Keithley 7999-2 Service manual

Model 7999-2

Multiplexer Card

Instruction Manual

Contains Operating and Servicing Information

WARRANTY

Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 1 year from
date of shipment.

Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batter­ies, diskettes, and documentation.

During the warranty period, we will, at our option, either repair or replace any product that proves to be defective.

To exercise this warranty, write or call your local Keithley representativ e, or contact Keithley headquarters in Cleveland, Ohio. Y ou
will be given prompt assistance and return instructions. Send the product, transportation prepaid, to the indicated service facility.
Repairs will be made and the product returned, transportation prepaid. Repaired or replaced products are warranted for the balance
of the original warranty period, or at least 90 days.

LIMITATION OF WARRANTY

This warranty does not apply to defects resulting from product modification without Keithley’s express written consent, or misuse
of any product or part. This warranty also does not apply to fuses, software, non-rechargeable batteries, damage from battery leak­age, or problems arising from normal wear or failure to follow instructions.

THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED
WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. THE REMEDIES PROVIDED HEREIN
ARE BUYER’S SOLE AND EXCLUSIVE REMEDIES.

NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT,
INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS INSTRU­MENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS BEEN ADVISED IN ADVANCE OF THE POS­SIBILITY OF SUCH DAMAGES. SUCH EXCLUDED DAMAGES SHALL INCLUDE, B UT ARE NOT LIMITED TO: COSTS
OF REMOVAL AND INSTALLATION, LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON, OR DAM­AGE TO PR OPERTY .

Keithley Instruments, Inc. • 28775 Aurora Road • Cleveland, OH 44139 • 440-248-0400 • Fax: [phone] • http://www.keithley.com

BELGIUM: Keithley Instruments B.V. Bergensesteenweg 709 • B-1600 Sint-Pieters-Leeuw • 02/363 00 40 • Fax: [phone]
CHINA: Keithley Instruments China Yuan Chen Xin Building, Room 705 • 12 Yumin Road, Dewai, Madian • Beijing 100029 • 8610-62022886 • Fax: [phone]
FRANCE: Keithley Instruments Sarl B.P. 60 • 3, allée des Garays • 91122 Palaiseau Cédex • 01 64 53 20 20 • Fax: [phone]
GERMANY: Keithley Instruments GmbH Landsberger Strasse 65 • D-82110 Germering • 089/84 93 07-40 • Fax: [phone]
GREAT BRITAIN: Keithley Instruments Ltd
INDIA: Keithley Instruments GmbH Flat 2B, WILOCRISSA • 14, Rest House Crescent • Bangalore 560 001 • 91-80-509-1320/21 • Fax: [phone]
ITALY: Keithley Instruments s.r.l. Viale S. Gimignano, 38 • 20146 Milano • 02/48 30 30 08 • Fax: [phone]
NETHERLANDS: Keithley Instruments B.V. Postbus 559 • 4200 AN Gorinchem • 0183-635333 • Fax: [phone]
SWITZERLAND: Keithley Instruments SA Kriesbachstrasse 4 • 8600 Dübendorf • 01-821 94 44 • Fax: [phone]
TAIWAN: Keithley Instruments Taiwan 1 Fl. 85 Po Ai Street • Hsinchu, Taiwan, R.O.C. • 886-3572-9077• Fax: [phone]

The Minster • 58 Portman Road • Reading, Berkshire RG30 1EA • 0118-9 57 56 66 • Fax: [phone]

6/99

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

Manual Print History

The print history shown below lists the printing dates of all Revisions and Addenda created
for this manual. The Revision Le vel letter increases alphabetically as the manual under goes sub­sequent updates. Addenda, which are released between Revisions, contain important change in­formation that the user should incorporate immediately into the manual. Addenda are numbered
sequentially. When a new Re vision is created, all Addenda associated with the previous Re vision
of the manual are incorporated into the new Revision of the manual. Each ne w 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 registered trademarks of Keithley Instruments, Inc.
Other brand names are trademarks or registered trademarks of their respective holders.

Safety Precautions

The following safety precautions should be observed before using this product and any associated instrumen­tation. Although some instruments and accessories would normally be used with non-hazardous v oltages, there
are situations where hazardous conditions may be present.

This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the
safety precautions required to avoid possible injury. Read the operating information carefully before using the
product.

The types of product users are:

Responsible body is the individual or group responsible for the use and maintenance of equipment, for ensuring

that the equipment is operated within its specifications and operating limits, and for ensuring that operators are
adequately trained.

Operators use the product for its intended function. They must be trained in electrical safety procedures and

proper use of the instrument. They must be protected from electric shock and contact with hazardous live circuits.

Maintenance personnel perform routine procedures on the product to keep it operating, for example, setting

the line voltage or replacing consumable materials. Maintenance procedures are described in the manual. The
procedures explicitly state if the operator may perform them. Otherwise, they should be performed only by ser­vice personnel.

Service personnel are trained to work on live circuits, and perform safe installations and repairs of products.

Only properly trained service personnel may perform installation and service procedures.
Exercise extreme caution when a shock hazard is present. Lethal voltage may be present on cable connector

jacks or test fixtures. The American National Standards Institute (ANSI) states that a shock hazard e xists when
voltage levels greater than 30V RMS, 42.4V peak, or 60VDC are present. 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 circumstances must be trained to protect themselves
from the risk of electric shock. If the circuit is capable of operating at or above 1000 volts, no conductive part

of the circuit may be exposed.

As described in the International Electrotechnical Commission (IEC) Standard IEC 664, digital multimeter
measuring circuits (e.g., Keithley Models 175A, 199, 2000, 2001, 2002, and 2010) are Installation Category II.
All other instruments’ signal terminals are Installation Category I and must not be connected to mains.

Do not connect switching cards directly to unlimited power circuits. They are intended to be used with imped­ance limited sources. NEVER connect switching cards directly to AC mains. When connecting sources to
switching cards, install protective devices to limit fault current and voltage to the card.

Before operating an instrument, make sure the line cord is connected to a properly grounded power receptacle.
Inspect the connecting cables, test leads, and jumpers for possible wear, cracks, or breaks before each use.

For maximum safety, do not touch the product, test cables, or any other instruments while power is applied to
the circuit under test. ALWAYS remove power from the entire test system and discharge any capacitors before:
connecting or disconnecting cables or jumpers, installing or removing switching cards, or making internal
changes, such as installing or removing jumpers.

Do not touch any object that could provide a current path to the common side of the circuit under test or power
line (earth) ground. Always make measurements with dry hands while standing on a dry, insulated surface ca­pable of withstanding the voltage being measured.

The instrument and accessories must be used in accordance with its specifications and operating instructions or
the safety of the equipment may be impaired.

Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications
and operating information, and as shown on the instrument or test fixture panels, or switching card.

When fuses are used in a product, replace with same type and rating for continued protection against fire hazard.
Chassis connections must only be used as shield connections for measuring circuits, NOT as safety earth ground

connections.
If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation

requires the use of a lid interlock.

If a screw is present, connect it to safety earth ground using the wire recommended in the user documen­tation.

!

The symbol on an instrument indicates that the user should refer to the operating instructions located in
the manual.

The symbol on an instrument shows that it can source or measure 1000 volts or more, including the com­bined effect of normal and common mode voltages. Use standard safety precautions to avoid personal contact
with these voltages.

The WARNING heading in a manual explains dangers that might result in personal injury or death. Always
read the associated information very carefully 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 circuits, including the
power transformer, test leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses,
with applicable national safety approvals, may be used if the rating and type are the same. Other components
that are not safety related may be purchased from other suppliers as long as they are equivalent to the original
component. (Note that selected parts should be purchased only through Keithley Instruments to maintain accu­racy and functionality of the product.) If you are unsure about the applicability of a replacement component,
call a Keithley Instruments office for information.

T o clean an instrument, use a damp cloth or mild, water based cleaner . Clean the e xterior of the instrument only .
Do not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument. Products that
consist of a circuit board with no case or chassis (e.g., data acquisition board for installation into a computer)
should never require cleaning if handled according to instructions. If the board becomes contaminated and op­eration is affected, the board should be returned to the factory for proper cleaning/servicing.

Rev. 2/99

SBG 8/11/99

7999-2 Three-Pole Multiplexer Card

RELAY SWITCH CONFIGURATION:

1 bank of 3:1 mux 3-pole switching.
1 bank of 4:1 mux 3-pole switching.

CONTACT CONFIGURATION: 3-pole Form A.
CONNECTOR TYPE:

Mux Common Connector (1): 6-pin LEMO.
Mux Input/Output Connectors (7):3-pin LEMO.
Control Connectors (1):15-pin male D-sub.

MAXIMUM SIGNAL: 30V DC, 42V peak between any two inputs or

chassis, 1A switched, CATI.

CONTACT LIFE: Cold Switching:10 × 10

6

closures.

At Maximum Signal Levels:2 × 10

5

closures.

CHANNEL RESISTANCE(per conductor): <1Ω.
CONTACT POTENTIAL: <10µV per contact.
ACTUATION TIME: 3ms.
ISOLATION: Channel to Channel: >10

9

Ω, <80pF.

Common Mode: >10

9

Ω, <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

Card

GENERAL

ENVIRONMENT:Operating: 0° to 50°C, up to 35°C <80% RH.

Storage: –25° to 65°C.

EMC: Conforms with European Union Directive 89/336/EEC, EN

55011, EN 50082-1, EN 61000-3-2 and 61000-3-3, FCC part 15
class B.

SAFETY: Conforms with European Union Directive 73/23/EEC, EN

61010-1.

DIMENSIONS: 152mm long × 102mm wide × 13mm deep (6˝ × 4˝

×

1

⁄2˝).

3:1 MUX 3-Pole Switch 4:1 MUX 3-Pole Switch

T able of Contents

1 General Information

Introduction ................................................................................ 1-2

Feature overview ........................................................................ 1-2

Warranty information ................................................................. 1-2

Manual addenda ......................................................................... 1-2

Safety symbols and terms .......................................................... 1-3

Specifications ............................................................................. 1-3

Unpacking and Inspection .......................................................... 1-3

Inspection for damage ......................................................... 1-3

Handling precautions .......................................................... 1-3

Shipment contents ............................................................... 1-4

Instruction manual .............................................................. 1-4

Repacking for shipment ...................................................... 1-4

Recommended 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

Switching considerations ........................................................... 3-2

Keeping connectors clean ................................................... 3-2

Path isolation ....................................................................... 3-3

Insertion loss ....................................................................... 3-4

Crosstalk ............................................................................. 3-4

RFI/EMI .............................................................................. 3-4

Ground loops ....................................................................... 3-5

4 Service Information

Introduction ................................................................................ 4-2

Handling and cleaning precautions ............................................ 4-2

Handling precautions ........................................................... 4-2

Card cleaning ....................................................................... 4-2

Performance verification ............................................................. 4-3

Environmental conditions .................................................... 4-3

Recommended equipment ................................................... 4-3

Multiplexer 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 schematic diagram ................................. 5-3

List of Illustrations

2 Connections

Figure 2-1 Card configuration ................................................................. 2-3

Figure 2-2 Simplified schematic .............................................................. 2-4

Figure 2-3 Input/output connector terminal designations ........................ 2-5

Figure 2-4 AUDIO IN AUDIO OUT connector terminals ....................... 2-6

Figure 2-5 CONTROL/MEASURE/POWER 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 ............................. 4-6

Figure 4-4 Common-mode isolation connections ................................... 4-7

List of T ables

2 Connections

Table 2-1 Input/output 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

1

General Information

1-2 General Information

Introduction

This section contains general information about the Model 7999-2 Three-Pole Multiplexer
Card. The information is organized as follows:

• Feature overview

• Warranty information

• Manual addenda

• Safety symbols and terms

• Specifications

• Unpacking and inspection

• Recommended mating connectors

If you have any questions after reviewing this information, please contact your local
Keithley representative or call a Keithley Applications Engineer at 1-800-348-3735 (U.S. and
Canada only). Worldwide phone numbers are listed at the front of this manual.

Feature overview

The Model 7999-2 is a three-pole multiplexer card with the following features:

• One bank of 3:1 multiplexer 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)

W arranty information

Warranty information is located at the front of this instruction manual. Should your Model
7999-2 require warranty service, contact a Keithle y representative or an authorized repair facil­ity in your area for further information. When returning the card for repair, be sure to fill out
and include the service form at the back of this manual to provide the repair facility with the
necessary information.

Manual addenda

Any improvements or changes concerning the multiplexer card or manual will be explained
in an addendum included with the manual. Be sure to note these changes and incorporate them
into the manual.

General Information 1-3

Safety symbols and terms

The following symbols and terms may be found on the multiplexer card or used in this

manual.

The symbol indicates that the user should refer to the operating instructions located in

!

the manual.

The

symbol

safety precautions to avoid personal contact with these voltages.

The

WARNING heading used in this manual explains dangers that might result in personal

injury or death. Always read the associated information very carefully before performing the
indicated procedure.

shows that high voltage may be present on the terminal(s). Use standard

The

CAUTION heading used in this manual explains hazards that could 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 remov­ing the card from the bag, observe the precautions on handling discussed below.

Handling precautions

• Always grasp the card by the covers. Do not touch board surfaces or components.

• After removing the card from its anti-static bag, inspect it for any obvious signs of
physical damage. Report any such damage to the shipping agent immediately.

• When the card is not installed and connected, keep the card in its anti-static bag, and
store it in the original packing carton.