Keithley 7999-5 Service manual

Model 7999-5

RS-232 Relay Controller

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 Keithley representative, 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.

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.ERTY.

Keithley Instruments, Inc.

BELGIUM: Keithley Instruments B.V.
CHINA: Keithley Instruments China
FRANCE: Keithley Instruments Sarl
GERMANY: Keithley Instruments GmbH
GREAT BRITAIN: Keithley Instruments Ltd
INDIA: Keithley Instruments GmbH
ITALY: Keithley Instruments s.r.l.
NETHERLANDS: Keithley Instruments B.V.
SWITZERLAND: Keithley Instruments SA
TAIWAN: Keithley Instruments Taiwan

• 28775 Aurora Road • Cleveland, OH 44139 • 440-248-0400 • Fax: [phone] • http://www.k eithley.com

Bergensesteenweg 709 • B-1600 Sint-Pieters-Leeuw • 02/363 00 40 • Fax: [phone]

Yuan Chen Xin Building, Room 705 • 12 Yumin Road, Dewai, Madian • Beijing 100029 • 8610-62022886 • Fax: [phone]

B.P. 60 • 3, allée des Garays • 91122 Palaiseau Cédex • 01 64 53 20 20 • Fax: [phone]

Landsberger Strasse 65 • D-82110 Germering • 089/84 93 07-40 • Fax: [phone]

The Minster • 58 Portman Road • Reading, Berkshire RG30 1EA • 0118-9 57 56 66 • Fax: [phone]
Flat 2B, WILOCRISSA • 14, Rest House Crescent • Bangalore 560 001 • 91-80-509-1320/21 • Fax: [phone]
Viale S. Gimignano, 38 • 20146 Milano • 02/48 30 30 08 • Fax: [phone]
Postbus 559 • 4200 AN Gorinchem • 0183-635333 • Fax: [phone]
Kriesbachstrasse 4 • 8600 Dübendorf • 01-821 94 44 • Fax: [phone]

1 Fl. 85 Po Ai Street • Hsinchu, Taiwan, R.O.C. • 886-3572-9077• Fax: [phone]

10/99

Model 7999-5 16-Channel RS-232 Relay Controller

Instruction Manual

©1998, Keithley Instruments, Inc.

All rights reserved.

Cleveland, Ohio, U.S.A.

Second Printing, December 1999

Document Number: 7999-5-901-01 Rev. B

Manual Print History

The print history shown below lists the printing dates of all Revisions and Addenda created
for this manual. The Revision Le vel letter increases alphabetically as the manual under goes sub­sequent updates. Addenda, which are released between Revisions, contain important change in­formation that the user should incorporate immediately into the manual. Addenda are numbered
sequentially . When a new Re vision is created, all Addenda associated with the previous Re vision
of the manual are incorporated into the new Revision of the manual. Each ne w Revision includes
a revised copy of this print history page.

Revision A (Document Number 7999-5-901-01).....................................................November 1999

Revision B (Document Number 7999-5-901-01)..................................................... December 1999

All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc.
Other brand names are trademarks or registered trademarks of their respective holders.

Safety Precautions

The following safety precautions should be observed before using this product and any associated in­strumentation. Although some instruments and accessories would normally be used with non-hazardous
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

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

Operators

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

Maintenance personnel

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

ucts. 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 con-

nector jacks or test fixtures. The American National Standards Institute (ANSI) states that a shock haz­ard exists when voltage lev els greater than 30V RMS, 42.4V peak, or 60VDC are present.

practice is to expect that hazardous voltage is present in any unknown circuit before measuring.

Users of this product must be protected from electric shock at all times. The responsible body must en­sure that users are prevented access and/or insulated from every connection point. In some cases, con­nections must be exposed to potential human contact. Product users in these circumstances must be
trained to protect themselves from the risk of electric shock. If the circuit is capable of operating at or
above 1000 volts,

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

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

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

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

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

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

are trained to work on live circuits, and perform safe installations and repairs of prod-

no conductive part of the circuit may be exposed.

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

A good safety

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. Alw ays make measurements with dry hands while standing on a dry, insulated surface ca­pable of withstanding the voltage being measured.

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

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

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

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

requires the use of a lid interlock.

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

!

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

The symbol on an instrument sho ws 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 av oid personal contact
with these voltages.

The

WARNING

read the associated information very carefully before performing the indicated procedure.

heading in a manual explains dangers that might result in personal injury or death. Always

The

CAUTION

invalidate the warranty.
Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and all test cables.
To maintain protection from electric shock and fire, replacement components in mains circuits, including the

power transformer, test leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses,
with applicable national safety approvals, may be used if the rating and type are the same. Other components
that are not safety related may be purchased from other suppliers as long as they are equivalent to the original
component. (Note that selected parts should be purchased only through Keithley Instruments to maintain ac­curacy and functionality of the product.) If you are unsure about the applicability of a replacement component,
call a Keithley Instruments office for information.

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

heading in a manual explains hazards that could damage the instrument. Such damage may

Rev. 10/99

Model 7999-5 Specifications

OUTPUTS: 16 open collector relay control lines, each capable of 300mA max. sink current. Coil suppression diodes included.
OUTPUT SATURATION VOLTAGE: 0.18V typ. @ 300mA.
MAXIMUM RELAYPOWER VOLTAGE: 28V DC (user supplied).
CONNECTORS: Two 10-position quick disconnect terminal blocks.
UPPER CONNECTOR: Relay power, relay common, relay control outputs 1–8.
LOWER CONNECTOR: Relay power, relay common, relay control outputs 9–16.

The relay common of the upper and lower connectors is internally connected together to chassis ground.
The relay power inputs of the upper and lower connectors are separate, allowing two different coil voltages to be used for each bank.

GENERAL

INTERFACE: RS-232 control (9600 baud, 8 data, 1 stop). Response terminator selectable (CR, LF, CRLF, LFCR).
ENVIRONMENT: Operating: 0° to 40°C, up to 35°C <80% RH. Storage: –25° to 65°C.
POWER CONSUMPTION: 7.3W.
WARRANTY: 1 year.
EMC: Conforms with European Union Directive 89/336/EEC, FCC part 15 class B.
SAFETY:Conforms with European Union Directive 73/23/EEC.
DIMENSIONS: 109mm long × 112mm wide × 59mm deep (4.3˝ × 4.4˝ × 2.3˝).
ACCESSORIES SUPPLIED: AC/DC power adapter (100–120VAC/ 220–240VAC, 50 or 60Hz) with line cord, user and service manual, two terminal

block mating connectors (part no. CS-846-1).

Specifications subject to change without notice.

T able of Contents

1 General Information

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

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

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

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

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

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

Unpacking and inspection .......................................................... 1-3

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

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

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

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

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

Connections ................................................................................ 1-4

2 Connections

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

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

Configuration ............................................................................. 2-3

Layout ................................................................................. 2-3

Connections ................................................................................ 2-4

RS-232 connection .............................................................. 2-4

Power connector .................................................................. 2-5

Quick disconnect connections ............................................. 2-5

3 Operation

Introduction ................................................................................ 3-2

Maximum voltage and current considerations ........................... 3-2

Operation (RS-232) .................................................................... 3-2

Sending and receiving data ................................................. 3-2

Termination characters ........................................................ 3-2

RS-232 command set .......................................................... 3-4

Command interpretation ..................................................... 3-5

Typical connection scheme ................................................. 3-7

4 Service Information

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

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

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

Card and connector cleaning ............................................... 4-2

Replacing components ................................................................ 4-3

Replacement parts ............................................................... 4-3

Replacement precautions ..................................................... 4-3

Soldering considerations ..................................................... 4-3

Disassembly ........................................................................ 4-3

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

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

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

Output saturation voltage verification procedure ................ 4-5

5 Replaceable Parts

Introduction ................................................................................ 5-2

Parts list ...................................................................................... 5-2

Ordering information .................................................................. 5-2

Factory service ............................................................................ 5-2

Component layout ...................................................................... 5-2

List of Illustrations

2 Connections

Figure 2-1 General layout ........................................................................ 2-3

Figure 2-2 RS-232 interface connector .................................................... 2-4

Figure 2-3 Relay control connector pinouts ............................................ 2-6

3 Operation

Figure 3-1 Jumper location ...................................................................... 3-3

Figure 3-2 Typical connection scheme .................................................... 3-7

4 Service Information

Figure 4-1 Output saturation voltage test connections ............................ 4-5

List of T ables

2 Connections

Table 2-1 RS-232 connector terminals ................................................... 2-4

Table 2-2 Upper relay connector pinouts ............................................... 2-5

Table 2-3 Lower relay connector pinouts ............................................... 2-6

3 Operation

Table 3-1 Jumper positions—termination characters ............................. 3-3

Table 3-2 Command set .......................................................................... 3-4

Table 3-3 Sample command interpretation ............................................ 3-6

4 Service Information

Table 4-1 Recommended verification equipment ................................... 4-4

5 Replaceable Parts

Table 5-1 Parts list—electronic components .......................................... 5-3

Table 5-2 Parts list—mechanical parts ................................................... 5-4

1

General Information

1-2 General Information

Introduction

This section contains general information about the Model 7999-5 16-channel RS-232 relay
controller. The information is organized as follows:

• Feature overview

• Warranty information

• Manual addenda

• Safety symbols and terms

• Specifications

• Unpacking and inspection

• Connections

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

Feature overview

The Model 7999-5 is a 16-channel open collector relay controller with the following
features:

• 16 open-collector relay control lines

• Quick-disconnect terminal block type connectors (mating connectors supplied)

• Coil suppression diodes

W arranty information

Warranty information is located at the front of this instruction manual. Should your Model
7999-5 require warranty service, contact the Keithley representative or authorized repair facil­ity in your area for further information. When returning the relay controller for repair, be sure
to fill out and include the service form at the back of this manual to provide the repair facility
with the necessary information.

Manual addenda

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

Safety symbols and terms

The following symbols and terms may be found on the relay controller or used in this

manual.

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

!

the manual.

General Information 1-3

The

symbol

safety precautions to avoid personal contact with these voltages.

The

WARNING

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

The

CAUTION

controller. Such damage may invalidate the warranty.

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

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

heading used in this manual explains hazards that could damage the relay

Specifications

Full Model 7999-5 specifications are included at the front of this manual.

Unpacking and inspection

Inspection for damage

The Model 7999-5 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 relay controller from the bag, observe the precautions on handling discussed below.

Handling precautions

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

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

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

1-4 General Information

Shipment contents

The following items are included with every Model 7999-5 order:

• Model 7999-5 16-channel relay controller

• PS-57A Power supply module (AC/DC converter 100-240VAC to 12VDC, IEC AC
inlet)

• Two 10-pin terminal block mating connectors

• Model 7999-5 Instruction Manual (this manual)

• Additional accessories as ordered

Instruction manual

If an additional Model 7999-5 Instruction Manual is required, order the manual package,
Keithley part number 7999-5-901-00. The manual package includes an instruction manual and
any pertinent addenda.

Repacking for shipment

Should it become necessary to return the Model 7999-5 for repair, carefully pack the unit in
its original packing carton or the equivalent, and include the following information:

• Call the Repair Department at 1-888-KEITHLEY for a Return Material Authorization

• Advise as to the warranty status of the relay controller.

• Write ATTENTION REPAIR DEPARTMENT and the RMA number on the shipping

• Fill out and include the service form located at the back of this manual.

Connections

The following are available Model 7999-5 connections:

• Two 10-position quick-disconnect connectors

• Power receptacle: 3-pin phoenix jack for supplied power module

• RS-232 port: DB-9 connector

NOTE

(RMA) number.

label.

Refer to Section 2 for detailed connection information.

2

Connections

2-2 Connections

Introduction

This section contains information about overall relay controller configuration and connec­tions and is organized as follows:

• Handling precautions

• Configuration

• Connections

Handling precautions

Care should be taken when handling the relay controller to avoid contamination from such
foreign materials as body oils. Such contamination can reduce isolation resistance. To avoid
possible contamination:

• Always grasp the relay controller by the case.

• Do not touch connector insulators.

• Operate the relay controller in a clean environment. If the relay controller becomes con­taminated, it should be thoroughly cleaned as explained in Section 4.

Connections 2-3

Configuration

Layout

Figure 2-1 shows the general layout of the Model 7999-5 which features:
Connectors:

• Power receptacle: 3-pin phoenix jack for supplied power module

• RS-232 port: DB-9 connector

• Two 10-pin quick disconnect connectors

Indicators:

• Power LED

Figure 2-1

General layout

2-4 Connections

Connections

RS-232 connection

The RS-232 serial port is connected to the serial port of a computer (controller) using a
straight-through RS-232 cable terminated with DB-9 connectors. Do not use a null modem
cable. The serial port uses the transmit (TXD), receive (RXD), and signal ground (GND) line
of the RS-232 standard. Figure 2-2 shows the Model 7999-5 connector with Table 2-1 contain­ing the pinouts for the connector.

If your computer uses a DB-25 connector for the RS-232 interface, an additional cable or
adapter (DB-25 to DB-9) is required.

NOTE In the RS-232 interface, only pins 2, 3, and 5 are used. Pins 7 and 8 are tied together ,

Table 2-1

RS-232 connector terminals

but not connected to the circuit board. Pins 1, 4, and 6 are also tied together and not
connected to the circuit board.

Pin number Description

1
2
3
4
5
6
7
8
9

Figure 2-2

RS-232 interface connector

Tied to pins 4 and 6
TXD, Transmit data
RXD, Receive data
Tied to pins 1 and 6
GND, Signal ground
Tied to pins 1 and 4
Tied to pin 8
Tied to pin 7
Not used

RS232

5 4 3 2 1

9 8 7 6

Power connector

Connect the supplied power adapter (Model PS-57A) to the power connector.

CAUTION To prevent damage to the Model 7999-5, use only the Keithley Model PS-

57A AC/DC power adapter. This is a universal input (100V-240VAC,
50/60Hz), 12VDC output (3A or less) supply.

Quick disconnect connections

CAUTION Each relay control line is capable of sinking up to a maximum of 300mA

with the maximum relay power voltage of 28VDC.

Two 10-position quick disconnect terminal blocks provide for relay control connections.
The upper connector is for relay control outputs 1–8, while the lower connector is for relay
control outputs 9–16. The relay common of both the upper and lower connector are connected
to chassis ground while the power connections for each connector are separate. The control
outputs are protected by coil suppression diodes (suppresses voltage spikes when relay coil is
de-energized). Refer to Table 2-2, Table 2-3, and Figure 2-3 for connector pinouts.

Connections 2-5

Table 2-2

Upper relay connector pinouts

Pin number Description

1
2
3
4
5
6
7
8
9

10

Relay power connection
Relay control output 1
Relay control output 2
Relay control output 3
Relay control output 4
Relay control output 5
Relay control output 6
Relay control output 7
Relay control output 8
Chassis ground connection

2-6 Connections

Table 2-3

Lower relay connector pinouts

Pin number Description

Figure 2-3

Relay control
connector pinouts

10

1
2
3
4
5
6
7
8
9

Relay power connection
Relay control output 16
Relay control output 15
Relay control output 14
Relay control output 13
Relay control output 12
Relay control output 11
Relay control output 10
Relay control output 9
Chassis ground connection

Relay

Control

87654321

Relay

Common

9 10111213141516

Relay

Control

Relay

Power

3

Operation

3-2 Operation

Introduction

This section contains operating information for the Model 7999-5. The information is orga-

nized as follows:

• Maximum voltage and current considerations

• Operation (RS-232)

Maximum voltage and current considerations

WARNING

CAUTION

Maximum voltage between any conductor and ground is 42V.

T o prevent damage to the Model 7999-5, do not exceed the following maxi­mum specifications:

•

•

Operation (RS-232)

Sending and receiving data

The Model 7999-5 relay controller is RS-232 controlled. Before the relays can be con­trolled, connect an appropriate and properly configured controller to the DB-9 port. The Model
7999-5 serial interface (RS-232) transfers data using eight data bits, no parity, and one stop bit
(8-N-1). The interface also transfers data at 9600 baud. Make sure that the controller selected
also uses these settings.

The relay controller can provide one of four different termination characters to the RS-232
controller (see “Termination characters”). The relay controller can receive any valid termina­tion character sent by the RS-232 controller (line feed and/or carriage return).

T ermination characters

Maximum relay coil voltage: 28VDC
Maximum current: 300mA maximum sink current per relay

The Model 7999-5 can be configured to terminate each program message transmitted to the
controller with any of the following combinations of <CR> or <LF>:

<CR> Carriage return (factory default setting)

<CR+LF> Carriage return and line feed

<LF> Line feed

<LF+CR> Line feed and carriage return

Operation 3-3

To configure the termination character, change the jumpers for PA6 (J1006) and PA7
(J1008) located on the Model 7999-5 printed circuit board. Refer to Figure 3-1 and Table 3-1
for jumper details. Refer to the first three steps of disassembly information in Section 4 to
access the circuit board.

Figure 3-1

Jumper location

NOTE

Changing the jumper settings sets the termination characters sent by the Model
7999-5 to the RS-232 controller. Any valid termination character sent by the RS-232
controller can be received by the Model 7999-5 (line feed and/or carriage
return).The send and receive termination characters do not have to match.

1

1

Table 3-1

Jumper positions—termination characters

Terminator J1006 pins J1008 pins

1

<CR>
<CR+LF>
<LF>
<LF+CR>

1

Factory default setting

1 and 2
2 and 3
1 and 2
2 and 3

1

1 and 2
1 and 2
2 and 3
2 and 3

1

3-4 Operation

RS-232 command set

NOTE

Table 3-2

Command set

ASCII Command Parameter Type Description

A or a None Opens all relays. After all relays are opened and the delay occurs

C or c <list> Closes specified relay(s). After this command is sent and a termina-

D or d <delay> Sets the variable relay settling time (delay) in milliseconds (msec).

ACSII characters not included in the command set are ignored.

Refer to Table 3-2 for list of commands included in the command set.

(the delay is relay settling time—see ASCII Command “D”), an
ASCII “1” is sent over the RS-232 bus indicating the settling time
has expired. Response must be “on” to send the “1” (see ASCII
command R).

tion character is received from the RS-232 controller, the relay(s)
close(s) and a delay occurs (the delay is relay settling time—see
ASCII Command “D”). After the relay settling time expires, an
ASCII “1” is sent over the RS-232 indicating settling time has
expired. Response must be “on” to send the “1” (see ASCII com­mand R).

This is the delay occurring after a command is issued that allows the
relays to change state. Commands that use this delay are the A, C,
and O commands. The default for this command is 15msec. Send­ing this command without a parameter queries the delay time.

I or i None Returns firmware information. This command retrieves firmware

information over the RS-232. After the command is sent, “Keithle y
Instruments Inc., Model 7999-5, rev A01” (or similar, due to firm­ware revision level) will be returned over the RS-232.

O or o <list> Opens specified relay. After the open command is sent and the ter-

mination character is received from the RS-232 controller, the
relay(s) open(s) and a delay occurs (the delay is relay settling
time—see ASCII Command “D”). After the relay settles, an ASCII
“1” is sent over the RS-232 indicating settling time has expired.
Response must be “on” to send the “1” (see ASCII command R).

<list> Comma separated relay list with values from 1–16
<delay> 1–250ms
<b> <0, 1> where 0 = OFF and 1 = ON

Operation 3-5

Table 3-2 (Continued)

Command set

ASCII Command Parameter Type Description

Q or q 1–16 Queries for a single relay setting. The parameter specifies the relay.

If the queried relay is open, an ASCII 0 will be returned. If the que­ried relay is closed, an ASCII 1 will be returned. If an invalid relay
number is sent, or inv alid parameter received (including no parame­ter), then an ASCII “?” is returned.

R or r <b> Response after delay (the delay is relay settling time—see ASCII

Command “D”). This response occurs when using the A, C, and O
commands. The default for this command is 1 (on). Sending this
command without parameters queries the response state (if a 1 is
returned, the response is on, if a 0 is returned, the response is off).

S or s None Queries all closed relays. Upon receiving this command, a comma

separated list in ASCII will be returned indicating the closed relays.
If no relays are closed, a comma will be returned.

<list> Comma separated relay list with values from 1–16
<delay> 1–250ms
<b> <0, 1> where 0 = OFF and 1 = ON

Command interpretation

The Model 7999-5 requires each command to end with a termination character.

On a single line, the first valid ASCII character is interpreted as the command. The remain­ing characters are interpreted as the parameter data. This parameter data processing continues
up to the termination character. When the termination character is received, the command is
performed. Therefore, end each command with a termination character (line feed and/or car­riage return) before sending a new command.

While processing the parameter data, if an ASCII character is invalid, it is ignored. Finding
an invalid character does not abort the parameter data from being processed.

Leading zeros contained in the parameter list for the C, O, and Q commands are ignored.
The parameter processing starts with the first non-zero digit and continues one additional digit.
Commas separate each individual parameter until a termination character. Leading zeros con­tained in the parameter data are also ignored for the D command. The parameter processing
starts with the first non-zero digit but continues two additional digits. Values interpreted as
greater than 250 are set to 250. The D command issued without parameters (or with a “0”,
which is ignored) issues a query.

Refer to Table 3-3 for command interpretation samples.

3-6 Operation

NOTE

In the following samples (Table 3-3), <term> represents a valid termination charac­ter (line feed and/or carriage return).

The sample commands shown (the “ASCII characters sent,” e.g., C1,02 <term>,
etc.,) assume they are the first command sent or the first command sent after a valid
termination character.

Termination characters issued by the Model 7999-5 do not have to match the termi­nation characters issued by the RS-232 control computer. Any valid termination
character can be received by the Model 7999-5 (line feed and/or carriage return).

Table 3-3

Sample command interpretation

ASCII characters sent Response

C1,O2 <term>

Relays 1 and 2 are closed. The O(pen) is ignored because, even though it is a
valid command (after a termination character), it is an in v alid parameter for the
C(losed) command. 1 and 2 are interpreted for the parameter list.

O1, C2, Q4 <term>

Relay 1, 2, and 4 are opened. The C(losed) and Q(uery) are ignored because
they are invalid parameters to the O(pen) command, while 1, 2, and 4 are inter­preted for the parameter list.

Q1;Q4 <term>

Relay 14 is queried. The 2nd Q(uery) command along with the “;” are ignored
because they are inv alid parameters to the Q(uery) command, while the 1 and 4
are interpreted as a 14 for the parameter.

O2, 3,

Relays 2 and 3 are opened when a termination character is received (a termina­tion character in addition to the ASCII characters shown at the left has to be
sent for the command to be performed). Since no termination character has
been sent, parameters can still be added to the list.

C1O2 <term>

Relay 12 is closed. The O(pen) command is ignored because it is an invalid
parameter to the C(losed) command.

Q1,6 <term>

Relay 16 is queried. The comma is ignored because it is an in v alid character for
the Q(uery) command (the command does not accept a parameter list).

D008 <term>
D0325 <term>

Delay is set to 8msec. If queried, a response of 008 is returned.
Delay is set to 250msec (maximum value). If queried, a response of 250 is

returned.

T ypical connection scheme

WARNING Relay contacts switching > 42 Vpk must be double insulated from relay

Figure 3-2 is a simplified schematic of a typical connection scheme. Although relay power
for each connector (upper and lower) can be provided from separate sources, both connectors
share a common chassis ground.

Figure 3-2

Typical connection scheme

Model 7999-5

coils.

Relay Power
(Upper Connector)

Relay power
(Lower Connector)

1

Relay Coils

Operation 3-7

+

≤ 28VDC

Relay Control

Relay Common
(Upper Connector)

Relay Common
(Lower Connector)

2–15

16

3-8 Operation

4

Service Information

4-2 Service Information

Introduction

This section contains service information for the Model 7999-5. The information is orga-

nized as follows:

• Handling and cleaning precautions

• Performance verification

• Component replacement

WARNING The information in this section is intended only for qualified service per-

sonnel. Some of the procedures may expose you to hazardous voltages that
could result in personal injury or death. Do not perform these procedures
unless you are qualified to do so.

Handling and cleaning precautions

Care should be taken when handling or servicing the relay controller to prevent possible
contamination. The following precautions should be observed when servicing the relay
controller.

Handling precautions

Observe the following precautions when handling the relay controller:

• Handle the relay controller only by the edges and cover.

• Do not touch any board surfaces or components not associated with the repair.

• Do not store or operate the relay controller in an environment where dust could settle on
the circuit board.

Card and connector cleaning

• Use dry nitrogen gas to clean any dust off the circuit board and components.

• Clean the contaminated area with methanol, then blow dry the entire board with dry
nitrogen gas.

• Before use, allow items cleaned to dry for several hours in a 50˚C low-humidity envi­ronment. Use dry nitrogen to decrease drying time.

Replacing components

Replacement parts

Replacement parts can be obtained directly from Keithley Instruments, Inc. See the parts list

in Section 5 for part numbers.

Replacement precautions

CAUTION Observe the following precautions when replacing components:

• To avoid contamination, which could degrade relay controller perfor-

mance, always handle the relay controller only by the covers and side
edges. Do not touch the connector, board surfaces, or components on
the relay controller.

• Use care when working with components from the PC board to avoid
pulling traces away from the circuit board.

Soldering considerations

Service Information 4-3

When using solder on the circuit board, observe the following precautions:

• Use an OA-based (organic activated) flux, and take care not to spread the flux to other

• Remove the flux from the work areas when the repair has been completed. Use pure

• Once the flux has been removed, swab only the repaired area with methanol, then blow

• After cleaning, allow the card to dry in a 50˚C low-humidity environment for several

Disassembly

Perform the following steps to disassemble the Model 7999-5 to gain access to parts on the

circuit board:

1. Remove the six screws that hold the case together and any hex-nuts on the connectors.

2. Separate the two halves of the case.

3. Unplug the connectors from the board (J1004 and J1002).

4. Remove the screws that secure the PC board to the case, then remove the board.

areas of the circuit board.

water along with clean cotton swabs or a clean soft brush to remove the flux.

dry the board with dry nitrogen gas.

hours before use.

4-4 Service Information

Performance verification

The following paragraphs discuss performance verification procedures for the Model 7999-5

and include an output saturation voltage verification procedure.

CAUTION Contamination will degrade the performance of the relay controller. To

avoid contamination, always grasp the relay controller by the cover; do not
touch the connectors.

NOTE Failure of any performance verification test may indicate that the multiplexer relay

controller is contaminated. See “Handling and cleaning precautions” earlier in this
section for information on cleaning the relay controller.

Environmental conditions

All verification measurements should be made at an ambient temperature between 18˚ and

28˚C, and at a relative humidity of less than 70%.

Recommended equipment

Table 4-1 summarizes the equipment necessary for performance verification (channel resis-

tance tests).

Table 4-1

Recommended verification equipment

Manufacturer/Model Equipment Description Specifications

Keithley 2010
Keithley 1681
No recommendations

Digital Multimeter
Test Lead Set
28VDC power supply

DCV
Banana plug/clips
Nominal 28V
@ 300mA (minimum)

Output saturation voltage verification procedure

Perform the following steps to verify that the relay control lines output saturation voltage is

within specification.

WARNING Use care around the resistor used in this test—the resistor will heat. Make

sure to take adequate precautions to avoid burns when disconnecting and
connecting the resistor.

1. Turn on the Model 2010 DMM, and allow it to warm up for one hour before making
measurements.

2. Connect a 100Ω, 10W resistor between the relay control line under test (start with line 1
and work through line 16) and the 28VDC power supply (see Figure 4-1).

3. Set the Model 2010 DMM for voltage (DCV) and connect the two test leads to the
INPUT HI and LO terminals.

4. Connect the Model 2010 DMM test leads as shown in Figure 4-1. Connection is made
to relay control line under test and relay common.

5. Turn on the relay control line under test’s output (see Section 3 for operation
information).

6. Measure voltage. Using the setup described in this procedure, the voltage measurement
will be made at the relay control line. Acceptable saturation voltage should be
≤ 0.18VDC.

7. Repeat the procedure for the other relay control lines (2–16).

Service Information 4-5

Figure 4-1

Output saturation
voltage test connections

POWER

Model 7999-5 Relay
Controller. See Section 2
for detailed connections.

CH1REM

SCAN

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

TALK

LSTN

SRQ
SHIFT
TIMER

MX+B

SHIFT

DCV

LOCAL

EX TRIG

HOLD TRIG FAST MED SLOW AUTO ERR

dBm

%

dB

ACI

ACV

DCI

HOLD

LIMITS ON/OFFDELAY

TRIG

STORE

RECALL

SAVE SETUP

CONFIG HALT

OPEN CLOSE

STEP SCAN

REL FILT

CONT

Ω2Ω

TYPE

RS232

GPIB

DIGITS RATE

Model 2010 DMM

Relay Common

MATH
REAR

4W

BUFFER

STAT

2010 MULTIMETER

PERIOD SENSOR

FREQ

TEMP

4

RATIO

DRYCKT O COMP

RELFILTER

CAL TEST

EXIT ENTER

Relay Power

16

SENSE

INPUT

Ω 4 WIRE

HI

350V

1000V

!

PEAK

PEAK

LO

500V
PEAK

INPUTS

F

R

RANGE

AUTO

FRONT/REAR

3A 250V

RANGE

AMPS

1

100Ω 10W

+

28VDC

(+)

( - )

4-6 Service Information

5

Replaceable Parts

5-2 Replaceable Parts

Introduction

This section contains replacement parts information and also a component layout for the

Model 7999-5.

Parts list

Parts lists for the Model 7999-5 are contained in Table 5-1 and Table 5-2.

Ordering information

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

• Model number (Model 7999-5)

• Serial number

• Part description

• Component designation (if applicable)

• Keithley part number

Factory service

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

• Call the Repair Department at 1-888-KEITHLEY for a Return Material Authorization
(RMA) number.

• Complete the service form at the back of this manual, and include it with the
instrument.

• Carefully pack the instrument in the original packing carton.

• Write ATTENTION REPAIR DEPARTMENT and the RMA number on the shipping
label.

Component layout

Component layout drawing (7999-5-100) is provided following parts list tables.

Replaceable Parts 5-3

Table 5-1

Parts list—electronic components

Circuit designation Description Keithley part number

C101, C102, C103, C104,

CAP, 0.1UF, 20%, 50V, CERAMIC C-418-.1

C106
C105,C114 CAP, 33PF, 10%, 100V, CERAMIC C-451-33P
C107, C108, C115, C116,

CAP, 0.1UF, 10%, 25V, CERAMIC C-495-.1

C117, C118, C119
C109, C111 CAP, 22UF, 20%, 25V, TANTALUM C-440-22
C112, C113 CAP, 10UF, 20%, 25V, TANTALUM C-440-10
CR102, CR103 DIODE, DUAL SWITCHING RF-82
DS101 PILOT LIGHT, GREEN, LED PL-78
J1002, J1004 LATCHING HEADER, FRICTION, SINGLE ROW CS-724-10
J1006, J1008, J1009 CONN, BERG CS-339
J1006, J1008, J1009 CONNECTOR, JUMPER CS-476
J1010 CONN, HORIZ, RECEPTACLE, 3-PIN CS-943-3
J1011 CONN, RT ANGLE, MALE, 9-PIN CS-761-9
R101, R102, R105, R106 RES, 150K, 1%, 100mW, THICK FILM R-418-150K
R103, R107-R110,

RES, 10K, 1%, 100mW, THICK FILM R-418-10K

R115-R118
R104 RES, 4.02K, 1%, 100mW, THICK FILM R-418-4.02K
R111, R112, R114 RES, 4.75K, 1%, 100mW, THICK FILM R-418-4.75K
R113 RES, 10M, 5%, 125mW, METAL FILM R-375-10M
RV101-109, RV111-119 TRANSIENT VOLTAGE SUPRESSOR VR-12
RV 120 TRANSIENT VOLTAGE SUPRESSOR VR-11
RV 121 300M TRANSIENT VOLTAGE SUPRESSOR

VR-13

ARRAY
SO101 SOCKET SO-143-44
TP101, TP102, TP103,

SURFACE MOUNT PCB TEST POINT CS-1026
TP104, TP105, TP106

U101, U102, U103, U104 IC, QUAD LOW SIDE DRIVER IC-1351
U105 IC, 8-BIT MICRO PROCESSOR 7999-5-800A01
U106 IC, +5V, REGULATOR, 500MA IC-93
U107 IC, UNDERVOLTAGE SENSE CIRCUIT IC-1067
U108 IC, RS-232 LINE DRIVER/RECEIVER IC-1129
VR101 DIODE, ZENER, 6.2V DZ-97
Y101 CRYSTAL, 4MHZ CR-36-4M

5-4 Replaceable Parts

Table 5-2

Parts list—mechanical parts

Description Keithley part number

Bumper
Cover (bottom)
Cover (top)
Female screw-lock
Lock-nut
Phillips Pan Head Screw
Phillips Pan Head Screw
Phillips Pan Head Screw SEMS (black)

FE-27A
7999-4-301-2A
7999-5-302A
CS-725
4-40KEPNUT
4-40X1/4PPH
4-40X3/8PPH
4-40X3/8PPHSEMBLK

Index

C

Card cleaning 4-2
Carriage return 3-2
Carriage return and line feed 3-2
Command interpretation 3-5
Component layout 5-2
Configuration 2-3
configure termination character 3-3
connections 1-4

introduction 2-2
Quick disconnect connections 2-5
RS-232 2-4

D

Disassembly 4-3

M

Manual addenda 1-2

Maximum voltage and current

considerations 3-2

O

Operation

Introduction 3-2
RS-232 3-2

Ordering information 5-2

Output saturation voltage verification

procedure 4-5

overview 1-2

P

Parts list 5-2
Performance verification 4-3, 4-4
Power connector 2-5

E

Environmental conditions 4-4

F

Factory service 5-2
Feature overview 1-2
flux 4-3

G

general information 1-2

H

Handling 4-2
Handling precautions 1-3, 2-2, 4-2

I

Inspection for damage 1-3
Instruction manual 1-4

J

J1006 3-3
J1008 3-3
Jumper location 3-3

L

Layout 2-3
Line feed 3-2

Line feed and carriage return

3-2

Q

Quick disconnect connections 2-5

R

Recommended equipment 4-4
Relay connector terminals 2-5, 2-6
Repacking 1-4
Repair Department Phone Number 5-2
Replacement parts 4-3
Replacement precautions 4-3
Replacing components 4-3
RS-232 Command set 3-4
RS-232 connector terminals 2-4

S

Safety Precautions

Safety symbols and terms 1-3
Sending and receiving data 3-2
Shipment contents 1-4

Soldering considerations

symbols and terms 1-3

4-3

T

Termination characters 3-2

U

Unpacking and inspection 1-3

W

Warranty 1-2

Service Form

Model No. _______________ Serial No. __________________ Date _________________
Name and Telephone No. ____________________________________________________
Company _______________________________________________________________________

List all control settings, describe problem and check boxes that apply to problem. _________________________

__________________________________________________________________________________________
__________________________________________________________________________________________

❑ Intermittent ❑ Analog output follows display ❑ Particular range or function bad; specify

_______________________________

❑ IEEE failure ❑ Obvious problem on power-up ❑ Batteries and fuses are OK
❑ Front panel operational ❑ All ranges or functions are bad ❑ Checked all cables

Display or output (check one)

❑ Drifts ❑ Unable to zero ❑ Unstable
❑ Overload ❑ Will not read applied input

❑ Calibration only ❑ Certificate of calibration required ❑ Data required

(attach any additional sheets as necessary)
Show a block diagram of your measurement including all instruments connected (whether power is turned on or

not). Also, describe signal source.

Where is the measurement being performed? (factory, controlled laboratory, out-of-doors, etc.)_______________

__________________________________________________________________________________________

What power line voltage is used?___________________ Ambient temperature?________________________ °F
Relative humidity? ___________________________________________Other? __________________________
Any additional information. (If special modifications have been made by the user, please describe.)

__________________________________________________________________________________________
__________________________________________________________________________________________

Be sure to include your name and phone number on this service form.

Keithley Instruments, Inc.

28775 Aurora Road
Cleveland, Ohio 44139

Printed in the U.S.A.