Harvard`s Research DC Signal Conditioner with Zero Suppression
Contents
1. iud ate pda 24 Signal CONNECT RAI RD RR RR 2 41 Iriput Gonfnectioh cipal Reel Rt e eoe didus 2 4 2 Output and Power 2 5 Installation of Optional Status Reporting Kit XX 2 6 Outline DIMENSIONS enenu oe et ni vin cee ie dd XX OPERATION Section 3 931 General etate da f id gd o t e pet ve ine XX 3 2 Control Descriptions cede A m cd A LR Rede FEE e Er a ee ced ere XX 3 9 Rear Panel Connectors de ah cid id de eie eng uice arte deus tee e qe ete XX 3 3 1 Input GOnnhectot iem P eto Rp UR DR ERU ao XX 3 3 2 Output Connector n aute pear Ri EP Eo a ep euge XX 3 4 Preliminary Operation 5 5 ouo E P EODD UP XX 3 5 Uncalibrated Operation eie e EG tret a eed da XX 3 6 Zero SUDpression none eie mel uei n enin i denim XX 3 6 1 Application of Zero Suppression nennt nne nnne nenne rn XX 3 7 Filter Operation ni censet A A a XX 3 8 Additlon of a Third Filter ooo ete eee e irte etel ee ea XX 3 9 iBalance Ad stment eoe ete eu EE EE uds XX 3 10 Main Amplifier Board Functional Test e XX 3 11 Status Reporting Kit dev ibe le diete e edet bap ta dc XX 3 12 Status Board Commands 2 Aia EIC RR ERROR GA XX 3 1271 SONG Stats Mick ts cL e te XX 3 12 2 Data Tag ine ERO Oen ei adi Mi XX 3 12 3 Personality ien deae UE t ae ens XX 32. 0 25 volts 400 mA Appendix A Status Reporting Kit Specifications Optional Description The Status Board enables the signal conditioner to report front panel settings to the 5900 Signal Conditioner Frame Assembly or an optional interchannel annotation head on the 3000 Series Recorder In order to print the signal conditioner s status in the interchannel margins the 5900 Signal Conditioner Frame Assembly and the 3000 Recorder must have the Interpreter Board and the Annotation Drive Board installed respectively If the signal conditioner s status is to be reported to a terminal or computer then the Interpreter Board and either the RS 232 or the IEEE 488 Interface Boards are needed The Status Board provides status tag personality and person ality length information on demand Connectors Input 20 pin ribbon cable that brings the front panel conditions into the board Output A 48 pin edge connector located in the rear of the board Input The input lines are controlled on the signal conditioner board The x1 x100 is optically isolated the other lines are mechanically isolated by contact closures Output Supplies digital logic signals to the 5900 Signal Conditioner Frame Assembly bus Power Requirements Less than 50 mA at 5 volts Appendix B General An understanding of signal sources and connections in electrical measurement is vital to prevent noise or ambient conditions from over shadowing desired physical or elec
3. 3 13 Status Reporting Kit Functional Test See Appendix C Performance Test Status Board 3 O peration 3 14 Software Commands 3 14 1 General The following paragraphs describe the software commands and their functions which are used when the 60 0125 Signal Conditioner is installed in a Harvard 5900 Signal Conditioner Frame Assembly The command set and two registers permit the user to send commands via the 5900 Signal Conditioner Frame Assembly to the 60 0125 Signal Conditioner 3 14 2 Command Format The software program for the 5900 Signal Conditioner Frame Assembly or Harvard 3000 Series Recorder uses the following format to execute commands The letter n in specific commands indicates the desired slot number A space must be entered between the command and slot number e When sending multiple commands each command must be separated by a semicolon When sending commands via the 3000 recorder interface each command or command string must be preceded by the command PC If commands are sent to a Harvard 3000 Recorder any commands to the recorder must precede the command Each line should be terminated with a carriage return lt gt 3 14 5 Command Set Table 3 8 is a list of the available commands for the Signal Conditioner Table 3 9 is a description of the commands and their functions TABLE 3 8 List of Software Commands Amp Busy Status AS Disable Service Request DQ
4. guardring See Figure 2 4 for the location of input connector Turn on the system power Set the x1 x100 switch in the x1 position and volts full scale knob to the 1 setting Record the reading on the voltmeter Turn the volts full scale knob to the 025 setting Adjust the bal control on the front panel to get the same reading as in step 7 10 Check the two readings again and re adjust if necessary NOTE As stated previously tbere will be an interaction between tbe sensitivity x1 control and tbe out put of tbe signal conditioner If tbe sensitivity x1 control is changed from tbe detent position a zero sbift can be expected 3 10 Main Amplifier Board Functional Test Procedure This procedure should be performed to verify operation and calibration of this unit If the out put is within the tolerances given no calibration is required If not refer to the Service Manual for the calibration procedure NOTE Ambient temperature should be 25 5 77 F 9 Balance input before performing functional test see BALANCE ADJUSTMENT Functional Test Steps 1 Connect a digital voltmeter to the signal conditioner output by following the procedure given in BALANCE ADJUSTMENT steps 1 thru 3 2 Set the front panel controls as follows volts full scale selected to the 025 position sensitivity x1 fully clockwise and the x1 x100 switch in the x1 position and the 1v off 10v switch to the off position
5. terminals in sequence A zero signal from one terminal and equal or similar signals from the other two indicates a bal lanced grounded source With the signal source turned OFF resistance readings from ground to each terminal identify the ground terminal and the source resistance of each active output termi nal to ground Equal 60 Hz noise signals from the three terminals and a resistance of several hundred megohms between all three terminals to ground indicates a balanced floating source With the source turned OFF ohmmeter readings across the three output terminals reveal the common terminal the source resistance of each leg to common and the total source resistance A usable signal from one terminal to ground and nearly equal signals from the other two indi cates a driven off ground source The terminal with the minimum signal or a signal different from the other two is prob ably the common terminal and the signal from it to ground is the off ground or common mode voltage With the source turned OFF equal resistance readings taken across the three output terminals reveal the common terminal the output resistance of each leg to common and the total source resistance Appendix A The Elusive Ground Loop The GROUND LOOP is the largest source of electrical noise between electronics modules More than one ground on a signal circuit or signal cable shield produces a common impedance cou pling or ground loop between these two points Thi
6. 12 4 gt Personality idet et MORE HD EROR RN Rd ists XX 3 13 Status Reporting Kit Functional Test sssssssssssssseeeeeenenneen eene nenne XX 3 14 Software Commands enceinte ci duc ee ees ee da t ae XX 314 1 Cee al D a XX 3 14 2 Command Format rms et e eerte ite OE A dence ede deae XX 3 14 3 Command Set x diee ais XX 3 15 Serial Poll Mode amp Error Registers sssssssssssssssseeeneeeeeneeneee nene XX MAINTENANCE Section 4 Title Page 4 1 Introduction nino ite e abu EE leas le e eiii dis XX 4 2 ssn ren ch edere teca a Ee de Ye pd eee eate E dee XX 4 2 1 Front Panel A metae a dae de I tai tette etu XX 4 22 Input Conector pee ale ent ate XX 4 2 3 Printed Circuit Board iacere eed avis A sek Nette pg ees XX 4 3 ACccessorl s Ie RIO p MH IS ine XX APPENDICES AppendbcA eee eee Uia ue ERU e XX Signal Conditioner nnne nnne nnne XX ueteri eh aet ient it Pete tuos XX Signal SOULCES eirag XX e Hato et ERE B t ee ERE XX Performance Test Optional Status XX LIST OF ILLUSTRATIONS Figure Title Page 1
7. Apparatus Service Representative Maintenance 4 1 Introduction 4 2 Cleaning 4 2 1 Front Panel Wipe off the front panel including the display window and keys with a damp rag using a mild soap Allow the panel and keys to thoroughly dry before placing the unit in operation 4 2 2 Input Connector Clean the pins and inside of the connector with isopropyl alcohol with 90 alcohol content A damp rag with mild soap may be used on the outside of the connector and the release mechanism See Figure 4 1 Allow the connector pins and release mechanism to air dry 4 2 3 Printed Circuit Board Any accumulated dust or dirt must be removed from the printed circuit board for the Signal Conditioner to operate properly To access the board for cleaning perform the following procedures 1 Turn power OFF to the Signal Conditioner Frame Assembly with the power switch located in the rear of the unit 2 Disconnect the input connector plug by unscrewing it counterclockwise See Figure 4 1 3 For 5900 Frame Assemblies loosen the extractor see Figure 4 2 located at the bottom of the slot by turning the screw counterclockwise Pull on the extractor until the Signal Conditioner releases 4 Carefully slide the entire Signal Conditioner from the frame assembly 5 Remove the right hand side cover as viewed from the front of the unit by unscrewing one posi drive 4 40 screw located at the top of the cover flange See Figure 4 1 Rem
8. Earth Ground No 2 produces ground loop current in the lower signal lead from the signal source to the input of the signal conditioner causing ground loop noise to be combined with the useful signal There is a sec ond ground loop in illustration A through the signal cable shield from the signal source to the signal conditioner The ground loop current in the shield is coupled to the signal pair through the distributed capacity in the signal cable This current is returned through the output imped ance of the signal source and back to Earth Ground No 1 adding a second source of noise to the useful signal Either one of these ground loops is capable of generating a noise signal that is at least one hundred times larger than a typical millivolt level signal The signal conditioner shown in illustration B of Figure B 2 is capable of being FLOATED a few volts off ground The ground loop through the signal lead can be broken by simply lifting the signal conditioner grounding strap The signal conditioner enclosure is still solidly grounded to Earth Ground No 2 but this will not create a ground loop since the signal conditioner enclosure is insulated from the signal circuit The ground loop through the signal cable shield is eliminated by removing the jumper from the cable shield to Earth Ground No 2 Now the sig nal source and the signal cable shield are grounded ONLY at the signal source which is the proper configuration for minimum
9. Short pins 1 and 2 of the input connector J101 and connect them to the ring shield signal common The output should read 0 000 volts 0 002 volts 3 Remove the jumper shorting the inputs and ring shield together Apply 40 025 volts 25uvolts to the inputs Output should read 5 000 volts 0 025 volts 3 4 Change volts full scale switch to the 5 volt position and apply 5 000 volts to the input Output should read 5 000 volts 0 005 volts O peration 5 Set zero suppression 1v off 10v switch to the 10v position switch to the position and vernier control fully clockwise Change input to 410 000 volts Output should read 0 000 volts 0 020 volts As the vernier control is rotated counter clockwise the 10 volts being applied to the input will begin to appear at the output of the signal conditioner When the vernier control is at 5 0 the zero suppression is at 5096 of the 10 volts suppression range so 5096 of the input will be suppressed out while the other 5096 appears at the signal conditioner output 6 Remove input signal power and test equipment Unit is ready for use 3 11 Status Reporting Kit The Status Reporting Kit contains the Status Board and its mounting hardware The Status Board transmits the volts full scale setting x1 x100 switch setting is incorporated into the response and reports the ON condition of the sensitivity x1 zero suppression and filter the custom filter is NOT recognized It recognizes t
10. a remote terminal or AMP PRINT key is pusbed on tbe 3000 Recorder tbe current status of tbe Signal Conditioner will be printed out listing tbe parameters and values tbat bave been entered for tbe selected mode See tbe application exam ple wbicb follows tbe paragrapbs on Bit Stream in tbis section 3 15 Serial Poll Mode and Error Registers The two registers Serial Poll Mode Register and the Error Register provide the software with the capability to read status and errors on the IEEE 488 bus The Signal Conditioner using the Serial Poll Mode Register has the controller to poll machine status and error bits See Table 3 10 for a description of the bits in the Serial Poll Mode Register A Service Request is generated whenev er an error arrears in the Error Register While a Service Request is asserted the register will not be read unless an Enable Service Request EQ command is sent This permits the con troller to continue operation without having to check every error asserted in the Error Register or status change in the Serial Poll Mode Register When an Enable Service Request which is the power on default is sent the software will read any errors asserted in the Error Register See Table 3 11 for a description of the bits in the Error Register The Disable Service Request command DQ suppresses the assertion of the Service Request bit and the Error Register is automatically cleared with a serial poll read
11. fixed settings of the volts full scale control When in the full clockwise detent position the sensitivity is fixed as indicated with the volts full scale knob When rotated counterclockwise the sensitivity decreases from that indicated A ratio of 2 5 to 1 provides overlapping gain on all ranges except 5 and 500 volts full scale The ratio on the 5 volts full scale setting is 2 to 1 allowing a full scale input of 10 volts when the sensitivity x1 control is at its minimum setting 5 5 off 15 filler Hz three position toggle switch which selects either of the filters or filter Off 6 A two position toggle switch which selects polarity of voltage to be suppressed 7 1v off 1 Ov A three position toggle switch which selects full scale zero suppression voltage or turns zero suppression off The x1 x100 switch ITEM 3 does extend the zero suppression range if placed in the x100 position 8 vernier A 10 turn potentiometer which allows calibrated settings of zero suppression voltage from 0 to 100 3 O peration D C Amplifier volts full scale 1 5 25 2 5 5 05 Off bal gt x1 9 x100 sensitivity rS filter Hz ii Q T zero suppression 7 Q 10v Le vernier b FIGURE 3 1 Front Panel Controls 3 e CAUTION N O peration NEVER APPLY MORE THAN 500 VOLTS TO THE SIGNAL CONDITIONER INPUT EVEN WITH THE UNIT SET TO 5 VOLTS FULL SCALE THE x1
12. output isolator installed or 500 if the jumper board is installed 3 Change the sensitivity x1 control to the uncalibrated position Request the status as before The response should be 700 or 708 Return the sensitivity x1 control back to the detent position 4 Change the x1 x100 switch to the x100 position and request the status The response should be 400 or 408 Return the x1 x100 switch back to the x1 position 5 Now change the volts full scale knob to the 5 0 position Request status from the signal conditioner as before The response should be 510 or 518 6 Check the remaining full scale settings according to Table C 1 Table C 1 Range Status Verification Response Response Response Volts Full Scale With Isolator Without Isolator Off 508 500 5 518 510 2 5 528 520 1 538 530 5 548 540 25 558 550 568 560 05 578 570 025 588 580 Tag Information Verification Plug the signal conditioner into channel 1 in the 5900 Signal Conditioner Frame Assembly Set the sensitivity x1 control to the detent position Set the volts full scale knob to each position listed in Table C 2 By typing 1T lt CR gt the responses listed next to the appropriate volts full scale setting should be received TABLE C 2 Tag Information Verification Volts Full Scale Tag Information Sent Off FS OFF 500 FS 500V 250 FS 250V 100 FS 100V 50 FS 50V 25 FS 25V 10 FS 10V 5 FS 5V 2 5 FS 2 5V 1 FS 1 0V 5 FS 0 5V 25 FS 0 25V 1 FS 0 1V 05
13. signal conditioner is a Status Board which reports front panel settings to the 5900 Signal Conditioner Frame Assembly The signal conditioner has full scale ranges from 25 millivolts to 500 volts selectable from the front panel The signal conditioner is compatible with Harvard s full range of output devices D C Amplifier volts full scale bale x1 P x100 sensitivity filter Hz Off 5 15 zero suppression 5 Off me vernier NL d FIGURE 1 1 Harvard Research DC Signal Conditioner Catalog No 60 0126 2 This section describes the inspections and checks that should be made upon receiving the Harvard Research DC Signal Conditioner with Zero Suppression Covered in this section are the installation procedures signal input connections and the outline dimensions Also contained in this section is the procedure for installing the optional Status Board Installation 2 1 General 2 2 Initial Inspection Prior to attempting any electrical connections or operation visually examine the unit for broken or loose knobs dented or nicked panels and broken or chipped rear connectors Make sure you read the Concealed Damage Card Form No 222640 which is enclosed in the shipping car ton 2 5 Installing Signal Conditioner into Frame Assembly This signal conditioner may be used in conjunction with any of Harvard s output device prod ucts The versatility in system configuration of the signal c
14. step 0 2 of full scale range lt 50 Instability After 15 minutes warm up Zero With Time Zero With Temperature Zero With Line Voltage Gain With Time Gain With Temperature Gain With Line Voltage Frequency Response filter off Noise Common Mode Rejection Either Input to Common DC to 60 Hz Common to Chassis 60 Hz DC 3 mV 24 hours on the most sensitive range decreasing on less sensitive ranges 3 1 mV C on the most sensitive range decreasing on less sensitive ranges 2 mV for 0 line change 0 015 for a 10 line charge 0 04 0 015 for a 10 line change 3 dB down at 10 kHz with 10 MV RMS from DC to 10 kHz 74 dB minimum at 1 unbalanced on the x1 ranges decreasing on the x100 ranges When used with a grounded nonisolated power supply as in the 3000 Oscillograph Recorder 2100 dB 2120 dB Common to Chassis when used with an isolated power supply as in the 3000 Oscillograph Recorder 60 Hz DC Zero Suppression Range Inaccuracy Non linearity Resolution Stability With Time With Temperature With Line 2100 dB gt 120 dB 10 1 Off 1 10 volts Range setting is multiplied by X1 x100 switch maximum of 500 volts 10 596 of suppression range at nominal line and 25 C 77 F 0 25 of full suppression range 0 1 of full suppression range 0 02 week 0 02 C 0 02 1 8 F 0 02 for 10 line change On Off Recovery Time Filt
15. volts full scale range Appendix A Maximum Save Voltage WARNING SIGNAL CONDITIONER CHASSIS ENCLOSURE SHOULD ALWAYS BE CONNECTED TO EARTH GROUND Either Input to Terminal to Input Common 500 volts peak Input Common to Output Common 500 volts peak Input Common to Chassis 500 volts peak Output Common to Chassis 500 volts peak when used with an isolated power supply of equal or greater isolation voltage common is connected to chassis through a 0 01 ufd capacitor CAUTION INPUT COMMON VOLTAGE MUST NOT EXCEED THE OUTPUT COMMON VOLTAGE BY MORE THAN 500 VOLTS PEAK Linear Common Mode Voltage Either Input to Common x100 500 volts full scale setting 2 5 volts full scale setting 2 Input Common to Chassis 500 volts peak with a nonisolated power supply Input Common to Chassis 500 volts peak with an isolated power supply Signal Output Circuit Voltage Linear Range Minimum Load Resistance Calibration Inaccuracy position at 25 and nominal line voltage Attenuator Inaccuracy Non linearity Impedance Single ended to common 5 volts into 2 or greater 0Q short circuit proof 0 14 of full scale range in the least sensitive 0 5 of calibrated
16. x1 on off each line is terminated with a carriage return lt cr gt Example 1 Front panel settings are as follows volts full scale set to 2 5 x1 x100 set to x100 position sensitivity x1 not in the detent position filter is off zero suppression is on Response FS 250V VAR SENSITIVITY SUPPRESSION ON 3 12 3 Personality Format nP lt CR gt Where n is the ASCII channel number P is the Personality command character CR is the carriage return terminator Response The ASCII data listed in Table 3 7 is transmitted in a continuous stream no CR or lt LF gt characters 3 O peration TABLE 3 7 Personality Data 0 1 2 100 DC PREAMP 1 4 4 2 3 1 3 2 1 4 1 1 5 0 1 6 8 1 7 9 1 1 VOLTS FULL SCALE R L 9 off 5 0 2 5 1 0 0 5 0 25 0 1 0 05 0 025 2 INPUT DIVIDER 5 R L 2 X100 X1 3 SENSITIVITY R L 2 calibrated variable 4 SUPPRESSION 7 1 R U L 2 0n off 5 FILTER 7 1 R U L 2 off on 6 ISOLATION R L 2 no yes 7 OPTIONS R L 2 none suppressions with filter 6C NOTE There are no carriage returns in the data stream Table 3 6 is arranged for convenience 3 12 4 Personality Length Format nL lt CR gt Where n is the ASCII channel number L is the Length command for personality data CR is the carriage return terminator Response 172 lt CR gt Where 172 is the hexadecimal number of bytes in the personality data CR is the terminator
17. x100 SWITCH TO THE x100 POSITION AND THE SENSITIVITY x1 POTENTIOMETER ROTATED ALL THE WAY IN THE COUNTER CLOCKWISE DIRECTION MAXIMUM SAVE INPUT VOLTAGE AS STATED IN SECTION 1 IS 500 VOLTS PEAK OR 350 VOLTS RMS Ne y NOTE There is no pen position control on tbe signal conditioner 3 5 Rear Panel Connectors Refer to Figure 2 1 for the following sections 3 3 1 Input Connector Input connector J101 is a guarded 2 pin connector proprietary The mating connector 11 5407 02 is supplied with the signal conditioner 3 3 2 Output Connector The card edge mates with a 16 pin AMP connector 582140 5 or equivalent 3 4 Preliminary Operation CAUTION ALL PROCEDURES OUTLINED IN SECTION 2 INSTALLATION SHOULD BE COMPLETED BEFORE ATTEMPTING PRELIMINARY OPERATION m J 3 O peration Follow these steps to operate the signal conditioner Set volts full scale to OFF position Place x1 x100 switch in x100 position Turn sensitivity x1 to full clockwise position Apply system power Operate oscillograph at moderate chart speed Adjust pen position control on recorder for approximate chart center for a bidirectional signal or chart edge for a unidirectional signal right chart edge for a positive going signal left edge for a negative going signal 7 Stop recorder and connect input cable to the signal conditioner see Figure 2 1 8 When ready to acquire data start chart moving a
18. 1 Harvard Research DC Signal Conditioner with Zero Suppression Catalog No 60 0125 ctio doe nnnc tei ic de tfo cet ee XX 2 1 Installing the Signal ccoo nana cnn nnne nne XX 2 2 Amplifier Board Card Edge Connections oocoocccnnccnnccnncnoncconcnnonc cnn nan ccn noc XX 2 3 installation of Status BOaId uir e e EDO EAR US EE XX 2 4 ads XX 3 1 Eront Panel Controls cuina la tee operis XX 3 2 Main Amplifier Boatd p tentent ere E ira XX 3 3 Status Board Output Gorinector ie DR eti Rr HE I Hn PRA UR ERRARE ine nde XX 4 1 56 1340 00 Signal Conditioner enne nnne nnne nnne rennen nennen nnns XX 4 2 5900 Signal Conditioner Frame Assembly ssssssssseeeeeeneneeeneee nennen nennen nnns XX B 1 Classification of Signal Sources nnne nnne tenen reser enne XX B 2 Eliminating GrounGikoOops Jioc coire ne rte vett eet ee rcc eit be te p XX Table 3 1 3 2 3 4 3 5 3 6 3 7 3 8 3 9 3 10 4 1 1 2 C 3 List of Tables Title Page ErontP nel CONOS A XX Flrst Status NibDlO ociosa rata XX Second Status rotulos e Ce e Ld XX Third Status ert berti pte ede debe XX First Partof Data e te pee tie e He e feda XX Second Pa
19. 2 Installation FIGURE 2 3 Installation of Status Board Installation 2 6 Outline Dimensions 1 maximum knob protrusion 10 88 Side View of Signal Conditioner 2 18 _ Rear View of Signal Conditioner FIGURE 2 4 Outline Dimensions 3 This section describes and illustrates the controls and their functions provides operating instruc tions and gives a functional test procedure for the Research DC Signal Conditioner with Zero Suppression covered in this manual O peration 3 1 General 3 2 Control Description Table 3 1 describes the functions and parameters of the front control panel keys displays and LEDs The item numbers in the table refer to the panel functions illustrated in Figure 3 1 TABLE 3 1 Front Panel Controls Item Control Description 1 Volts full scale nine position rotary switch allows selection of 025 05 1 25 5 1 0 2 5 5 0 volts full scale and Off position 2 Balance The DC balance control is a screwdriver adjust used for setting the zero line between 025 and 1 volts full scale 3 x1 x100 A two position toggle switch which permits selecting sensitivities of 100 times the indicated control markings sensitivity ranges in the x100 position become 2 5 5 0 10 0 25 0 50 0 100 250 and 500 volts full scale 4 sensitivity x1 A single turn potentiometer with detent which provides intermediate sensitivities between
20. Enable Service Request EQ Error Reporting Status ER Pass Command PC Prompt Enable PE Prompt Disable PD Send Configuration SC Send PMD Header SHn Send Slot Mask SM Send Status SSn Send Tag STn Send Who Configuration WH Zero Offset ZAn TABLE 3 9 Description of Software Commands Name Command Amp Busy Status AS Disable Service Request DQ Enable Service Request EQ Description When this command is received it instructs the 5900 Interpreter to query the signal conditioners for their ready busy status Typically a signal conditioner is busy when the user or program has invoked any kind of a balance operation When addressed to talk the 5900 reports this status in two ASCII encoded HEX bytes followed by a carriage return the EOS character The format is as follows Send 1st byte 2nd byte 3rd byte EOS O F O F ODH For Slots For Slots 1 4 5 8 Example Sent 30 41 ODH ASCII 0 A CR HEX 0000 1010 Binary 1234 5678 Slot This indicates the signal conditioners in Slot 5 and 7 are busy Signal Conditioners in 1 2 3 4 6 and 8 are ready Suppresses the assertion of the Service Request Bit B6 in the Serial Poll Mode Register see Table 3 4 when an error is detected This mode of operation stays in effect until negated by the Enable Service Request command EQ When his command is implemented the Service Request Bit B6 in the Serial Poll Mode Register see Table 3 4 will always be asser
21. FS 0 05V 025 FS 0 025V Personality Information Verification Make sure the signal conditioner is plugged into channel 1 in the Signal Conditioner Frame Assembly and request personality information by typing 1P lt CR gt The information received should match the information in Table C 3 The information should be one continuous stream with no lt CR gt or lt LF gt characters TABLE C 3 Personality Information Verification 0 1 2 100 DC PREAMP 1 4 4 2 3 1 3 2 1 4 1 1 5 0 1 6 8 1 7 9 1 1 VOLTS FULL SCALE R L 9 off 5 0 2 5 1 0 0 5 0 25 0 1 0 05 0 025 2 INPUT DIVIDER R L 2 X100 X1 3 SENSITIVITY R L 2 calibrated variable 4 SUPPRESSION 7 1 R U L 2 0n off 2 5 FILTER 7 1 R U L 2 off on 6 ISOLATION R L 2 no yes 7 OPTIONS R L 2 none suppression with filter 6C lt CR gt NOTE There are no carriage returns in the data stream Table C 3 is arranged for convenience Personality Length Command Verification Request personality length from the signal conditioner by typing IL CR The response should be 172 lt CR gt The number 172 represents the length in hexadecimal of the personality informa tion The CR terminator should cause the cursor on the terminal to return to the beginning of the line which it was currently printing on
22. P P A R A T U S Manual for Catalog No 60 0125 User s Manual For Harvard s Research DC Signal Conditioner With Zero Suppression Catalog No 60 0125 The information contained herein is the exclusive prop erty of Harvard Apparatus except as otherwise indicat ed and shall not be reproduced in whole or in part with out explicit written authorization from the company The distribution of this material outside the company may occur only as authorized by the company in writ ing All information contained in this manual is the latest product information available at the time of printing The right is reserved to make changes at any time with out notice Harvard Apparatus Inc Printed 8 93 22 Pleasant Street South Natick Massachusetts 01760 3rd Printing Copyright 1990 Printed in U S A Safety Summary The general safety information is for both user and service personnel Specific WARNINGS and CAUTIONS will be found throughout the manual where they apply Terms in this Manual CAUTION statements identify conditions or practices that could result in damage to the equip ment or other property They will appear in boldfaced capital letters WARNING statements identify conditions or practices that could result in personal injury or loss of life They will appear in boldfaced capital letters Symbols in this Manual 1 This symbol indicates where cautionary information is to be found Terms as Marked on Equipment CAUTION indic
23. Serial Poll Mode Register B7 B6 B5 B4 B3 A A Reserved for Service Request Bit 3000 Recorder No service requested 1 Service requested This bit is asserted if the EQ command has been invoked and any error detected Automatically cleared with a serial poll 5900 Machine Status Ready State 1 Busy State This bit is asserted whenever the 5900 is busy communicating with another device e g signal conditioner or recorder It is automatically negated when ready again and may be polled for synchronous communication 5900 Interpreter Status No Error Detected 1 Error Detected TABLE 3 10 Serial Poll Mode Register Serial Poll Mode Register B7 5 B4 B2 B X X X X X X i A 5900 Syntax Error 5900 Parameter Error Signal Conditioner Unavailable Signal Conditioner Command Error Signal Conditioner Busy Error Signal Conditioner Timeout Error TABLE 3 11 Error Register 4 This section describes the preventive maintenance that should be performed annually on the Research DC Signal Conditioner and lists the signal conditioner s accessories If the Signal Conditioner is used in a dusty or dirty environment the maintenance periods should be more fre quent i e more than every twelve months If the unit requires repair refer to the Service Manual on the 60 0125 or consult your Harvard
24. a 15 Hz or a 5 Hz bandwith 3dB The filter is a two pole 12dB octave 3 8 Addition of a Third Filter A two pole low pass filter may be added to the signal conditioner to eliminate unwanted fre quencies This involves the addition of two capacitors which are located on the Main Amplifier Board inside the signal conditioner housing NOTE Tbe filter switcb must be in tbe Off position for tbe custom filter to be activated Steps to install the filter 1 Remove the right hand side cover as viewed from the front of the unit by unscrewing the 44 40 screw on the top of the right side cover flange and pull top of side cover out and lift up 2 If the optional Status Board is installed remove it by unscrewing the five 4 40 screws attaching it to the amplifier enclosure and unplug the flat cable connector from the socket on the Main Amplifier Board 3 Locate XC1 and XC2 sockets on the Main Amplifier Board They are positioned near the edge connector close to the rear of the unit See Figure 3 2 3 4 To calculate the approximate values of XC1 and XC2 for a TWO POLE LOW PASS FILTER use the following formula where f hz is the frequency for the 3dB change in the output amplitude XC1 uf 7 5 f hz where XC1 XC2 O peration 5 Plug XC1 and XC2 into their proper locations and replace the Status Board and the side cover NOTE Quality non polarized capacitors with leakage current less than 0 1 uamps should be used Ther
25. and the number on the dial will be 0 this means 100 of the zero suppres sion range is being applied The zero suppression range is figured by multiplying the numerical settings of the x1 x100 and the 1v off 10v switches NOTE Zero suppression is not independent of the x1 x100 switch setting 3 To examine the dynamic component of a signal with a static DC level proceed as follows O peration 3 6 1 Application of Zero Suppression 1 Set signal conditioner controls to the setting described in Preliminary Operation except for Step 8 Operate the recorder at moderate speeds Advance the volts full scale control clockwise until the pen approaches full scale Observe the polarity of the signal and set the suppression polarity switch accordingly Use the zero suppression range switch and calibrated vernier to bring the pen to the base line on the chart gn go G9 p 6 Advance the volts full scale control clockwise until the desired sensitivity of the dynamic signal is obtained Bring the signal to the base line on the chart by using the zero suppression vernier control 7 Read the peak to peak value of the dynamic signal from the chart NOTE On bigb sensitivity settings witb tbe Range controls set to 10 volts tbe resolution of tbe vernier control may limit tbe ability to set tbe pen to tbe base line 3 7 Filter Operation To eliminate unwanted frequencies a two position low pass filter is provided The filter options are
26. ates a personal injury hazard not immediately accessible as one reads the marking or a hazard to property including the equipment itself DANGER indicates a personal injury hazard immediately accessible as one reads the marking Symbols as Marked on Equipment DANGER High Voltage S Protective ground earth terminal MN ATTENTION Refer to manual Safety Summary Continued Power Source This instrument is intended to operate from a power source that does not apply more than 250 volts rms between the supply conductors or between either supply conductor and ground protective ground connection by way of the grounding conductor in the power cord is essential Grounding the Instrument This instrument is grounded through the grounding conductor of the power cord To avoid electrical shock plug the power cord into a properly wired receptacle A protective ground connection by way of the grounding conductor in the power cord is essential for safe operation Danger Arising From Loss of Ground Upon loss of the protective ground connection all accessible conductive parts including knobs and controls that may appear to be insulating can render an electric shock Use the Proper Power Cord Use only the power cord and connector specified for your instrument Use only a power cord that is in good condition For detailed information on power cords and connections see Section 2 Installation in the User s Manual Use the Proper Fus
27. der The Device Codes for the Signal Conditioners are 100 56 1340 and 1440 200 56 1300 fixed filter 201 56 1302 202 56 1301 and 203 56 1300 programmable filter and 204 57 1303 Example If the 5900 Frame Assembly is loaded with three Signal Conditioners a 560015 in slot 1 a 5600 DC in slot 3 and 5600 bridge in slot 7 the response would be 5900 A2 100 200 202 Send WH Receive Who Configuration String Name Command Description Send Status SSn Queries the Signal Conditioner in slot n for its status The response will be an ASCII string representing the cur rent front panel status See the Signal Conditioner bit stream information for decoding the string Send SS n Receive lt Bit Stream gt Send PM Header SHn Queries Signal Conditioner n for its PMD Personality Module Definition and responds with PMD header data received The can be any number from 1 to 8 corre sponding to the slot or channel which the desired Signal Conditioner occupies Send Tag STn Queries the Signal Conditioner in slot for its status The response will be the Signal Conditioner s status in a text format ASCII string See NOTE on this page Zero Off Adjust ZAn Recalibrates the specified Signal Conditioner s zero offset The n can be any number from 1 to 8 corresponding to the slot or channel in which the desired signal conditioner occupies NOTE Wben tbe command Set Tag is sent via
28. e To avoid fire hazard use only a fuse of the correct type voltage rating and current rating as specified in the parts list for your instrument Do Not Operate Without Covers and Panels Installed To avoid personal injury and equipment damage the user should disconnect power before removing covers panels or any grounding straps Reinstall covers panels and any grounding straps before reconnecting power Warnings For Authorized Service Personnel Do not perform internal service or adjustment of this instrument unless another person capable of rendering first aid and resuscitation is present Dangerous voltages exist at several points in this instrument To avoid personal injury do not touch exposed connections or components while power is on Disconnect power before removing protective panels soldering or replacing components Table of Contents Title Page SAFETY Safety SUMMA Y iia XX GENERAL INFORMATION Section 1 1 1 Scope of XX 1 2 Description aye ccs be ee ee a ee XX INSTALLATION Section 2 2 1 General eee ante teed ia i edd aae dee eee e Beene eatin ea XX 2 2 Initial Inspection 2 cee eee eat ette a tenen e dee cete leet ce veta XX 2 3 Installing Signal Conditioner into Frame XX 2 931 Insertion uer cedet e e d eel do vase aue a ce cade 2 3 2 Hemloval
29. e are no restrictions on the value of capacitors a Connector J 1 FIGURE 3 2 Main Amplifier Board 3 9 Balance Adjustment With the input shorted the signal conditioner output may not be zero As the signal conditioner warms up or as the ambient temperature changes the input offset voltage may vary The front panel bar control allows this offset voltage to be nulled out During operation with a Harvard Oscillograph Recorder the small amount of offset voltage dose not cause a problem since any drift or instability of of the signal conditioner can be compensat ed for with the pen position control on the recorder When the output of the signal conditioner is used to drive some other instrument like the Harvard DASA 4600 System the offset may present a problem 3 The following steps describe how to balance the output of the signal conditioner O peration 1 Remove the side cover as described in Application of Filter steps 1 and 2 2 Power can be obtained by plugging the signal conditioner into the extender card and cable assembly part number 887291 so that the Main Amplifier Board is accessible when connected to the recorder frame assembly 3 Connect a digital voltmeter between the output of the signal conditioner and the signal common TP11 and TP9 respectively on the Main Amplifier Board Figure 3 2 4 Short the inputs of the signal conditioner to common pins 1 and 2 of the input connector to the
30. ecorder plus an ohmmeter To identify a two terminal source the ground or low recorder input terminal is connected to a good solid ground at the signal source With the source turned ON the high side of the recorder input is connected to one output terminal of the signal source and the other The amplitude and character of these two measurements provide the required information about the source A zero signal from one signal source terminal and a usable signal from the other indicate a sin gle ended grounded source Equal 60 Hz noise signals from both terminals indicate a floating source and if there are only two terminals a floating source is probably single end floating A resistance of several hundred megohms from each terminal to ground confirms that the source is floating Usable but unequal signals from the two terminals indicate a driven off ground output The average of the two signals is the off ground or common mode voltage the difference is the signal amplitude If the two terminal source is turned OFF and the ohmmeter shows unequal resistance from the terminals to ground the source is prob ably single ended driven off ground For all these source types an ohmmeter across the two terminals with the source turned OFF indicates the source resistance To identify a three terminal source the ground or low recorder input terminal is again grounded at the signal source The high recorder terminal is connected to each of the three source output
31. eps to installing the status reporting kit see Figure 2 3 1 Remove the right hand side cover as viewed from the front of the unit by unscrewing the 44 40 see Figure 2 1 screw on the top of right side cover flange and pulling top of side cover out and lift ing up 2 Plug connector P 1 part of Status Board into socket receptacle J 1 part of Main Amplifier Board Refer to Figure 3 2 for an illustration of the Main Amplifier Board 3 Place Status Board 897802 into signal conditioner case enclosure with component side of board facing toward the Main Amplifier Board 4 Secure the Status Board to the case enclosure with the five 244 40 screws provided in the Status Reporting Kit Part No 11 4220 00 5 Replace side cover and 24 40 screw on top of side cover flange NOTE Tbis option requires tbe signal conditioner to be plugged into a Harvard 5900 Signal Conditioner Frame Assembly or 3000 Series Recorder to make tbe necessary electrical and inter face connections Tbe 5900 Signal Conditioner Frame Assembly must bave tbe optional Interpreter Board installed in order to decode tbe Status Board If intercbannel annotation is desired tbe optional Drive Board and Intercbannel Annotation Assembly must be installed in tbe 3000 Recorder See Harvard Manual Part No M11 183 05 for information about tbe Signal Conditioner Frame Assembly Interface and Harvard Manual Part No MU30 VX202 00 for infor mation about tbe 3000 Series Recorder
32. er Range Cut Off Frequency at 5 Hz at 15 Hz Roll Off Rate Environment Temperature Storage Operation Within Specification Humidity Non condensing Storage Operating Vibration amplitude ing from 10 Hz to 55 Hz at Shock Physical Characteristics Dimensions Hx WxL Weight Mounting 2000S Recorder 3000 Series Recorder 5900 Signal Conditioner Frame Assembly Finish Power Input from Recorder Supply 1 Voltage Current Supply 2 Voltage Current Frequency Isolation Requirements Supply 3 Voltage Current Specifications Maximum recovery time 3 seconds less than 50 mV referred to output 5 Hz 15 Hz Off 3 dB at 5 Hz 10 3 dB at 15 Hz 10 12 dB octave 40 C to 70 C 40 F to 158F 0 C to 50 C 32 C to 4122 F 425 C 5 0 77 9 F 9596 maximum 75 relative humidity from 0 to 35 C 32 F to 95 F Unit will withstand vibration for 30 minutes at 0 15 mm sweep a rate of one octave minute All external parts will withstand an impact of 0 5 newtonmeters 15 3 x 5 6 x 33 cm 6 x 2 2 x 13 inches 1 59 kg 3 5 Ib Retention from rear of the unit Retention from the front of the unit Retention from the front of the unit Overlay Front Panel gray color 15 volts 0 6 volts 150 mA maximum each side 5 volts 0 25 volts 400 mA 45 Hz to 440 Hz sine wave 500 volts peak isolated for chassis ground and other supplies 5 volts
33. he location of the signal conditioner by channel number when mounted in a 5900 Frame Assembly Information acquired by the Status Board can be sent to the optional inter channel annotation head in the 3000 Recorder or to the optional interface board RS 232C or IEEE 488 plugged into the 3000 Series Recorder or the 5900 Signal Conditioner Frame Assembly The baud rate is fixed at 1200 bits per second with a format of 1 start bit 8 data bits 1 stop bit and no parity bit The character data transmit signal CD OUT L and receive signal CD IN L are available at the rear connector see Figure 3 3 A signal NOTIFY L assumes a low state when current status has changed from the previously requested status NOTIFY L will go to a high state when status or tag are requested 3 O peration o O E L pe 2 E L E ZO N D OUT OTIFY e 600060066666 666090 oD 900 OXCO 00 IIl cl Only those pins marked in row C are utilized FIGURE 3 3 Status Board Output Connector 3 12 Status Board Commands The Status Board recognizes these 4 character string commands their responses follow Send Status ASCII channel no S CR Send Tag ASCII channel no T CR Send Personality ASCII channel no P CR Send Personality Length ASCII cha
34. immunity from electromagnetic interference 2 4 2 Output and Power Power and output for the signal conditioner are provided by the 8 pin card edge connector on the rear of the unit see Figure 2 2 The signal conditioner requires 15 volts at 150 mA and 13 volts RMS at 30 mA maximum If the optional Status Board is installed 5 volts at 400 mA is also required The signal conditioner provides a 5 volt full scale signal at its output If the signal conditioner is used in conjunction with a 2000S Oscillograph Recorder the signal conditioner output is available at the rear of the recorder from the phone jack on the drive amp board or with the 3000 Oscillograph Recorder from the BNC connector on the rear Optional Status Board 2 Installation Input Connector J101 Ring Guard Input Pin 2 Input Pin 1 Card Edge Connector Input Connector Plug Side View Rear View Size Cover Screw Side View FIGURE 2 1 Installing the Signal Conditioner 2 Installation E l4 Power Common 4 Signal Conditioner Output 15 Volts 15Volts Signal Common l Connection 13 Volts RMS FIGURE 2 2 Signal Conditioner Board Card Edge Connections 2 5 Installation of Optional Status Reporting Kit St
35. nnel no gt L lt CR gt The ASCII channel numbers are characters 1 to 8 when installed into a 5900 Signal Conditioner Frame Assembly Each signal conditioner compares input command channel numbers to the actual channel location to verify the signal conditioner being addressed The signal conditioner only responds to commands if it is in the proper rack location Any character can be be received prior to a valid command sequence If it is not a valid character it will be ignored Only those sequences listed above are recognized Each command line is terminated with a car riage return lt gt 3 12 1 Send Status Format nS CR Where n is the ASCII channel number S is the Send Status command character CR is the carriage return terminator Response XYZ0 lt CR gt Where X upper nibble of the first byte Table 3 1 Y lower nibble of the first byte Table 3 2 Z upper nibble of the second byte Table 3 3 0 is always zero 3 O peration NOTE X Y and Z are ASCII cbaracters 0 9 and A F TABLE 3 2 First Status Nibble FRONT PANEL SETTINGS X Sensitivity X1 X100 Nibble Filter Suppression X1 Switch 0 Off On Cal x1 1 Off On Cal x100 2 Off On Var x1 3 Off On Var x100 4 Off Off Cal x1 5 Off Off Cal x100 6 Off Off Var x1 7 Off Off Var x100 8 On On Cal x1 9 On On Cal x100 A On On Var x1 B On On Var x100 C On Off Cal x1 D On Off Cal x100 E On Off Var x1 F On Off Var x100 TABLE 3 3 Second Stat
36. noise pickup In off ground measurements the signal cable shield should NOT be grounded Effective shield ing is secure by stabilizing the signal cable shield with respect to the useful signal The signal cable should be connected to either the center tap of the low side of the signal source Since the signal cable shield is being driven by an off ground common mode voltage it is necessary that the cable have appropriate insulation between the shield and the outside of the cable THIS IS VERY IMPORTANT Guidelines on Grounding The following guidelines should be maintained when grounding signal sources See Figure B 2 The recording system should have a stable system ground The signal circuit should never be grounded at more than one point The signal cable shield should not be attached to more than one ground and this ground should be at the signal source More than one intentional or accidental ground on the signal circuit or signal cable shield will produce excessive electrical noise in any low level circuit Appendix C PERFORMANCE TEST OPTIONAL STATUS BOARD Because of the digital design on the status board the only practical way to check its perform ance is to verify operation Steps to verify operation 1 2 Plug the signal conditioner into the 5900 Signal Conditioner Frame Assembly channel 1 Connect the RS 232C terminal to the 5900 frame assembly or to the 3000 Series Recorder depending on which one has
37. nterface Set Up Okay message along with the prompt character gt In this mode all command characters will be echoed back to the screen Send PE Disables the prompt and returns the 5900 or 3000 Recorder to its default communication mode Send PD Name Command Description Send Slot Mask SM Queries the 5900 Frame Assembly to indicate which slots are occupied Operator will receive a byte for every four slots e g a two or four Frame Assembly will respond with two status bytes The data is displayed in a hexadecimal format and left justified where a 1 indicates the presence of a Signal Conditioner when the byte is converted to binary Example If user has an eight channel 5900 Frame Assembly and slots 1 thru 6 are occupied a 2 status bytes FC would be received when the command was sent Slot 1 2 3 4 5 6 7 8 1 1 1 1 1 1 0 0 Send SM Receive lt byte1 gt lt byte2 gt Send Configuration SC Queries the 5900 Frame Assembly to send the available options which are configured into the Frame Assembly The response will be an ASCII text format Works in the PE mode only Send SC Receive lt ASCII string gt Send Who Configuration WH Queries the Frame Assembly to send information on what type of Signal Conditioners are installed in the Frame Assembly The 5900 will respond with the device number the slot mask followed by the device numbers nested in it in a left justified or
38. onditioner is made possible by the 5900 Signal Conditioner Frame Assembly The frame assembly is a separate unit in six and eight channel recorder chassis widths but is built into the recorder case in two and four channel widths The 5900 Signal Conditioner Frame Assembly also allows the signal conditioner to be sold as a stand alone product interfacing with the customer s equipment 2 3 1 Insertion To install the signal conditioner into its appropriate slot in the Signal Conditioner Frame Assembly 1 With the power OFF slide the signal conditioner into the frame assembly until its front panel is flush with the front panel on the Signal Conditioner Frame Assembly 2 Tighten the retaining screw this locks the signal conditioner into the Signal Conditioner Frame Assembly NOTE In tbe 2000 Oscillograpb Recorder Systems tbe retaining screw is in tbe rear of tbe unit In systems wbere tbe 5900 Signal Conditioner Frame Assembly is incorporated retention is from the front of tbe unit 3 Connect the 2 pin plastic input connector and secure it by turning the threaded plastic locking ring clockwise 2 5 2 Removal Steps to remove the Signal Conditioner 1 Turn the power OFF and disconnect the input connector with a counterclockwise turn and a pull 2 Loosen the retaining screw 3 Carefully slide the entire signal conditioner out of the Signal Conditioner Frame Assembly 2 The Harvard Research DC Signal Conditioner with Zero Supp
39. ove the side cover by pulling up and out from the conditioner case 6 Wipe off the board with a clean dry rag Spray the board with Micro Care Polar Flux Remover Allow the board to air dry 7 Apply a thin coat of silicone grease to all contacts of the Volts Full Scale Selector Replace the right hand side cover and secure with the one posi drive screw at the top 9 For 5900 Frame Assemblies slide the Signal Conditioner into the cage until it makes contact with the backplane connector It will then require a little force to seat the signal conditioner into the backplane connector The front panel of the Signal Conditioner should be flush with the front panel of the Frame Assembly Lock the extractor by pushing it in and tightening the screw 10 Install the input connector plug at the back of the Signal Conditioner by screwing it on in a clock wise direction e 4 Maintenance Input Connector Ring Guard Input Pin 2 Input Pin 1 Card Edge Connector Input Connector Plug Side View Rear View Side Cover Screw Side View FIGURE 4 1 60 0126 Signal Conditioner Rear and Side Views 4 Maintenance FIGURE 4 2 MISSING FIGURE 4 2 5900 Signal Conditioner Frame Assembly Front View 4 3 Accessories TABLE 4 1 Accessories Description Part Number Input Connector male 11 5407 02 one supplied with each unit Two wire shielded cable
40. ression Catalog No 60 0125 is a direct coupled balanced to common differential input DC signal conditioner able to suppress DC voltages of up to 500 volts from the input signal The input and output are isolated from chassis channel to channel isolation An available option for the signal conditioner is a Status Board which represents the front panel settings Installation 2 4 Signal Connections The signal conditioner can be used with any signal input up to 500 volts peak The source may be floating balanced to ground or single ended grounded For details on signal input connec tions and sources refer to Appendix B NOTE For signal input connections use tbe special connector provided witb tbe signal conditioner Harvard Part No 11 5407 02 2 4 1 Input Connection Input connections to the signal conditioner are made at the rear of the unit see Figure 2 1 To maintain the high level of integrity a two wire shielded cable must be used See Acces sory List for Harvard Catalog Number Connect input to pin 1 of the input connector 11 5407 02 and input to pin 2 For best results connect either side of the input cable shield to ground DO NOT CONNECT INPUT CABLE SHIELD AT BOTH ENDS For most applications connect cable shield to the brass ring input common inside the input connector housing In certain cases connecting input cable shield at the signal source to either earth ground or chassis ground provides better
41. riven off ground by Resistive shunt in hot side driven off ground vv second voltage source Cannot be or line or buss for mea C e grounded suring current gt A Balanced grounded Terminals have equal impedance to Four arm Wheatstone D common ground bridge excited from grounded DC supply Balanced floating Terminals have equal impedance to float Four arm Wheatstone E ing common point Common point bridge excited from floating be grounded without disturbing circuit DC supply Center tapped transformer VW gt Balanced Terminals have equal impedance to Differential output recorder driven off ground common point driven off ground by a amplifier e g a device F second voltage source Cannot be with 30 V output operates Q grounded in 0 60 V range e E e mm FIGURE B 1 Classification of Signal Sources Appendix A Balanced Driven Off Ground This source has two active output terminals which have equal impedance to a common point which is driven off ground by a second voltage as shown in illustration F The active output terminals can be grounded without disturbing or destroying the signal source An example is a differential output amplifier which produces an output of 30 volts but operates at about 60 volts DC off ground Identification of Signal Sources If an electrical schematic is not available a single source may be identified by using one chan nel of a Harvard r
42. rt of Data Tag String croire tnr ien E pP bre dett ir dg XX Personality Data ett e ee f e XX List of Software Commanhds i terree lar XX Description of Software Commands sss eene XX Serial Poll Mode Register XX ACCOSSOMIOS m X XX Range Status Verification sess sententie nens nnns XX Tag Information Verification XX Personality Information Verification nennen nnn XX Section 1 GENERAL INFORMATION 1 1 Scope of Manual This manual describes the Harvard Research Signal Conditioner with Zero Suppression Catalog No 60 0125 Its contents include the signal conditioner s description specifications mainte nance instructions for installation and operation Also included in this manual are installation instructions and operating procedures for the optional Status Board This manual contains material on the signal conditioner listed above It does not contain infor mation on other components in the system refer to the appropriate User s Manuals of each Harvard product 1 2 Description This Harvard Research DC Signal Conditioner with Zero Suppression Catalog No 60 0125 Figure 1 1 is a single channel medium gain DC signal conditioner with differential input zero suppression filtering and input to output isolation Optional for the
43. s 232434 Extender Assembly 887291 Input Connector Adapter converts input 11 5407 09 connector to 3 binding post terminals Input Connector Adapter converts input 11 5407 06 connector to 6 pin common connector receptacle Status Reporting Kit 11 4220 00 reports from panel settings WARNING IN PATIENT CARE APPLICATIONS INPUT TO OUTPUT ISOLATION MUST BE INSTALLED CAUTION EQUIPMENT DAMAGE MAY RESULT IF INPUT TO OUTPUT ISOLATION IS NOT INSTALLED IEC 348 Model 60 0125 has been designed to conform to LE C 348 Class I for nonconductively connected apparatus Signal Conditioner Specifications NOTE Tbe unit is not bumidity sealed or sealed in any way to eliminate degradation of tbese specifica tions under adverse conditions Signal Input CI CUIE ie eee sd Balance to Common Impedance Position sssss 100 MA differential 56 MQ each terminal to common x100 2 MQ differential 1 MQ each terminal to common Measurement Range 25 millivolts full scale to 500 volts full scale Sensitivity Steps XT POSO eerte 025 05 10 25 50 1 0 2 5 5 0 volts full scale and off x100 2 5 5 10 25 50 100 250 500 volts full scale and off Variable Sensitivity Minimum of 2 5 times multiplication of calibrated steps on all ranges except 5
44. s generates large 60 Hz electrical noise cur rents which are in series and combined with the useful signal The magnitude of ground loop current is directly proportional to the difference in absolute potential between the two grounds In most cases a ground loop through either a cable shield or a signal circuit will produce so much 60 Hz noise that it will obscure millivolt level signals Appendix A WRONG Signal Shield Source Recorder Chassis Osillograph EN Signal Conditioner Circuit Grounds Notes F Floating G Ground to Chassis Earth Ground No 1 Earth Ground No 2 ILLUSTRATION A Typical ground loop is created by more than one ground on a single circuit RIGHTJ Signal Source Osillograph No Path for Current FL ignal Conditioner to Circulate Circuit Grounds Notes Floating G Ground to Chassis Earth Ground No 1 Earth Ground No 2 ILLUSTRATION B Ground loops are eliminated by turning the signal conditioner input switch to the FLOATING position and removing jumper from Earth Ground No 2 to signal cable shield FIGURE B 2 Eliminating Ground Loops Appendix A Two separate grounds are seldom if ever at the same absolute voltage This potential differ ence creates unwanted current in series with one of the signal leads In illustration A of Figure B 2 the potential difference between Earth Ground No 1 and
45. t desired speed and turn the volts full scale knob one position at a time until the signal on the chart is the desired amplitude If the desired amplitude cannot be obtained turn the volts full scale knob to the 5 volt position Then turn the x1 x100 switch to the x1 position and turn up the sensitivity of the volts full scale knob until the desired amplitude is reached o0 WD 3 5 Uncalibrated Operation To obtain a more useful record it may be desirable to operate the signal conditioner with the sensitivity x1 control in other than the detent position The only change in specification is that the calibrated sensitivity is something less than the volts full scale control indicates The sensitiv ity may now be set to indicate units of the user s choice 3 6 Zero Suppression Zero suppression permits the DC component of a complex waveform to be suppressed or blocked out allowing a small dynamic portion to be amplified Zero suppression is independent of the attenuator setting and the sensitivity x1 control this permits the attenuator settings to be changed without resetting the zero suppression controls The zero suppression voltage is com puted from the vernier control setting as a percentage of the zero suppression range The num ber in the vernier window represents tenths and the number of the dial which lines up with the window represents units When the vernier control is rotated fully clockwise the number in the window will be 10
46. ted along with the 5900 Error Bit B4 upon detection of an error see Table 3 5 for error bits The Enable Service Request command is the 5900 s power on default Name Command Error Reporting Status ER Pass Command PC Prompt Enable PE Prompt Disable PD Description When received the 5900 s Interpreter when enable to talk will send the Error Register the EOS character in HEX followed by a carriage return A 1 indicates an error occurred see Table 3 5 When this command is executed the Error Register and the 5900 Error Bit B4 in the Serial Port Mode Register is automatically cleared Example Send 08H 00001000 76543210 Bit This indicates a Signal Conditioner Command Error B3 asserted Passes a command or a string of commands received by the 3000 Recorder to the 5900 Frame Assembly When used in a string all commands following it will be sent to the Signal Conditioner and all commands preceding it are for the recorder In a stand alone 5900 Frame Assembly where this command is received via the 5900 s own interface it is recognized and ignored Send PC lt command s gt Enables the 5900 or 3000 Recorder prompt for discrete terminal use using RS 232 C transmission The initial power on default is Prompt Disable In this state com mand characters received are characters which will NOT be echoed back The initial execution of this command will display an I
47. the RS 232C Interface Board installed Configure the terminal and the interface board so that they have the same baud rate and word format Consult operators manual 3000 Series Recorder or 5900 Signal Conditioner Frame Assembly for configuration of the RS 232C Interface Board Channel Number Addresses 1 Request status from the signal conditioner by typing 1S lt CR gt where 15 is requesting status information from channel number 1 in the 5900 Signal Conditioner Frame Assembly CR is the return key on the terminal response XYZO where XYZ are ASCII bytes 0 9 or A F Request status from the unused channels by typing channel S lt CR gt in the same format as step 1 The signal conditioner should not respond to any channel number but the one it is plugged into Turn the power off Remove the signal conditioner from the present channel and plug it into the next higher channel location Repeat steps 1 and 2 for each channel location in the 5900 Signal Conditioner Frame Assembly The signal conditioner should only respond to the channel number it is plugged into Status Information 1 Plug the signal conditioner into channel 1 in 5900 Signal Conditioner Frame Assembly and set the front panel controls as follows volts full scale off x1 x100 x1 sensitivity x1 x1 detent position 2 Request status from the signal conditioner by typing 1S lt CR gt The response should be 508 if the signal conditioner has the input to
48. trical variables Final data may be useless unless a signal source is properly selected or identified and used with an appropriate signal conditioner The following explanation of signal sources has been extracted from Harvard Applications Booklet No 101 Signal Conditioning Signal Sources Selection of transducer or signal source s is the first step in most measurement or recording applications Low impedance devices are preferred to reduce system noise and to minimize the shunting effect loading which the measuring instrument imposes on the source The signal source must be properly identified so that it can be matched with an appropriate sig nal conditioner Signal sources fall into six classes according to the configuration of the output circuit These are summarized below Signal Ended Grounded This signal source has two output terminals one of which is connected to source ground as shown in illustration A of Figure B 1 Classification of Signal Sources The AC line powered signal generator with a two terminal grounded output is typical Signal Ended Floating This source has two output terminals which are isolated from ground as shown in illustration A floating output can be grounded or reversed without disturbing the circuit The dry cell battery the output from a magnetic head or a two terminal battery powered signal generator are typical examples Signal Ended Driven Off Ground This source has
49. two output terminals which are driven off ground by a second voltage as shown in illustration A driven off ground signal source can NEVER be grounded resis tive shunt installed in the hot side of a power line or DC bus for measuring current is a classic example Balanced Grounded This signal source has two active output terminals which have equal impedance to a common ground as shown in illustration D The output terminals can be reversed without disturbing the circuit A four arm wheatstone bridge output that is excited from a grounded power supply is a good example Balanced Floating This source is one that has two active output terminals which have equal impedance to common point that is floating is shown in illustration E A four arm wheatstone bridge output that is excited from a floating power supply or a center tapped transformer secondary are typical exam ples The output terminals can be reversed or the common terminal can be grounded without disturbing the circuit Appendix A Source Description Examples Single ended grounded Two output terminals one of which is AC line powered signal A r ww connected to ground generator gt Single ended floating Unbalanced output isolated from ground Dry cell battery Magnetic B Can be grounded without disturbing head Battery powered 2 circuit signal generator p Single ended Unbalanced output d
50. us Nibble Y Nibble Front Panel Settings Volts Full Scale Off 5 0 2 5 1 0 0 5 0 25 0 1 0 05 0 025 ON DOOR O 3 O peration TABLE 3 4 Third Status Nibble Z Nibble Isolation Possible Model 4 No 56 1140 00 or 56 1140 00 C Yes 56 1340 00 or 56 P1340 00 3 12 2 Data Tag Format nT CR Where n is the ASCII channel number T is the Tag command character CR is the carriage return terminator Response The response is derived from Tables 3 5 and 3 6 by combining the appropriate line from each table to form the data string TABLE 3 5 First Part of Data Tag String Tag Information Sent Volts Full Scale With X1 X100 Switch Incorporated FS OFF Off FS 500V 500 FS 250V 250 FS 100V 100 FS 50V 50 FS 25V 25 FS 10V 10 FS 5V 5 FS 2 5V 2 5 FS 1 0V 1 FS 0 5V 5 FS 0 25V 25 FS 0 1V 4A FS 0 05V 05 FS 0 025V 025 These full scale settings overlap between the x1 x100 ranges This results in the same tag information being sent while different status information is sent 3 O peration TABLE 3 6 Second Part of Data Tag String Tag Information Sent Front Panel Settings Sensit x 1 Filter Zero Supp VAR SENSITIVITY variable off on SUPPRESSION ON SUPPRESSION ON x1 off on VAR SENSITIVITY variable off off cr x1 off off VAR SENSITIVITY SUPPRESSION variable on on ON FILTER ON SUPPRESSION ON FILTER x1 on on VAR SENSITIVITY FILTERZON variable on off FILTER ON
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