Keithley 2001-SCAN Service manual
Model 2001-SCAN
Scanner Card
Instruction Manual
Contains Operating and Servicing Information
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 Keithle y representative, or contact Keithle y 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.
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
CHINA: Keithley Instruments China • Yuan Chen Xin Building, Room 705 • 12 Yumin Road, Dewai, Madian • Beijing 100029 • 8610-62022886 • Fax: 8610-62022892
FRANCE: Keithley Instruments SARL • BP 60 • 3 Allée des Garays • 91122 Palaiseau Cédex • 33-1-60-11-51-55 • Fax: 33-1-60-11-77-26
GERMANY: Keithley Instruments GmbH • Landsberger Strasse 65 • D-82110 Germering, Munich • 49-89-8493070 • Fax: 49-89-84930759
GREAT BRITAIN: Keithley Instruments, Ltd. • The Minster • 58 Portman Road • Reading, Berkshire RG30 1EA • 44-1189-596469 • Fax: 44-1189-575666
ITALY: Keithley Instruments SRL • Viale S. Gimignano 38 • 20146 Milano • 39-2-48303008 • Fax: 39-2-48302274
NETHERLANDS: Keithley Instruments BV • Avelingen West 49 • 4202 MS Gorinchem • 31-(0)183-635333 • Fax: 31-(0)183-630821
SWITZERLAND: Keithley Instruments SA • Kriesbachstrasse 4 • 8600 Dübendorf • 41-1-8219444 • Fax: 41-1-8203081
TAIWAN: Keithley Instruments Taiwan • 1FL., 85 Po Ai Street • Hsinchu, Taiwan • 886-3-572-9077 • Fax: 886-3-572-9031
Model 2001-SCAN Scanner Card
Instruction Manual
©1992, Keithley Instruments, Inc.
All rights reserved.
Cleveland, Ohio, U.S.A.
Third Printing, June 1998
Document Number: 2001-SCAN-901-01 Rev. C
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 2001-SCAN-901-01)..................................................................... April 1992
Addendum A (Document Number 2001-SCAN-901-02)................................................................. May 1992
Revision B (Document Number 2001-SCAN-901-01) .......................................................................June 1992
Addendum B (Document Number 2001-SCAN-901-02)........................................................... October 1995
Revision C (Document Number 2001-SCAN-901-01).......................................................................June 1998
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, 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 exists 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 bef ore
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)
measuring circuits 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.
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.
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 the 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.
The CAUTION heading in a manual explains hazards that could
damage the instrument. Such damage may invalidate the warranty.
SCANNER OPTION 2001-SCAN
GENERAL
10 Channels: 8 channels of 2-pole relay input.
CAPABILITIES
a. Multiplex one of ten 2-pole or one of five 4-pole signals into DMM and/or
any combination of 2 or 4-pole signals, or
b. Two channel, high speed multiplexing into the DMM, or
c. High speed ratio or delta measurements.
FUNCTIONS (can be mixed from channel to channel)
Relay Channels: Yes Yes* Yes
Solid State Channels: Yes — —
*On 2 channels, using user-supplied
RELAY INPUTS
Maximum Signal Level:
DC Signals: 110V DC, 1A switched, 30VA maximum (resistive load).
AC Signals: 125V AC rms or 175V AC peak, 100kHz maximum, 1A switched,
62.5VA maximum (resistive load).
Contact Life: >10
switching.
Contact Resistance: <1
Actuation Time: 2.5ms maximum on/off.
2 channels of 2-pole solid state input.
All channels configurable to 4-pole.
Ω
DCV, ACV, 4-Wire
, 2-Wire
4-Wire RTD, Frequency DCI, ACI 2-Wire RTD
1
⁄4W shunt resistor.
5
operations at maximum signal level; >108 operations cold
Ω
at end of contact life.
Ω
SOLID STATE INPUTS
Ω
Resistance: <275
(including 200Ω series resistor).
Maximum Signal Level: 110V DC, 175V peak AC, 50mA, 100kHz maximum.
µ
Actuation Time: 150
s maximum on, 100µs maximum off.
ALL INPUTS
±
Contact Potential: <
500nV typical per contact, 1µV max.
±
500nV typical per contact pair, 1µV max.
<
Operating Speed: See Operating Speed section for complete speed specifications.
Connector Type: Screw terminal, #22 AWG wire size.
Isolation Between Any Two Terminals: >10
Isolation Between Any Terminal and Earth: >10
9
Ω
, <75pF.
9
Ω
, <150pF.
Common Mode Voltage: 350V peak between any terminal and earth.
Maximum Voltage Between Any Two Terminals: 200V peak.
Maximum Voltage Between Any Terminal and Model 200 1 Input LO: 200V peak.
ENVIRONMENTAL: Meets all Model 2001 environmental specifications.
DIMENSIONS, WEIGHT: 21mm high × 72mm wide × 221mm deep (0.83 in. ×
2.83 in. × 8.7 in.). Adds 0.4kg (10 oz.).
SCANNER CONFIGURATION:
Channel 1
Channels 2–4
Channel 5
Channel 6
Channels 7–9
Channel 10
HI
LO
HI
LO
HI
LO
HI
LO
HI
OUT A
LO
HI
OUT B
LO
2-POLE4-POLE
Specifications subject to change without notice.
Table of Contents
1 General Information
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 ................................................................................................................................1-2
1.6 Specifications .....................................................................................................................................................1-2
1.7 Unpacking and inspection ............................................................................................................................... 1-2
1.7.1 Inspection for damage..............................................................................................................................1-2
1.7.2 Handling precautions...............................................................................................................................1-2
1.7.3 Shipment contents..................................................................................................................................... 1-2
1.7.4 Instruction manual....................................................................................................................................1-2
1.8 Repacking for shipment ...................................................................................................................................1-2
2 Card Connections and Installation
2.1 Introduction .......................................................................................................................................................2-1
2.2 Handling precautions.......................................................................................................................................2-1
2.3 Connections........................................................................................................................................................ 2-2
2.3.1 Card configuration....................................................................................................................................2-2
2.3.2 Card connectors......................................................................................................................................... 2-3
2.3.3 Wiring procedure......................................................................................................................................2-3
2.3.4 Output connections................................................................................................................................... 2-4
2.3.5 Dressing leads............................................................................................................................................ 2-4
2.4 Typical connecting schemes ............................................................................................................................2-6
2.4.1 Voltage connections..................................................................................................................................2-6
2.4.2 Resistance connections ............................................................................................................................. 2-8
2.4.3 Current measurements...........................................................................................................................2-10
2.4.4 High-speed multiplexer and ratio/delta connections .......................................................................2-13
2.5 Card installation and removal....................................................................................................................... 2-14
2.5.1 Scanner Card Installation.......................................................................................................................2-14
i
2.5.2 Output connections to multimeter........................................................................................................2-16
2.5.3 Scanner card removal..............................................................................................................................2-16
3 Operation
3.1 Introduction........................................................................................................................................................3-1
3.2 Signal limitations ...............................................................................................................................................3-2
3.2.1 Relay input signal limitations..................................................................................................................3-2
3.2.2 Solid-state input signal limitations .........................................................................................................3-2
3.3 Scanner card detection......................................................................................................................................3-2
3.3.1 Power-up detection ...................................................................................................................................3-2
3.3.2 Scanner option bus query.........................................................................................................................3-2
3.4 Front panel scanner controls............................................................................................................................3-2
3.4.1 Open and close channels (CHAN)..........................................................................................................3-3
3.4.2 Configure channels (CONFIG-CHAN)..................................................................................................3-4
3.4.3 Scan configuration (CONFIG-SCAN).....................................................................................................3-5
3.4.4 Using SCAN to configure scan parameters...........................................................................................3-6
3.4.5 Using EXIT to stop scanning....................................................................................................................3-7
3.4.6 Manual scanning........................................................................................................................................3-7
3.5 IEEE-488 bus scanner commands....................................................................................................................3-7
3.6 Closing and opening channels.........................................................................................................................3-9
3.6.1 Closing channels........................................................................................................................................3-9
3.6.2 Opening channels......................................................................................................................................3-9
3.7 Scanning channels .............................................................................................................................................3-9
3.7.1 Front panel scanning.................................................................................................................................3-9
3.7.2 IEEE-488 bus scanning............................................................................................................................3-10
3.8 Ratio and delta .................................................................................................................................................3-11
3.8.1 Ratio and delta computation..................................................................................................................3-11
3.8.2 Ratio and delta measurement functions...............................................................................................3-11
3.8.3 Solid-state switching ...............................................................................................................................3-11
3.8.4 Ratio and delta triggering ......................................................................................................................3-11
3.8.5 Ratio operation.........................................................................................................................................3-11
3.8.6 Delta operation.........................................................................................................................................3-13
3.9 RTD temperature measurements ..................................................................................................................3-14
3.10 Using the scanner with the buffer.................................................................................................................3-15
3.11 Typical applications ........................................................................................................................................3-16
3.11.1 Resistor testing.........................................................................................................................................3-16
3.11.2 High-speed multiplexing........................................................................................................................3-19
3.11.3 Current measurements ...........................................................................................................................3-19
3.12 Measurement considerations.........................................................................................................................3-20
3.12.1 Path isolation............................................................................................................................................3-20
3.12.2 Channel resistance...................................................................................................................................3-21
3.12.3 Magnetic fields.........................................................................................................................................3-21
3.12.4 Electromagnetic interference (EMI) ......................................................................................................3-21
3.12.5 Ground loops ...........................................................................................................................................3-22
3.12.6 Keeping connectors clean.......................................................................................................................3-22
ii
4 Service Information
4.1 Introduction .......................................................................................................................................................4-1
4.2 Handling and cleaning precautions ...............................................................................................................4-1
4.2.1 Handling precautions...............................................................................................................................4-1
4.2.2 Soldering precautions...............................................................................................................................4-2
4.3 Performance verification..................................................................................................................................4-2
4.3.1 Environmental conditions........................................................................................................................4-2
4.3.2 Recommended equipment.......................................................................................................................4-2
4.3.3 Scanner card connections.........................................................................................................................4-2
4.3.4 Path resistance tests ..................................................................................................................................4-3
4.3.5 Contact potential tests .............................................................................................................................. 4-4
4.3.6 Isolation tests .............................................................................................................................................4-6
4.4 Special handling of static-sensitive devices...................................................................................................4-9
4.5 Principles of operation....................................................................................................................................4-10
4.5.1 Block diagram..........................................................................................................................................4-10
4.5.2 Relay control ............................................................................................................................................ 4-10
4.5.3 Switching circuits ....................................................................................................................................4-10
4.5.4 Power-on safeguard................................................................................................................................ 4-10
4.6 Troubleshooting ..............................................................................................................................................4-10
4.6.1 Troubleshooting equipment .................................................................................................................. 4-10
4.6.2 Troubleshooting access...........................................................................................................................4-11
4.6.3 Troubleshooting procedure ................................................................................................................... 4-11
5 Replaceable Parts
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 layouts and schematic diagrams...............................................................................................5-1
iii
List of Illustrations
2 Card Connections and Installation
Figure 2-1 Model 2001-SCAN simplified schematic ............................................................................................ 2-2
Figure 2-2 Card connectors...................................................................................................................................... 2-4
Figure 2-3 Output Connections............................................................................................................................... 2-5
Figure 2-4 Routing wires through cable clamp..................................................................................................... 2-6
Figure 2-5 Connections for voltage scanning........................................................................................................ 2-7
Figure 2-6 Typical connections for 2-wire resistance scanning .......................................................................... 2-8
Figure 2-7 Typical connections for 4-wire resistance scanning .......................................................................... 2-9
Figure 2-8 Current shunt locations....................................................................................................................... 2-10
Figure 2-9 Current connections............................................................................................................................. 2-12
Figure 2-10 Typical connections for high-speed switching................................................................................. 2-13
Figure 2-11 Card installation ................................................................................................................................... 2-15
Figure 2-12 2-pole output connections................................................................................................................... 2-16
Figure 2-13 4-pole output connections................................................................................................................... 2-17
3 Operation
Figure 3-1 Model 2001 front panel scanner controls............................................................................................ 3-3
Figure 3-2 2-wire resistance test connections...................................................................................................... 3-17
Figure 3-3 4-wire resistance test connections...................................................................................................... 3-17
Figure 3-4 Combining 2-pole and 4-pole switching........................................................................................... 3-18
Figure 3-5 Connections for high-speed multiplexing ........................................................................................ 3-19
Figure 3-6 Connections for current measurements............................................................................................ 3-20
Figure 3-7 Path isolation resistance ...................................................................................................................... 3-20
Figure 3-8 Voltage attenuation by path isolation resistance............................................................................. 3-21
Figure 3-9 Power line ground loops ..................................................................................................................... 3-22
Figure 3-10 Eliminating ground loops ................................................................................................................... 3-22
v
4 Service Information
Figure 4-1 Connections for path resistance checks............................................................................................... 4-4
Figure 4-2 Connections for contact potential tests................................................................................................ 4-5
Figure 4-3 Connections for same-channel isolation tests..................................................................................... 4-7
Figure 4-4 Connections for channel-to-channel isolation tests ........................................................................... 4-8
Figure 4-5 Connections for HI and LO terminal to chassis ground isolation tests.......................................... 4-9
Figure 4-6 Block diagram........................................................................................................................................ 4-10
vi
List of Tables
3 Operation
Table 3-1 Summary of IEEE-488 bus scanner commands.................................................................................. 3-8
4 Service Information
Table 4-1 Recommended verification equipment............................................................................................... 4-2
Table 4-2 Recommended troubleshooting equipment..................................................................................... 4-10
Table 4-3 Troubleshooting procedure ................................................................................................................ 4-12
vii
1
General Information
1.1 Introduction
This section contains general information about the
Model 2001-SCAN scanner card option for the Model
2001 Multimeter. The Model 2001-SCAN provides 10
channels, including eight channels of 2-pole relay
switching, and two channels of 2-pole solid-state
switching. All channels can be conÞgured for 4-pole
operation.
Section 1 is arranged in the following manner:
1.2 Features
1.3 Warranty information
1.4 Manual addenda
1.5 Safety symbols and terms
1.6 SpeciÞcations
1.7 Unpacking and inspection
¥ Eight channels of 2-pole relay input.
¥ Two channels of 2-pole solid-state switching.
¥ All channels conÞgurable for 4-pole operation.
¥ Multiplex one of ten 2-pole, or one of Þve 4-pole
channels into the Model 2001 Multimeter.
¥ Two-channel, high-speed multiplexing into Model
2001 Multimeter.
¥ High-speed ratio and delta measurements.
1.3 Warranty information
Warranty information is located on the inside front
cover of this instruction manual. Should your Model
2001-SCAN require warranty service, contact the
Keithley representative or authorized repair facility in
your area for further information. When returning the
scanner card for repair, be sure to Þll out and include
the service form at the back of this manual in order to
provide the repair facility with the necessary
information.
1.8 Repacking for shipment
1.2 Features
The Model 2001-SCAN is scanner card designed to be
installed in the Model 2001 Multimeter. Key features
include:
1.4 Manual addenda
Any improvements or changes concerning the scanner
card or manual will be explained in an addendum
included with the card. Addenda are provided in a
page replacement format. Simply replace the obsolete
pages with the new pages.
1-1
General Information
1.5 Safety symbols and terms
The following symbols and terms may be found on an
instrument or used in this manual.
The symbol on an instrument indicates that the
user should refer to the operating instructions located
in the instruction manual.
The symbol on an instrument shows that high voltage may be present on the terminal(s). Use standard
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 that could damage the scanner card. Such
damage may invalidate the warranty.
!
and store it in the original packing carton. 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.
1.7.3 Shipment contents
The following items are included with every Model
2001-SCAN order:
¥ Model 2001-SCAN Scanner Card
¥ Model 2001-SCAN Instruction Manual
¥ CA-109 test lead set for output connections (two
red, two black)
¥ Additional accessories as ordered
1.7.4 Instruction manual
1.6 Specifications
Model 2001-SCAN speciÞcations are found at the front
of this manual. These speciÞcations are exclusive of the
Model 2001 Multimeter speciÞcations.
1.7 Unpacking and inspection
1.7.1 Inspection for damage
The Model 2001-SCAN 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 below on handling.
1.7.2 Handling precautions
¥ Always grasp the card by the side edges and cov-
ers. Do not touch the board surfaces or components.
The Model 2001-SCAN Instruction Manual is threehole drilled so that it can be added to the three-ring
binder of the Model 2001 Multimeter Instruction Manual. After removing the plastic wrapping, place the
manual in the binder following the Model 2001 Instruction Manual.
If an additional Model 2001-SCAN Instruction Manual
is required, order the manual package, Keithley part
number 2001-SCAN-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 2001SCAN 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 scanner
card.
¥ Write ATTENTION REPAIR DEPARTMENT on
the shipping label.
¥ When the card is not installed in a Model 2001
Multimeter, keep the card in the anti-static bag,
1-2
¥ Fill out and include the service form located at the
back of this manual.
2
Card Connections and Installation
2.1 Introduction
WARNING
The procedures in this section are intended only for qualiÞed service personnel. Do not perform these
procedures unless you are qualiÞed
to do so. Failure to recognize and observe normal safety precautions
could result in personal injury or
death.
This section includes information on making connections to the Model 2001-SCAN and on installing the
card in the Model 2001 Multimeter. This section is
arranged as follows:
2.2 Handling precautions: Explains precautions that
must be followed to prevent contamination to the
scanner card assembly. Contamination could
degrade the performance of the scanner card.
2.3 Connections: Covers the basics for connecting
external circuitry to the scanner card.
2.4 Typical connection schemes: Provides some
typical connection schemes for 2-pole and 4-pole
operation, and summarizes information on
installing current shunts and high-speed
multiplexing.
2.5 Card installation and removal: Summarizes the
procedure to install the scanner card in the Model
2001 Multimeter, outlines scanner card output
connections, and describes how to remove the
card.
2.2 Handling precautions
To maintain high impedance isolation between channels, care should be taken when handling the scanner
card to avoid contamination from such foreign materials as body oils. Such contamination can substantially
lower leakage resistances, degrading card performance. To avoid possible contamination, always grasp
the scanner card by the side edges or covers. Do not
touch board surfaces, components, or areas adjacent to
electrical contacts.
Dirt build-up over a period of time is another possible
source of contamination. To avoid this problem, operate the multimeter and scanner card in a clean environment. If the card becomes contaminated, it should be
thoroughly cleaned as explained in paragraph 4.2.
2-1
Card Connections and Installation
2.3 Connections
This paragraph provides the information necessary to
connect your external test circuitry to the scanner card.
WARNING
The following connection information is intended to be used by qualiÞed service personnel. Failure to
recognize and observe standard safety precautions could result in personal injury or death.
NOTE
All connecting wires or leads must be
connected to the card before it is installed in the Model 2001 Multimeter.
User-installed
current shunt
2.3.1 Card configuration
Figure 2-1 shows a simpliÞed schematic diagram of the
Model 2001-SCAN. The scanner card has ten input
channels and two outputs. Channels 1-4 and 6-9 are
switched by relays, while channels 5 and 10 are solidstate inputs. Channels 1 and 6 can be modiÞed for
current measurements by installing on-card shunt
resistors.
4-pole paired channels are as follows:
¥ Channels 1 and 6
¥ Channels 2 and 7
¥ Channels 3 and 8
¥ Channels 4 and 9
¥ Channels 5 and 10
Channel 1
Channel 2-4
Channel 5
(Solid State)
User-installed
current shunt
Channel 6
Channel 7-9
Channel 10
(Solid State)
HI
LO
HI
LO
HI
LO
HI
LO
HI
OUT A (To Model 2001
input jacks)
LO
HI
OUT B (To Model 2001
sense jacks)
LO
2-Pole4-Pole
Figure 2-1
Model 2001-SCAN simplified schematic
2-2
Card Connections and Installation
2.3.2 Card connectors
Figure 2-2 shows the input/output connectors for the
card. Card connections include:
¥ CH 1-10 (channels 1-10): HI and LO input termi-
nals are provided for each of the 10 channels on the
card.
NOTE
Channels 5 and 10 use solid-state
switching, while channels 1-4 and 6-9
use relay switching.
¥ OUT A: HI and LO output connections for all ten
channels in the 2-pole mode or channels 1-5 in the
4-pole mode.
¥ OUT B: HI and LO output connections for channels
6-10 in the 4-pole mode.
WARNING
Make sure all power is off and any
stored energy in external circuitry is
discharged before connecting or disconnecting wires.
CAUTION
Mechanical shock may open or close
latching relays on the scanner card.
Before enabling any external sources,
open all relays by inserting the
Model 2001-SCAN into the Model
2001 and turning on the power.
1. Open the plastic shield to gain access to the
connectors.
2. Strip approximately 5/16Ó of insulation from the
end of each wire, then twist the strands together.
NOTE
In order to gain access to the connections, Þrst open the
plastic shield by pressing in on the locking tab. Swing
the shield away from the circuit board.
2.3.3 Wiring procedure
Perform the following procedure to wire circuitry to
the screw terminals on the scanner card.
#22 AWG stranded wire is recommended for scanner card connections.
3. Loosen the screw terminal, then insert the wire
into the access hole.
4. While holding the wire in place, tighten the connector screw securely.
5. Repeat steps 1 through 3 for each wire to be connected.
6. Dress input wires through the cable clamp, as discussed in paragraph 2.3.5.
2-3
Card Connections and Installation
H L
CH 1
Channels 1-5, OUT A Channels 6-10, OUT B
H L
H L
H L
H L
CH 2
CH 3
CH 4
CH 5
H L
OUT A
H L
CH 6
H L
CH 7
H L
CH 8
H L
CH 9
H L
CH 10
H L
OUT B
Locking Tab
Plastic Shield
Figure 2-2
Card connectors
2.3.4 Output connections
Use the supplied test leads for scanner output connections. Connect red leads to the output (OUT A and
OUT B) HI terminals, and connect black leads to the
output LO terminals. See Figure 2-3 for details. Dress
output test leads through the cable clamp, as described
in paragraph 2.3.5. After all wires are connected and secure, close the plastic shield, and secure it with the
locking tab.
NOTE
If you intend to use the scanner card
only in the 2-pole mode, it is not necessary to connect output leads to both
OUT A and OUT B. Use only OUT A
for the 2-pole mode.
After the scanner card is installed, the output leads
must be connected to the multimeter rear panel input
jacks. See paragraph 2.5.2 for details.
2.3.5 Dressing leads
After wires are connected to the terminal blocks, they
should be dressed through the cable clamp as shown in
Figure 2-4. To do so, unlatch the clip that holds the
cable clamp together, then route all wires ßat against
the lower half of the clamp. Clamp the wires down,
then secure the clamp with the metal clip unlatched
earlier.
2-4
Card Connections and Installation
H L
CH 1
H L
CH 2
H L
CH 3
H L
CH 4
Red
H L
CH 5
H L
OUT A
HI
To 2001
Input
LO
Red
Black
H L
H L
H L
H L
H L
H L
CH 6
CH 7
CH 8
CH 9
CH 10
OUT B
Note: OUT B connections not required
for 2-pole operation. Plastic shield
not shown.
HI
LO
To 2001
Sense
Black
Figure 2-3
Output Connections
2-5
Card Connections and Installation
H L
CH 1
H L
CH 2
H L
CH 3
Metal Clip
H L
H L
CH 4
CH 5
H L
OUT A
H L
CH 6
H L
CH 7
H L
CH 8
H L
CH 9
H
CH 10
LHL
OUT B
Cable Clamp
Note : Plastic shield not shown.
Figure 2-4
Routing wires through cable clamp
2.4 Typical connecting schemes
The following paragraphs discuss typical connections
for the scanner card.
2.4.1 Voltage connections
Figure 2-5 shows typical connections for voltage
measurements. Note that all channels are used in the 2pole mode, and that up to 10 voltage sources can be
switched with this conÞguration. This basic
conÞguration can be used for the following types of
measurements:
¥ DCV
¥ ACV
¥ Frequency (voltage only)
All channels (1-10) can be used with this conÞguration.
2-6
Card Connections and Installation
CH 1
CH 2
CH 3
CH 4
CH 5
OUT A
CH 6
CH 7
CH 8
CH 9
CH 10
OUT B
H
L
H
L
H
L
H
L
H
L
H
L
HI
LO
To 2001
Input
HI
V
LO
HI
V
LO
HI
V
LO
HI
V
LO
HI
V
LO
Voltages
Under Test
H
L
H
L
H
L
H
L
H
L
H
L
HI
V
LO
HI
V
LO
HI
V
LO
HI
V
LO
HI
V
LO
2001-SCAN Card
Figure 2-5
Connections for voltage scanning
2-7
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