors to each input of the group Be sure to connect the resistors using proper 4 lead connection techniques Input group configured to 2 5 V input all inputs of the group are enabled Front panel display must be set
139. rature Monitor User s Manual IEEE 488 SERIAL INTERFACE COMMANDS ALPHABETICAL LISTING CLS Input Returned Remarks KESE Input Returned Remarks Example KESE Input Returned Remarks ESR Input Returned Remarks IDN Input Returned Remarks OPC Input Returned Remarks 6 18 Clear Interface Command CLS Nothing Clears bits in the Status Byte Register and Standard Event Status Register and terminates all pending operations Clears the interface but not the instrument See RST command Configure Status Reports in the Standard Event Status Register ESE lt bit weighting gt Nothing Each bit is assigned a bit weighting and represents the enable disable status of the corresponding event flag bit in the Standard Event Status Register To enable an event flag bit send the command ESE with the sum of the bit weighting for each desired bit See the ESR command for a list of event flags To enable event flags 0 3 4 and 7 send ESE 143 term 143 is the bit weighting sum for each bit Bit Bit Weighting Event Name 0 1 OPC 3 8 DDE 4 16 EXE 7 128 PON 143 Query the Configuration of Status Reports in the Standard Event Status Register KESE lt ESE bit weighting gt Format nnn term The integer returned represents the sum of the bit weighting of the enable bits in the Standard Event Status Enable Register See the ESR command for a list of event flags Query Standard Event
140. reading rises above 250 0 K plus the deadband or 251 0 K lt high value gt lt low value gt lt deadband gt Query Input Alarm Parameters ALARM lt input gt lt off on gt lt source gt lt high value gt lt low value gt lt deadband gt lt latch enable gt Format n n nn nnn nn nnn nn nnn n term Returns the alarm parameters of an input See ALARM command for returned parameter descriptions lt input gt specifies which input to query 1 8 Query Input Alarm Status ALARMST lt input gt lt high status gt lt low status gt Format n n term Returns the alarm status of an input lt input gt Specifies which input to query lt high status gt Specifies high alarm status 0 Unactivated 1 Activated lt low status gt Specifies low alarm status 0 Unactivated 1 Activated Configure Audible Alarm ALMB lt off on gt Nothing Enables or disables system alarm beeper lt off on gt disables enables beeper 1 On 0 Off Query Audible Alarm Parameters ALMB lt beeper status gt Format n term Returns system beeper parameters Clear Alarm Status for All Inputs ALMRST Nothing Resets a latched active alarm after the alarm condition has cleared Remote Operation ANALOG Input Returned Remarks Example ANALOG Input Returned Remarks AOUT Input Returned Remarks BAUD Input Returned Remarks BAUD Input Returned Remarks Remote Operati
141. ress Enter to assign that mode to the selected output Analog Output OFF Select Off to set the selected analog output to zero volts and return to the normal display Analog Output Manual Mode Select Manual to control output voltage from the front panel After selecting manual mode select unipolar or bipolar operation then press Enter Set the output value in percent with a range of 100 00 to 100 00 corresponding to 10 V to 10 V The setting resolution is 0 01 but actual output voltage resolution is 0 0125 Press Enter again to return to the Normal display Operation 4 11 Lake Shore Model 218 Temperature Monitor User s Manual Analog Outputs Continued Analog Output Input Mode Select Input to set output voltage proportional to an input reading Several parameters associated with this mode allow flexibility After selecting Input mode the screen to the right appears Use the Data Selection keys to select the sensor input 1 8 that the selected analog output follows Press Enter when the desired input appears The second display in the Input mode setting sequence appears Use the Data Selection keys to select the appropriate source for the selected sensor input K Kelvin temperature reading from input C Celsius temperature reading from input Sensor Sensor units reading from input Linear Linear equation data from input Press Enter when the desired unit appears The third display in the Input mode setting
142. rface features intended for system integration and automated data collection that make it useful for cryogenic and noncryogenic applications The Model 218S includes two computer interfaces IEEE 488 and serial Data logging memory and printer capability are included to help automate data collection Two analog voltage outputs an alarm feature and eight relays enhance system integration The Model 218E is configured to have a lower selling price but maintains the same level of performance It includes a serial computer interface data logging memory and printer capability The alarm feature is also present on the Model 218E but there are no relays The 218E has all the features and specifications of the 218S except IEEE 488 interface analog voltage outputs and relays Table 1 1 Supported Lake Shore Sensors Diodes Positive Temperature Coefficient RTDs 100 Q Platinum PT 100 250 Q Full Scale 30 675 K 100 Q Platinum PT 100 500 Q Full Scale 30 800 K Rhodium lron RF 800 4 4 400 K Negative Temperature Coefficient RTDs Sensors sold separately Introduction 1 1 1 1 1 2 Lake Shore Model 218 Temperature Monitor User s Manual MODEL 218 FEATURES PTC Resistor Measurements The Model 218 can read up to eight 100 Q 1000 Q PTC positive temperature coefficient or any other PTC resistive sensors using their standard curves or individual calibrations Platinum RTDs are known for their wide range of operation and uniform sensit
143. ription of returned parameters lt reading number gt specifies an individual reading number 1 8 within a log record to query Configure Logging Parameters LOGSET lt mode gt lt overwrite gt lt start gt lt period gt lt readings gt Nothing Configures logging parameters lt mode gt Specifies logging mode 0 Off 1 Log Continuous 2 Log event 3 Print Continuous 4 Print Event lt overwrite gt Specifies overwrite mode 0 Do not overwrite data 1 overwrite data lt start gt Specifies start mode 0 Clear 1 Continue lt period gt Specifies period in seconds 1 3600 If mode is Print Continuous minimum period is 10 lt readings gt Specifies number of readings per record 1 8 Query Logging Parameters LOGSET lt mode gt lt overwrite gt lt start gt lt period gt lt readings gt Format n n n nnnn n term Returns logging parameters See LOGSET command description of returned parameters Query a Logged Data Record LOGVIEW lt record number gt lt reading number gt lt date gt lt time gt lt reading gt lt status gt lt source gt Format nn nn nn nn nn nn nn nnn nn n term Returns a single reading from a logged data record lt date gt Date reading was recorded lt time gt Time reading was recorded lt reading gt Reading logged lt status gt Represents the sum of the bit weighting of the reading status flag bits Bit Bit Weighting Status Indicator 0 1 Low Alar
144. rn to the normal display Press Escape at any time to return to the normal display The instrument retains values changed prior to pressing Escape ANALOG OUTPUTS MODEL 218S ONLY The Model 218S has two analog voltage outputs numbered 1 and 2 They are commonly configured to send a voltage proportional to temperature to a strip chart recorder or data acquisition system The outputs can also be manually controlled as a voltage source for any other application The analog outputs are variable DC voltage sources that can vary from 10V to 10V The voltage is generated by a 14 bit D A converter with resolution of 1 25 mV or 0 0125 of full scale The output is short protected but should never be used to drive a resistance lower than 1 kQ Analog output terminals are in the detachable terminal block on the Model 218S rear panel The analog outputs each have three modes of operation off input and manual Once a mode is selected the parameters associated with that mode follow on setting screens The two outputs are configured independently and can have different modes To set the operating mode of an analog output press Analog Outputs The first display appears Use the Data Selection keys to choose which output to configure 1 2 the press Enter The second display in the setting sequence appears Use the Data Selection keys to cycle through different modes for the selected analog output Off Manual Input When the desired mode appears p
145. rve Header EE ees eet 5 1 5 1 2 C me e 5 2 9 1 3 EGiting An EXSINO le 5 2 9 1 4 Entering ANS WC EE 5 3 9 1 5 Erasing USer cn o ono a a ico anida 5 4 9 1 6 Viewing Standard US a 5 4 dll COD VIG CUNY CS ic ai Ate ee 5 4 5 2 O E EE 5 5 9 2 1 SoftCal and Silicon Diode SensorS rissin na a a e a Eea e aa 5 6 5 2 2 SoftCal Accuracy with Silicon Diode Sensors ooooccncccccccccnoccnconononnnnnnnononononnonanennnnancnnnnnns 5 7 9 2 3 softGal and Platinum SENSO Susi ib 5 7 9 2 4 SoftCal Accuracy with Platinum Sensors oooccccccoccncoconcnnccnncnnconononnonnncncnnarcnnonancnnonancnnonnos 5 8 529 Creating a SoftCal Calibration Curve ococonccncococconoconnnnconanoncononenonnnnnnnonanonnonanennonancnnnnnos 5 8 5 3 DATA EO GGIING igi isis a in 5 9 9 3 1 A a a a odualaetanseas te eucastnasanansees 5 9 9 3 2 Slartingand Stopping Data LOG aci oa lod 5 11 9 3 3 Viewing Logged Dalla AAA AA 9 11 9 3 4 LINO OW Clr OSS gico iaa 9 11 5 4 PRINTING 0200 SAA 5 12 5 4 1 Printer lee 5 12 9 4 2 Printer Gonnector and el 5 13 5 4 3 PANE PODE SUON moreniniai a ao N A 5 13 6 REMOTE OPERATION iia ada 6 1 6 0 GENERA Lied 6 1 6 1 EEES IN TERTAGE gt dd tio taa er nee et eae ie dle cea ds eee reer 6 1 6 1 1 IEEE 488 Interface Settings EE 6 2 6 1 2 EEE 488 Command Stlclute iaa 6 2 6 1 3 SEUS Registe Go E O ener See Sentient meee ree er ee nee een ae ee en eee eee eee ee 6 3 6 1 4 Example IEEE Setup and Prod Medico 6 5 6 1 5 Notes On Using the IEEE Interface
146. s Manual SoftCal Accuracy with Platinum Sensors NOTE A SoftCal calibration is only as good as the accuracy of the calibration points The accuracies listed for SoftCal assume 0 05 K for 77 35 K liquid nitrogen and 305 K room temperature points Users performing a SoftCal with Lake Shore instrumentation should note that liquefied nitrogen and ice point temperatures can vary as much as 0 5 K Use a calibrated standard sensor if possible One point SoftCal calibrations with platinum sensors have no specified accuracy Two point SoftCal calibrations for applications above 70 K are performed at liquid nitrogen 77 35 K and room temperature 305 K Accuracy for the PT 102 PT 103 or PT 111 platinum sensor is 250 mK from 70 K to 325 K 500 mK from 325 K to 1400 mK at 480 K DIN Class A or Class B tolerance Three point SoftCal calibrations are performed at liquid nitrogen 77 35 K room temperature 305 K and high temperature 480 K Accuracy for the PT 102 PT 103 or PT 111 platinum sensor is 250 mK from 70 K to 325 K 250 mK from 325 K to 480 K SoftCal Calibration Curve Creation Obtain calibration data points Press SoftCal The display to the right appears Use the Data Selection keys to cycle through the curves to use as a basis for calibration Press Enter when the desired curve appears The second display in the setting sequence appears Use the Data Selection keys to cycle through the inputs where the new Soft
147. s are addressed commands The Model 218 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 Model 218 device specific commands are detailed in Paragraphs 6 3 2 thru 6 3 4 and summarized in Table 6 5 Status Registers There are two status registers the Status Byte Register described in Paragraph 6 1 3 1 and the Standard Event Status Register in Paragraph 6 1 3 2 Status Byte Register and Service Request Enable Register The Status Byte Register is a single byte of data containing six bits of information about Model 218 status STATUS BYTE REGISTER FORMAT Bit Weighting Bit Name DOG SRQ ESB Error E 4 2 ae Done Used RDG If the Service Request is enabled any of these bits being set will cause the Model 218 to pull the SRQ management low to signal the BUS CONTROLLER These bits are reset to zero upon a serial poll of the Status Byte Register These reports can be inhibited by turning their corresponding bits in the Service Request Enable Register to off The Service Request Enable Register allows the user to inhibit or enable any of the status reports in the Status Byte Register The SRE command is used to set the bits If a bit in the Service Request Enable Register is set 1 then that function is enabled Refer to the SRE comman
148. s using proper 4 lead connection techniques Input group configured for 7 5 kQ input all inputs of the group are enabled Via the interface obtain the RAWAD value of the 1 input To determine the calibration constant add the 7 5 kQ range zero offset constant to the value read and divide 5000 by that value or 5000 RAWAD reading zero offset constant For example if the value read was 1 66552 and the zero offset constant was 0 00010 the gain calibration constant is 5000 1 66542 3002 24 This gain calibration constant is provided back to the Model 218 using the GCAL command for the 1 input of the group only The above process must be repeated for the remaining 3 inputs of the group Once gain calibration constants for all ranges have been determined and provided back to the Model 218 the CALSAVE command is issued to save the constants in the E prom Service Lake Shore Model 218 Temperature Monitor User s Manual 7 13 12 5kQ Input Gain Calibration PURPOSE To determine the input gain errors when the input is configured for 5 KQ input and provide gain calibration constants back to the Model 218 CONFIG Attach the precision 5 kQ resistors to each input of the group Be sure to connect the resistors using proper 4 lead connection techniques Input group configured for 5 KQ input all inputs of the group are enabled PROCESS Via the interface obtain the RAWAD value of the 1 input To determine the calibration constant add the 5 kQ range
149. setting sequence appears Use the number keys to input an appropriate upper temperature limit for the installed sensor then press Enter Refer to Table 5 1 for recommended temperature limits for specific sensors The final display in the setting sequence appears Use the number keys to input individual breakpoint pairs of the curve Press Enter both after inputting the sensor units and the temperature After entry of a breakpoint pair the instrument displays a zero breakpoint Enter up to 200 breakpoints To exit the curve entry mode and store the new curve press Enter on a new breakpoint line To enter a zero sensor units value press zero before pressing Enter The curve stores but users must select it for the appropriate input before it is used NOTE Escape returns a single setting to its previous value It cannot return a complete breakpoint or an entire curve to a previous state Use the Data Selection keys to scroll up or down the breakpoint table Only the breakpoint located at the bottom line of the display is active for entry or editing Special Features 5 3 5 4 Lake Shore Model 218 Temperature Monitor User s Manual Erasing User Curves To erase a user curve press Curve Entry The screen below appears Use the Data Selection keys to select Erase Curve then press Enter The second display in the sequence appears Use the Data Selection keys to cycle to the input to which the curve applies 1 8 When the desire
150. sor measurement as well as the sensor Thermal gradients instrument accuracy and other measurement errors can be significant Calibration can be no better than user supplied data e Purchased Lake Shore sensors with SoftCal calibration include a set of calibration points in the calibration report Lake Shore generates these points in a controlled calibration facility for best accuracy Users enter the calibration points into the Model 218 to generate a curve If the user buys the CalCurve service with the calibrated sensor the factory generates a curve that can be entered like any other curve Special Features 5 5 Lake Shore Model 218 Temperature Monitor User s Manual 5 2 1 SoftCal and Silicon Diode Sensors Lake Shore Silicon Diode Sensors incorporate remarkably uniform sensing elements that exhibit precise monotonic and repeatable temperature response For example the Lake Shore DT 470 Series of silicon diode sensors has a repeatable temperature response from 2 K to 475 K These sensors closely follow the Standard Curve 10 response and are interchangeable SoftCal is an inexpensive way to improve the accuracy of an already predictable sensor NOTE Standard Curve 10 is the name of the temperature response curve not its location inside the Model 218 Standard Curve 10 stores in Curve Location 1 in the Model 218 under the name DT 470 SoftCal Point 1 SoftCal Point 2 SoftCal Point 1 Liquid Helium Liquid Nitrogen Room Temperature Bo
151. t 200 point maximum for each Improves accuracy of DT 470 diode to 0 25 K from 30 K to 375 K Improves accuracy of Platinum RTDs to 0 25 K from 70 K to 325 K Stored as user curves Maximum Minimum and Linear Equation Averages 2 to 64 input readings 4 line by 20 character backlit LCD display 1 to 8 K CM Q All displayed inputs twice in one second 0 001 between 0 99 999 0 01 between 100 999 99 0 1 above 1000 Sensor dependent to 5 digits Remote R Alarm A Data Logging D Max gt Min lt Linear 20 Key membrane numeric and specific functions Yes SH1 AH1 T5 L4 SR1 RL1 PP0 DC1 DT0 C0 E1 RS 232C Electrical DE 9 Connector 9600 BAUD Support for serial printer through serial interface Used with Data Log parameters 16 High and low for each input Temperature sensor units linear equation Units High Setpoint Low Setpoint Deadband Latching or Non Latching Audible on or off Display annunciator beeper relays 218S 8 Normally Open NO Normally Closed NC and Common C 30 VDC at5A Each input may be configured to actuate any or all of the 8 relays Relays may be activated on high low or both alarms for any input or manually User selected 10 V 1 25 mV 2 5 mV 1 kQ 1 8 per record Store Data Log records in memory or send them to the printer Users may display print or retrieve stored data by computer interface Maximum of 1500 single reading records non v
152. t 1 min max function processes data from input sensor units reading Query Minimum and Maximum Input Function Parameters MNMX lt input gt lt source gt Format n term Returns an input min max configuration lt input gt Specifies input to query 1 8 lt source gt Specifies input data to process through max min 1 Kelvin 2 Celsius 3 sensor units 4 linear data MNMXRDG Query Min Max Data for an Input Input Returned Remarks MNMXRST Input Returned Remarks MODE Input Returned Remarks Example MODE Input Returned Remarks 6 28 MNMXRDG lt input gt lt min value gt lt max value gt Format nn nnn nn nnn term Returns the minimum and maximum input data lt input gt specifies which input to query Resets Min Max Function for All Inputs MNMXRST Nothing Resets the minimum and maximum data for all inputs Configure Remote Interface Mode MODE lt mode gt Nothing Configures the remote interface mode lt mode gt specifies which mode to operate 0 local 1 remote 2 remote with local lockout MODE 2 term Places the Model 218 into remote mode with local lockout Query Remote Interface Mode MODE lt mode gt Format n term Returns the remote interface mode 0 local 1 remote 2 remote with local lockout Remote Operation RDGST Input Returned Remarks RELAY Input Returned Remarks Examples RELAY Input Return
153. t pot of the analog output being calibrated until the DVM displays 0 000 0 002 V 7 13 14 2 Analog Output Gain Adjust PURPOSE To adjust the full scale gain error of the analog output amplifier CONFIG The positive lead of the DVM is connected to the analog output positive terminal the negative lead is connected to the analog output negative terminal The DVM should be set to read DC VOLTS Via the front panel manually set the analog output to 10 V TOLERANCE 2 5 mV PROCESS Adjust the gain adjust pot of the analog output being calibrated until the DVM displays 10 000 0 002 V 7 13 14 3 Analog Output Negative Full Scale Test PURPOSE To check the 10 V output of the Analog Outputs CONFIG The positive lead of the DVM is connected to the analog output positive terminal the negative lead is connected to the analog output negative terminal The DVM should be set to read DC VOLTS Via the front panel manually set the analog output to 10 V TOLERANCE 2 5 mV PROCESS Check the DVM reading and verify it displays 10 000 0 003 V Service 7 13 Lake Shore Model 218 Temperature Monitor User s Manual 7 13 15 CALIBRATION SPECIFIC INTERFACE COMMANDS ADCAL Input Returned Remarks ZCAL Input Returned Remarks ZCAL Input Returned Remarks GCAL Input Returned Remarks 7 14 Calibrates A D Linearity ADCAL lt input group gt Nothing Calibrates the A D linearity of the selected input group Be
154. t s to query 0 all inputs 1 8 individual input NOTE Use 0 all inputs when reading two or more inputs at the maximum update of 16 rdgs sec Delete User Curve CRVDEL lt curve gt Nothing Deletes a user curve lt curve gt specifies which curve to delete 21 28 for inputs 1 8 CRVDEL 21 term Deletes User Curve 21 input 1 user curve Configure Curve Header CRVHDR lt curve gt lt name gt lt SN gt lt format gt lt limit value gt lt coefficient gt Nothing lt curve gt Specifies which curve to configure 21 28 for inputs 1 8 lt name gt Specifies curve name Limited to 15 characters lt SN gt Specifies curve serial number Limited to 10 characters lt format gt Specifies curve data format 2 V K 3 Ohm K 4 log Ohm K lt limit value gt Specifies curve temperature limit in Kelvin lt coefficient gt Specifies curve temperature coefficient 1 negative 2 positive CRVHDR 21 Custom 00011134 2 325 0 1 term Configures User Curve 21 input 1 user curve with a name of CUSTOM serial number 00011134 data format of volts vs Kelvin upper temperature limit of 325K and negative coefficient Query Curve Header CRVHDR lt curve gt lt name gt lt SN gt lt format gt lt limit value gt lt coefficient gt Format aaaaaaaaaaaaaaa aaaaaaaaaa n nnn nnn n term Returns a standard or user curve header See CRVHDR command for parameter descriptions lt curve gt specifies which curve
155. ta Selection keys to cycle through the different sensor types for Input group 5 8 When the desired type appears press Enter The third display in the setting sequence appears Use the Data Selection keys to turn the displayed input On or Off then press Enter to advance to the next input Turn all unused inputs off for maximum reading rate Press Escape at any time to return to the normal display The instrument retains values changed prior to pressing Escape After setting all Input Type parameters the normal display appears The message Disabled appears in the display location of any inputs that are turned off Table 4 1 Sensor Input Type Display Messages Display Message Sensor Type 2 0V Diode Silicon Diode 7 5V Diode GaAlAs Diode 250 Ohm Plat 100 Ohm Platinum RTD lt 675K Rhodium lron RTD 500 Ohm Plat 100 Ohm Platinum RTD gt 675K 5k Ohm Plat 1000 Ohm Platinum RTD Cernox Any NTC RTD 0 75000hm Germanium Carbon Glass Cernox Rox Thermox 4 6 Operation 4 5 1 4 6 Lake Shore Model 218 Temperature Monitor User s Manual Optimizing the Update Rate The maximum update rate of the Model 218 is 16 readings per second allowing all eight inputs to be read twice each second Turning off unused inputs Paragraph 4 1 5 permits a higher reading rate on fewer sensors refer to Table 4 2 For maximum efficiency split sensors evenly between the two input groups when using fewer than eight sensors All new readings can
156. terminal block simultaneously Accessories included with a new Model 218 Accessories 8 1 Lake Shore Model 218 Temperature Monitor User s Manual Accessories Continued Model Description of Accessories 9001 00X Lake Shore Cryogenic Wire Lake Shore sells the following types of cryogenic wire DT Duo Twist MN Single Strand MW Manganin NC Nichrome Heater ND Heavy Duty QL Quad Lead and QT Quad Twist Refer to the Lake Shore Temperature Measurement and Control Catalog for details 9004 020 Apiezon N Grease 25 gram Tube General purpose grease well suited for cryogenic use because of its low viscosity It is often used as a means of thermally anchoring cryogenic sensors as well as lubricating joints and o rings Contains high molecular weight polymeric hydrocarbon additive which gives it a tenacious rubbery consistency allowing the grease to form a cushion between mating surfaces temperatures May be used as a Sealing gasket for covers flanges and windows in cryogenic applications 9007 002 Indium Foil 5 Pieces Indium is a semi precious non ferrous metal softer than lead and extremely malleable and ductile It stays soft and workable down to cryogenic near the instrument rear panel MAN 218 Model 218 Temperature Monitor User s Manual RM 1 2 Half Rack Mounting Kit for One Model 218 Temperature Monitor Half length mounting panel and mounting ears to attach one Model 21
157. the NOVRAM then press Enter Select Yes to reset all Model 218 parameters to the defaults listed in Table 4 4 below The second screen in the setting sequence displays Use the Data Selection keys to select Yes or No to clear all user curves stored in the Model 218 Standard curves are unaffected Press Enter The instrument performs the operations specified then displays the Normal display Table 4 4 Model 218 Parameter Defaults Parameter Befaut parameter Default Audible Alarm Display 4 16 Locations 1 8 Inputs 1 8 Source K Operation 5 0 9 1 Lake Shore Model 218 Temperature Monitor User s Manual CHAPTER 5 SPECIAL FEATURES GENERAL This chapter covers Front Panel Curve Entry in Paragraph 5 1 SoftCal in Paragraph 5 2 Data Logging in Paragraph 5 3 and Printing in Paragraph 5 4 Most users will not find it necessary to use these special features during normal operation FRONT PANEL CURVE ENTRY A unique 200 point user curve can be stored for each of the eight inputs CalCurves for Lake Shore calibrated sensors can be stored as user curves The built in SoftCal algorithm Paragraph 5 2 uses the same memory space so it is not possible to enter a user curve and SoftCal curve for the same input User curves must be stored in the same location number as the sensor input Once an appropriate user curve is stored for a sensor input it can be selected just like standard curves A user curve may not b
158. then press Log View If logging is active when Log View is pressed logging pauses while data is viewed and resumes after Log View is exited When viewing logged records the screen shown below displays The data log screen includes a record number time date and the readings specified in the log setup The instrument tags any readings in which an alarm or error occurs with alarm error designations listed below L Low Alarm H High Alarm B Both Alarms T Temperature Over or Under Range S Sensor Over or Under Range Use the Data Selection keys to scroll up and down Scrolling up past the first record will show the last record Line Power Loss Data log memory is non volatile and will not erase when line power is lost The Model 218 cannot log data while power is off but it resumes the data log sequence when power is restored Date and time are also non volatile and do not have to be entered after power loss Special Features 5 11 9 4 9 4 1 9 12 Lake Shore Model 218 Temperature Monitor User s Manual PRINTING The Model 218 can send sensor input data to a printer for a hard copy temperature record The instrument s serial port interfaces with standard printers The serial computer interface and a printer cannot be used at the same time Some printer operating parameters are shared with the data log feature It is important to setup data log before trying to print Table 5 3 Serial Printer Interface Specifications Co
159. tle current in the voltage leads so their resistance does not enter into the measurement Resistance in the current leads will not change the current as long as the voltage compliance of the current source is not reached When two lead sensors are used in four lead measurements the short leads on the sensor have an insignificant resistance NOTE The Model 218 does not have three lead measurement capability Two Lead Sensor Measurement Sometimes a crowded cryogenic system forces users to read sensors in a two lead configuration because there are not enough feedthroughs or room for lead wires If this is the case plus voltage to plus current and minus voltage to minus current leads are attached at the back of the instrument or at the vacuum feedthrough E Two Lead Diod iode V The error in a resistive measurement is the resistance of the lead wire run with current and voltage together If the leads contribute 2 or 3 Q to a 10 KQ reading the error can probably be tolerated When measuring voltage for diode sensors the error in voltage can be calculated as the lead resistance times the current typically 10 uA For example a 10 Q lead resistance times 10 uA results in a 0 1 mV error in voltage Given the sensitivity of a silicon diode at 4 2 K the error in temperature would be only 3 mK At 77 K the sensitivity of a silicon diode is lower so the error would be close to 50 mK Again this may not be a problem for every user NOTE
160. to display all inputs of the group in sensor units 7 11 PROCESS Lake Shore Model 218 Temperature Monitor User s Manual Adjust the four current source calibration pots on the Model 218 main board until each of the 4 inputs display exactly 2 0000 V 7 13 9 250 Q Input Gain Calibration PURPOSE CONFIG PROCESS To determine the input gain errors when the input is configured for 250 Q input and provide gain calibration constants back to the Model 218 Attach the precision 250 Q resistors to each input of the group Be sure to connect the resistors using proper 4 lead connection techniques Input group configured for 250 Q input all inputs of the group are enabled Via the interface obtain the RAWAD value of the 1 input To determine the calibration constant add the 250 2 range zero offset constant to the value read and divide 250 by that value or 250 RAWAD reading zero offset constant For example if the value read was 2 48540 and the zero offset constant was 0 00005 the gain calibration constant is 250 2 48545 100 585 This gain calibration constant is provided back to the Model 218 using the GCAL command for the 1 input of the group only The above process must be repeated for the remaining 3 inputs of the group Once gain calibration constants for all ranges have been determined and provided back to the Model 218 the CALSAVE command is issued to save the constants in the E prom 7 13 10 500 Q Input Gain Calibrat
161. to end program Caption Command Caption Response Text lt blank gt Text2 Name txtResponse Text lt blank gt Command1 Name cmdSend Caption Send Default True Name frmSerial Caption Serial Interface Program Interval 10 12 Add code provided in Table 6 4 a Inthe Code Editor window under the Object dropdown list select General Add the statement Public gSend as Boolean b Double Click on cmdSend Add code segment under Private Sub cmdSend_Click as shown in Table 6 4 c Inthe Code Editor window under the Object dropdown list select Form Make sure the Procedure dropdown list is set at Load The Code window should have written the segment of code Private Sub Form_Load Add the code to this subroutine as shown in Table 6 4 d Double Click on the Timer control Add code segment under Private Sub Timer1_Timer as shown in Table 6 4 e Make adjustments to code if different Com port settings are being used 13 Save the program 14 Run the program The program should resemble the following Serial Interface Program OF ES Type exit to end program Command Response E 15 Type in a command or query in the Command box as described in Paragraph 6 2 7 3 16 Press Enter or select the Send button with the mouse to send command 17 Type Exit and press Enter to quit 6 12 Remote Operation Lake Shore Model 218 Temperature Monitor User s Manual Table 6 4 Visual Basic Serial Interface Progr
162. to query 1 5 Standard Diode Curves 6 9 Standard Platinum Curves 21 28 User Curves NOTE Curve Locations 10 20 not used Configure Curve Data Point CRVPT lt curve gt lt index gt lt units value gt lt temp value gt Nothing Configures a user curve data point lt curve gt Specifies which curve to configure 21 28 for inputs 1 8 lt index gt Specifies the points index in the curve 1 200 lt units value gt Specifies sensor units for this point to 6 digits lt temp value gt Specifies corresponding temperature in Kelvin for this point to 6 digits CRVPT 21 2 0 10191 470 000 term Sets User Curve 21 input 1 user curve second data point to 0 10191 sensor units and 470 000 K Remote Operation CRVPT Input Returned Remarks DATETIME Input Returned Remarks Example Lake Shore Model 218 Temperature Monitor User s Manual Query Curve Data Point CRVPT lt curve gt lt index gt lt units value gt lt temp value gt Format nnn nnn nnn nnn term Returns a standard or user curve data point See CRVPT command for parameter descriptions lt curve gt Specifies which curve to query 1 5 Standard Diode Curves 6 9 Standard Platinum Curves 21 28 User Curves NOTE Curve locations 10 20 not used lt index gt Specifies the points index in the curve 1 200 Configure Date and Time DATETIME lt MM gt lt DD gt lt YY gt lt HH gt lt mm gt lt SS gt Noth
163. trument retains values changed prior to pressing Escape twice Most data entry operations are combined with other settings and grouped under a function key Temperature or sensor unit parameters have the same setting resolution as the display resolution for their corresponding readings TURNING POWER ON After verifying line voltage Paragraph 3 3 plug the instrument end of the line cord included with the connector kit into the power and fuse assembly receptacle on the instrument rear Plug the opposite end of the line cord into a properly grounded three prong receptacle Flip power switch located next to the line cord receptacle to the On I position The instrument initiates the following power up sequence the instrument alarm sounds once the display shows a startup message then clears the normal reading display appears If the instrument does not complete the sequence or if a general error message displays there may be a problem with the line power or the instrument Individual messages in a reading location normally indicate that input setup is required DISPLAY SETUP The Model 218 has a 4 line by 20 character backlit LCD During normal operation it is divided into eight reading locations Each of the eight reading locations can be configured by the user with the Display Format feature Data from a sensor input can be displayed in any location Sensor readings can be displayed in temperature or sensor units Results of the math feature
164. ts a log record every 10 seconds NOTE When using Print Continuous small delays in log period may occur up to 120 ms per printed record For time critical applications Log Continuous mode is recommended Print Event Directs log records to the printer instead of internal memory when an input alarm or an error event either occurs or is removed No period is set by user The instrument checks for an event every 10 seconds and prints if one exists If an event occurs and then is removed within the 10 second window it will not print Use the Data Selection keys to cycle through the different modes When the desired mode appears press Enter to activate that mode Select Print Stored Log to print data immediately The screen below displays To stop printing at any time and return to the normal display press Escape If the mode is Print Continuous or Print Event use the Log On Off key to start and stop printing With Print Continuous or Print Event selected only the Data Log D annunciator displays during printing The data log prints in the format below MM DD YY HH MM SS 1 123 45US 2 123 45US 3 123 45US 4 123 45US 5 123 45US 6 4 123 45US 7 4 123 45US 8 123 45US where MM DD YY Month Day Year HH MM SS Hour Minutes Seconds U Units Kelvin Celsius Volts Ohms Linear Low Alarm High Alarm Both Alarms Temperature Over or Under Range Sensor Over or Under Range S Status VAVI E Oe CH ZS 5 14 Speci
165. ude both the large interpolation table and the smaller breakpoint interpolation table A CalCurve refer to Paragraph 2 2 4 or front panel curve entry refer to Paragraph 5 2 may be required to get the breakpoint table into a Model 218 where it is called a temperature response curve The Model 218 also performs SoftCal calibration The user provides 1 2 or 3 known temperature reference points Calibration range and accuracy depend on these points Paragraph 5 2 Sensor Considerations Lake Shore Model 218 Temperature Monitor User s Manual 2 2 3 Standard Curves Some types of sensors behave very predictably and a standard temperature response curve can be created for them Standard curves are a convenient and inexpensive way to get reasonable temperature accuracy Sensors with a standard curve are often used when interchangeability is important Some individual sensors are selected for their ability to match a published standard curve and sold at a premium but in general these sensors do not provide the accuracy of a calibrated sensor For convenience the Model 218 has several standard curves included in firmware Lake Shore DT 400 Series Silicon Diode Temperature Sensor SoftCal Calibration A 2 point SoftCal uses data points at 77 35 K and 305 K A 3 point SoftCal uses data points at 4 2 K 77 35 K and There are 3 ways to improve temperature sensor accuracy Standard Standard sensors are interchangeable within
166. ues changed prior to pressing Escape Operation 4 15 Lake Shore Model 218 Temperature Monitor User s Manual 4 12 LOCKING THE KEYPAD The Model 218 keypad lock feature prevents accidental changes to parameter values When the keypad is locked some parameter values may be viewed but most cannot be changed over the front panel Alarm Reset is the only keypad function that remains active when the keypad is locked A three digit keypad lock code locks and unlocks the keypad The factory default code is 123 The code can be changed only through the computer interface If instrument parameters are reset to default values the lock code resets also The instrument cannot reset from the front panel with the keypad locked To lock the keypad press and hold Enter for 10 seconds to display the screen to the right Use the number keys to enter the 3 digit lock code The keypad locks and the normal display appears Changes attempted to any of the Model 218 parameters result in a brief display of the LOCKED message To unlock the keypad press and hold Enter for 10 seconds to display the screen to the right Use the number keys to enter the 3 digit lock code The keypad unlocks and the normal display appears All Model 218 parameters are now accessible 4 13 RESETTING MODEL 218 TO DEFAULTS To reset the Model 218 to defaults press and hold Escape until the screen to the right appears Use the Data Selection keys to select Yes or No to reset
167. ument error not related to the bus Alarm Bit 3 This bit is set when there is an alarm condition Overload Bit 2 This bit is set when any input is in either SOVER TOVER SUNDER or TUNDER New Reading Bit 0 New data is available from at least one of the inputs Standard Event Status Register and Standard Event Status Enable Register The Standard Event Status Register supplies various conditions of the Model 218 STANDARD EVENT STATUS REGISTER FORMAT Bip 24 1 a ae 2 AA EE Weighting 128 64 32 16 8 4 2 1 Bit Name Bits 2 and 6 are not used The user will only be interrupted with the reports of this register if the bits have been enabled in the Standard Event Status Enable Register and if bit 5 of the Service Request Enable Register has been set The Standard Event Status Enable Register allows the user to enable any of the Standard Event Status Register reports The Standard Event Status Enable command kESE sets the Standard Event Status Enable Register bits If a bit of this register is set then that function is enabled To set a bit send the command ESE with the bit weighting for each bit you want to be set added together Refer to the KESE command discussion for further details The Standard Event Status Enable Query ESE reads the Standard Event Status Enable Register ESR reads the Standard Event Status Register Once this register has been read all of the bits are reset to z
168. ure to develop the Serial Interface Program in Quick Basic Start the Basic program Enter the program exactly as presented in Table 6 5 Adjust the Com port and Baud rate in the program as necessary Lengthen the TIMEOUT count if necessary Save the program Run the program Type a command query as described in Paragraph 6 2 7 3 E ee ON een eS e Type EXIT to quit the program Table 6 5 Quick Basic Serial Interface Program CLS Clear screen PRINT SERIAL COMMUNICATION PROGRAM PRINT TIMEOUT 2000 Read timeout may need more BAUDS 9600 TERMS CHR 13 CHRS 10 Terminators are lt CR gt lt LF gt OPEN COM1 BAUDS 0 7 1 RS FOR RANDOM AS 1 LEN 256 LINE INPUT ENTER COMMAND or EXIT CMDS Get command from keyboard CMD UCASES CMDS Change input to upper case IF CMDS EXIT THEN CLOSE 1 END Get out on Exit CMDS CMDS TERMS PRINT 1 CMDS Send command to instrument IF INSTR CMDS lt gt O THEN Test for query RS mn 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 RS RSS INS Add next chr to string WEND Get chrs until terminators IF RS lt gt THEN See if return string is empty RS MIDS RS S 1 INSTR RS TERMS 1 Strip off terminators PRIN
169. urement resolution that same resolution may not be required to monitor warm up to room temperature Two different sensors may be required to tightly cover the range from helium to room temperature but lowering the requirement on warm up may allow a less expensive one sensor solution Another thing to consider when choosing a temperature sensor is that instruments like the Model 218 are not able to read some sensors over their entire temperature range Lake Shore sells calibrated sensors that operate down to 50 mK but the Model 218 is limited to operation above 1 K in its standard configuration Sensor Sensitivity Temperature sensor sensitivity measures how much a sensor signal changes when the temperature changes It is important because so many measurement parameters relate to it Resolution accuracy and noise floor depend on sensitivity Many sensors have different sensitivities at different temperatures For example platinum sensor sensitivity is good at higher temperatures but drops sharply below 30 K It may be difficult to determine if a sensor has adequate sensitivity over the experimental temperature range Table 1 2 lists sensor sensitivity translated into temperature resolution and accuracy at different points This is typical sensor response and can be used as a guide to choose a sensor for the Model 218 Environmental Conditions Environmental factors such as high vacuum magnetic field corrosive chemicals or even radiation ma
170. ustrates suggested cables that can be used between the instrument and common computers The instrument uses drivers to generate the transmission voltage levels required by the RS 232C standard These voltages are considered safe under normal operating conditions because of their relatively low voltage and current limits The drivers are designed to work with cables up to 50 feet in length To maintain Electromagnetic Compatibility EMC add the clamp on ferrite filter P N 9009 020 included with the connector kit to the Serial Interface cable near the instrument rear panel when that interface is used Hardware Support The Model 218 interface hardware supports the following features Asynchronous timing is used for the individual bit data within a character This timing requires start and stop bits as part of each character so the transmitter and receiver can resynchronized between each character Half duplex transmission allows the instrument to be either a transmitter or a receiver of data but not at the same time Communication speeds of 300 1200 or 9600 baud are supported The Baud rate is the only interface parameter that can be changed by the user Hardware handshaking is not supported by the instrument Handshaking is often used to guarantee that data message strings do not collide and that no data is transmitted before the receiver is ready In this instrument appropriate software timing substitutes for hardware handshaking User programs
171. ve these general safety precautions during all phases of instrument operation service and repair Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended instrument use Lake Shore Cryotronics assumes no liability for Customer failure to comply with these requirements The Model 218 protects the operator and surrounding area from electric shock or burn mechanical hazards excessive temperature and spread of fire from the instrument Environmental conditions outside of the conditions below may pose a hazard to the operator and surrounding area e Indoor use e Altitude to 2000 m e Temperature for safe operation 5 to 40 C e Maximum relative humidity 80 for temperature up to 31 C decreasing linearly to 50 at 40 C e Power supply voltage fluctuations not to exceed 10 of the nominal voltage e Overvoltage category Il e Pollution degree 2 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 the power cable into an approved three contact electrical outlet or use a three contact adapter with the grounding wire green firmly connected to an electrical ground safety ground at the power outlet The power jack and mating plug of the power cable meet Underwriters Laboratories UL and International Electrot
172. verifying voltage leads are symmetrical in the type of metal used and how they are joined and by keeping unnecessary heat sources away from the leads Even in a well designed system thermal EMF voltages can be an appreciable part of a low voltage sensor measurement The Model 218 has no thermal correction algorithm Other instruments automatically reverse the current source polarity and average the positive and negative sensor readings to cancel the thermal EMF voltage Account for thermal EMF errors when estimating Model 218 measurement accuracy Sensor Considerations 3 0 3 1 3 2 Lake Shore Model 218 Temperature Monitor User s Manual CHAPTER 3 INSTALLATION GENERAL This chapter covers general Model 218 installation instructions Inspection and Unpacking in Paragraph 3 1 Repackaging for Shipment in Paragraph 3 2 and Rear Panel Definition in Paragraph 3 3 INSPECTION AND UNPACKING Inspect shipping containers 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 please notify the shipping agent immediately Open the shipping containers Use the packing list included with the system to verify receipt of the instrument sensor accessories and manual Inspect for damage Inventory all components supplied before discarding any shipping materials If there is freight damage to the instrum
173. y limit effectiveness of some sensors Lake Shore offers sensor packages that withstand environmental factors found in typical cryogenic cooling systems Magnetic field experiments are very common Field dependence is an important selection criteria for temperature sensors used in these experiments Table 1 2 states the field dependence of most common sensors The Lake Shore Temperature Measurement and Control Catalog includes detailed field dependence tables along with specific data on other environmental factors when available Sensor Considerations 2 1 2 2 2 2 1 2 2 2 2 2 Lake Shore Model 218 Temperature Monitor User s Manual Measurement Accuracy Temperature measurements have several sources of error Account for errors induced by both the sensor and the instrumentation when computing accuracy The instrument has measurement error in both reading the sensor signal and calculating a temperature using a temperature response curve Error results from the sensor comparison to a calibration standard the sensor temperature response shifts with time and repeated thermal cycling Instrument and sensor makers specify these errors but some things help maintain good accuracy For example choose a sensor with good sensitivity in the most critical temperature range as sensitivity minimizes the effect of most error sources Install the sensor properly Paragraph 2 3 Recalibrate the sensor and instrument periodically Use a sensor calibration
174. y string The instrument will respond only to the last query it receives The response can be a reading value status report or the present value of a parameter Response data formats are listed along with the associated queries in Paragraph 6 3 The response is sent as soon as possible after the instrument receives the query Typically it takes 10 ms for the instrument to begin the response Some responses take longer Remote Operation 6 9 Lake Shore Model 218 Temperature Monitor User s Manual 6 2 5 Message Flow Control It is important to remember that the user program is in charge of the serial communication at all times The instrument can not initiate communication determine which device should be transmitting at a given time or guarantee timing between messages All of this is the responsibility of the user program When issuing commands only the user program should e Properly format and transmit the command including terminators as one string e Guarantee that no other communication is started for 50 ms after the last character is transmitted e Not initiate communication more than 20 times per second When issuing queries or queries and commands together the user program should e Properly format and transmit the query including terminators as one string e Prepare to receive a response immediately e Receive the entire response from the instrument including the terminators e Guarantee that no other communication is started durin
175. ystems include a radiation shield The purpose of the shield is to surround the load sample and sensor with a surface that is at or near their temperature to minimize radiation The shield is exposed to the room temperature surface of the vacuum shroud on its outer surface so some cooling power must be directed to the shield to keep it near the load temperature If the cooling system does not include an integrated radiation shield or one cannot be easily made one alternative is to wrap several layers of super insulation aluminized mylar loosely between the vacuum shroud and load This reduces radiation transfer to the sample space Thermal EMF Compensation with Voltage Excitation Sensors used at low temperatures must operate with little power dissipated in the sensor To keep power low the voltage across the sensor is kept low Two major problems occur when measuring small DC voltages The first is external noise entering the measurement through the sensor leads which is discussed with sensor setup The second is the presence of thermal EMF voltages sometimes called thermocouple voltages in the lead wiring Thermal EMF voltages appear whenever there is a temperature gradient across a piece of voltage lead They can be canceled in the measurement with a similar temperature gradient in the other voltage lead Thermal EMF voltages must exist because the sensor is almost never the same temperature as the instrument Minimize them by careful wiring

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