Keithley 7074 Service manual
Model 7074General Purpose Multiplexer Card
Instruction Manual
A GREATER MEASURE OF CONFIDENCE
W ARRANTY
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 representative, or contact Keithley headquarters in Cle veland, Ohio.
You 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.
LIMIT A TION OF W ARRANTY
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, BUT ARE NOT LIMITED TO: COSTS OF REMOVAL AND INSTALLATION, LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY
PERSON, OR DAMAGE TO PROPERTY.
Keithley Instruments, Inc. • 28775 Aurora Road • Cleveland, OH 44139 • 440-248-0400 • Fax: 440-248-6168 • http://www.keithley.com
BELGIUM: Keithley Instruments B.V.
CHINA: Keithley Instruments China Y uan Chen Xin Building, Room 705 • 12 Yumin Road, Dewai, Madian • Beijing 100029 • 8610-62022886 • F ax: 8610-62022892
FRANCE: Keithley Instruments Sarl 3, allée des Garays • 91127 Palaiseau Cedex • 01-64 53 20 20 • Fax: 01-60 11 77 26
GERMANY: Keithley Instruments GmbH Landsberger Strasse 65 • 82110 Germering • 089/84 93 07-40 • Fax: 089/84 93 07-34
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: 91-80-509-1322
ITALY: Keithley Instruments s.r.l. Viale S. Gimignano, 38 • 20146 Milano • 02-48 39 16 01 • Fax: 02-48 30 22 74
NETHERLANDS: Keithley Instruments B.V. Postbus 559 • 4200 AN Gorinchem • 0183-635333 • Fax: 0183-630821
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TAIWAN: Keithley Instruments Taiwan 1 Fl. 85 Po Ai Street • Hsinchu, Taiwan, R.O.C. • 886-3572-9077 • Fax: 886-3572-903
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The Minster • 58 Portman Road • Reading, Berkshire RG30 1EA • 0118-9 57 56 66 • Fax: 0118-9 59 64 69
9/00
Model 7074 General Purpose Multiplexer Card
Instruction Manual
©1989, Keithley Instruments, Inc.
All rights reserved.
Cleveland, Ohio, U.S.A.
Document Number: 7074-901-01 Rev. B
Manual Print History
The print history shown below lists the printing dates of all Revisions and Addenda created for this manual. The
Revision Level letter increases alphabetically as the manual undergoes 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 Revision is created, all Addenda 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 7074-901-01)................................................................................... January 1989
Addendum A (Document Number 7074-901-02)............................................................................. February 1996
Revision B (Document Number 7074-901-01)..................................................................................... March 2001
All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc.
Other brand and product 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 voltages, 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.
Keithley products are designed for use with electrical signals that
are rated Installation Category I and Installation Category II, as described in the International Electrotechnical Commission (IEC)
Standard IEC 60664. Most measurement, control, and data I/O signals are Installation Category I and must not be directly connected
to mains voltage or to voltage sources with high transient over -voltages. Installation Category II connections require protection for
high transient over-voltages often associated with local AC mains
connections. The user should assume all measurement, control, and
data I/O connections are for connection to Category I sources unless otherwise marked or described in the Manual.
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 exists when voltage levels greater than 30V RMS, 42.4V
peak, or 60VDC are present.
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,
exposed.
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.
When installing equipment where access to the main power cord is
restricted, such as rack mounting, a separate main input power disconnect device must be provided, in close proximity to the equipment and within easy reach of the operator.
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.
A good safety practice is to expect
no conductive part of the circuit may be
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. Alw ays read the associated infor mation 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.
To clean an instrument, use a damp cloth or mild, water based
cleaner. Clean the exterior 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.
2/01
7074-D General Purpose Eight 1 xl 2
Multiplexer Card (Dry Reed)
MULTIPLEX CONFIGURATION: Eight 1x12 banks. Adjacent banks can be connected together. Jun
can be removed to isolate any bank from the backplane.
CONTACT CONFIGURATION: 3 pole Form A (HI, LO, GUARD).
CONNECTOR TYPE: Four 75 pin connectors for bank connections, one 38 pin connector for row
connections.
MAXIMUM SIGNAL LEVEL: ZOOV, 1A tarry/0.5A switched, 1OVA peak (resistive load).
COMMON MODE VOLTAGE: ZOOV maximum behveen any 2 pins or chassis.
CONTACT LIFE:
Cold Switching: 108 closures.
At Maximum Signal Level: 105 closures.
CHANNEL RESISTANCE (per conductor): <0.6Q initial, <1.6R at end of contact life.
CONTACT POTENTIAL: <5pV per contact pair (HI to LO, <1 minute after actuation).
OFFSET CURRENT: <lOOpA.
ISOLATION:
Bank: >lOlOQ, <lOpF.
Channel: >lOIOQ <lOpF.
Differential: >109R, 55pF nominal.
Common Mode: >lOgn, 300pF nominal.
CROSSTALK:
Bank: <-55dB at IMHz, 5OQ load.
Channel: c-55dB at IMHz, 5OQ load.
INSERTION LOSS (lMHz, 5OS2 source, 5OQ load): O.ldB typical.
3dB BANDWIDTH (50R load): 1OMHz typical.
RELAY DRIVE CURRENT(per relay): 15mA.
RELAY SETTLING TIME: <3msec.
ENVIRONMENT:
Operating: 0” to 5O”C, up to 35°C @ 70% R.H.
Storage: -25” to 65°C.
ACCESSORIES SUPPLIED: Instruction manual, 8 spare backplane jumpers.
ACCESSORIES AVAILABLE:
Bank Connector Accessories:
Model 7074~CITz
Model 7074HCT:
Model 7074-m
Model 7074MTC.20:
Model 7074MTR:
Model 7074RTc:
Row Connector Accessories:
Model 7078-CIT:
Model 7078.HCT:
Model 7078-KIT:
Model 7078~MTC-5:
Model 7078MTC-20:
Model 7078MTR:
Specifications subject to change without notice.
All specifications applicable to eight 1x12 configuration only.
Contact Extraction Tool
Hand Crimping Tool
Mass Terminated Plug with Contacts
Mass Terminated Cable Assembly, 6m(20 ft.)
Mass Terminated Receptacle with Contacts
Relay Test Shorting Connector
Contact Insertion and Extraction Tools
Hand Crimping Tool
Mass Terminated Plug with Contacts
Mass Terminated Cable Assembly, 1.5m (5 ft.)
Mass Terminated Cable Assembly, 6x1(20 ft.)
Mass Terminated Receptacle with Contacts
7074-M General Purpose Eight 1x12
Multiplexer Card (Mercury Wetted Reed)
MULTIPLEX CONFIGURATION: Eight 1x12 banks. Adjacent banks can be connected together.
Jumpers can be removed to isolate any bank from the backplane.
CONTACT CONFIGURATION: 3 pole Form A (HI, LO, GUARD).
CONNECTOR TYPE: Four 75 pin connectors for bank connections, one 38 pin connector for row
connections.
MAXIMUM SIGNAL LEVEL: 2OOV, 3A cany/2A switched, SOVA peak (resistive load).
COMMON MODE VOLTAGE: ZOOV maximum between any 2 pins or chassis.
CONTACT LIFE:
Cold Switching: 109 closures.
At Maximum Signal Level: 108 closures.
CHANNEL RESISTANCE (per conducted: co.60 initial, cO.7Q at end of contact life.
CONTACT POTENTIAL: <IO&V per contact pair (HI to LO, <I minute after actuation).
OFFSET CURRENT: <lOOpA.
ISOLATION:
Bank: >lOl&, <IOpF.
Channel: >lO%-L, <lOpF.
Differential: >I094 55pF nominal.
Common Mode: >lOgQ. 300nF nominal.
CROSSTALK:
Bank: <-55dB at IMHz, 5OQ load.
Channel: <-55dB at IMHz, 5On load.
INSERTION LOSS (lMHz, 5OQ source, 5OQ load): O.ldB typical.
3dB BANDWIDTH (5OQ load): 1OMHz typical.
RELAY DRIVE CURRENT(per relay): 5OmA.
RELAY SETTLING TIME: <3msec.
ENVIRONMENT:
Operating: 0” to 5O”C, up to 35°C @ 70% R.H.
Storage: -25 to 65°C.
ACCESSORIES SUPPLIED: Instruction manual, 8 spare backplane jumpers.
ACCESSORIES AVAILABLE:
Bank Connector Accessories:
Model 7074~CIT: Contact Extraction Tool
Model 7074-HCT: Hand Crimping Tool
Model 7074-KIT: Mass Terminated Plug with Contacts
Model 7074-MTC-20: Mass Terminated Cable Assembly, 6m (20 ft.)
Model 7074-MTR:
Model 7074-RTC: Relay Test Shorting Connector
Row Connector Accessories:
Model 7078~CIT:
Model 7078-HCT: Hand Crimping Tool
Model 7078-KIT:
Model 7078-MTC-5:
Model 7078-MTC-20: Mass Terminated Cable Assembly, 6m (20 ft.)
Model 7078-MTR: Mass Terminated Receptacle with Contacts
Specifications subject to change without notice.
All specifications applicable to eight 1x12 configuration only.
.
Mass Terminated Receptacle with Contacts
Contact Insertion and Extraction Tools
Mass Terminated Plug with Contacts
Mass Terminated Cable Assembly, 1.511-t (5 ft.)
HOW TO USE THIS MANUAL
Contains information on Model 7074 features, specifications, and accessories.
Details installation of the Model 7074 General Purpose Multiplexer Card within the Model 707 Switching Matrix, ccw
ers card signal paths, and describes connections.
Gives typical applications for the Model 7074.
Contains performance verification procedures, troubleshooting information, and principles of operation for the multiplexer card.
SECTION 1
General Information
SECTION 2
Operation
SECTION 3
Applications
SECTION 4
Service Information
Lists replacement parts, and also includes component layout
and schematic drawings for the Model 7074.
SECTION 5
Replaceable Parts
Table of Contents
SECTION 1 —
1.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.2 FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.3 WARRANTY INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.4 MANUAL ADDENDA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.5 SAFETY SYMBOLS AND TERMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.6 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.7 UNPACKING AND INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.7.1 Inspection for Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.7.2 Shipment Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.7.3 Instruction Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.8 REPACKING FOR SHIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.9 OPTIONAL ACCESSORIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.9.1 BANK Receptacle Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.9.2 ROW Receptacle Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
SECTION 2 —
2.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.2 HANDLING PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.3 ENVIRONMENTAL CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.4 MULTIPLEXER CARD CONFIGURATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.4.1 Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.4.2 1
2.4.3 Multiplexer Bank Jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
2.4.4 Backplane Connection Jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
2.4.5 Switching ConÞgurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
2.5 CARD INSTALLATION AND REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
2.6 CONNECTION METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
2.6.1 Connection Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
2.6.2 Connection Methods Using Mass Terminated Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
2.6.3 Connection Method Using Connector Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17
2.6.4 Wiring Receptacles (Models 7074-MTR and 7078-MTR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
2.7 TYPICAL CONNECTION SCHEMES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28
2.7.1 Single Mainframe, Single Multiplexer Card System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28
2.7.2 Expanding the Multiplexer Using Multiple Cards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-29
2.7.3 Using the Multiplexer with Matrix Cards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-29
2.8 MULTIPLEXER PROGRAMMING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33
2.8.1 Banks and Rows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33
2.8.2 Front Panel Multiplexer Programming Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33
2.8.3 IEEE-488 Bus Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33
General Information
Operation
×
12 Multiplexer Banks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
2.9 MEASUREMENT CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-34
2.9.1 Path Isolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-34
2.9.2 Magnetic Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35
2.9.3 Electromagnetic Interference (EMI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35
2.9.4 Ground Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35
2.9.5 Keeping Connectors Clean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-36
2.9.6 Shielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-36
2.9.7 Guarding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-36
2.9.8 Multiple Card Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37
2.9.9 AC Frequency Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37
SECTION 3 —
3.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.2 RESISTOR TESTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.2.1 2-Wire Resistance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.2.2 4-Wire Resistance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
3.2.3 Low-Level Resistance Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
3.2.4 Example Resistor Test Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
3.3 TRANSISTOR TESTING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
3.3.1 Current Gain Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
3.3.2 Common-Emitter Characteristics Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
3.3.3 Example Transistor Test Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
3.4 TESTING WITH MATRIX CARDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
3.4.1 Multiplexer and Matrix Card Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
3.4.2 Resistivity Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
3.4.3 Example Resistivity Test Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
SECTION 4 —
4.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4.2 HANDLING AND CLEANING PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4.3 RELAY TEST PROGRAM SETUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4.3.1 Recommended Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
4.3.2 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
4.3.3 Running the Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
4.4 PERFORMANCE VERIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
4.4.1 Environmental Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
4.4.2 Recommended Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
4.4.3 Performance Record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
4.4.4 Initial Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
4.4.5 Path Resistance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
4.4.6 Offset Current Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
4.4.7 Contact Potential Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
4.4.8 Path Isolation Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
4.4.9 Differential and Common Mode Isolation Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
4.5 SPECIAL HANDLING OF STATIC-SENSITIVE DEVICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
Applications
Service Information
4.6 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
4.6.1 Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
4.6.2 Rear Shield Removal and Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
4.7 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
4.7.1 Recommended Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
4.7.2 Using the Extender Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
4.7.3 Input/Output Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
4.7.4 Troubleshooting Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
4.7.5 Relay Replacement Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
4.8 PRINCIPLES OF OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
4.8.1 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
4.8.2 ID Data Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
4.8.3 Relay Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
4.8.4 Power-on Safeguard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21
SECTION 5 —
5.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.2 PARTS LISTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.3 ORDERING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.4 FACTORY SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.5 COMPONENT LAYOUT AND SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Replaceable Parts
SECTION 2 - Operation
List Of Illustrations
Figure 2-l
Figure 2-2
Figure 2-3
Figure 2-4
Figure 2-5
Figure 2-6
Figure 2-7
Figure 2-8
Figure 2-9
Figure 2-10
Figure 2-l 1
Figure 2-12
Figure 2-13
Figure 2-14
Figure 2-15
Figure Z-16
Figure 2-17
Figure 2-18
Figure 2-19
Figure 2-20
Figure 2-21
Figure 2-22
Figure 2-23
Figure 2-24
Figure 2-25
Figure 2-26
Figure 2-27
Figure 2-28
Figure 2-29
Figure 2-30
Figure 2-31
Figure 2-32
Figure 2-33
Figure 2-34
Figure 2-35
Figure 2-36
Figure 2-37
Figure 2-38
Model 7074 Rear Panel ..............................
Model 7074 Multiplexer Organization (Factory Configuration)
Model 7074 Card Showing Jumper Locations
Eight 1 x 12 Multiplexer Configured (No jumpers installed)
Four 1 x 24 Multiplexer Configuration
Two 1 x 48 Multiplexer Configuration
1 x 96 Multiplexer Configuration
Model 7074 Multiplexers Connected to Model 7071 Rows using Backplane Jumpers
Guarded Switching ................................................
Unguarded Switching .............................
4.Wire DMM Switching ...........................
SMU Connections .................................
Model 7074 Installation .............................
Connections Using Mass Terminated Cables
Connecting 75-I% Plug to Bank Receptacle
Connecting 38.Pin Plug to ROW Receptacle
Connecting Method using MTC Cables Cut in Half
Cable Preparation
38-I% Plug Cable Position
38-I% Plug (7078-KIT) Wire Color Coding
75-I+ Disassembly ...............................
75-l% Plug Cable Positions
75-I% Plug (7074-KIT) Wire Color Colding
Model 7078Xit (ROW A-H) Plug Contact Assignments
Model 7074~KIT (Bank) Plug Contact Assignments
Bank Receptacle Connector (Wiring side view)
ROW A-H Receptacle Connector
Single Card System Example
Multiple Card System Example
Using the Multiplexer with a Model 7071 Matrix Card
Using the Multiplexer with a Model 7071-4
Path Isolation Resistance ...........................
Voltage Attenuation by Path Isolation Resistance
Power Line Ground Loops
Eliminating Ground Loops
Shielding Example
Guarded Circuit
Typical Guarded Signal Connections
................................
......................................
.........................
.........................
........................
......................
.........................
.........................
...
............
.................
.................
.............
..............
.............
........
.............
.............
....
.......
.....
.............
........
2-2
2-3
2-4
2-5
2-5
2-6
2-6
2-7
2-8
2-8
2-9
2-9
Z-10
2-13
2-14
2-14
2-15
2-18
2-18
2-19
2-20
2-21
2-22
2-23
2-24
2-26
2-27
2-28
Z-30
2-31
2-32
2-34
2-34
2-35
2-36
2-36
2-37
2-38
Figure 2-39
Figure Z-40 Model 7074 Frequency Response (RL = lMQ, 1 x 96 Configuration) 2-39
Figure 2-41
Figure 242 Model 7074 Frequency Response (Rr = 504 Eight 1 x 12 Configuration 2-41
Figure 243 Model 7074 Frequency Response (RL = 5OQ Eight 1 x 12 Configuration 242
AC Frequency Response Test Configuration
Model 7074 Frequency Response (RL = 50Q 1 x 96 Configuration 2-40
2-38
:SECTION 3 - Applications
Figure 3-l 2-Wire Resistance Testing
Figure 3-2 4-Wire Resistance Testing
Figure 3-3 Low Resistance Testing .................................... 3-3
Figure 3-4 Configuration for Current Gain and Common-Emitter Tests
Figure 3-5
Figure 3-6 Connecting Multiplexer and Matrix Cards Together
Figure 3-7 Resistivity Test Configurations ..............................
Figure 3-8 Measurement Required for Resistivity Test
Typical Common-Emitter Characteristics
..................................
..................................
........
...................... 3-6
..............
..................... 3-9
3-1
3-2
3-5
3-7
3-8
SECTION 4 - Service Information
Figure 4-l
Figure 4-2
Figure 4-3
Figure 4-4
Figure 4-5
Figure 4-6
Figure 4-7
Figure 4-8
Figure 4-9
Figure 4-10
Figure 4-11
Figure 4-12
Figure 4-13
Figure 4-14
Figure 4-15
Figure 4-16
Test Cable Preparation .....................................................
Connecting the Test Cable to the Model 7074 .....................................
Connecting Test Leads to Receptacle ...........................................
ROW A-H Receptacle Contact Assignments (Rear Panel View)
Bank Receptacle Assignments (Rear Panel View)
Connections for Path Resistance Test ...........................................
Differential Offset Current Test Connections
Common Mode Offset Current Test Connections ..................................
Contact Potential Test Connections ............................................
Path Isolation Test Connections ..............................................
Differential Isolation Test Connections .........................................
Connections for Common Mode Isolation Tests ...................................
Card Disassembly
RearShieldLocation
IDDataTiming
Model7074BlockDiagram..
.........................................................
.......................................................
...........................................................
................................................
..................................
.....................................
.......................
4-2
4-3
4-5
4-6
4-7
4-8
4-9
4-10
4-l 1
4-12
4-14
4-15
4-16
4-17
4-19
4-20
SECTION 2 - Operation
List of Tables
Table 2-l
Table 2-2
Table 2-3
Cables, Receptacles, and Special Tools
Model 7074-MTC Cable Color Codes
Model 7078.MTC Cable Color Codes
SECTION 4 - Service Information
Table 4-l
Table 4-2
Table 4-3
Table 4-4
Table 4-5
Table 4-6
Recommended Verification Equipment
Performance Record
Path Isolation Test Summary
Differential and Common Mode Isolation Test Summary
Recommended Troubleshooting Equipment
Troubleshooting Procedure
...........................
..............
...............
...............
.............
.....................
......................
.........
...........
...........
...........
...........
...........
...........
...........
2-12
2-16
2-17
4-4
4-5
4-13
4-15
4-1s
4-18
SECTION 1
General Information
1 .l INTRODUCTION
This section contains general information about the
Model 7074.
Section 1 is arranged in the following manner:
1.2 Feafures
1.3 Warranty Information
1.4 Manual Addenda
1.5 Safety Symbols and Terms
1.6 Specifications
1.7 Unpacking and Inspection
1.8 Repacking for Shipment
1.9 Optional Accessories
1.2 FEATURES
The Model 7074 General Purpose Multiplexer Card con-
sists of eight banks of 1 x 12 multiplexers that can be configured in various combinations. Three-pole switching
(HI, LO, guard) is provided for any of the 96 inputs.
Easy jumper configuration of single, dual, quad, or octal multiplexer banks.
Each of the eight multiplexer banks can be connected
to the 3-p& general-purpose backplane pathways
with user-installed jumpers, allowing simple internal
connections to the rows of those matrix cards.
Five mass-termination receptacles located on the rear
panel for quick-disconnect input and output connections.
1.3 WARRANTY INFORMATION
Warranty information is located on the inside front cover
of this instruction manual. Should your Model 7074 require warranty service, contact the Keithley representative or 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 in order to provide the repair facility with the
necessary information.
1.4 MANUAL ADDENDA
Any improvements or changes concerning the multi-
plexer card or manual will be explained in an addendum
included with the the unit. Be sure to note these changes
and incorporate them into the manual before using or
servicing the card.
1.5 SAFETY SYMBOLS AND TERMS
The following symbols and terms may be found on an instrument or used in this manual.
The Model 7074 is available with either dry or mercurywetted reed relays. The dry-reed version (Model 7074-D)
has lower thermal offset performance, while the mercury-wetted version (Model 7074-M) offers minimal contact bounce for and constant contact resistance overlife.
Throughout this manual, Model 7074 is used to refer to
both versions unless otherwise indicated.
Key features of the Model 7074 include:
The A
user should refer to the operating instructions located in
the instruction manual.
The symbol on an instrument shows that 1kV or
greater may be present on the terminal(s). Use standard
symbol on an instrument indicates that the
1-l
SECTION I
General Information
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.
The CAUTION heading used in this manual explains
hazards which could damage the multiplexer card. Such
damage may invalidate the warranty.
1.6 SPECIFICATIONS
Model 7074-D and Model 7074-M specifications may be
found at the front of this manual. Note that some specifications, such as contact life, path resistance, and contact
potential, differ between the two versions of the card.
These specifications are exclusive of the matrix mainframe specifications, which are located in the Model 707
Instruction Manual.
removing the plastic wrapping, place the manual in the
binder after the mainframe instruction manual. Note that
a manual identification tab is included and should precede the multiplexer card instruction manual.
If an additional instruction manual is required, order the
manual package, Keithley part number 7074-901-00. The
manual package includes an instruction manual and any
pertinent addenda.
1.8 REPACKING FOR SHIPMENT
Should it become necessary to return the Model 7074 for
repair, carefully pack the unit in its original packing carton or the equivalent, and include the following~information:
Advise as to the warranty status of the multiplexer
card.
Write ATTENTION REPAIR DEPARTMENT on the
shipping label.
Fill out and include the service form located a’t theback
of this manual.
1.7 UNPACKING AND INSPECTION
1.7.1 Inspection for Damage
Upon receiving the Model 7074, carefully unpack it from
its shipping carton and inspect the card for any obvious
signs of physical damage. Report any such damage to the
shipping agent immediately. Save the original packing
carton for possible future reshipment.
1.7.2 Shipment Contents
The following items are included with every Model 7074
order:
. Model 7074-D or 7074-M Multiplexer Card
l Model 7074 Instruction Manual
l Eight spare configuration jumpers
l Additional accessories as ordered
1.7.3 Instruction Manual
1.9 OPTIONAL ACCESSORIES
The following paragraphs discuss optional cables, connecting kits, and special tools that are available for use
with the Model 7074.
1.9.1 BANK Receptacle Accessories
The following accessories are designed for use with the
four BANK receptacles.
Model 7074-CIT Contact Extraction Tool -The Model
7074~CR includes a tool that is used to remove wire
crimp tail contacts from 75-pin “rack and panel” plugs
and receptacles.
Model 7074-HCT Hand Crimping Tool - The Model
7074-HCT is used to attach wire crimp tail contacts (for
75-pin connectors) to #l&3 to #26 AWG stranded wire.
However, provided contacts should only be used with
#20 to #24 AWG wire.
The Model 7074 Instruction Manual is three-hole drilled
so that it can be added to the three-ring binder of the
Model 707 Switching Matrix Instruction Manual. After
1-2
Model 7074-KIT Connector Kit-The Model 7074~KIT
contains the parts to assemble one 75pin “rack and
General Information
SECTION1
panel” plug. This plug will mate to the BANK receptacle
on the rear panel of the card. Parts contained in the kit include the plug, 80 wire crimp tail contacts (for use with
#20 to #24 AWG wire), four corner pins, one tunable
male jackscrew, one tunable female jackscrew, and one
shield.
Model 7074-MTC-20 Mass Terminated Cable Assembly - The Model 7074~MTC-20 is a 20-foot (6-meters),
72-conductor cable terminated with a “rack and panel”
plug on both ends. This cable connects to the the BANK
receptacles on the rear panel of the card. This cable can be
cut in half to provide two separate cables, each of which
can be connected to one of the BANK receptacles. The unterminated ends of the cables are then connected to instrumentation and DUTs.
Model 7074-MTR Mass Terminated Receptacle with
Contacts-The Model 7074~MTR includes a 75-pin con-
nector, 80 crimp tail contacts, (for #20 to #24AWG wire),
one fixed female jackscrew, one fixed male jackscrew,
and four corner pins. The Model 7074-MTR mates with
the Model 7074MTC cables and the Model 7074-KIT
plug kit.
Model 707%CIT Contact Insertion and Extraction Tools
-The Model 7078~CIT includes an insertion tool that is
used to insert wire crimp tail contacts into 38-pin “rack
and panel” plugs and receptacles. Conversely, the extraction tool is required for the removal of the contacts.
Model 707%HCT Hand Crimping Tool - The Model
707%HCT is used to attach wire crimp tail contacts to #18
to #26 AWG stranded wire.
Model 7078-KIT Connector Kit-The Model 707%KIT
contains the parts to assemble one 38-pin “rack and
panel” plug. This plug will mate to the ROW A-H recep-
tacle on the rear panel of the card. Parts contained in the
kit include the plug, plug housing and 40 wire crimp tail
contacts.
Model 707%MTC-5 Mass Terminated Cable Assembly
-The Model 7078MTC is a 5-foot (1.5~meters), 36-conductor cable terminated with a “rack and panel” plug on
both ends. This cable connects to ROW A-H receptacle on
the rear panel of the card. This cable can be cut in half to
provide two separate cables when using two or more
Model 7074 cards. The unterminated ends of the cables
are then connected to instrumentation and DUTs.
Model 7074-RTC Relay Test Shorting Plug - The
Model 7074-RTC is intended for use with the relay test
software, as described in paragraph 4.2. The Model
7074-RTC consists of a 75-pin plug with pins and jumper
wires.
1.9.2 ROW Receptacle Accessories
The following accessories are intended for use with the
ROW A-H receptacle.
Model 707%MTC-20 Mass Terminated Cable Assembly - Thii cable is the same as the Model 707%MTC-5,
except that it is 20.feet (6-m&& in length.
Model 707%MTR Mass Terminated Receptacle with
Contacts-The Model 707%MTR includes a 3%pin connector and 40 crimp tail contacts. The Model 707%MTR
mates with the Model 7078-MTC cables and the Model
7078-KIT plug kit.
l-3
SECTION 2
Operation
2.1 INTRODUCTION
This section contains information on multiplexer configuration, card connections, installation, and programming, and is arranged as follows:
2.2 Handling Precautions: Discusses precautions that
should be taken when handling the card to avoid contamination that could degrade performance.
2.3 Environmental Considerations: Outlines environmental aspects of using the Model 7074.
2.4 Multiplexer Card Configuration: Discusses the multiplexer rear panel as well as multiplexer configuration,
and expansion by jumpering two or more multiplexer
sections together.
2.5 Card Installation and Removal: Details installation
in and removal from the Model 707 Switching Matrix
mainframe.
2.6 Connection Methods: Discusses card connectors, cables, and ways to connect the card to other instruments
and test fixtures.
2.7 Typical Connection Schemes: Gives typical connections to other cards, mainframes, and test instrumentation.
safety precautions located at the front of this
manual before using the multiplexer card.
2.2 HANDLING PRECAUTIONS
To maintain high impedance isolation, care should be
taken when handling the multiplexer card to avoid contamination from such foreign materials as body oils. Such
contamination can substantially lower leakage resistances, degrading performance. To avoid any possible
contamination, always grasp the card by the handle or
the card edges. Do not touch board surfaces, components, or edge connectors.
Dirt build-up over a period of time is another possible
source of contamination. To avoid this problem, operate
the mainframe and matrix card only in a clean environment. If contamination is suspected, clean the card as discussed in Section 4. Also, the performance verification
procedures in Section 4 can be used to test the card for
low leakage resistances that could indicate contamination.
2.3 ENVIRONMENTAL CONSIDERATIONS
For rated performance, the card should be operated
within the temper&w and humidity limits given in the
specifications at the front of this manual.
2.8 Multiplexer Programming: Summarizes programming steps to control the multiplexer card from the
Model 707 Switching Matrix.
2.9 Measurement Considerations: Reviews a number of
considerations when making measurements using the
Model 7074.
WARNING
The information in this section is intended
for qualified personnel who have experience
with potentially hazardous voltages. Do not
attempt to perfolm these procedures unless
you are qualified to do so. Carefully read the
2.4 MULTIPLEXER CARD CONFIGURATION
The following paragraphs discuss the rear panel of the
card, the eight 1 x 12 multiplexers of the Model 7074, as
well as how to connect two or moremultiplexer banks together to make multiplexers as large as 1 x 96.
2.4.1 Rear Panel
The rear panel of the Model 7074 is shown in Figure 2-1.
The rear panel has a total of five receptacles for input/
2-1
SECTION2
Operation
output connections. The four BANK connectors (148, J49,
J51, and J52) would normally be used for multiplexer in-
puts and are labeled with multiplexer bank letters
(BANKS A and B appear on J48, BANKS C and D are on
J49, BANKS E and F are on J51, and BANKS G and H appear on J52). The eight multiplexer bank outputs are lo-
cated on the ROW A-H connector (JSO). Detailed connection information can be found in paragraphs 2.6 and 2.7.
2.4.2
As shown in Figure 2-2, the Model 7074 is organized as
eight 1 x 12 multiplexer banks. These multiplexer banks
are labeled rows A through H in order to conform to
Model 707 Switching Matrix commands.Throughout this
manual, the terms “banks” and “rows” are used interchangeably.
The inputs for each row are labeled 1 through 12 inclusive, and these numbers correspond to mainframe columns. Note that 3-p& switching is provided for each
multiplexer input, with HI, LO, and guard switched. Two
or more banks canbe jumpered together to expand multiplexer inputs, as discussed below. Note that inputs are
also referred to as channels in this manual.
2.4.3
Jumpers can be installed on the card in order to connect
multiplexer banks together to form multiplexers as large
as 1 x 96. To connect adjacent multiplexer banks, simply
install the jumpers between the adjacent bank jumper
pins, which are shown in Figure 2-3. These jumpers are
included with the Model 7074, but they are not installed
at the factory. Note that you should install the jumpers
for all three signal paths (HI, LO, and guard).
1 x 12 Multiplexer Banks
Multiplexer Bank Jumpers
By installing the jumpers in the appropriate places, you
can configure the multiplexer card in a variety of ways.
Typical examples include:
l Eight 1 x 12 multiplexers: no jumpers installed
(Figure 2-4).
l Four 1 x 24 multiplexers: jumper A to B, C to D, E to F,
G to H (Figure 2-5).
l Two 1 x 48 multiplexers: jumper all except D to E
(Figure 2-6).
l One 1 x 96 multiplexer: install all bank jumpers
(Figure 2-7).
2-2
Figure 2-l. Model 7074 Rear hnel
1
Many other combinations are possible, including multiplexers of various sizes (in multiples of 12 channels) by
installing jumpers as required. For example, you could
install jumpers to configure the card as two 1 x 24 multiplexers and one 1 x 48 multiplexer.
SECTION 2
Opr&XI
for all Channels
Figure 2-2. Model 7074 Multiplexer Organization (Factmy Configuration)
Note : Factory Configuration Shown
- Jumper installed at factory
“““’ Jumper not installed at factory
2-3
SECTION 2
Operation
0
Rear 0 -
Panel
::: - AlOB
::: EbaF
0
Figure 2-3. Model 7074 Card Showing Jumper Locations
::: F,OG
::: GbH
Z-4
SECTION 2
Operation
-
Figure 2-4. Eight 1 x 12 Multiplexer Configured
(No jumpers installed)
Figure 2-5.
Four 2 x 24 Multiplexer Configuvntion
2-S
SECTION 2
Operarion
?gure 2-6.
Two 1 x 48 Multiplexer Confi,quration
Tgure 2-7.
1 x 96 Multiplexer Configuration
2-6
SECTION 2
Operarion
2.4.4 Backplane Connection Jumpers
The multiplexer banks on the Model 7074 can be connected to row A through H 3-p&, general-purpose backplane pathways of the matrix mainframeby installing the
appropriate backplane jumpers. These pathways provide connection to rows A through H of any Model 7071
General Purpose or Model 7071-4 Dual 4 x 12 Matrix
Cards installed in the mainframe. Figure 2-8 shows multiplexer bank rows A through H of the Model 7074 connected through the mainframe backplane to rows A
through H of the matrix card. Appendix B provides additional card-backplane information.
The backplane jumpers can also be used to expand the
multiplexerbanksusingotherModel7074cardsinstalled
in the same mainframe. For example, three Model 7074
cards installed in a mainframe with the proper bank and
backplane jumper configuration would result in a 1 x 288
or 2 x 144 multiplexer configuration.
The backplane jumpers are located on the right edge of
the card (see Figure 2-3). Note that HI, LO, and guard for
a particular bank would all normally be jumpered to the
corresponding row of the 3-pole, general-purpose backplane.
2.4.5 Switching Configurations
Guarded Switching
Each multiplexer switch is a 3-p& relay that switches,
HI, LO, and guard, allowing 3-p& switching, an exam-
ple of which is shown in Figure 2-9. In this case, a driven
guard is provided by the measuring/sourcing instmment (guarding helps to minimize the effects of leakage
resistance and capacitance, especially where long pathways are involved; see paragraph 2.9).
WARNING
Hazardous voltages up to 2OOV may be present on GUARD. Install an earth-grounded
safety shield around the DUT and make sure
all cable shields are properly insulated.
Backplane
Jumpers
---~q[----r ------------- ~~“m, -----------IZU
7071 Matrix Card
I
/
Figure 2-8. Model 7074 Multiplexers Connected to Model 7071 Rows using B&plane Jumpers
2-7
SECTION 2
Operation
Unguarded Switching
In cases where no guard is required or available, the
guard path, which is connect to the cable shield, should
be connected to signal LO at the source/measurement instrument in order to shield the entire pathway. Such an
arrangement is shown in Figure Z-10. An optional shield,
surrounding the DUT, can also be added to ensure complete shielding. This shield should be connected to circuit
LO rather than earth ground. An additional safety shield
should also be included as shown.
Multiple-pole Switching
In sc~me cases, it may be necessary to switch more than
three poles for a given input or output channel. Two such
cases are four-wire resistance measurements, or when
using SMUs
(source/measure
units). Since the Model
7074 can be split up into several multiplexers, two or
more multiplexer banks can be used together to add the
desired number of poles.
Figure 2-11 shows an example for 4-wire resistance
measurements using a DMM. Note that VOLTS/OHMS
HI and SENSE HI are routed through one bank, while
VOLTS/OHMS LO and SENSE LO are routed through a
second bank.
Figure 2-12 demonstrates a typical configuration when
using a Model 236 SMU. Here, source and sense are
routed through separate banks. If a guard shield SLITrounding the DUT is to be used, a safety shield must also
be incorporated.
WARNING
Hazardous voltages up to ZOOV may be present on GUARD. Install an earth-grounded
safety shield around the DUT and make sure
all cable shields are properly insulated.
-
Warning :
Hazardous voltages up to ZOOV may be present
on GUARD. install ear?h-grounded safety shield and
make sure all cable shieldsare properly insulated.
Figure 2-9. Guarded Switching
Figure 2-10. Unguarded Switching
-Safety Shield
2-8
SECTION 2
Operarim
Figure Z-11. 4.Wire
DMM Switching
236
SMU
Warning :
Hazardous voltages up to 110” may be present
on GUARD. ,hs,a,l earth-grounded sa‘ety shield and
make sure al, cable shields are properly insulated.
=igure 2-12. SMU Connections
2-9
SECTION 2
Operation
2.5
After selecting the jumper configuration, the Model 7074
should be installed within the Model 707 Switching Matrix, as summarized below. Figure 2-13 shows the install&ion procedure.
CARD INSTALLATION AND REMOVAL
WARNING
Turn off the mainframe power and disconnect the line cord before installing orremoving cards.
CAUTION
Disconnect all connecting cables before in-
stalling or removing the multiplexer card.
l. Before installing the card, make sure the access door
on top of the Model 707 is fully closed and secured.
The access door contains tracks for the card slots and
must be in place to properly install the card.
2. With one hand grasping the handle, and the other
holding the back bottom edge of the card, line up the
card with the tracks in the desired slot. Make certain
that the component side of the card is facing the fan
on the mainframe.
‘igure Z-13. Model 7074 Installation
Z-10
Mounting Screws
SECTION 2
Operarion
CAUTION CAUTION
Do not touch the card surfaces oranycompo- Do not touch the card surfaces oranycomponents to avoid contamination
grade card performance.
Slide the card into the mainframe until it is properly
seated in the edge connectors at the back of the slot.
Once the card is properly seated, secure it to the
mainframe by finger tightening the spring-loaded
screws.
WARNING
The mounting screws must be secured to ensure a proper chassis ground connection between the card and the mainframe. Failure to
properly secure this ground connection may
result in personal injury or death due to electric shock.
To remove a card, first turn off the power and disconnect the line cord from the mainframe. Disconnect all cables from the multiplexer card. Loosen the
mounting screws, then pull the card out of the mainframeby the handle. When theback of the card clears
the mainframe, support it by grasping the bottom
edge near the rear of the card.
that
that
could de- nents to avoid contamination
could de-
2.6 CONNECTION METHODS
The Model 7074 has two types of “rack and panel” receptacles mounted on the rear panel. The four BANK (input)
receptacles are 75.pin receptacles that will mate with
either the optional mass terminated cables (Models
7074~MTC-5 or 7074~MTC-20) or the plug provided with
the optional connector kit (Model 7074~KIT). The ROW
A-H (output) receptacle is a 3%pin connector that will
mate with either the optional mass terminated cables
(Models 7078-MTC-5 or 7078-MTC-20) or the plug provided with the optional connector kit (Model 7078~KIT).
Model numbers for the two groups of cables, plugs, receptacles, and special tools are similar and are called out
together. Table 2-l summarizes the cables, receptacles,
and special tools that canbe obtained directly from Keithley Instruments. To avoid confusion, remember that all
7074 numbers pertain to the four BANK receptacles, and
all 7078 numbers are associated with the ROW A-H receptacle.
NOTE
The term receptacle refers to a connector
mounted on the rear panel of the multiplexer
card (and the connector supplied with the
Model 7074.MTR and 7078~MTR kits). The
term plug refers to a connector that attaches to
a cable such as the Model 7074.MTC and
7078-MTC cables, and the plugs supplied
with the Model 7074XIT and 7078-KIT kits.
2.6.1 Connection Methods
There are several ways to make connections to the Model
7074. These include:
Unmodified Mass Terminated Cable Method (Models
7074-MTC and 7078-MTC) - This method is probably
the most convenient method to make connections to the
multiplexer card. Using the whole cable (both plugs in-
tact) makes it most convenient to connect the multiplexer
card to a test fixture that uses the same “rack and panel”
receptacles as the multiplexer card. Additional receptacles that mate with these cables can be ordered from
Keithley Instruments; order Model 7074-MTR for the
BANK receptacles, or Model 707%MTR for the ROW
A-H receptacle. Detailed information on wiring these re-
ceptacles is located in paragraph 2.6.4.
Modified Mass Terminated Cable Method -By cutting
each MTC cable in half (or wherever appropriate), two
separate cables, unterminated at one end, will result.
These cables can then be hard-wired to DUTs or to your
test fixture. The plug on each Model 7074-MTC cable will
then connect to one of the BANK (input) receptacles, and
the plug on one end of a Model 7078-MTC cable will connect to the ROW A-H receptacle on the card.
The following paragraphs discuss how to make connections using the two connector types. Since the procedures
for the two connector types are virtually identical, only
one procedure for each type is given. Where applicable,
differences between the two connector types are called
out separately.
Connector Kit Method (Models 7074-KIT and
7078-KIT) - These kits contain plugs that mate to the
“rack and panel” receptacles, and they are designed for
custom-built mass terminated cables. An alternative to
building a complete cable from scratch is to cut the Model
2-11
SECTION 2
Operadon
Table 2-1. Cables, Receptacles, and Special Tools
Model or Part
Model 7074~CIT: Extraction Tool
Model 7074-HCT: Hand Crimping Tool
Model 7074-m Connection Kit
Model 7074-MTC: Mass Terminated Cable
Model 7074~MTR: Mass Terminated Receptacle Contains one 75-pin “rack and panel” receptacle and contact sock-
Model 707%ClTz Insertion and Extraction Tools Used to install/remove wire crimp tails into/from 3%pin “rack
Model 707%HCT: Hand Crimping Tool
Model 7078-m Connection Kit
Model 707%MTC: Mass Terminated Cable
Description
Used to remove wire crimp tails in 75-pin “rack and panel” plugs
and receptacle
Used to connect wire crimp tails to #lt? to #26 gauge wire.
Contains one “rack and panel” plug, housing and 80 wire crimp
tail pins. Note: These pins are intended for use with #20 to #24
AWG wires.
6-meter (20 ft.) 72 conductor cable terminated with 75-pin “rack
and panel” plugs. Mates to “rack and panel” receptacles.
ets. Note: These sockets are intended for use with #20 to #24
AWG wire.
and panel” plugs and receptacles.
Used to connect wire crimp tails to #18 to #26 gauge wire.
Contains one 38-pin “rack and panel” plug, housing, and 40 wire
crimp tails.
6-meter (20 ft.), 36 conductor cable terminated with “rack and
panel” plugs. Mates to 3%pin “rack and panel” receptacles.
Model 707%MTR: Mass Terminated Receptacle
NOTE: All Model 7074 numbers pertain to BANK receptacles/plugs. All Model 7078 numbers pertain to ROW receptacle/plug
7074~MTC or 707%MTC cable at a length that is suitable
and then attach the plug to it.
WARNING
To avoid electrical shock, which could result
in injury or death, make sure all power is off
and stored energy in external circuitry is discharged before making any connections to
the multiplexer card. Do not exceed the voltage and current ratings for the card or connecting cables as stated in the specifications
and safety precautions at the front of this
manual. Do not connect this card to unlimited power circuits or directly to ac mains. Install appropriate protection devices to limit
fault currents from any supply connected to
this card.
3%pin “rack and panel” receptacle and contact pins.
CAUTION
Contamination will degrade the performance of the multiplexer card. To avoid contamination, always grasp the card by the
handle and side edges. Do not touch the edge
connectors of the card, and do not touch the
board surfaces or components. On “rack and
panel” receptacles and plugs, do not touch
areas adjacent to the electrical contacts.
2.6.2
Connection Methods Using Mass
Terminated Cables
The Model 7074~MTC-20 is a 6meter (20-foot), 75-conductor cable terminated with a 75.pin “rack and panel”
plug on each end. This cable is used to connect the BANK
(input) receptacles on the rear panel of the card to external equipment.
2-12
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