Tektronix 2001-SCAN Instruction Manual

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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

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

⁄4W shunt resistor.

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.

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

Ω

, <75pF.

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

OUT A

OUT B

2-POLE4-POLE

Specifications subject to change without notice.

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

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

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

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

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

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.

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)

OUT A (To Model 2001 input jacks)

OUT B (To Model 2001 sense jacks)

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

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

To 2001 Input

Red

Black

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.

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

CH 4

CH 5

H L

OUT A

H L

CH 6

H L

CH 7

H L

CH 8

H L

CH 9

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

To 2001

Input

Voltages

Under Test

LO HI

2001-SCAN Card

Figure 2-5

Connections for voltage scanning

2-7

Card Connections and Installation

2.4.2 Resistance connections

2-Pole connections

(<275

Ω

) internal resistance of solid-

state channels.

Figure 2-6 shows typical 2-pole resistor test connections. The 2-pole resistance conÞguration can be used to test up to eight DUTs.

NOTE

Channels 5 and 10 should not be used to switch 2-wire resistance measurements because of the relatively high

CH 1

CH 2

CH 3

CH 4

CH 5

OUT A

4-Pole connections

Typical 4-pole resistance connections are shown in Figure 2-7. This general conÞguration can be used with all channels to scan:

¥ 4-wire resistance measurements.

¥ 4-wire RTD temperature measurements.

Resistors

Under Test

To 2001

Input

CH 6

CH 7

CH 8

CH 9

CH 10

OUT B

2001-SCAN Card

Figure 2-6

Typical connections for 2-wire resistance scanning

2-8

Resistors

Under Test

CH 1

CH 2

CH 3

CH 4

CH 5

OUT A

CH 6

CH 7

CH 8

CH 9

CH 10

OUT B

Card Connections and Installation

To 2001 Sense

Resistors

Under Test

2001-SCAN Card

Figure 2-7

Typical connections for 4-wire resistance scanning

LO HI

To 2001 Input

2-9

Card Connections and Installation

2.4.3 Current measurements

Current shunts can be installed on the circuit board to allow indirect AC and DC current measurements to be made through channels 1 and 6 only. The following paragraphs discuss installing current shunts and the basic methods used to determine currents.

CAUTION

Board mounted current shunt resistors can be installed only for chan-

R145 (Channel 1 shunt) R146 (Channel 6 shunt)

H L

CH 1

CH 2

CH 3

CH 4

CH 5

OUT A

nels 1 and 6. A channel that has been modiÞed with a current shunt resistor should not be used for voltage or resistance measurements.

Current shunt locations

Figure 2-8 shows the locations for the user-installable current shunts. Location R145 is for channel 1 and R146 is for channel 6.

H L

CH 6

CH 7

CH 8

CH 9

CH 10

OUT B

Figure 2-8

Current shunt locations

2-10

V R

--- -=

Card Connections and Installation

Recommended current shunt values

Hole spacing on the circuit board is intended for 1/4W resistors. The resistance value will depend on the current you intend to measure; 1k optimum for many applications. A 1k allow you to switch currents up to 15mA without exceeding the power rating of the resistor.

For larger currents, decrease the shunt value. Conversely, the shunt value can be increased for smaller currents.

Ω

resistors should be

Ω

resistor will

Board cleaning

CAUTION

Failure to observe the following precautions may result in degraded card performance.

Current measurements

Even with the current shunts installed, you cannot make direct current measurements with the scanner card. Instead, you must close the channel to be measured, and measure the voltage across the shunt. The current can then be calculated as follows:

Where: I = current being determined

V = voltage measured by Model 2001 R = shunt resistance value

Instead of manually calculating current, set up a Model 2001 mx + b math calculation function. (Here, m = 1/R and b = 0.). The Model 2001 will then display the actual current value. Refer to the Model 2001 OperatorÕs Manual for details on using math functions.

When soldering resistors, be sure not to touch areas not associated with resistor installation or spread ßux around to other areas of the circuit board. Use solder with an OA (organic activated) ßux. The circuit board should be thoroughly cleaned with pure water after soldering to remove all contaminants. After cleaning with water, swab the area with pure methanol, then allow the board to dry for several hours in a 50¡C environment before use.

Current connections

Figure 2-9 shows typical connections for measuring currents using the Model 2001-SCAN with current shunts installed. As noted previously, only channels 1 and 6 have current shunts installed, and this conÞguration can be used to scan the following:

¥ DC current

¥ AC current

2-11

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

Note: Current shunts must be installed for channels 1 and 6.

AC or DC

To 2001

Input

AC or DC

Current

Figure 2-9

Current connections

2-12

2001-SCAN Card

Card Connections and Installation

2.4.4 High-speed multiplexer and ratio/delta connections

If you intend to use the high-speed multiplexer or ratio/delta features of the Model 2001, you must connect the two input sources to channels d 10. These two channels use solid-state switching and are the only

CH 1

CH 2

CH 3

CH 4

CH 5

OUT A

channels that can be used for high-speed switching. Output signals should be taken from OUT A.

Figure 2-10 shows connections for high-speed switching. Note that only 2-pole switching is available for this operating mode.

CH 6

CH 7

CH 8

CH 9

CH 10

OUT B

2001-SCAN Card

Figure 2-10

Typical connections for high-speed switching

To 2001

Input

Note: Only Channels 5 and 10 can be used for high-speed switching.

2-13

Card Connections and Installation

2.5 Card installation and removal

This paragraph explains how to install and remove the Model 2001-SCAN card assembly from the Model 2001 Multimeter.

WARNING

Installation or removal of the Model 2001-SCAN should be performed only by qualiÞed service personnel. Failure to recognize and observe standard safety precautions could result in personal injury or death.

CAUTION

To prevent contamination to the scanner card that could degrade performance, handle the card assembly only by the card edges and covers.

NOTE

Wiring connections must made before installing the scanner card. See paragraph 2.4 for wiring details.

2.5.1 Scanner Card Installation

Perform the following steps and refer to Figure 2-11 to install the card assembly in the Model 2001 Multimeter:

WARNING

Turn off power to all instrumentation (including the Model 2001 Multimeter) and disconnect all line cords. Make sure all power is removed and any stored energy in external circuitry is discharged.

1. Remove the cover plate from the SCANNER slot on the rear panel of the Model 2001 Multimeter. To do so, pry out the two fasteners, then remove the cover plate.

2. Slide the card edges into the guide rails inside the multimeter (solder side up).

3. With the ejector arms in the unlocked position, carefully push the card all the way forward until the arms engage the ejector clips. Push both arms inward to lock the card into the multimeter.

4. After installation, connect the output leads to the multimeter as discussed below.

2-14

Unlock card

Ejector Arms (2)

Card Connections and Installation

Figure 2-11

Card installation

Lock card

2-15

Card Connections and Installation

2.5.2 Output connections to multimeter

After installation, connect the scanner card output leads to the Model 2001 rear panel jacks as follows:

¥ For 2-pole operation, connect OUT A HI (red) to

INPUT HI, and connect OUT A LO (black) to INPUT LO. See Figure 2-12.

¥ For 4-pole operation, connect OUT A HI (red) to

INPUT HI, and connect OUT A LO (black) to INPUT LO. Also connect OUT B HI (red) to SENSE HI, and connect OUT B LO (black) to SENSE LO. See Figure 2-13.

NOTE

Be sure to select the rear inputs with the Model 2001 front panel INPUTS switch when using the scanner.

Input HI

2.5.3 Scanner card removal

Follow the steps below to remove the scanner card from the multimeter:

WARNING

Turn off power to all instrumentation (including the Model 2001 Multimeter) and disconnect all line cords. Make sure all power is removed and any stored energy in external circuitry is discharged.

1. Unlock the card by pulling the latches outward.

2. Carefully slide the card out of the multimeter.

3. If the multimeter is to be operated without the scanner card installed, install the cover plate over the SCANNER slot.

Out A

HI (Red)

Figure 2-12

2-pole output connections

Input LO

Out A

LO (Black)

2-16

Sense HI

Out A

HI (Red)

Out B

HI (Red)

Input HI

Sense LO

Input LO

Card Connections and Installation

Figure 2-13

4-pole output connections

Out B

LO (Black)

Out A

LO (Black)

2-17

Operation

3.1 Introduction

This section contains detailed information on front panel and IEEE-488 bus operation of the Model 2001SCAN. The information in this section is organized as follows:

3.2 Signal limitations: Summarizes the maximum

signals that can be applied to the Model 2001SCAN.

3.3 Scanner card detection: Discusses how the scan-

ner card is detected and how to determine whether or not the card is installed with a bus command.

3.4 Front panel scanner controls: Gives an overview

of the Model 2001 Multimeter front panel controls used to control the scanner card.

3.5 IEEE-488 bus scanner commands: Summarizes

bus commands necessary to control the scanner card.

3.6 Opening and closing channels: Covers the basic

methods for closing and opening channels.

3.7 Scanning channels: Details how to conÞgure scan

parameters and how to perform scanning.

3.8 Ratio and delta: Describes how to conÞgure the

instrument for ratio and delta operation.

3.9 RTD temperature measurements: Provides

detailed information on using RTD probes when scanning.

3.10 Using the buffer with the scanner: Provides

detailed instructions for using the Model 2001 internal data buffer to store readings taken using the scanner.

3.11 Typical applications: Discusses typical applica-

tions for the Model 2001-SCAN.

3.12 Measurement considerations: Discusses a num-

ber of measurement considerations that should be taken into account when using the scanner.

NOTE

Before using the Model 2001-SCAN scanner card, you should be thoroughly familiar with the operation of the Model 2001 Multimeter. See the Model 2001 OperatorÕs Manual for details.

3-1

Operation

3.2 Signal limitations

CAUTION

To prevent damage to the Model 2001-SCAN, do not exceed the maximum signal level speciÞcations of the card.

3.2.1 Relay input signal limitations

Channels 1-4 and 6-9 are the relay inputs. To prevent over-heating or damage to the relays, never exceed the following maximum signal levels for these channels:

DC signals: 110V DC, 1A switched, 30VA (resistive load).

AC signals: 125V rms or 175V AC peak, 1A switched,

62.5VA (resistive load).

3.2.2 Solid-state input signal limitations

Channels 5 and 10 are solid-state inputs. To prevent damage, never exceed the following maximum signal levels for these channels:

If the card is not present at power-on, scanner bus commands or queries will generate a ÒMissing hardware errorÓ, and front panel operations pertaining to the scanner will inform you that no scanner is present.

3.3.2 Scanner option bus query

*OPT? is an IEEE 488.2 common query which will allow you determine whether or not the Model 2001SCAN card is installed. The response to this query has two Þelds. The Þrst Þeld identiÞes the presence or absence of expansion memory, and the second Þeld indicates whether or not the scanner is present as follows:

¥ 0: Scanner not installed.

¥ 2001-SCAN: Scanner installed.

Refer to paragraph 4.9 of the Model 2001 OperatorÕs manual for more details on using the *OPT? query.

Maximum signal level: 110V DC, 175V peak AC, 50mA.

3.3 Scanner card detection

3.3.1 Power-up detection

The scanner card is detected only at power-on. If the card is plugged into the Model 2001 after the power is turned on, the card will not be recognized as being present by the Model 2001.

CAUTION

Plugging in the scanner card with power turned on may result in damage to both the Model 2001-SCAN and the Model 2001 Multimeter.

3.4 Front panel scanner controls

The following paragraphs give an overview of the various Model 2001 Multimeter controls used with the scanner. Figure 3-1 shows the front panel of the Model

2001. Controls that affect Model 2001-SCAN operation include:

¥ CHAN: Allows you to open and close channels

directly.

¥ CONFIG-CHAN: DeÞnes the measurement func-

tions for each scanner channel.

¥ CONFIG-SCAN: Selects internal/external scan

list, and controls ratio/delta operation.

¥ SCAN: Enters scan conÞguration menu.

¥ and : Manually scans through channels.

3-2

Operation

ERR REM TALK LSTN SRQ REAR REL FILT MATH 4W AUTO ARM TRIG SMPL

DISPLAY

POWER

DCV ACV DCI ACI Ω2 Ω4

REL TRIG

INFO LOCAL EXIT ENTER

CHAN

• Close channel

• Open channel

CONFIG-CHAN

• Define internal channel functions

• Define external channel functions

• Define alternate function

STORE RECALL

CHAN SCAN

FILTER MATH

CONFIG MENU

SCAN

• Scan configuration

CONFIG-SCAN

• Select internal scan list

• Select external scan list

• Enable ratio/delta

2001 MULTIMETER

FREQ TEMP

SENSE

Ω 4 WIRE

RANGE

AUTO

RANGE

350V PEAK

INPUTS

FRONT/REAR

CAL

• Manually scan channels

EXIT

• Disable scanning

INPUT

2A 250V

AMPS

1100V

PEAK

500V

PEAK

Figure 3-1

Model 2001 front panel scanner controls

3.4.1 Open and close channels (CHAN)

The CHAN key allows you directly:

¥ Open any closed channel(s) immediately.

¥ Close a speciÞc channel (or channel pair for 4-wire

functions).

Pressing CHAN will display the following menu choices:

CHANNEL SELECTION

CLOSE-CHANNEL OPEN-ALL-CHANNELS

OPEN-ALL-CHANNELS

Selecting OPEN-ALL-CHANNELS will immediately open any closed scanner card channel(s).

CLOSE-CHANNELS

Selecting CLOSE-CHANNEL will display the following message prompting you to select the channel to close:

ENTER CHAN#00 (1-10)

The Þeld entry after ÒENTER CHAN#Ó indicates the channel to close. Ò00Ó will be displayed if all channels

3-3

Operation

are open. (Pressing ENTER with Ò00Ó displayed will display a message that no channel has been closed.) To close a channel, simply use the cursor and range keys to select the number of the channel to close, then press ENTER. The number of the closed channel will be displayed on the front panel along with normal readings.

Selecting a different channel from the one that is presently closed will cause the closed channel to open and allow a settling time before closing the selected channel. Note that you cannot select channel 00 to open channels; instead you must use the OPEN-ALLCHANNELS selection in the menu.

Channel relays will be closed according to the presently selected function. If a 2-wire function is used, only the relay for that one channel will be closed. If a 4-wire function is selected, both the selected channel relay and the matching relay pair will close. For example, closing channel 2 will also close the channel 7 relay. Fixed 4pole relay pairs are:

¥ 1 and 6

¥ 2 and 7

¥ 3 and 8

¥ 4 and 8

INTERNAL-CHANS

The INTERNAL-CHANS selection allows you to set the measuring function for each of the Model 2001SCAN channels. When this selection is made, the following submenu will be displayed:

SET INTERNAL CHANS

1=DCV 2=DCV 3=DCV 4=DCV 5=DCV

6=DCV 7=DCV 8=DCV 9=DCV 10=DCV

With this menu displayed, use the cursor keys to select the channel, and use the up arrow and down arrow (range) keys to select the desired measuring function for each channel:

DCV: DC volts

ACV: AC volts

Ω

2W: 2-wire ohms

Ω

4W: 4-wire ohms

FRQ: frequency

TMP: temperature

ALT: alternate function (see below)

¥ 5 and 10.

3.4.2 Conﬁgure channels (CONFIG-CHAN)

CONFIG-CHAN allows you to:

¥ Select measurement functions for internal (Model

2001-SCAN) channels.

¥ Select measurement functions for channels in an

external scanner used with the Model 2001.

¥ DeÞne an alternate measurement function which

can then be assigned to speciÞc channels.

Pressing CONFIG then CHAN will display the following menu:

CONFIGURE CHANNELS

INTERNAL-CHANS EXTERNAL-INPUTS

SAVE-ALT-FCN RESTORE-ALT-FCN

--- : None

Ω

4W function: The channels 1-5. If selected, ÒPRDÓ (paired) will be shown on the corresponding paired channel 6-10. Once is selected on channels 1 to 5, changing the assignment to a different function will de-assign the paired channel and change the function to Ò---Ó (none).

TMP function: Similarly, the TMP selection is valid only for channels 1-5 if the temperature sensor is a 4wire RTD type. If a 2-wire RTD type is used, channels 6-10 could be assigned to the TMP function, but if the sensor type is later change to 4- wire RTD, any channel from 6-10 will then be set to Ò---Ó (none).

No function (---): Selecting none (---) effectively removes that channel from the scan list. When scanning, the instrument will skip any channels that have no function deÞned.

Ω

4W function is valid only for

Ω

3-4

Operation

EXTERNAL-INPUTS

This menu item allows you to select measurement functions for an external scanner used with the Model 2001 Multimeter. When the EXTERNAL-INPUTS menu item is selected, the instrument will prompt you to enter the number of channels being used:

# EXTERNAL INPUTS=00

Use the cursor and range keys to select the number of channels (1-80), then press ENTER. Once the number of inputs is selected, you will be prompted for channel functions:

SET CHAN FUNCTIONS

DEFAULT CHOOSE-FUNCTIONS

Brießy, these menu items allow you to select the following:

DEFAULT:

measurement function to all external channels.

This selection assigns the presently selected

You can also use the ALT function to store an existing main function but with a different set of operating parameters. For example, you could set up a speciÞc set of operating parameters for the straight DCV function and a second DCV setup as the ALT function. This arrangement allows you to specify changes in virtually any measurement parameter from channel to channel even if the measurement functions are the same.

SAVE-ALT:

all its conÞgured settings as the ALT function.

RESTORE-ALT:

the ALT function and all associated settings as if a normal function change were taking place.

Stores the presently selected function and

Restores the function that was saved as

3.4.3 Scan conﬁguration (CONFIG-SCAN)

CONFIG-SCAN allows you to conÞgure the following scanner aspects:

¥ Select the internal or external channel list for

scanning.

CHOOSE-FUNCTION:

deÞne functions for each channel through the following prompt:

This menu choice allows you to

SELECT CHAN= 01 (DCV)

Here, the parameter in parenthesis deÞnes the presently selected function: DCV, ACV, ACI, DCI, FRQ, TMP, ALT, JN1...JN5. As with other menu choices, use the range and cursor keys to select channels and functions. Note that current functions (DCI, ACI) are allowed for external, but not internal scan list.

Ω

2W,

Ω

4W,

SAVE-ALT-FCN/STORE-ALT-FCN

An ALT (alternate) function is one that cannot be directly accessed with one of the eight function keys. For example, assume that you select the ACV peak function using CONFIG-ACV. You can then use SAVEALT to assign peak ACV to the ALT function. Whenever the ALT function is encountered in the scan list, the instrument will switch to the ACV peak function for that channel even if the instrument is measuring a different type of ACV (RMS for example).

¥ Enable ratio and delta operation.

Pressing CONFIG-SCAN will display the following menu:

SCAN OPERATION

INTERNAL EXTERNAL RATIO DELTA

These choices select the action the instrument will take when it is triggered.

INTERNAL

This selection enables scanning with the internal Model 2001- SCAN scanner card. When this selection is chosen, the Model 2001 will change to the function speciÞed for the Þrst channel and then close the channel and take a reading. When the next trigger is received, the instrument will open the present channel, change to the speciÞed measuring function for the next channel, and then close the relay and take a reading. The process repeats until all channels in the list are scanned.

3-5

Operation

EXTERNAL

This menu selection enables scanning with an external scanner card located in a switching mainframe. This selection operates in a manner similar to the INTERNAL except that the internal scanner card is not used. When this menu item is selected, the instrument will immediately change to the selected measuring function for the Þrst channel. When the multimeter is triggered, it will take a measurement and then change to the measurement function for the next channel. This process repeats until all channels in the scan list are scanned.

RATIO/DELTA

Either of these two selections will conÞgure the Model 2001 to measure the two speciÞed channels and then compute the ratio or difference (delta) between them. When RATIO or DELTA is selected, and the instrument is appropriately triggered, the measure relay will be closed. A reading will be taken, then the reference relay will be closed, and a second reading will be taken. The reference relay will then be opened, and the ratio or delta computation will be performed and displayed using the two measured values.

Again, use the cursor keys to select the channel to be used as the ratio reference channel.

The FUNCTION menu appears as follows:

SET RATIO FUNCTION

DCV

Ω

Use the cursor keys to select the desired function: DCvolts, ohms (2-wire), or 4-wire ohms.

Selections for DELTA measure and reference channels, and function are essentially the same except, of course, that you would select DELTA under the SCAN OPERATION menu.

Solid-state switching considerations

The solid-state relays on the scanner card are used for switching only under the following circumstances:

¥ Scan operation is set to USE INTERNAL LIST, and,

RATIO/DELTA channel selection

To select channels for RATIO and DELTA, select RATIO or DELTA as appropriate.

Selecting RATIO will display the following menu and allow you to set the measure or reference channel:

CONFIGURE RATIO

MEASURE REFERENCE FUNCTION

Selecting MEASURE will display the following:

RATIO MEASURE CHAN

CH12345678910

Use the cursor keys to select the measure channel.

Similarly, selecting REFERENCE will display:

¥ Only internal channels 5 and 10 are selected, and,

¥ The measurement functions for channels 5 and 10

are the same.

Under any other circumstances, latching relays will be used for signal switching. (Solid state relays and mechanical relays for channels 5 and 10 are in series.)

3.4.4 Using SCAN to conﬁgure scan

parameters

Once the internal or external scan list is enabled, you use the SCAN key to conÞgure scan count, scan interval, and enable buffer storage. The steps below outline the basic procedure for using the SCAN key to conÞgure internal scanner operation.

1. From normal display, press CONFIG-SCAN. The instrument will display the following:

RATIO REFERENCE CHAN

CH12345678910

3-6

SCAN OPERATION

INTERNAL EXTERNAL RATIO DELTA

Operation

2. Select INTERNAL, then press ENTER.

3. Press SCAN. The unit will display the following message:

SCAN COUNT = 00010

4. Using the range and cursor keys, select the number of scan sequences, then press ENTER. The instrument will display the following:

USE SCAN TIMER?

YES NO

5. If you do not wish to use the scan timer (interval between scans), select NO, then press ENTER, and go on to step 7. If you wish to use and program the interval between scans, select YES, then press ENTER. The instrument will display the following:

INTRVL = 000002.500

6. Using the range and cursor keys, select the desired interval between scan sequences, then press ENTER.

7. The instrument will then prompt you as to whether or not you wish to store data in the buffer as follows:

Press ENTER to begin

0010 scans of 10 channels

11. The instrument will then scan using selected scanning parameters. If you elected to store data in memory, the instrument will display the reading number on the bottom line of the display as readings are stored.

12. After readings are stored, the following will be displayed:

SCAN COMPLETE

RECALL-DATA SCAN-AGAIN EXIT

13. Select the desired operation, then pressENTER.

3.4.5 Using EXIT to stop scanning

To temporarily halt triggering of ratio/delta measurements, simply press the EXIT key. You can then press SCAN to restart the process.

To disable scanning, press the EXIT key.

DATA TO MEMORY?

NO YES

8. To store scanned data in the buffer, select YES; otherwise choose NO, then press ENTER.

9. If you elected to store data in memory, the instrument will prompt you as follows:

00100 RDGS TO BUFFER

Press ENTER to continue.

NOTE

Use CONFIG-STORE to program the number of readings to store.

10. Press ENTER to begin scanning at the following prompt:

3.4.6 Manual scanning

The and keys can be used to manually scan through channels. In order to use this feature, Þrst close a channel using the CHAN key. Use to increment channels, or use to decrement channels.

3.5 IEEE-488 bus scanner commands

Table 3-1 summarizes commands that control scanner operations over the IEEE-488 bus. For more detailed information on these and other bus commands, refer to Section 4 of the Model 2001 Multimeter OperatorÕs Manual.

3-7

Operation

Table 3-1

Summary of IEEE-488 bus scanner commands

Command Description

:ROUTe

:CLOSE <list>

:STATe?

:OPEN <list>|ALL

:ALL

:SCAN

[:INTernal] <list>

:FUNCtion <list>,<function> :EXTernal <list> :RATio

:RCHannel <list>

:MCHannel <list>

:FUNCtion <function> :DELTa

:RCHannel <list>

:MCHannel <list>

:FUNCtion <function> :LSELect INTernal | EXTernal | RATio |

DELTa | NONE

[:SENSe[1]]

:ALTernate[1]

: S AVe :RECall

Route subsystem.

Close channels.

Return all closed channels.

Open channels.

Open any closed channels.

Scanning commands.

Program internal scan list.

Program channel functions. Program external scan list. Program ratio mode.

Select reference channel.

Select measurement channel

Select ratio function Program delta mode.

Select reference channel.

Select measurement channel.

Select delta function. Select scan list.

Sense subsystem

Program alternate function.

Save alternate function. Recall alternate function.

The INT or EXT <function> parameter is one of the following:

VOLTage: DC VOLTage:AC TEMPerature FREQuency RESistance FRESistance RJUNctionX NONE ALTernate[1]

DC volts AC volts Temperature Frequency 2-wire resistance 4-wire resistance Reference junction (X=1 to 5) No function (skips listed channel during scan.) Alternate function

The RATio or DELTa <function> parameter is one of the following:

VOLTage:DC RESistance FRESistance

NOTES:

1. The :ROUT:SCAN:LSEL command is coupled to the :ROUT:SCAN:INT command. When the :ROUT:SCAN:INT command is executed, the :ROUT:SCAN:LSEL parameter will be set to INTernal.

2. Upper-case letters indicate short form of commands.

3. Brackets indicate optional command and should not be used when sending commands to instrument.

DC volts 2-wire resistance 4-wire resistance

3-8

Operation

3.6 Closing and opening channels

Individual scanner card channels are closed and opened using the CHAN key. The following paragraphs discuss closing and opening channels from the front panel as well as with bus commands.

3.6.1 Closing channels

Front panel

Use the front panel CHAN key to close speciÞc channels as follows:

14. From normal display, press the CHAN key. The instrument will display the following menu:

CHANNEL SELECTION

CLOSE-CHANNEL OPEN-ALL-CHANNELS

3.6.2 Opening channels

Front panel

Use the front panel CHAN key to open any closed channels as follows:

1. Press the CHAN key. The instrument will display the following menu:

CHANNEL SELECTION

CLOSE-CHANNEL OPEN-ALL-CHANNELS

2. Select OPEN-ALL-CHANNELS, then press ENTER. The closed channel will open immediately.

IEEE-488 bus

Use the :ROUT:OPEN command to open the closed channel. For example, the following command would be used to open channel 3:

OUTPUT 716; Ò:rout:open (@3)Ó

15. Select CLOSE-CHANNEL, then press ENTER. The Model 2001 will display the following prompt:

ENTER CHANNEL# 00 (1-10)

16. Use the cursor and range keys to select the channel you wish to close (1-10), then press ENTER. Any previously closed channel will open, and the selected channel will close.

NOTE

Once a channel is closed, use the or

key to manually scan through channels. Also, you can use the NEXT display to view three successive channels simultaneously.

IEEE-488 bus

Use the :ROUT:CLOSE command to close the desired channel. For example, assume you wish to close channel 3. The following command would be used:

(You can also use :ROUT:OPEN:ALL or :ROUT:OPEN ALL to open channels.)

3.7 Scanning channels

Scanner channels are scanned by conÞguring scan channels and programming the Model 2001 to perform a scan. The following paragraphs outline step-by-step procedures for performing basic scanning from the front panel and over the IEEE-488 bus.

3.7.1 Front panel scanning

Step 1: Conﬁgure channels

Use CONFIG-CHAN to select the measurement functions for each of the scanner channels as follows:

1. Press CONFIG-CHAN. The instrument will display the following menu:

CONFIGURE CHANNELS

INTERNAL-CHANS EXTERNAL-INPUTS

OUTPUT 716; Ò:rout:close (@3)Ó

2. Select INTERNAL-CHANS, then press ENTER. The multimeter will display the following menu:

3-9

Operation

SET INTERNAL CHANS

1=DCV 2=DCV 3=DCV 4=DCV 5=DCV

3. Using the cursor keys, select the desired channel (press the right cursor key to display channels 6 through 10).

4. Using the range keys, select the desired measure-

ment function: DCV, ACV, Ω2W, Ω4W, FRQ, TMP,

ALT, --- (None)

5. Repeat steps 3 and 4 for each of the channels you wish to scan. NOTE: Select --- (none) to omit a channel from the scan list.

6. After selecting all measurement functions, press ENTER.

7. Press EXIT to return to normal display.

Step 2: Conﬁgure and start scan

ConÞgure the scan as follows:

1. Press CONFIG-SCAN. The Model 2001 will display the following:

SCAN OPERATION

INTERNAL EXTERNAL RATIO DELTA

2. Select INTERNAL, then press ENTER.

3. Press SCAN, and follow the prompts to conÞgure scanning. See paragraph 3.4.4 for details.

3.7.2 IEEE-488 bus scanning

Step 1: Program channel functions

Use :ROUT:SCAN:INT:FUNC to program functions for the selected channels. For example, assume that you want to measure DC volts on channel 1, AC volts on channel 3, and 2-wire resistance on channel 5. The commands to do so are as follows:

OUTPUT 716; Ò:rout:scan:int:func (@1),Õvolt:dcÕÓ

OUTPUT 716; Ò:rout:scan:int:func (@3),Õvolt:acÕÓ

OUTPUT 716; Ò:rout:scan:int:func (@5),ÕresÕÓ

If, on the other hand, you wish to use the same function (DCV, for example) on all three channels, a single command would sufÞce:

OUTPUT 716; Ò:rout:scan:int:func (@1,3,5),Õvolt:dcÕÓ

3-10

Operation

Step 2: Program internal scan list and start scan

Use the :ROUT:SCAN:INT command to program a scan list (channels you wish to scan). For example, assume that you wish to scan channels 1, 3, and 5. This scan list would be programmed as follows:

OUTPUT 716; Ò:rout:scan:int (@ 1,3,5)Ó

Scanning will begin immediately when this command is sent.

To disable scanning, send the :ROUT:SCAN:LSEL NONE command:

OUTPUT 716; Ò:rout:scan:lsel noneÓ

NOTE

The :ABORT command will abort the present scan in progress and reset the channel list to the beginning. Depending on various trigger layer parameters, :ABORT may also stop the scanning process.

3.8.2 Ratio and delta measurement functions

The following measurement functions are available in the ratio and delta modes:

¥ DC volts

¥ 2-wire ohms

¥ 4-wire ohms

3.8.3 Solid-state switching

Channels 5 and 10 on the scanner card have solid-state inputs. Solid state switching is used only if all of the following conditions are satisÞed:

¥ Channels 5 and 10 are deÞned as the measurement

and reference channels.

¥ The internal scan list is enabled.

¥ Both channels 5 and 10 use the same measurement

function.

3.8 Ratio and delta

The Model 2001 can display the difference (DELTA) or quotient (RATIO) between the signal on any two scanner channels. The following paragraphs discuss ratio and delta calculations and also give step-by-step procedures for using ratio and delta.

3.8.1 Ratio and delta computation

During conÞguration, one channel is deÞned as the reference channel, and a second channel is deÞned as the measurement channel. Ratio and delta are computed from signals measured on these channels as follows:

Ratio

Delta Measurement Reference–=

Measurement

------------------------------------=

Reference

3.8.4 Ratio and delta triggering

When the instrument is Þrst placed in the ratio or delta mode, it will close the scanner reference channel and then wait for a trigger. When the reading is triggered, the unit will make a measurement on the reference channel, switch to the measurement channel, and then take a second measurement. After measuring the measurement channel, the unit will compute and display the ratio or delta value, and switch back to the reference channel to wait for the next trigger.

3.8.5 Ratio operation

Ratio display formatting

All ratio measurements are displayed using 4-½ digit scientiÞc notation format. This format allows the widest possible dynamic range, although at the expense of some small loss in resolution. Note that no sufÞxes such as mV are used since ratio readings. The function (for example VDC) is displayed only to indicate the selected measurement function.

3-11

Operation

Because of the scientiÞc notation format, the ADVANCED Þlter cannot be used with the ratio mode. The advanced Þlter uses a noise-tolerance window that is expressed in terms of display counts, which do not apply to scientiÞc notation display. An appropriate warning message will be displayed if you attempt to enable the ratio mode and advanced Þlter simultaneously.

Front panel ratio operation

Step 1: Connect inputs

Input signals must be connected to the two channels you intend to deÞne as measurement and reference channels.

Step 2: Deﬁne measurement channel

1. From normal display, press CONFIG-SCAN. The instrument will display the following:

SCAN OPERATION

INTERNAL EXTERNAL RATIO DELTA

2. Select RATIO, then press ENTER. The Model 2001 will display the following:

CONFIGURE RATIO

MEASURE REFERENCE FUNCTION

3. Select MEASURE, then press ENTER. The instrument will display the following:

RATIO MEASURE CHAN

CH12345678910

4. Using the cursor keys, select the channel you wish to deÞne as the measure channel, then press ENTER.

Step 3: Deﬁne reference channel

Step 4: Select measurement function

1. From the CONFIGURE RATIO menu, select FUNCTION, then press ENTER. The instrument will display the following:

SET RATIO FUNCTION

DCV Ω 2 Ω4

Note that only DC volts, and 2- and 4-wire ohms functions are available for ratio mode.

2. Use the cursor keys to select the desired function, then press ENTER.

3. Press EXIT to return to normal display.

Step 5: Display ratio readings

Once the reference channel, measurement channel, and ratio function have been deÞned, press SCAN to halt triggers. Then press SCAN to start ratio measurements. The instrument will automatically display ratio readings computed from signals applied to the reference and measurement channels. If you have a selected trigger mode that requires a separate trigger for each reading, you will, of course, have to trigger the instrument to obtain each ratio reading (refer to the Model 2001 OperatorÕs Manual for details on triggering).

Canceling the ratio mode

Press SCAN to temporarily halt the ratio mode. To disable scanning, press EXIT.

IEEE-488 bus ratio operation

Step 1: Connect inputs

Input signals must be connected to the two channels you intend to deÞne as measurement and reference channels.

1. From the CONFIGURE RATIO menu, select REFERENCE, then press ENTER. The Model 2001 will display the following message:

RATIO REFERENCE CHAN

CH12345678910

2. Using the cursor keys, select the channel to be deÞned as the reference channel, then press ENTER.

3-12

Step 2: Deﬁne measurement channel

Use the :ROUT:SCAN:RAT:MCH command to deÞne the measurement channel. For example, assume you wish to deÞne channel 10 as the measurement channel. The following command would be used:

OUTPUT 716; Ò:rout:scan:rat:mch (@10)Ó

Operation

Step 3: Deﬁne reference channel

Use :ROUT:SCAN:RAT:RCH to deÞne the reference channel. The following command would be used to deÞne channel 5 as the reference channel:

OUTPUT 716; Ò:rout:scan:rat:rch (@5)Ó

Step 4: Select measurement function

Send the :ROUT:SCAN:RAT:FUNC command to select the ratio measurement function. For example, to select DCV, send the following:

OUTPUT 716; Ò:rout:scan:rat:func Ôvolt:dcÕÓ

Step 5: Enable ratio mode

Send the :ROUT:SCAN:LSEL RAT command to enable the ratio mode:

OUTPUT 716; Ò:rout:scan:lsel ratÓ

Step 2: Deﬁne measurement channel

1. From normal display, press CONFIG-SCAN. The instrument will display the following:

SCAN OPERATION

INTERNAL EXTERNAL RATIO DELTA

2. Select DELTA, then press ENTER. The Model 2001 will display the following:

CONFIGURE DELTA

MEASURE REFERENCE FUNCTION

3. Select MEASURE, then press ENTER. The instrument will display the following:

DELTA MEASURE CHAN

CH12345678910

4. Using the cursor keys, select the channel you wish to deÞne as the measure channel, then press ENTER.

Step 6: Request ratio readings

Once the reference channel, measurement channel, and ratio function have been deÞned, use the DATA? query to request readings. The following code fragment demonstrates the process:

100 OUTPUT 716; Ò:data?Ó 110 ENTER 716; A$ 120 PRINT A$

Canceling the ratio mode

To cancel the ratio mode, send the :ROUT:SCAN:LSEL NONE command as follows:

OUTPUT 716; Ò:rout:scan:lsel noneÓ

3.8.6 Delta operation

Front panel delta operation

Step 1: Connect inputs

Step 3: Deﬁne reference channel

1. From the CONFIGURE DELTA menu, select REFERENCE, then press ENTER. The Model 2001 will display the following message:

DELTA REFERENCE CHAN

CH12345678910

2. Using the cursor keys, select the channel to be deÞned as the reference channel, then press ENTER.

Step 4: Select measurement function

1. From the CONFIGURE DELTA menu, select FUNCTION, then press ENTER. The instrument will display the following:

SET DELTA FUNCTION

DCV Ω 2 Ω4

Note that only DC volts, and 2- and 4-wire ohms functions are available for delta mode.

Input signals must be connected to the two channels you intend to deÞne as measurement and reference channels.

2. Use the cursor keys to select the desired function, then press ENTER.

3. Press EXIT to return to normal display.

3-13

Operation

Step 5: Display delta readings

Once the reference channel, measurement channel, and delta function have been deÞned, press SCAN to halt triggers. Then press SCAN to start delta measurements. The instrument will automatically display delta readings computed from signals applied to the reference and measurement channels. If you have selected a trigger mode that requires a separate trigger for each reading, you will, of course, have to trigger the instrument to obtain each delta reading (refer to the Model 2001 OperatorÕs Manual for details on triggering).

Canceling the delta mode

Press SCAN to temporarily halt delta readings. To disable scanning, press EXIT.

IEEE-488 bus delta operation

Step 1: Connect inputs

Input signals must be connected to the two channels you intend to deÞne as measurement and reference channels.

Step 5: Enable delta mode

Send :ROUT:SCAN:LSEL DELT to enable the delta mode:

OUTPUT 716; Ò:rout:scan:lsel deltÓ

Step 6: Request delta readings

Once the reference channel, measurement channel, and delta function have been deÞned, use the DATA? query to request readings. The following code fragment demonstrates the process:

100 OUTPUT 716; Ò:data?Ó

110 ENTER 716; A$

120 PRINT A$

Canceling the delta mode

To cancel the delta mode, send the :ROUT:SCAN:LSEL NONE command as follows:

OUTPUT 716; Ò:rout:scan:lsel noneÓ

Step 2: Deﬁne measurement channel

Use the :ROUT:SCAN:DELT:MCH command to deÞne the measurement channel. For example, assume you wish to deÞne channel 10 as the measurement channel. The following command would be used:

OUTPUT 716; Ò:rout:scan:delt:mch (@10)Ó

Step 3: Deﬁne reference channel

Use :ROUT:SCAN:DELT:RCH to deÞne the reference channel. The following command would be used to deÞne channel 5 as the reference channel:

OUTPUT 716; Ò:rout:scan:delt:rch (@5)Ó

Step 4: Select measurement function

Send the :ROUT:SCAN:DELT:FUNC command to select the delta measurement function. For example, to select DCV, send the following:

3.9 RTD temperature measurements

The following paragraphs outline the procedures for making temperature measurements from the front panel using the scanner. For more detailed information on temperature measurements in general, refer to the Model 2001 OperatorÕs Manual.

Step 1: Connect RTD probes

Connect RTD probes to the scanner using the basic resistance connections outlined in Section 2. For 4-wire probes, pair the connections as follows:

¥ Channels 1 and 6: probe #1

¥ Channels 2 and 7: probe #2

¥ Channels 3 and 8: probe #3

¥ Channels 4 and 9: probe #4

OUTPUT 716; Ò:rout:scan:delt:func Ôvolt:dcÕÓ

3-14

¥ Channels 5 and 10: probe #5

Operation

Step 2: Select sensor type and units

1. From normal display, press CONFIG-TEMP. The instrument will display the following:

CONFIG TEMPERATURE

SENSOR UNITS SPEED FILTER RESLN

2. Select SENSOR, then press ENTER. The following will be displayed:

TEMP SENSOR TYPE

RTD 4-WIRE-RTD THERMOCOUPLE

3. Select RTD or 4-WIRE-RTD as appropriate for the sensor type you are using, then press ENTER. The instrument will display the following:

SET RTD TYPE

PT385 PT3916 USER-RTD

4. Select the RTD type from among the displayed types, then press ENTER.

5. Press EXIT to return to the CONFIG TEMPERATURE menu.

6. Select UNITS, then press ENTER. The unit will display the following selections:

SET TEMP UNITS

DEG-C DEG-F K

3. Use the cursor and range keys to select channels and functions. Set the function type to TMP for all channels connected to RTD probes. Select --- (none) for channels without probes connected.

4. Press ENTER to return to normal display.

Step 4: Conﬁgure scan and scan channels

1. From normal display, press CONFIG-SCAN. The instrument will display the following:

SCAN OPERATION

INTERNAL EXTERNAL RATIO DELTA

2. Select INTERNAL, then press ENTER.

3. Press SCAN, then follow the prompts. See paragraph 3.4.4.

3.10 Using the scanner with the buffer

The Model 2001 internal buffer can be used to store readings taken while using the scanner. The following paragraphs outline the steps necessary for fundamental data storage of scanner readings.

7. Choose the type of temperature units you desire to use: ¡F, ¡C, or K, then press ENTER.

8. Before exiting the temperature conÞguration menu, select speed, Þlter, and resolution operating modes, if desired.

9. Press EXIT to return to normal display.

Step 3: Conﬁgure channels

1. Press CONFIG-CHAN. The instrument will display the following:

CONFIGURE CHANNELS

INTERNAL-CHANS EXTERNAL-INPUTS

2. Select INTERNAL-CHANS. The Model 2001 will display the following:

SET INTERNAL CHANNELS

1=DCV 2=DCV 3=DCV 4=DCV 5=DCV

Step 1: Conﬁgure channels

1. Press CONFIG-CHAN. The instrument will display the following:

CONFIGURE CHANNELS

INTERNAL-CHANS EXTERNAL-INPUTS

2. Select INTERNAL-CHANS. The Model 2001 will display the following:

SET INTERNAL CHANNELS

1=DCV 2=DCV 3=DCV 4=DCV 5=DCV

3. Use the cursor and range keys to select channels and functions, then press ENTER when you have set all functions.

4. Press EXIT to return to normal display.

3-15

Operation

Step 2: Conﬁgure buffer

1. Press CONFIG-STORE. The unit will display the following:

CONFIG DATA STORE

BURST-MODE DATA GROUP CONTROL

CLEAR-ALL COUNT FEED

2. Select COUNT, then press ENTER. The instrument will display the following:

SET BUFFER SIZE

ENTER-COUNT USE-TRIGGER-MODEL

3. Select ENTER-COUNT and press ENTER to view the following:

BUFFER SIZE = 00010

4. Using the cursor and range keys, select the number of readings to store. Usually, this number will be the same as the number of channels you are scanning. For example, if you are using all 10 scanner channels, select 10 readings.

5. Press ENTER to complete programming data storage; then EXIT to return to normal display.

Step 3: Conﬁgure scan, perform scan, and recall readings

1. From normal display, press CONFIG-SCAN. The instrument will display the following:

using 4-wire measurements. Such tests use the Model

2001 Ω2 and Ω4 resistance functions.

2-wire resistance tests

Figure 3-2 shows a typical test setup for making 2-wire resistance measurements. The Model 2001-SCAN card provides the switching function, while the resistance measurements are made by a Model 2001 Multimeter. Since only 2-pole switching is required for this application, one Model 2001-SCAN card can be used to

switch up to 8 resistors. Note, however, that the 275Ω

on resistance of channels 5 and 10 may affect the measurement accuracy of 2-wire resistance measurements made using these channels. Generally, channels 5 and 10 should not be used for 2-wire resistance measurements.

Measurement accuracy can be optimized by minimizing residual resistance: make connecting wires as short as possible and limit the number of connectors to minimize path resistance. Another technique is to short one of the scanner channel inputs, close the shorted channel, and then enable the multimeter REL feature to null out path resistance. Leave REL enabled for the entire test.

SCAN OPERATION

INTERNAL EXTERNAL RATIO DELTA

2. Select INTERNAL, then press ENTER.

3. Press SCAN, then follow the prompts. See paragraph 3.4.4.

3.11 Typical applications

3.11.1 Resistor testing

The Model 2001-SCAN can be used to test up to 8 resistors using 2-wire measurements, or up to Þve resistors

3-16

4-wire resistance tests

More precise measurements over a wider range of system and DUT conditions can be obtained by using the 4-wire measurement scheme shown in Figure 3-3. Here, separate sense leads from the Model 2001 Multimeter are routed through the scanner to the resistor under test. The extra set of sense leads minimizes the effects of voltage drops across the test leads, greatly reducing measurement errors with lower DUT resistances. Note, however, that an extra two poles of switching are required for each resistor tested. For this reason, only Þve resistors can be tested using this conÞguration.

Operation

HI LO

Model 2001

Rear Panel

2001-SCAN

Out A

A. Test Configuration

Ω

2001

Multimeter

2001-SCAN DUT

B. Simplified Equivalent Circuit

2001-SCAN

DUTs (10)

Model 2001

Rear Panel

Out A

Sense HI

Sense LO

Out B

A. Test Configuration

DUTs (5)

HI Sense HI

Ω

Sense LO LO

Figure 3-2

2-wire resistance test connections

2001

B. Simplified Equivalent Circuit

2001-SCAN

Figure 3-3

4-wire resistance test connections

DUT

3-17

Operation

Combining 2-pole and 4-pole switching

The Model 2001-SCAN can combine 2- and 4-pole switching in various combinations. For example, you might require 4-pole switching for only two resistors, while the remaining resistors could be tested using conventional 2-pole switching.

2001-SCAN

Out A HI

InputHIInput

Figure 3-4 shows a test conÞguration using mixed 2pole and 4-pole switching. Four-pole switching is used only for device 1 (connected to channels 1 and 6) and device 2 (connected to channels 2 and 7). Four more resistors are tested using 2-pole switching.

CH 1

4-Pole

Connections

CH 2

CH 3

Sense

Model 2001

Rear Panel

Out B HI

CH 4

CH 5

CH 6

CH 7

CH 8

CH 9

CH 10

2-Pole

Connections

Figure 3-4

Combining 2-pole and 4-pole switching

3-18

DUT's (8)

Operation

Measurement functions for each scanner channel are deÞned using the INTERNAL-CHANS menu available by pressing CONFIG-CHAN (see paragraph 3.4). Measurement functions for this test would be set up as follows:

Channels 1 and 2: Ω4W Channels 3, 4 and 8, 9: Ω2W

Note that functions cannot be deÞned for channels 6 and 7 with this application because these channels are paired with channels 1 and 2 for 4-pole switching.

3.11.2 High-speed multiplexing

Channels 5 and 10 use solid-state switching and can be used for high-speed multiplexing, as shown in Figure 3-5. In order to use high-speed multiplexing, the scanner card must be operated as follows:

¥ The two inputs must be connected to channels 5

and 10.

HI LO

Model 2001

Rear Panel

2001-SCAN

Out A

A. Test Configuration

2001

2001-SCAN DUT

B. Simplified Equivalent Circuit

CH 5

CH 10

DUTs

¥ The Model 2001 must be set to use the internal scan

list.

¥ Both channels 5 and 10 must be set for the same

function.

Some typical uses for high-speed multiplexing include:

¥ Rapidly switching between two similar signals for

comparison.

¥ Automatic ratio and delta computations using the

built-in ratio or delta modes.

Figure 3-5

Connections for high-speed multiplexing

3.11.3 Current measurements

Although the Model 2001-SCAN is not intended for direct current measurements, on-card shunt resistors can be installed for channels 1 and 6 to allow for indirect current measurements. Figure 3-6 shows the typical conÞguration for current measurements. Refer to Section 2 for speciÞc information on recommended shunt resistors and their installation.

3-19

Operation

The current through each shunt resistor can be calculated as follows:

--- -=

Where: I = current being determined

V = voltage measured by Model 2001 R = shunt resistance value

User-installed

Shunts

DUTs

(2)

Model 2001

Rear Panel

2001-SCAN

CH 1

Out A

HI LO

CH 6

A. Test Configuration

3.12 Measurement considerations

Many measurements made with the Model 2001SCAN are subject to various effects that can seriously affect low-level measurement accuracy. The following paragraphs discuss these effects and ways to minimize them.

3.12.1 Path isolation

The path isolation is simply the equivalent impedance between any two test paths in a measurement system. Ideally, the path isolation should be inÞnite, but the actual resistance and distributed capacitance of cables and connectors results in less than inÞnite path isolation values for these devices.

Path isolation resistance forms a signal path that is in parallel with the equivalent resistance of the DUT, as shown in Figure 3-7. For low-to-medium device resistance values, path isolation resistance is seldom a consideration; however, it can seriously degrade measurement accuracy when testing high-impedance devices. The voltage measured across such a device, for example, can be substantially attenuated by the voltage divider action of the device source resistance and path isolation resistance, as shown in Figure 3-8. Also, leakage currents can be generated through these resistances by voltage sources in the system.

User-installed

2001

B. Simplified Equivalent Circuit

2001-SCAN DUT

Figure 3-6

Connections for current measurements

3-20

Shunt

DUT

PATH

DUT

= Source Resistance of DUT

DUT

= Source EMF of DUT

DUT

= Path Isolation Resistance

PATH

= Input Resistance of Model 2001

Scanner

Card

Model 2001

Figure 3-7

Path isolation resistance

Operation

DUT

OUT

DUT

PATH

DUT

OUT

Figure 3-8

Voltage attenuation by path isolation resistance

3.12.2 Channel resistance

The on resistance of channels 5 and 10 (the solid-state

channels) is speciÞed as <275Ω. For this reason, you

should not use channels 5 and 10 for low-to-medium

resistance measurements (<100kΩ). For example, measuring a 1kΩ resistor using channel 5 or channel 10 will

result in an error of more than 25%.

produced by various signals such as the AC power line voltage. Large inductors such as power transformers can generate substantial magnetic Þelds, so care must be taken to keep the switching and measuring circuits a good distance away from these potential noise sources. At high current levels, even a single conductor can generate signiÞcant Þelds. These effects can be minimized by using twisted pairs, which will cancel out most of the resulting Þelds.

3.12.4 Electromagnetic interference (EMI)

The electromagnetic interference characteristics of the Models 2001/2002 Multimeters comply with the electromagnetic compatibility (EMC) requirements of the European Union (EU) directives as denoted by the CE mark. However, it is still possible for sensitive measurements to be affected by external sources. In these instances, special precautions may be required in the test setup.

Sources of the EMI include:

¥ Radio and TV broadcast transmitters.

¥ Communications transmitters, including cellular

phones and handheld radios.

3.12.3 Magnetic ﬁelds

When a conductor cuts through magnetic lines of force, a very small current is generated. This phenomenon will frequently cause unwanted signals to occur in the test leads of a scanning system. If the conductor has sufÞcient length, even weak magnetic Þelds like those of the earth can create sufÞcient signals to affect lowlevel measurements. Two ways to reduce these effects are: (1) reduce the lengths of the test leads, and (2) minimize the exposed circuit area. In extreme cases, magnetic shielding may be required. Special metal with high permeability at low ßux densities (such as mu metal) is effective at reducing these effects.

Even when the conductor is stationary, magneticallyinduced signals may still be a problem. Fields can be

¥ Devices incorporating microprocessors and high-

speed digital circuits.

¥ Impulse sources as in the case of arcing in high-

voltage environments.

The instrument, measurement leads, and other cables should be kept as far away as possible from any EMI sources. Shielding measurement leads and the multimeter may reduce EMI to acceptable levels. In extreme cases, a specially constructed screen room may be required to sufÞciently attenuate troublesome signals.

Many instruments incorporate internal Þltering that may help reduce EMI effects. In some cases, additional external Þltering may be required. Keep in mind, however, that Þltering may have detrimental effects on the measurement.

3-21

Operation

3.12.5 Ground loops

When two or more instruments are connected together, care must be taken to avoid unwanted signals caused by ground loops. Ground loops usually occur when sensitive instrumentation is connected to other instrumentation with more than one signal return path such as power line ground. As shown in Figure 3-9, the resulting ground loop causes current to ßow through the instrument LO signal leads and then back through power line ground. This circulating current develops a small but undesirable voltage between the LO terminals of the two instruments. This voltage will be added to the source voltage, affecting the accuracy of the measurement.

Signal Leads

Instrument 1 Instrument 2 Instrument 3

Ground Loop

Current

Power Line Ground

Figure 3-9

Power line ground loops

Instrument 1 Instrument 2 Instrument 3

Power Line Ground

Figure 3-10

Eliminating ground loops

3.12.6 Keeping connectors clean

As is the case with any high-resistance device, the integrity of connectors can be compromised if they are not handled properly. If connector insulation becomes contaminated, the insulation resistance will be substantially reduced, affecting high-impedance measurement paths. Oils and salts from the skin can contaminate connector insulators, reducing their resistance. Also, contaminants present in the air can be deposited on the insulator surface. To avoid these problems, never touch the connector insulating material. In addition, the scanner card should be used only in clean, dry environments to avoid contamination.

Figure 3-10 shows how to connect several instruments together to eliminate this type of ground loop problem. Here, only one instrument is connected to power line ground. Ground loops are not normally a problem with instruments having isolated LO terminals. However, all instruments in the test setup may not be designed in this manner. When in doubt, consult the manual for all instrumentation in the test setup.

3-22

If the connector insulators should become contaminated, either by inadvertent touching, or from airborne deposits, they can be cleaned with a cotton swab dipped in clean methanol. After thoroughly cleaning, they should be allowed to dry for several hours in a low-humidity environment before use, or they can be dried more quickly using dry nitrogen.

Service Information

WARNING

The information in this section is intended only for qualiÞed service personnel. Some of the procedures may expose you to hazardous voltages that could result in personal injury or death. Do not attempt to perform these procedures unless you are qualiÞed to do so.

4.1 Introduction

This section contains information necessary to service the Model 2001-SCAN scanner card and is arranged as follows:

4.2 Handling and cleaning precautions: Discusses

handling precautions and methods to clean the card should it become contaminated.

4.3 Performance veriÞcation: Covers the procedures

necessary to determine if the scanner card meets stated speciÞcations.

4.4 Special handling of static-sensitive devices: Re-

views precautions necessary when handling static-sensitive devices.

4.5 Principles of operation: Brießy discusses circuit

operation.

4.6 Troubleshooting: Presents some troubleshooting

tips for the Model 2001-SCAN including relay replacement precautions.

4.2 Handling and cleaning precautions

Because of the high-impedance areas on the Model 2001-SCAN, care should be taken when handling or servicing the card to prevent possible contamination. The following precautions should be observed when servicing the card.

4.2.1 Handling precautions

¥ Handle the card only by the edges and shields.

¥ Do not touch any board surfaces or components

not associated with the repair.

¥ Do not touch areas adjacent to electrical contacts.

¥ When servicing the card, wear clean cotton gloves.

¥ Do not store or operate the card in an environment

where dust could settle on the circuit board.

¥ Use dry nitrogen gas to clean dust off the board if

necessary.

4-1

Service Information

4.2.2 Soldering precautions

Should it become necessary to use solder on the circuit board, observe the following precautions:

¥ Use an OA-based (organic activated) ßux, and take

care not to spread the ßux to other areas of the circuit board.

¥ Remove the ßux from the work areas when the

repair has been completed. Use pure water along with clean cotton swabs or a clean, soft brush to remove the ßux.

¥ Once the ßux has been removed, swab only the

repaired area with methanol, then blow dry the board with dry nitrogen gas.

¥ After cleaning, the card should be allowed to dry

in a 50¡C low-humidity environment for several hours before use.

4.3 Performance veriﬁcation

The following paragraphs discuss performance veriÞcation procedures for the Model 2001-SCAN, including path resistance, contact potential, and isolation.

touch connector insulators, board surfaces, or components.

NOTE

Failure of any performance veriÞcation test may indicate that the scanner card is contaminated. See paragraph

4.2 for information on cleaning the card.

4.3.1 Environmental conditions

All veriÞcation measurements should be made at an ambient temperature between 18¡ and 28¡C, and at a relative humidity of less than 70%.

4.3.2 Recommended equipment

Table 4-1 summarizes the equipment necessary for performance veriÞcation, along with an application for each item.

CAUTION

Contamination will degrade the performance of the card. To avoid contamination, always grasp the card by the side edges and covers. Do not

Table 4-1

Recommended veriﬁcation equipment

Description Model/part SpeciÞcations Application

Multimeter Keithley Model 2001 20

Electrometer with voltage source

Sensitive Digital Voltmeter Keithley Model 182 3mV; 60ppm Contact potential

Triax cable (unterminated) Keithley Model 7025 -- Path isolation

Low-thermal cable Keithley Model 1484 -- Contact potential

#22AWG solid copper wire -- -- Path resistance

#22AWG Teßon-insulated stranded wire

Keithley Model 617 10pA, 100pA; 1.6%.

-- -- Path isolation

4.3.3 Scanner card connections

Jumper wires or connecting cables can simply be hardwired directly to the screw terminals of the Model 2001-SCAN. Detailed connection information is provided in Section 2.

Ω

; 72ppm Control card, measure path

resistance

Path isolation

100V source; 0.2%

4-2

Service Information

4.3.4 Path resistance tests

Perform the following steps to verify that the path resistance of each channel is with speciÞed values.

1. Connect the HI and LO terminals of all 10 channel inputs together to make one common terminal using #22AWG solid copper jumper wires (see Figure 4-1).

NOTE

Make sure that all jumper wires are clean and free of oxides.

2. Connect the output cables to OUT A HI and LO, as shown in Figure 4-1.

3. With the power off, install the scanner card in the Model 2001 Multimeter.

4. Turn on the Model 2001, and allow it to warm up for one hour before proceeding.

5. Select the Model 2001.

6. Temporarily connect a second set of output leads, identical in length and type to the leads connected to the scanner card output, to the Model 2001 rear panel HI and LO INPUT jacks. Be sure to select the rear panel terminals with the front panel INPUT switch.

7. Short the free ends of the temporary leads together, and allow the reading to settle. Enable the Model 2001 REL mode after settling, and leave REL enabled for the remainder of the path resistance tests.

8. Disconnect the temporary leads from the multimeter, and connect the output leads from the scanner card to the rear panel HI and LO INPUT jacks (see Figure 4-1).

Ω

2W function and the 20

Ω

range on the

9. Close channel 1 as follows;

A. From normal display, press CHAN. The instru-

ment will display the following:

CHANNEL SELECTION

CLOSE-CHANNEL OPEN-ALL-CHANNELS

B. Select CLOSE-CHANNEL, then press ENTER.

The Model 2001 will display the following:

ENTER CHAN#01 (1-10)

C. Using the range and cursor keys, select channel

01, then press ENTER.

D. Press EXIT to return to normal display.

10. Note the resistance reading on the Model 2001. Verify that the reading is <2

11. Repeat steps 9 and 10 for channels 2-9. Verify that the path resistance for each channel is as follows:

¥ Channels 1-4, 6-9: <2

¥ Channels 5 and 10: <550

NOTE

Change to the 2k when measuring channels 5 and 10. Always use the lowest possible range for best accuracy.

12. After completing the tests, turn off the Model 2001 power, remove the scanner card, and remove all jumper wires (leave HI and LO shorted for each channel if you intend to perform contact potential tests).

Ω

resistance range

4-3

Service Information

Jumper HI and LO of all 10 Channels

Channel 1

Channel 2-4

Channel 5

4-Pole

2-Pole

OUT A

OUT B

InputHIInput

Model 2001

Rear Panel

Channel 6

Channel 7-9

Channel 10

Model 2001-SCAN

Figure 4-1

Connections for path resistance checks

4.3.5 Contact potential tests

These tests check the EMF (contact potential) generated by each relay contact pair (HI and LO) for each channel. The tests use a sensitive digital voltmeter (Model 182) to measure the contact potential.

3. With the power off, install the scanner card in the Model 2001 Multimeter.

4. Turn on the Model 2001 and the Model 182 Sensitive Digital Voltmeter. Allow the Model 182 to warm up for two hours before measurement.

5. Select the 3mV range on the Model 182.

Perform the following procedure to check contact potential of each channel.

1. Connect 1Ó #22AWG copper jumper wires between the HI and LO terminals of each channel input (see Figure 4-2).

2. Connect the Model 182 to OUT A HI and LO using the low-thermal cable (see Figure 4-2).

4-4

6. Select the DCV function on the Model 2001.

7. Using the CHAN key, close channel 1 (see paragraph 4.3.4 for procedure).

8. Verify that the Model 182 reading is <1µV.

9. Repeat steps 7 and 8 for all 10 channels.

10. After completing all measurements, turn off the Model 2001 power, remove the scanner card, and disconnect all jumpers and test leads.

Service Information

Model 1484 Low Thermal Cable (Unterminated)

KEITHLEY

182 SENSITIVE DIGITAL VOLTMETER

TRG SRQ

REM TALK LSTN

Connect bare copper jumpers between HI and LO of each channel

Channel 1

Channel 2-4

Channel 5

4-Pole

Channel 6

Channel 7-9

Channel 10

2-Pole

Model 182

OUT A

OUT B

Model 2001-SCAN

Figure 4-2

Connections for contact potential tests

4-5

Service Information

4.3.6 Isolation tests

These tests check the leakage resistance (isolation) between all HI and LO terminals and from HI and LO terminals to chassis ground. In general, the test is performed by applying a voltage (100V) across the terminals and then measuring the leakage current. The isolation resistance is then calculated as R = V/I. In the following procedure, the Model 617 functions as a voltage source and as an ammeter. In the V/I function, the Model 617 internally calculates the resistance from the known voltage and current levels, and displays the resistance value.

Perform the following steps to check isolation:

1. Connect a 4Ó length of Teßon-insulated #22AWG stranded wire to every HI and LO terminal on the scanner card (both inputs and outputs). Mark the free end of each wire so you can identify wires when the scanner card is installed.

2. With the power off, install the scanner card in the multimeter.

3. Turn on the Model 2001 power.

4. Turn on the Model 617, and allow the unit to warm up for two hours for rated accuracy.

5. Select the Model 617 2pA range, and enable zero check and zero correct in that order. Leave zero correct enabled for the entire procedure.

WARNING

The following steps use high voltage (100V). Be sure to remove power from the circuit before making connection changes.

6. Set the Model 617 voltage source for +100V, and select the 200nA current range. Make sure the voltage source is still in standby.

7. Place the Model 617 in the V/I measurement function by pressing SHIFT OHMS.

8. With the Model 617 in standby, connect the electrometer to OUT A HI and LO terminals of the scanner card, as shown in Figure 4-3.

9. Close channel 1 using the CHAN key (see paragraph 4.3.4 for details).

10. On the Model 617, disable zero check, and press OPERATE to source 100V.

11. After allowing the reading on the Model 617 to settle, verify that the reading is >1G

Ω

(10

Ω

). This

measurement represents the isolation resistance between the HI and LO terminals of channel 1.

12. Place the Model 617 in standby, and enable zero check.

13. Repeat steps 9 through 12 for channels 2 through

10. Be sure that the channel under test is closed.

14. With the Model 617 voltage source in standby, connect the electrometer to the HI terminals of scanner card channels 1 and 2, as shown in Figure 4-4.

15. Close channel 1 using the CHAN key.

16. On the Model 617, disable zero check, and press OPERATE to source 100V.

17. After allowing the reading on the Model 617 to settle, verify that the reading is >1G

Ω

(10

Ω

). This measurement represents the isolation resistance between the HI terminals of channels 1 and 2.

18. Place the Model 617 in standby, and enable zero check.

19. Repeat steps 14 through 18 to measure isolation resistance between the channel 1 HI terminal and channels 3 through 10 HI terminals. Be sure that the electrometer is connected to the HI terminals of the two channels being tested, and that channel 1 is closed.

20. Repeat steps 14 through 19 for the LO terminals of channels 1 through 10. Be sure the electrometer is connected to the LO terminals of the two channels being tested, and that channel 1 is closed.

21. With the electrometer voltage source in standby, connect the electrometer to channel 1 HI and chassis ground, as shown in Figure 4-5.

22. Program the Model 2001 to close channel 1.

23. On the Model 617, disable zero check, and press OPERATE to source +100V.

24. After allowing the reading on the Model 617 to settle, verify that it is >1G

Ω

(10

Ω

25. Put the electrometer in standby, and enable zero check.

26. Repeat steps 21 through 25 for channels 2 through

10. One electrometer lead should be connected to the HI terminal of the channel being testing, and the other lead should be connected to chassis ground.

27. Repeat steps 21 through 26 for channels 1 through 10 LO terminals. One electrometer lead should be connected to the LO terminal of the channel being tested, and the other lead should be connected to chassis ground. In addition, channel 1 should be closed.

4-6

V-Source LO V-Source HI

Source V and Measure V/I

Banana to Banana Cable

Ground Link Removed

INPUT

Com

Model 617

Unterminated to

Banana Cable

Model 7025 Unterminated Triax Cable

(Red)

Channel 1

Channel 2-4

Channel 5

4-Pole

Service Information

OUT A

OUT B

2-Pole

Figure 4-3

Connections for same-channel isolation tests

Channel 6

Channel 7-9

Channel 10

Model 2001-SCAN

4-7

Service Information

Banana to Banana Cable

Ground Link Removed

V-Source LO V-Source HI

Source V and Measure V/I

INPUT

Model 617

Com

Unterminated to

Banana Cable

Model 7025 Unterminated Triax Cable

(Red)

Channel 1

Channel 2-4

Channel 5

2-Pole

HI LO

OUT A

OUT B

4-Pole

Figure 4-4

Connections for channel-to-channel isolation tests

Channel 6

Channel 7-9

Channel 10

Model 2001-SCAN

4-8

V-Source LO V-Source HI

Source V and Measure V/I

Banana to Banana Cable

Ground Link Removed

INPUT

Com

Model 617

Unterminated to

Banana Cable

Model 2001

Chassis Ground

Model 7025 Unterminated Triax Cable

(Red)

Channel 1

Channel 2-4

Channel 5

4-Pole

Service Information

OUT A

OUT B

2-Pole

Channel 6

Channel 7-9

Channel 10

Figure 4-5

Connections for HI and LO terminal to chassis ground isolation tests

4.4 Special handling of static-sensitive devices

CMOS and other high-impedance devices are subject to possible static discharge damage because of the high-impedance levels involved. When handling such devices, use the precautions listed below.

dissipate static build-up. Typically, these devices will be received in anti-static containers made of plastic or foam. Keep these parts in their original containers until ready for installation or use.

2. Remove the devices from their protective containers only at a properly grounded workstation. Also, ground yourself with an appropriate wrist strap while working with these devices.

Model 2001-SCAN

NOTE

In order to prevent damage, assume that all parts are static-sensitive.

1. Such devices should be transported and handled only in containers specially designed to prevent or

3. Handle the devices only by the body; do not touch the pins or terminals.

4. Any printed circuit board into which the device is to be inserted must Þrst be grounded to the bench or table.

5. Use only anti-static type de-soldering tools and grounded-tip soldering irons.

4-9

Service Information

4.5 Principles of operation

The following paragraphs discuss the basic operating principles for the Model 2001-SCAN, and can be used as an aid in troubleshooting the card. The schematic drawing of the card is shown on drawing number 2001-176, located at the end of Section 5.

4.5.1 Block diagram

Figure 4-6 shows a simpliÞed block diagram of the Model 2001-SCAN. Key elements include the relay drivers and relays, as well as the solid-state switches, and the power-up reset circuit. These various elements are discussed in the following paragraphs.

To 2001

Multimeter

Clock Data

Strobe

+5V

Relay

Drivers

U101-U103

Power-on

Reset

U104

Enable

Relays,

Solid-state

Switches

K101-K111

U105, U106

User Connections

4.5.3 Switching circuits

Relays K101 through K106 and K108 to K111 perform input switching, while K107 conÞgures the card for 2pole or 4-pole operation. U105 and U106 are the solidstate switching elements used for channels 5 and 10.

Note that relay switching is also incorporated into channels 5 and 10 along with the solid-state switches. K110 switches channel 5, and K111 switches channel

10. Solid-state switching is only used when the internal scan listed is selected, when only channels 5 and 10 are in the internal scan list, and if the same function is used for both channels 5 and 10. Otherwise, the latching relays K110 and K111 are used to switch channels 5 and

10.

4.5.4 Power-on safeguard

A power-on safeguard circuit, made up of U104 and associated components, ensures that relays do not change state on power-up and power-down. This circuit disables all relay actuation during power-up and power-down periods by holding the OE (output enable lines) high during these periods.

Figure 4-6

Block diagram

4.5.2 Relay control

Card relays are controlled by serial data transmitted via the relay DATA line. A total of three bytes are shifted in serial fashion into latches located in the card relay driver ICs. The serial data is clocked in by the CLOCK line. As data overßows one register, it is fed out the QÕS line of the register down the chain.

Once all three bytes have shifted into the card, the STROBE line is set high to latch the relay information into the Q outputs of the relay drivers, and the appropriate relays are energized (assuming the driver outputs are enabled, as discussed below). Note that a relay driver output goes low to energize the corresponding relay.

4.6 Troubleshooting

4.6.1 Troubleshooting equipment

Table 4-2 summarizes recommended equipment for troubleshooting the Model 2001-SCAN.

Table 4-2

Recommended troubleshooting equipment

Manufacturer

Description

Multimeter Keithley 2001 DCV checks

Oscilloscope TEK 2243 View logic wave-

and model Application

forms

4-10

Service Information

4.6.2 Troubleshooting access

In order to gain access to the scanner card circuit board to measure voltages under actual operating conditions, perform the following steps:

1. Turn off the Model 2001 power, and disconnect the line cord and all other equipment.

2. If wires are connected to the scanner card, remove the scanner card from the multimeter.

3. Remove the Model 2001 cover as follows: A. Remove the handle by rotating it to align the

arrows on the handle mounting ears. Pull out and remove the handle.

B. Remove the screws that secure the handle

mounting ears, then remove the ears.

C. Remove the screws that attach the rear bezel to

the case, then remove the bezel.

D. Remove the bottom screw that grounds the

case to the chassis.

WARNING

Be sure to install and tighten the grounding screw after replacing the cover.

E. Remove the cover by pulling it off towards the

rear.

4. Disconnect any wires connected to the scanner card terminal blocks.

5. Install the scanner card in the multimeter.

6. Connect the line cord, and turn on the power to measure voltages (see following paragraph).

4.6.3 Troubleshooting procedure

Table 4-3 summarizes scanner card troubleshooting steps. Refer to the schematic diagram and component

layout drawings at the end of Section 5 for component locations.

WARNING

Lethal voltages are present within the Model 2001. Some of the procedures may expose you to hazardous voltages. Observe standard safety precautions for dealing with live circuits. Failure to do so could result in personal injury or death.

CAUTION

Observe the following precautions when troubleshooting or repairing the switch card:

To avoid contamination, which could degrade card performance, always handle the card only by the side edges and covers. Do not touch edge connectors, board surfaces, or components on the card. Also, do not touch areas adjacent to electrical contacts on connectors.

Use care when removing relays from the PC board to avoid pulling traces away from the circuit board. Before attempting to remove a relay, use an appropriate de-soldering tool, such as a solder sucker, to clear each mounting hole completely free of solder. Each relay pin must be free to move in its mounting hole before removal. Also, make certain that no burrs are present on the ends of the relay pins.

4-11

Service Information

Table 4-3

Troubleshooting procedure

Step Item/component Required condition Comments

1 Digital ground P1034, pin 1,

3, 5

All voltages referenced to digital ground.

2 P1034, pin 9 +5VDC Card power supply volt-

age.

3 U101, pin 2 CLOCK pulses Serial clock pulses.

4 U101, pin 3 DATA pulses Serial data pulses.

5 U101, pin 7 STOBE pulse End of relay update

sequence.

6 U101-U103, pins 10-18 Low when relay state is changed.

Relay driver outputs. High when relay is not changing state.

4-12

Replaceable Parts

5.1 Introduction

This section contains replacement parts information, schematic diagram, and component layout drawing for the Model 2001-SCAN.

5.2 Parts list

A parts list for the scanner card is included in a table integrated with schematic diagram and component layout drawing for the board. Parts are listed alphabetically in order of circuit designation.

5.3 Ordering information

To place an order, or to obtain information concerning replacement parts, contact your Keithley representative or the factory (see inside front cover for addresses). When ordering parts, be sure to include the following information:

¥ Card model number (2001-SCAN)

¥ Card serial number

¥ Part description

5.4 Factory service

If the card is to be returned to Keithley Instruments for repair, perform the following:

¥ Call the Instruments Division Repair Department

at 1-800-552-1115 for a Return Material Authorization (RMA) number.

¥ Complete the service form at the back of this man-

ual and include it with the card.

¥ Carefully pack the card in the original packing

carton.

¥ Write ATTENTION REPAIR DEPT and the RMA

number on the shipping label.

NOTE: It is not necessary to return the Model 2001 Multimeter with the card.

5.5 Component layout and schematic diagrams

A component layout drawing and schematic diagram are included on the following pages integrated with the parts list for the Model 2001-SCAN.

¥ Circuit description, if applicable

¥ Keithley part number

5-1

IEEE-488 Reference

Model 2001-SCAN, parts list

Circuit Desig. Description

CARD EJECTOR SHIELD, SCANNER BOTTOM STRAIN RELIEF, BOTTOM SHIELD, SCANNER TOP SLEEVED BANANA PLUG TEST LEAD

C101-103,105,106 C104 C107

CAP,.1UF, 20%,50V,CERAMIC(1206) CAP, 10UF,20%, 25V, TANTALUM (D7243) CAP,100UF,20%,25V,ALUM ELEC

Keithley Part No.

FA-237 2001-341 2001-344 2001-342 CA-109

C-418-.1 C-440-10 C-413-100

E100-107 SURGE ARRESTOR CG2-300L SA-2

J1035,1036 TERMINAL BLOCK CS-768-12

K101-111 RELAY, MINATURE (DPDT) TQ2E-L2-5V RL-155

P1034 CONN, FEMALE, DUAL 16-PIN CS-455

R134 R135,136 R137-144 R147

U101-103 U104 U105,106

RES,1K,5%,125MW,METAL FILM(1206) RES, 470,5%, 125MW, METAL FILM(1206) RES, 100, 10%, 1/2W, COMPOSITION RES,4.7K,5%,125MW,METAL FILM(1206)

IC, 8 STAGE SHIFT/STORE UCN5841 IC,SUPPLY VOLTAGE SUPERVISOR,TL7705AC IC-PHOTOVOLTAIC RELAY, PVR3301

R-375-1K R-375-470 R-1-100 R-375-4.7K

IC-536 IC-602 IC-525

5-2

Replaceable Parts

5-3

Index

Numerics

2-Pole connections 2-8 2-wire resistance tests 3-16 4-Pole connections 2-8 4-wire resistance tests 3-16

Block diagram 4-10 Board cleaning 2-11

Card configuration 2-2 Card connections and installation 2-1 Card connectors 2-3 Card installation and removal 2-14 Channel resistance 3-21 Closing and opening channels 3-9 Closing channels 3-9 Combining 2-pole and 4-pole switching

3-18

Component layout and schematic diagram

5-1 Configure channels (CONFIG-CHAN) 3-5 Connections 2-2 Contact potential tests 4-4 Current connections 2-11 Current measurements 2-10, 2-11, 3-19 Current shunt locations 2-10

Delta operation 3-13 Dressing leads 2-4

Electromagnetic interference 3-21 Environmental conditions 4-2

Factory service 5-1 Features 1-1 Front panel scanner controls 3-2 Front panel scanning 3-9

General information 1-1 Ground loops 3-22

Handling and cleaning precautions 4-1 Handling precautions 1-2, 2-1, 4-1 High-speed multiplexer and ratio/delta

connections 2-13

High-speed multiplexing 3-19

IEEE-488 bus scanner commands 3-7 IEEE-488 bus scanning 3-10 Inspection for damage 1-2 Instruction manual 1-2 Introduction 1-1, 2-1, 3-1, 5-1 Isolation tests 4-6

Keeping connectors clean 3-22

Magnetic fields 3-21 Manual addenda 1-1 Manual scanning 3-7 Measurement considerations 3-20

Open and close channels (CHAN) 3-3 Opening channels 3-9 Operation 3-1 Ordering information 5-1 Output connections 2-4 Output connections to multimeter 2-16

i-1

Parts list 5-1 Path isolation 3-20 Path resistance tests 4-3 Performance verification 4-2 Power-on safeguard 4-10 Power-up detection 3-2 Principles of operation 4-10

Ratio and delta 3-11 Ratio and delta computation 3-11 Ratio and delta measurement functions

3-11 Ratio and delta triggering 3-11 Ratio operation 3-11 RATIO/DELTA channel selection 3-6 Recommended current shunt values 2-11 Recommended equipment 4-2 Relay control 4-10 Relay input signal limitations 3-2 Repacking for shipment 1-2 Replaceable parts 5-1 Resistance connections 2-8

Resistor testing 3-16 RTD temperature measurements 3-14

Safety symbols and terms 1-2 Scan configuration (CONFIG-SCAN) 3-5 Scanner card connections 4-2 Scanner card detection 3-2 Scanner card installation 2-14 Scanner card removal 2-16 Scanner option bus query 3-2 Scanning channels 3-9 Service information 4-1 Shipment contents 1-2 Signal limitations 3-2 Soldering precautions 4-2 Solid-state input signal limitations 3-2 Solid-state switching 3-11 Solid-state switching considerations 3-6 Special handling of static-sensitive devices

4-9 Specifications 1-2 Switching circuits 4-10

Troubleshooting 4-10 Troubleshooting access 4-11 Troubleshooting equipment 4-10 Troubleshooting procedure 4-11 Typical applications 3-16 Typical connecting schemes 2-6

Unpacking and inspection 1-2 Using EXIT to stop scanning 3-7 Using the scanner with the buffer 3-15

Voltage connections 2-6

Warranty information 1-1 Wiring procedure 2-3

i-2

Test Instrumentation Group Keithley Instruments, Inc.

28775 Aurora Road Cleveland, Ohio 44139

Tektronix 2001-SCAN Instruction Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Safety Precautions

Table of Contents

List of Illustrations

List of Tables

General Information

1.1 Introduction

1.2 Features

1.3 Warranty information

1.4 Manual addenda

1.5 Safety symbols and terms

1.7 Unpacking and inspection

1.8 Repacking for shipment

Card Connections and Installation

2.1 Introduction

2.2 Handling precautions

2.3 Connections

2.4 Typical connecting schemes

2.5 Card installation and removal

Operation

3.1 Introduction

3.2 Signal limitations

3.3 Scanner card detection

3.4 Front panel scanner controls

3.5 IEEE-488 bus scanner commands

3.6 Closing and opening channels

3.7 Scanning channels

3.8 Ratio and delta

3.9 RTD temperature measurements

3.10 Using the scanner with the buffer

3.11 Typical applications

3.12 Measurement considerations

Service Information

4.1 Introduction

4.2 Handling and cleaning precautions

4.4 Special handling of static-sensitive devices

4.5 Principles of operation

4.6 Troubleshooting

Replaceable Parts

5.1 Introduction

5.2 Parts list

5.3 Ordering information

5.4 Factory service

5.5 Component layout and schematic diagrams

Index

Numerics