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Service Information

4-3

 

Performance verification

 

The following paragraphs discuss performance verification procedures for the Model 

7999-2, including channel resistance, contact potential, and channel-to-channel and common-
mode isolation.

 

CAUTION

 

Contamination will degrade the performance of the card. To avoid 
contamination, always grasp the card by the cover; do not touch the 
connectors.

 

NOTE

 

Failure of any performance verification test may indicate that the multiplexer card is 
contaminated. See “Handling and cleaning precautions” earlier in this section for 
information on cleaning the card.

 

Environmental conditions

 

All verification measurements should be made at an ambient temperature between 18˚ and 

28˚C, and at a relative humidity of less than 70%.

 

Recommended equipment

 

Table 4-1 summarizes the equipment necessary for performance verification, along with an 

application for each unit.

 

Table 4-1

 

Recommended verification equipment

 

Description

Manufacturer/Model

Specifications

Test

 

Digital Multimeter
Nanovoltmeter
Electrometer
Test Lead Sets (2)
Low Thermal Cable
Triax Cable

Keithley 2010
Keithley 2182
Keithley 6517A
Keithley 1681
Keithley 2107-4
Keithley 237-ALG-2

10

 

 

 range, 60ppm

10mV range, 50ppm
2G

 

 

 range, 0.225%

Banana plug/clips
Low thermal/lugs
Triax/clips

Channel resistance
Contact potential
Isolation
Channel resistance
Contact potential
Isolation

Summary of Contents for 7999-2

Page 1: ...Contains Operating and Servicing Information Model 7999 2 Multiplexer Card Instruction Manual ...

Page 2: ... OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS INSTRU MENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS INC HAS BEEN ADVISED IN ADVANCE OF THE POS SIBILITY OF SUCH DAMAGES SUCH EXCLUDED DAMAGES SHALL INCLUDE BUT ARE NOT LIMITED TO COSTS OF REMOVAL AND INSTALLATION LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERS...

Page 3: ...Model 7999 2 Three Pole Multiplexer Card Instruction Manual 1999 Keithley Instruments Inc All rights reserved Cleveland Ohio U S A First Printing September 1999 Document Number 7999 2 901 01 Rev A ...

Page 4: ...d incorporate immediately into the manual Addenda are numbered sequentially When a new Revision is created allAddenda associated with the previous Revision of the manual are incorporated into the new Revision of the manual Each new Revision includes a revised copy of this print history page Revision A Document Number 7999 2 901 01 September 1999 All Keithley product names are trademarks or registe...

Page 5: ...ent A good safety practice is to expect that hazardous voltage is present in any unknown circuit before measuring Users of this product must be protected from electric shock at all times The responsible body must ensure that users are prevented access and or insulated from every connection point In some cases connections must be exposed to potential human contact Product users in these circumstanc...

Page 6: ... before performing the indicated procedure The CAUTION heading in a manual explains hazards that could damage the instrument Such damage may invalidate the warranty Instrumentation and accessories shall not be connected to humans Before performing any maintenance disconnect the line cord and all test cables To maintain protection from electric shock and fire replacement components in mains circuit...

Page 7: ... 3ms ISOLATION Channel to Channel 109Ω 80pF Common Mode 109Ω 150pF CROSSTALK 1MHz 50Ω load 40dB INSERTION LOSS 50Ω source 50Ω load 0 1dB 20kHz 25dB 2GHz RELAY DRIVE CURRENT per relay 8 5mA 24V user supplied USER SUPPLIED VOLTAGE 24V 4V DC 175mA max RELAY CONTROL INPUT Relay Closed 2 0V Relay Open User supplied voltage RELAY DRIVE CONFIGURATION User Supplied Voltage Relay Control Input Relay Coil C...

Page 8: ...ed connectors 1 4 2 Connections Introduction 2 2 Handling precautions 2 2 Card configuration 2 3 Card layout 2 3 Simplified schematic 2 4 Card connections 2 5 Input output connectors 2 5 AUDIO IN and AUDIO OUT connector 2 6 CONTROL MEASURE POWER connector 2 7 Relay power and control 2 7 3 Operating Considerations Introduction 3 2 Maximum signal considerations 3 2 Relay power and control 3 2 Switch...

Page 9: ...exer card connections 4 4 Channel resistance tests 4 4 Contact potential tests 4 5 Channel to channel isolation tests 4 6 Common mode isolation tests 4 7 Replacing components 4 8 Replacement parts 4 8 Replacement precautions 4 8 Soldering considerations 4 8 Disassembly 4 8 5 Replaceable Parts Introduction 5 2 Parts list 5 2 Ordering information 5 2 Factory service 5 2 Component layout and schemati...

Page 10: ...WER connector terminals 2 7 3 Operating Considerations Figure 3 1 Path isolation resistance 3 3 Figure 3 2 Voltage attenuation by path isolation resistance 3 4 Figure 3 3 Ground loops 3 5 Figure 3 4 Eliminating ground loops 3 5 4 Service Information Figure 4 1 Channel resistance test connections 4 4 Figure 4 2 Contact potential connections 4 5 Figure 4 3 Channel to channel isolation connections 4 ...

Page 11: ...ut connector terminals 2 5 Table 2 2 AUDIO IN AUDIO OUT connector terminals 2 6 Table 2 3 CONTROL MEASURE POWER connector terminals 2 7 4 Service Information Table 4 1 Recommended verification equipment 4 3 5 Replaceable Parts Table 5 1 Parts list 5 3 ...

Page 12: ...1 GeneralInformation ...

Page 13: ...iplexer 3 pole switching One bank of 4 1 multiplexer 3 pole switching External relay control and 24V DC power connections Lemo style connectors for multiplexer input output and common connections Low insertion loss for audio frequencies 0 1dB up to 20kHz Warranty information Warranty information is located at the front of this instruction manual Should your Model 7999 2 require warranty service co...

Page 14: ...uld damage the multi plexer card Such damage may invalidate the warranty Specifications Full Model 7999 2 specifications are included at the front of this manual Unpacking and Inspection Inspection for damage The Model 7999 2 is packaged in a re sealable anti static bag to protect it from damage due to static discharge and from contamination that could degrade its performance Before remov ing the ...

Page 15: ... Model 7999 2 for repair carefully pack the unit in its original packing carton or the equivalent and perform the following Call the Repair Department at 1 800 552 1115 for a Return Material Authorization RMA number Advise as to the warranty status of the card Write ATTENTION REPAIR DEPARTMENT and the RMA number on the shipping label Fill out and include the service form located at the back of thi...

Page 16: ...2 Connections ...

Page 17: ...to recognize and observe normal safety precautions could result in personal injury or death Handling precautions To maintain high impedance isolation between channels care should be taken when han dling the card to avoid contamination from such foreign materials as body oils Such contami nation can reduce isolation resistance To avoid possible contamination Always grasp the card by the case Do not...

Page 18: ...AL_AUDIO AUDIO_IN AUDIO_OUT A 6 pin Lemo connector provides audio input output terminals CONTROL MEASURE POWER This DB 15 connector provides terminals for relay control DVM measurement connections and 24V DC power connections XEAR BUZZ_MIC EAR_MIC LEVELING_MIC XMIC LSP SPECIAL_AUDIO Input Output Connectors CONTROL MEASURE POWER AUDIO_IN AUDIO_OUT CONTROL MEASURE POWER Connector AUDIO IN AUDIO OUT ...

Page 19: ... L and G indicates separate HI LOW and GND signal switching and switched to HI and LOW where applicable See the schematic diagram at the end of Section 5 for details XEAR H L G BUZZ_MIC H L G EAR_MIC H L G LEVELING_MIC H L G XMIC H L G LSP H L G SPECIAL_AUDIO H L G NOTE Single pole switching shown for simplicity H L G indicate separate HI LOW and GND signals and switched to HI and LOW where applic...

Page 20: ...inal configuration for the input output connectors XEAR BUZZ_MIC EAR_MIC LEVELING_MIC XMIC LSP SPECIAL_AUDIO while Table 2 1 summarizes signals Table 2 1 Input output connector terminals Connector pin Signal 1 2 3 HI LOW GND 1 2 3 Figure 2 3 Input output connector terminal designations ...

Page 21: ...n for the AUDIO IN AUDIO OUT connector and Table 2 2 summarizes signals Table 2 2 AUDIO IN AUDIO OUT connector terminals Connector pin Signal 1 2 3 4 5 6 AUDIO OUT HI AUDIO OUT LO AUDIO OUT GND AUDIO IN HI AUDIO IN LO AUDIO IN GND 1 2 3 6 5 4 Figure 2 4 AUDIO IN AUDIO OUT connector terminals ...

Page 22: ...R connector A relay channel can be closed by setting the associated CONTROL line listed in Table 2 3 low Table 2 3 CONTROL MEASURE POWER connector terminals Terminal Description Switched signal s 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 DVM CONTROL 6 DVM CONTROL 7 24V CONTROL 8 CONTROL 1 CONTROL 9 CONTROL 2 MEASVOLT CONTROL 3 MEASVOLT CONTROL 4 NO CONNECTION CONTROL 5 EAR_MIC MEASVOLT LEVELING_MIC XMIC...

Page 23: ...3 OperatingConsiderations ...

Page 24: ...EASURE POWER connector A channel is closed by setting the corresponding control signal low See Section 2 for complete connection information Table 2 3 in Section 2 lists switched signals Switching considerations Signals switched by the Model 7999 2 may be subject to various effects that can seriously affect their integrity The following paragraphs discuss these effects and ways to minimize them Ke...

Page 25: ...apacitance of cables and connectors results in less than infinite path isolation values for these devices Path isolation resistance forms a signal path that is in parallel with the equivalent resistance of the DUT as shown in Figure 3 1 For low to medium device resistance values path isolation resistance is seldom a consideration however it can seriously degrade measurement accuracy when testing h...

Page 26: ...ence over a wide range of frequencies across the spectrum Such interference can be particularly troublesome at low signal levels but is can also affect measurements at high levels if the problem is of sufficient severity EMI can be caused by steady state sources such as radio or TV broadcast signals or some types of electronic equipment microprocessors high speed digital circuits etc or it can res...

Page 27: ...e between the LO terminals of the two devices This voltage will be induced into the desired signal affecting its integrity Figure 3 4 shows how to connect several devices together to eliminate this type of ground loop problem Here only one device is connected to power line ground Ground loops are not normally a problem with isolated LO terminals However all devices in the test setup may not be des...

Page 28: ...4 ServiceInformation ...

Page 29: ...d to prevent possible contamination The following precautions should be observed when servicing the card Handling precautions Observe the following precautions when handling the multiplexer card Handle the card only by the edges and cover Do not touch connector insulators Do not touch any board surfaces or components not associated with the repair Do not touch areas adjacent to electrical contacts...

Page 30: ...ng the card Environmental conditions All verification measurements should be made at an ambient temperature between 18 and 28 C and at a relative humidity of less than 70 Recommended equipment Table 4 1 summarizes the equipment necessary for performance verification along with an application for each unit Table 4 1 Recommended verification equipment Description Manufacturer Model Specifications Te...

Page 31: ...Model 2010 INPUT and SENSE Ω 4 WIRE jacks to the relay contact to be tested as shown in Figure 4 1 Note that 4 wire connections to the card terminals are used 5 Close the relay being tested 6 Note the resistance reading on the Model 2010 and verify that it is 1Ω 7 Open the relay being tested 8 Repeat steps 4 through 7 for every relay contact on the card 2010 MULTIMETER RANGE F 500V PEAK FRONT REAR...

Page 32: ...erify that the Model 2182 reading is 10µV 9 Open the relay being tested 10 Repeat steps 6 through 9 for all relays on the card 2182 NANOVOLTMETER RANGE CHANNEL 1 SHIFT LOCAL POWER RANGE SHIFT CH1 REM TALK LSTN SRQ STAT REL FILT 4W BUFFER MATH REAR SCAN TIMER STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10 HOLD TRIG FAST MED SLOW AUTO ERR AUTO HI LO CHANNEL 2 HI 120V MAX 12V MAX LSYNC CAT I 350V PEAK ANY...

Page 33: ...g is 1GΩ 7 Enable zero check and place the Model 6517A voltage source in standby 8 Repeat steps 3 through 7 for all other two channel combinations on the card WARNING NO INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY WARNING NO INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAME T...

Page 34: ...e resistance reading is 1GΩ 7 Enable zero check and place the Model 6517A voltage source in standby 8 Repeat steps 3 through 7 for all other channels on the card WARNING NO INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY WARNING NO INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAM...

Page 35: ...ends of the relay pins Soldering considerations When using solder on the circuit board observe the following precautions Use an OA based organic activated flux and take care not to spread the flux to other areas of the circuit board Remove the flux from the work areas when the repair has been completed Use pure water along with clean cotton swabs or a clean soft brush to remove the flux Once the f...

Page 36: ...5 ReplaceableParts ...

Page 37: ... When ordering parts be sure to include the following information Card model number Model 7999 2 Serial number Part description Component designation if applicable Keithley part number Factory service If the card is to be returned to Keithley Instruments for repair perform the following Call the Repair Department at 1 800 552 1115 for a Return Material Authorization RMA number Complete the service...

Page 38: ... designation Description Keithley part no C1 C40 CR1 CR16 J1 J2 J3 J4 J5 J6 J7 J8 J9 J10 K1 K16 L1 L41 CAP 22PF 10 100V CERAMIC DIODE SWITCHING 250MA BAV103 CONN RT ANGLE RECEPTACLE LATCHING HEADER FRICTON SGL ROW CONN HEADER STRAIGHT SOLDER PIN NON LATCHING RELAY FERRITE BEAD CONN FIXED RECEPTACLE CONNECTOR CONNECTOR HOUSING TOP COVER BOTTOM COVER C 451 22P RF 89 CS 1064 CS 724 3 CS 368 16 RL 233...

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Page 43: ... Insertion loss 3 4 Inspection for damage 1 3 Instruction manual 1 4 Introduction 1 2 2 2 3 2 4 2 5 2 K Keeping connectors clean 3 2 M Manual addenda 1 2 Maximum signal considerations 3 2 Multiplexer card connections 4 4 O Operating considerations 3 1 Ordering information 5 2 P Parts list 5 2 Path isolation 3 3 Performance verification 4 3 R Recommended connectors 1 4 Recommended equipment 4 3 Rel...

Page 44: ...Keithley Instruments Inc 28775 Aurora Road Cleveland Ohio 44139 Printed in the U S A ...

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