Keithley 7037 Service manual

I
nstruction Manua
l
Model 703
Single-Pole Relay-Digital I/O Card
Contains Operating and Servicing Information
7037-901-01 Rev. A / 5-97
WARRANTY
Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 1 year from date of shipment.
Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batteries, diskettes, and documentation.
During the warranty period, we will, at our option, either repair or replace any product that proves to be defective.
To exercise this warranty, write or call your local Keithley representati v e, or contact Keithley headquarters in Cleveland, Ohio. You will be given prompt assistance and return instructions. Send the product, transportation prepaid, to the indicated service facility. Repairs will be made and the product returned, transportation prepaid. Repaired or replaced products are warranted for the balance of the origi­nal warranty period, or at least 90 days.
LIMITATION OF WARRANTY
This warranty does not apply to defects resulting from product modification without Keithley’s express written consent, or misuse of any product or part. This warranty also does not apply to fuses, software, non-rechargeable batteries, damage from battery leakage, or problems arising from normal wear or failure to follow instructions.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. THE REMEDIES PROVIDED HEREIN ARE BUYER’S SOLE AND EXCLUSIVE REMEDIES.
NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT, INDI­RECT , SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS INSTRUMENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF SUCH DAMAGES. SUCH EXCLUDED DAMAGES SHALL INCLUDE, 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 • 216-248-0400 • Fax: 216-248-6168 • 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 • 44-118-9575666 • Fax: 44-118-9596469 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., 1, Min Yu First Street • Hsinchu, Taiwan, R.O.C. • 886-35-778462 • Fax: 886-35-778455
Model 7037 Single-Pole Relay-Digital I/O Card
Instruction Manual
©1997, Keithley Instruments, Inc.
All rights reserved. Cleveland, Ohio, U.S.A. First Printing, May 1997
Document Number: 7037-901-01 Rev. A
Manual Print History
The print history shown below lists the printing dates of all Revisions and Addenda created for this manual. The Revision 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 7037-901-01)........................................................................................ May 1997
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.

Table of Contents

1 General Information
Introduction..........................................................................................................................................................1-1
Features............................................................................................................................................................... 1-1
Warranty information.......................................................................................................................................... 1-2
Manual addenda.................................................................................................................................................. 1-2
Safety symbols and terms ................................................................................................................................... 1-2
Specifications...................................................................................................................................................... 1-2
Unpacking and inspection................................................................................................................................... 1-2
Inspection for damage................................................................................................................................. 1-2
Handling precautions ...................................................................................................................................1-2
Shipping contents........................................................................................................................................ 1-2
Instruction manual....................................................................................................................................... 1-3
Repacking for shipment ...................................................................................................................................... 1-3
Optional accessories............................................................................................................................................ 1-3
2 Relay Switch Configuration
Introduction......................................................................................................................................................... 2-1
Basic switch configuration (SPST)..................................................................................................................... 2-1
3 Digital I/O Configuration
Introduction......................................................................................................................................................... 3-1
Digital outputs..................................................................................................................................................... 3-1
Controlling pull-up devices................................................................................................................................. 3-1
Controlling devices using pull-up resistors......................................................................................................... 3-2
Digital inputs....................................................................................................................................................... 3-2
i
4 Card Connections and Installation
Introduction ......................................................................................................................................................... 4-1
Handling precautions........................................................................................................................................... 4-2
Digital I/O connections........................................................................................................................................ 4-2
Voltage source jumper................................................................................................................................. 4-2
Pull-up resistors........................................................................................................................................... 4-2
Configuring digital I/O output logic............................................................................................................ 4-4
Configuring digital I/O input pull-up resistance ......................................................................................... 4-4
Multi-pin (mass termination) connector card...................................................................................................... 4-5
Typical relay switch connection scheme........................................................................................................... 4-10
Typical digital I/O connection schemes ............................................................................................................ 4-11
Output connection schemes....................................................................................................................... 4-11
Input connection scheme........................................................................................................................... 4-12
Model 7037 installation and removal................................................................................................................ 4-13
Card installation......................................................................................................................................... 4-13
Card removal............................................................................................................................................. 4-13
5 Operation
Introduction ......................................................................................................................................................... 5-1
Power limits......................................................................................................................................................... 5-1
Digital I/O maximum signal levels.............................................................................................................. 5-1
Relay switch maximum signal levels.......................................................................................................... 5-1
Reactive loads.............................................................................................................................................. 5-1
Mainframe control of the card............................................................................................................................. 5-2
Channel assignments................................................................................................................................... 5-3
Closing and opening channels..................................................................................................................... 5-5
Scanning channels....................................................................................................................................... 5-5
Reading input channels................................................................................................................................ 5-6
IEEE-488 bus operation .............................................................................................................................. 5-6
Measurement considerations ............................................................................................................................... 5-8
Path isolation............................................................................................................................................... 5-8
Magnetic fields............................................................................................................................................ 5-8
Radio frequency interference ...................................................................................................................... 5-9
Ground loops............................................................................................................................................... 5-9
Keeping connectors clean.......................................................................................................................... 5-10
AC frequency response.............................................................................................................................. 5-10
ii
6 Service Information
Introduction......................................................................................................................................................... 6-1
Handling and cleaning precautions..................................................................................................................... 6-1
Performance verification..................................................................................................................................... 6-2
Environmental conditions ........................................................................................................................... 6-2
Recommended equipment........................................................................................................................... 6-2
Card connections......................................................................................................................................... 6-2
Channel resistance tests .............................................................................................................................. 6-3
Offset current tests ...................................................................................................................................... 6-4
Contact potential tests................................................................................................................................. 6-5
Channel to channel isolation tests............................................................................................................... 6-5
Common-mode isolation tests..................................................................................................................... 6-8
Channel functionality test ................................................................................................................................... 6-9
Special handling of static-sensitive devices........................................................................................................ 6-9
Principles of operation ...................................................................................................................................... 6-10
Block diagram........................................................................................................................................... 6-10
ID data circuits.......................................................................................................................................... 6-11
Relay control............................................................................................................................................. 6-12
Relay power control.................................................................................................................................. 6-12
Digital I/O output channel control ............................................................................................................ 6-12
Digital I/O input channel control .............................................................................................................. 6-12
Power-on safeguard................................................................................................................................... 6-12
Troubleshooting ................................................................................................................................................ 6-13
Troubleshooting equipment ...................................................................................................................... 6-13
Troubleshooting access............................................................................................................................. 6-13
Troubleshooting procedure ....................................................................................................................... 6-14
7 Replaceable Parts
Introduction......................................................................................................................................................... 7-1
Parts lists ..............................................................................................................................................................7-1
Ordering information .......................................................................................................................................... 7-1
Factory service.................................................................................................................................................... 7-1
Component layouts and schematic diagrams...................................................................................................... 7-1
Index
iii

List of Illustrations

2 Relay Switch Configuration
Figure 2-1 Model 7037 relay switch configuration (simplified schematic) ................................................................. 2-1
3 Digital I/O Configuration
Figure 3-1 Output configuration for pull-up devices.................................................................................................... 3-1
Figure 3-2 Output configuration using pull-up resistance ............................................................................................ 3-2
Figure 3-3 Input configuration...................................................................................................................................... 3-2
4 Card Connections and Installation
Figure 4-1 Voltage source jumper for output channels ................................................................................................ 4-2
Figure 4-2 Component locations - connector board ..................................................................................................... 4-3
Figure 4-3 Voltage source jumper installation ............................................................................................................. 4-3
Figure 4-4 Digital I/O output logic location ................................................................................................................. 4-4
Figure 4-5 Digital I/O output logic selection................................................................................................................ 4-4
Figure 4-6 Digital I/O input pull-up resistance selection.............................................................................................. 4-5
Figure 4-7 Multi-pin connector card terminal identification ........................................................................................ 4-6
Figure 4-8 Typical round cable connection techniques ................................................................................................ 4-8
Figure 4-9 Model 7011-MTR connector pinout ........................................................................................................... 4-9
Figure 4-10 Model 7011-KIT-R (with cable) assembly................................................................................................. 4-9
Figure 4-11 Typical connection scheme for Model 7037............................................................................................. 4-10
Figure 4-12 Digital output, solenoid control ................................................................................................................ 4-11
Figure 4-13 Digital output, motor control .................................................................................................................... 4-11
Figure 4-14 Digital output, logic device control........................................................................................................... 4-12
Figure 4-15 Digital input, monitoring micro-switches................................................................................................. 4-12
Figure 4-16 Model 7037 card installation in Model 7001............................................................................................ 4-13
v
5 Operation
Figure 5-1 Limiting inductive reaction voltage............................................................................................................. 5-2
Figure 5-2 Limiting capacitive reaction current............................................................................................................ 5-2
Figure 5-3 Model 7001 channel status display.............................................................................................................. 5-3
Figure 5-4 Model 7022 channel status display (slot 1) ................................................................................................. 5-3
Figure 5-5 Channel display organization ...................................................................................................................... 5-3
Figure 5-6 Model 7037 programming channel assignments......................................................................................... 5-4
Figure 5-7 Path isolation resistance .............................................................................................................................. 5-8
Figure 5-8 Voltage attenuation by path isolation resistance ......................................................................................... 5-8
Figure 5-9 Power line ground loops.............................................................................................................................. 5-9
Figure 5-10 Eliminating ground loops............................................................................................................................ 5-9
6 Service Information
Figure 6-1 Channel resistance testing ........................................................................................................................... 6-3
Figure 6-2 Offset current testing ................................................................................................................................... 6-4
Figure 6-3 Contact potential testing.............................................................................................................................. 6-5
Figure 6-4 Channel to channel testing........................................................................................................................... 6-6
Figure 6-5 Common-mode isolation testing.................................................................................................................. 6-8
Figure 6-6 Testing an input or output channel .............................................................................................................. 6-9
Figure 6-7 Model 7037 block diagram........................................................................................................................ 6-10
Figure 6-8 Start and stop sequences............................................................................................................................ 6-11
Figure 6-9 Transmit and acknowledge sequence ........................................................................................................ 6-11
vi

List of Tables

4 Card Connections and Installation
Table 4-1 Mass termination accessories...................................................................................................................... 4-5
Table 4-2 Multi-pin connector card terminal designation cross-reference.................................................................. 4-7
6 Service Information
Table 6-1 Verification equipment ............................................................................................................................... 6-2
Table 6-2 Channel to channel isolation tests............................................................................................................... 6-7
Table 6-3 Recommended troubleshooting equipment............................................................................................... 6-13
Table 6-4 Troubleshooting procedure ....................................................................................................................... 6-14
7 Replaceable Parts
Table 7-1 Relay card for Model 7037 parts list............................................................................................................7-2
Table 7-2 Mass terminated connector card for Model 7037 parts list..........................................................................7-3
Table 7-3 Model 7011-KIT-R 96-pin female DIN connector kit parts list..................................................................7-3
vii
1

General Information

Introduction

This section contains general information about the Model 7037 single-pole relay-digital I/O card.
The Model 7037 consists of a multi-pin (mass termination) connector card and a relay card. External test circuit connec­tions are made via the 96-pin male DIN connector on the connector card. Keithley offers a v ariety of optional accesso­ries that can be used to make connections to the connector card. (See the available accessories at the end of this section.)
The rest of Section 1 is arranged in the following manner:
• Features
• Warranty information
• Manual addenda
• Safety symbols and terms
• Specifications
• Unpacking and inspection
• Repacking for shipment
• Optional accessories

Features

The Model 7037 has 30 independent channels of single-pole switching. It also has ten independent inputs and outputs for digital I/O capabilities. Some of the key features include:
• Low contact potential and offset current for minimal effects on low-level signals.
• High density switching and control.
• High capacity digital output sink of 250mA.
• 1A pathway current carrying capacity.
• High isolation resistance >1G Ω for minimal load effects.
• Model 7011-KIT-R connector kit that includes a 96-pin female DIN connector that will mate directly to the con­nector on the Model 7037 or to a standard 96-pin male DIN bulkhead connector (see Model 7011-MTR). This connector uses solder cups for connections to external circuitry and includes an adapter for a round cable and the housing.
1-1
General Information

Warranty information

Warranty information is located at the front of this instruc­tion manual. Should your Model 7037 require warranty ser­vice, contact the Keithley representativ e or authorized repair facility in your area for further information. When returning the card for repair, be sure to fill out and include the service form at the back of this manual in order to provide the repair facility with the necessary information.

Manual addenda

Any improvements or changes concerning the card or man­ual will be explained in an addendum included with the card. Addenda are provided in a page replacement format. Replace the obsolete pages with the new pages.

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 card. Such damage may invali­date the warranty.
Specifications
Model 7037 specifications are found at the front of this man­ual. These specifications are exclusive of the mainframe specifications.

Unpacking and inspection

Inspection for damage
The Model 7037 is packaged in a resealable, 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 following pre­cautions on handling.
Handling precautions
1. Always grasp the card by the side edges and shields. Do not touch the board surfaces or components.
2. When not installed in a Model 7001/7002 mainframe, keep the card in the anti-static bag 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.
Shipping contents
The following items are included with every Model 7037 order:
• Model 7037 Single-Pole Relay-Digital I/O Card
• Model 7011-KIT-R 96-pin Female DIN Connector Kit
• Model 7037 Instruction Manual
• Additional accessories as ordered
1-2
General Information
Instruction manual
The Model 7037 Instruction Manual is three-hole drilled so it can be added to the three-ring binder of the Model 7001 or 7002 Instruction Manual. After removing the plastic wrap­ping, place the manual in the binder following the mainframe instruction manual. Note that a manual identification tab is included and should precede the Model 7037 Instruction Manual.
If an additional instruction manual is required, order the manual package, Keithley part number 7037-901-00. The manual package includes an instruction manual and any per­tinent addenda.

Repacking for shipment

Should it become necessary to return the Model 7037 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 card.
• Write ATTENTION REPAIR DEPARTMENT on the shipping label.
• Fill out and include the service form located at the back of this manual.

Optional accessories

The following accessories are available for use with the Model 7037:
Model 7011-MTC-2  This two-meter round cable assem-
bly is terminated with a 96-pin female DIN connector on each end. It will mate directly to the connector on the Model 7037 and to a standard 96-pin male DIN bulkhead connector (see Model 7011-MTR).
Model 7011-MTR  This 96-pin male DIN bulkhead con-
nector uses solder cups for connections to external circuitry. It will mate to the Model 7011-KIT-R connector and Model 7011-MTC-2 cable assembly.
1-3
IN1
OUT1
One of 30 Channels
2 -
2
Relay Switch Configuration

Introduction

This section covers the basic single-pole, single-throw (SPST) switch configuration.
Basic switch configuration (SPST)
A simplified schematic of the Model 7037 relay switch con­figuration is shown in Figure 2-1. The card has 30 indepen­dent channels. Each channel is made up of a single-pole, single-throw (SPST), normally open (NO) switch.
Figure 2-1
Model 7037 relay switch configuration (simplified schematic)
1
3
Digital I/O Configuration

Introduction

This section covers the basic digital input and output config­urations for the Model 7037. Connection information for these configurations is provided in Section 4 of this manual, while operation (front panel and IEEE-488 bus) is explained in Section 5.

Digital outputs

Output channels are user configurable for negative (low) or positive (high) true logic. That is, the output can be high or low when the channel is turned on (closed) depending upon user configuration. Conversely, the output can be high or low when the channel is turned off (open). Refer to Section 4 to configure the logic to your requirement.
7037
Jumper
5V
10k

Controlling pull-up devices

T ypically , the digital outputs are used to provide driv e for rel­atively high current devices such as solenoids, relays, and small motors. The configurations for these applications are shown in Figure 3-1. Figure 3-1 allows you to use an external voltage source (V) for devices that require a higher voltage (42V maximum). An internal jumper is used to select the internal pull-up voltage. At the factory, the internal 5V source is selected.
Each output channel uses a fly-back diode for protection when switching an inductive device, such as a solenoid coil. This diode diverts the potentially damaging fly-back voltage away from the driver.
V
(42V maximum)
V
EXT
Solenoid or relay coil
Driver
Figure 3-1
Output configuration for pull-up devices
NOTE: Output configuration uses
an external voltage source (42V maximum).
3-1
Digital I/O Configuration
7037
Jumper
5V
Driver
Figure 3-2
Output configuration using pull-up resistance
R
10k
V
EXT
P
GND
+V
A
Or
B
Gate
Device
Y
Logic

Controlling devices using pull-up resistors

CAUTION
Failure to set J201 to the Vext position when using external pull-up voltages may result in damage to the output drivers.
When interfacing outputs to high-impedance devices (i.e., logic devices), internal pull-up resistors are used to achieve the appropriate logic level. Figure 3-2 shows the output configuration using the 10k Ω pull-up resistor (Rp).
The configuration in Figure 3-2 uses the internal 5V source as the high logic level. If you need a higher logic level, you can place the jumper in the alternate position and apply an external voltage (via V
EXT
).

Digital inputs

Input channels use positive true logic but can be pulled up or pulled down based on the configuration of the pull-up resis­tor. Each channel uses a 10k Ω pull-up resistor (R up resistors can be pulled up to 5V or pulled down to ground depending on the positioning of the jumper on the input logic bank. Refer to Section 4 for more information. Figure 3-3 shows the resistor being pulled up to 5V.
). The pull-
1
When the resistor is connected to 5V, the channel is pulled high. Thus, with nothing connected to the channel, the input is pulled high to 5V which displays the channel as on.
When the resistor is connected to ground, the channel is pulled low. Thus, with nothing connected to the channel, the input is pulled low to ground which displays the channel as off.
The digital input is compatible with external TTL logic. Each built-in pull-up resistor provides level shifting so devices such as micro-switches can be monitored. Each input has a protection network that clamps the input at 5.7V. This allows logic levels up to 42V peak to be monitored.
7037
5V
R
1
R
2
10k
R
= Pull-up resistor
1
R
= Input protection resistor
2
10k
INPUT
GND
3-2
Figure 3-3
Input configuration
4
Card Connections and
Installation

Introduction

WARNING
The procedures in this section are intended only for qualified service per­sonnel. Do not perform these proce­dures unless qualified to do so. Failure to recognize and observe normal safety precautions could result in personal injury or death.
The information in this section is arranged as follows:
• Handling precaution — Explains precautions that
must be followed to prevent contamination to the card. Contamination could degrade the performance of the card.
• Digital I/O connections — Explains the voltage source jumpers, pull-up resistors, output logic, and input resis­tance and how to configure them.
• Multi-pin (mass termination) connector card — Cov-
ers the basic connections to the 96-pin DIN male con­nector and identifies each terminal.
• Typical relay switch connection scheme — Provides
a typical connection scheme for a relay switch configuration.
• Typical digital I/O connection schemes — Provides
some typical connection schemes for output solenoid, relay, motor, and logic device control and for input micro-switch monitoring.
• Model 7037 installation and removal — Provides the
procedures to install and remove the card from the Model 7001/7002 mainframe.
4-1
Card Connections and Installation

Handling precautions

To maintain high impedance isolation, care should be taken when handling the relay and connector cards to avoid con­tamination from such foreign materials as body oils. Such contamination can substantially lower leakage resistances, thus degrading performance.
To avoid possible contamination, always grasp the relay and connector cards by the side edges or shields. Do not touch the board surfaces or components. On connectors, do not touch areas adjacent to the electrical contacts. Dirt buildup over a period of time is another possible source of contami­nation. To avoid this problem, operate the mainframe and card in a clean environment.
If a card becomes contaminated, it should be thoroughly cleaned as explained in Section 6.

Digital I/O connections

Voltage source jumper
Digital output high uses the internal +5V source as the high logic level. If higher voltages are required, a user-supplied voltage can be used (42V maximum). At the factory, the internal jumper is set to use the internal +5V source.
CAUTION
A plug-in jumper for the bank allows you to select the inter­nal +5V source or an external source. In Figure 4-1, the banks are using the external voltage source.
5V
J201
V
ext
39 40
U203
31 32 33
34
35 36
U201 U202
37 38
Figure 4-1
Voltage source jumper for output channels
The voltage source jumper is located on the connector board as shown in Figure 4-2. Figure 4-3 shows how the plug-in jumper is installed on J201.
Pull-up resistors
When interfacing outputs to high-impedance devices (i.e., logic devices), pull-up resistors are used to achieve the appropriate logic level. These resistors are installed at the factory.
Failure to set J201 to the Vext position when using external pull-up voltages may result in damage to the output drivers.
4-2
Card Connections and Installation
U203
Figure 4-2
Component locations — connector board
Jumper
V
EXT
A. 5V Source Selected
U201 U202
5V
V
J201
5V
Vext
Jumper
EXT
B. External Source Selected
5V
Figure 4-3
Voltage source jumper installation
4-3
Loading...
+ 50 hidden pages