Racal Instruments 1256E User manual

SWITCHING SYSTEM
MODEL 1256E
PUBLICATION NO. 980873
RACAL INSTRUMENTS
United States
(Corporate Headquarters and Service Center)
4 Goodyear Street, Irvine, CA 92618
Tel: [phone]; Fax: [phone]
5730 Northwest Parkway Suite 700, San Antonio, TX 78249
Tel: [phone]; Fax: [phone]
Europe
(European Headquarters and Service Center)
18 Avenue Dutartre, 78150 LeChesnay, France
Tel: [phone]; Fax: [phone]
29-31 Cobham Road, Wimborne, Dorset BH21 7PF, United Kingdom
Tel: [phone]; Fax: [phone]
Via Milazzo 25, 20092 Cinisello B, Milan, Italy
Tel: [phone]; Fax: [phone]
Racal Instruments Group Limited, Technologie Park, D-51429 Bergisch Gladbach, Germany
Tel: [phone]; Fax: [phone]
[email protected]
[email protected]
[email protected]
http://www.racalinstruments.com
[email protected]
www.racalinstruments.de
PUBLICATION DATE: July 18, 2005
Copyright 2002 by Racal Instruments, Inc. Printed in the United States of America. All rights reserved.
This book or parts thereof may not be reproduced in any form without written permission of the publisher.

THANK YOU FOR PURCHASING THIS RACAL INSTRUMENTS PRODUCT.
For this product, or any other Racal Instruments product that incorporates software drivers, you may access
our web site to verify and/or download the latest driver versions. The web address for driver downloads is:
http://www.racalinstruments.com/downloads
If you have any questions about software driver downloads or our privacy policy, please contact us at
[email protected]
WARRANTY STATEMENT
All Racal Instruments, Inc. products are designed and manufactured to exacting standards and in full
conformance to Racal’s ISO 9001:2000 processes.
This warranty does not apply to defects resulting from any modification(s) of any product or part without Racal
Instruments express written consent, or misuse of any product or part. The warranty also does not apply to
fuses, software, non-rechargeable batteries, damage from battery leakage, or problems arising from normal
wear, such as mechanical relay life, 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.
For the specific terms of your standard warranty, or optional extended warranty or service agreement, contact
your Racal customer service advisor. Please have the following information available to facilitate service.
1. Product serial number
2. Product model number
3. Your company and contact information
You may contact your customer service advisor by:
E-Mail: [email protected]
Telephone: [phone] (USA)
[phone] (UK)
Fax: [phone] (USA)
[phone] (UK)

RETURN of PRODUCT
Authorization is required from Racal Instruments before you send us your product for service or calibration.
Call your nearest Racal Instruments support facility. A list is located on the last page of this manual. If you are
unsure where to call, contact Racal Instruments, Inc. Customer Support Department in Irvine, California, USA
at 1-800-722-3262 or 1-949-859-8999 or via fax at 1-949-859-7139. We can be reached at:
[email protected].
PROPRIETARY NOTICE
This document and the technical data herein disclosed, are proprietary to Racal Instruments, and shall not,
without express written permission of Racal Instruments, be used, in whole or in part to solicit quotations from
a competitive source or used for manufacture by anyone other than Racal Instruments. The information
herein has been developed at private expense, and may only be used for operation and maintenance
reference purposes or for purposes of engineering evaluation and incorporation into technical specifications
and other documents which specify procurement of products from Racal Instruments.
DISCLAIMER
Buyer acknowledges and agrees that it is responsible for the operation of the goods purchased and should
ensure that they are used properly and in accordance with this handbook and any other instructions provided
by Seller. Racal Instruments products are not specifically designed, manufactured or intended to be used as
parts, assemblies or components in planning, construction, maintenance or operation of a nuclear facility, or
in life support or safety critical applications in which the failure of the Racal Instruments product could create
a situation where personal injury or death could occur. Should Buyer purchase Racal Instruments product for
such unintended application, Buyer shall indemnify and hold Racal Instruments, its officers, employees,
subsidiaries, affiliates and distributors harmless against all claims arising out of a claim for personal injury or
death associated with such unintended use.

FOR YOUR SAFETY
Before undertaking any troubleshooting, maintenance or exploratory procedure, read carefully the
WARNINGS and CAUTION notices.
This equipment contains voltage hazardous to human life and
safety, and is capable of inflicting personal injury.
If this instrument is to be powered from the AC line (mains) through an
autotransformer, ensure the common connector is connected to the neutral (earth
pole) of the power supply.
Before operating the unit, ensure the conductor (green wire) is connected to the
ground (earth) conductor of the power outlet. Do not use a two-conductor extension
cord or a three-prong/two-prong adapter. This will defeat the protective feature of the
third conductor in the power cord.
Maintenance and calibration procedures sometimes call for operation of the unit with
power applied and protective covers removed. Read the procedures and heed
warnings to avoid “live” circuit points.
Before operating this instrument:
1. Ensure the proper fuse is in place for the power source to operate.
2. Ensure all other devices connected to or in proximity to this instrument are properly grounded or
connected to the protective third-wire earth ground.
If the instrument:
- fails to operate satisfactorily
- shows visible damage
- has been stored under unfavorable conditions
- has sustained stress
Do not operate until, performance is checked by qualified personnel.

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1256E User Manual
i
Table of Contents
Chapter 1..............................................................................................................................1-1
INTRODUCTION ............................................................................................................................1-1
Overview ......................................................................................................................................1-1
Features....................................................................................................................................1-2
Ease Of Use..........................................................................................................................1-2
Front and Rear Panels..........................................................................................................1-2
Powerful Software.................................................................................................................1-4
Items Shipped with the 1256........................................................................................................1-5
Chapter 2..............................................................................................................................2-1
Getting Started................................................................................................................................2-1
Mounting Options.........................................................................................................................2-1
Main AC Power ............................................................................................................................2-1
Installing Plug-Ins.........................................................................................................................2-3
Numbering of Plug-In Slots.......................................................................................................2-3
Connecting to Plug-Ins .............................................................................................................2-4
Activating Main AC Power............................................................................................................2-4
Self-Test.......................................................................................................................................2-5
Verifying the Installed Plug-Ins.................................................................................................2-5
Closing a Relay.........................................................................................................................2-6
Opening a Relay.......................................................................................................................2-7
In Case of Trouble....................................................................................................................2-8
Switching and Heat Dissipation................................................................................................2-8
Chapter 3..............................................................................................................................3-1
Using the Front-Panel Controls ......................................................................................................3-1
Introduction...................................................................................................................................3-1
Front Panel...................................................................................................................................3-2
Understanding the Hierarchical Menu..........................................................................................3-2

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ii
The Five Menus........................................................................................................................3-7
Operations Menu...................................................................................................................3-8
Path Control Menu..............................................................................................................3-14
Settings Menu.....................................................................................................................3-18
Store/Recall Menu...............................................................................................................3-26
System Menu......................................................................................................................3-29
Complete Menu Listing...........................................................................................................3-30
Chapter 4..............................................................................................................................4-1
COMPUTER INTERFACES ...........................................................................................................4-1
Introduction ..................................................................................................................................4-1
Commands...................................................................................................................................4-1
Using the Ethernet Interface.....................................................................................................4-2
Basic Ethernet Information....................................................................................................4-2
Ethernet Cabling Guidelines .................................................................................................4-2
Connecting the Ethernet Cables...........................................................................................4-3
Selecting the Ethernet Interface............................................................................................4-3
Entering the Ethernet Communication Settings....................................................................4-5
Using the IEEE-488 (GPIB) Interface.....................................................................................4-10
Basic GPIB Information.......................................................................................................4-10
GPIB Cabling Guidelines ....................................................................................................4-11
Connecting the GPIB Cables..............................................................................................4-11
Selecting the GPIB Interface...............................................................................................4-12
Setting the GPIB Address...................................................................................................4-13
Service Request (SRQ).......................................................................................................4-14
Using the RS-232 Interface ....................................................................................................4-14
Basic RS-232 Information...................................................................................................4-14
Equipment Required ...........................................................................................................4-15
Connecting to a Computer or Data Terminal ......................................................................4-15
Connecting to a Modem......................................................................................................4-16
Selecting the RS-232 Interface...........................................................................................4-18
Setting the Flow Control Option..........................................................................................4-19
Setting the Baud Rate.........................................................................................................4-21
Setting the Message Termination Characters.....................................................................4-22
Setting the Data Bits, Stop Bits, and Parity.........................................................................4-23

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iii
Using Microsoft HyperTerminal...........................................................................................4-25
Chapter 5..............................................................................................................................5-1
SCPI COMMAND BASICS .............................................................................................................5-1
SCPI Command Overview............................................................................................................5-1
Input Format .............................................................................................................................5-1
Command Keyword Long Form and Short Form......................................................................5-3
Case Sensitivity.....................................................................................................................5-3
Optional Keywords................................................................................................................5-4
Querying Parameter Setting..................................................................................................5-4
SCPI Command Terminator..................................................................................................5-4
IEEE-STD-488.2 Common Commands.................................................................................5-5
IEEE 488.2 Common Commands.........................................................................................5-6
IEEE-488.2 Status Description..............................................................................................5-7
Standard EVENT STATUS Register.....................................................................................5-9
STATUS BYTE Register .......................................................................................................5-9
SERVICE Register ENABLE Register.................................................................................5-11
*CLS Command...............................................................................................................5-13
*ESE Command ..............................................................................................................5-14
*ESE? Query...................................................................................................................5-15
*ESR? Query...................................................................................................................5-15
*SRE Command ..............................................................................................................5-15
*SRE? Query...................................................................................................................5-15
*STB? Query ...................................................................................................................5-16
*OPC Command..............................................................................................................5-16
*OPC? Query...................................................................................................................5-16
*IDN? Query....................................................................................................................5-17
*RST Command ..............................................................................................................5-17
*TST? Query....................................................................................................................5-19
*RCL Command ..............................................................................................................5-19
*SAV Command ..............................................................................................................5-19
*SPE Command ..............................................................................................................5-20
*TRG Command..............................................................................................................5-21
*WAI Command...............................................................................................................5-21
SCPI Status Registers ........................................................................................................5-21

1256E User Manual
iv
SCPI Parameter Type.........................................................................................................5-23
Numeric Parameters........................................................................................................5-24
Discrete Parameters........................................................................................................5-24
Boolean Parameters........................................................................................................5-25
Command Input Buffer........................................................................................................5-25
Reply Output Buffer.............................................................................................................5-27
Specifying Channels in Commands........................................................................................5-29
Naming Relay Cards...............................................................................................................5-30
Defining Module Names......................................................................................................5-30
Removing Module Names...................................................................................................5-32
Reading the Presently Defined Module Names..................................................................5-32
Reading the Module Address for a Module Name..............................................................5-33
Storing the Module Names in Non-Volatile Memory...........................................................5-33
Naming a Path ....................................................................................................................5-34
Defining Path Names.......................................................................................................5-34
Removing Path Names....................................................................................................5-36
Reading the Presently Defined Path Names...................................................................5-36
Reading the Channel List for a Path Name.....................................................................5-37
Storing Path Names in Non-Volatile Memory..................................................................5-37
Closing Relays....................................................................................................................5-38
Opening Relays...................................................................................................................5-39
Checking for Installed Plug-Ins...............................................................................................5-40
System Commands ................................................................................................................5-41
Reading Error Messages ....................................................................................................5-41
SCPI Compliance Information.............................................................................................5-42
User-Interface Lockout........................................................................................................5-42
Non-Volatile Update............................................................................................................5-43
Chapter 6............................................................................................................................5-44
SCPI Command REFERENCE.......................................................................................................6-1
General ........................................................................................................................................6-1
Chapter 7..............................................................................................................................7-1
Digital Module operation.................................................................................................................7-1

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v
General.........................................................................................................................................7-1
Digital Module Ports..................................................................................................................7-1
Asynchronous Digital Operation............................................................................................7-1
Synchronous Digital Operation .............................................................................................7-2
Mixing Synchronous and Asynchronous Modes of Operation ..............................................7-2
Specifying Ports on a Digital Module ....................................................................................7-3
Selecting the Mode of Operation...........................................................................................7-4
Enabling and Disabling the Ports..........................................................................................7-5
Using the Asynchronous Mode of Operation ........................................................................7-5
Using the Synchronous Mode of Operation..........................................................................7-7
Setting Up the Synchronous Test .........................................................................................7-9
Arming the Digital Modules.................................................................................................7-13
Checking for Data Transfer Completion..............................................................................7-14
Reading Data from a Synchronous Input Port ....................................................................7-15
Clearing Data from Synchronous Input and Output Ports...................................................7-16
Synchronous Control and Status Pins ................................................................................7-16
Synchronous and Asynchronous Example .........................................................................7-17
Chapter 8..............................................................................................................................8-1
Advanced SCPI operations.............................................................................................................8-1
Introduction...................................................................................................................................8-1
Using ROUTE: CONFIGURE to Control Switching Sequence .................................................8-1
Include Lists..............................................................................................................................8-2
Using Exclude Lists ..................................................................................................................8-5
Using External Triggering.........................................................................................................8-7
Selecting the Trigger Source.................................................................................................8-7
Selecting the Trigger Count ..................................................................................................8-9
Selecting a Trigger Delay......................................................................................................8-9
Arming and Disarming the 1256..........................................................................................8-10
Generating a Single Trigger ............................................................................................8-11
Output Trigger Signals from the 1256 .............................................................................8-12
Selecting an Output Trigger Destination..........................................................................8-12
Using Scan Lists and External Trigger Input ..........................................................................8-13
Scan Lists...............................................................................................................................8-13
Defining a Scan List............................................................................................................8-16

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vi
Advance Verification Features................................................................................................8-18
Confidence Mode................................................................................................................8-18
Using Relay Verification......................................................................................................8-19
Saving/Recalling the Verification Masks.............................................................................8-21
Automatically Recalling Verification Masks at Startup........................................................8-21
Chapter 9..............................................................................................................................9-1
Product Support ...........................................................................................................................9-1
Reshipment Instructions...............................................................................................................9-1
Support Offices ............................................................................................................................9-2
INDEX................................................................................................................................................1
Appendix A: SPECIFICATIONS……………..…………………………………………………..………A-1
Appendix B: RACK MOUNTING…………………………………………………………….…………..B-1
Appendix C: TROUBLESHOOTING…………………………………………………………………....C-1

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vii
List of Figures
Figure 1-1, 1256 Switching System.................................................................................................1-1
Figure 1-2, 1256 Features, Front Panel...........................................................................................1-2
Figure 1-3, 1256 Features, Rear Panel ...........................................................................................1-3
Figure 1-4, Dimensions....................................................................................................................1-3
Figure 2-1, Changing Fuse for Main AC Power...............................................................................2-1
Figure 2-2, Inserting a Plug-In .........................................................................................................2-3
Figure 2-3, Numbering of Switch Plug-In Slots................................................................................2-4
Figure 2-4, Activating Main AC Power.............................................................................................2-4
Figure 3-1, Front-Panel Controls .....................................................................................................3-2
Figure 4-1, Connecting the Ethernet Interface.................................................................................4-3
Figure 4-2, Connecting the GPIB Interface....................................................................................4-12
Figure 4-3, Using the RS-232 Interface.........................................................................................4-16
Figure 4-4a, Using the 1256 with a Computer...............................................................................4-17
Figure 4-4b, Using the 1256 with a Modem...................................................................................4-17
Figure 4-5, HyperTerminal Connection Dialog Box .......................................................................4-26
Figure 4-6, Phone Number Dialog Box..........................................................................................4-26
Figure 4-7, COM Properties Dialog Box ........................................................................................4-27
Figure 4-8, Main Communications Screen.....................................................................................4-28
Figure 4-9, Properties Dialog Box..................................................................................................4-29
Figure 4-10, Settings Dialog Box...................................................................................................4-29
Figure 4-11, ASCII Setup Dialog Box ............................................................................................4-30
Figure 5-1, IEEE-488.2 Status Reporting Model..............................................................................5-8
Figure 7-1 (A), Port 4 Data after DIG:SYNC:DATA (@7(4)),10,20,30,40......................................7-11
Figure 7-1 (B), Port 4 Data after DIG:SYNC:DATA (@7(4)),50,60,70,80,90.................................7-11
Figure 7-1 (C), Port 4 Data after DIG:SYNC:INDEX (@7(4)),3......................................................7-12
Figure 7-1 (D), Port 4 Data after DIG:SYNC:DATA (@7(4)),77,78................................................7-12
Figure 8-1, State Transition Diagram For Arming and Triggering the 1256...................................8-11
Figure 8-2, External Trigger In and External Trigger Out...............................................................8-13

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viii
List of Tables
Table 3-1, Accessibility of Features.................................................................................................3-1
Table 5-1, Power-On and Reset State...........................................................................................5-18
Table 6-1, Commands Implemented by the 1256............................................................................6-3
Table B-1, Installing the Rack-Mount Ears ..................................................................................... B-1
Table B-2, Rack Mounting ..............................................................................................................B-2

1256E User Manual
Racal Instruments ©2002 Introduction 1-1
Chapter 1
INTRODUCTION
Overview The 1256 Switching System is a high-performance switching and
control system in a compact 2U rack-mountable package. The
1256 can contain up to eight Adapt-a-Switch plug-ins for switching
and digital I/O. These plug-ins provide a wide range of switching
capability:
•High-current to 13A,
•High-voltage to 1kV,
•RF and microwave to 18GHz,
•Digital I/O with 96 channels per plug-in.
The user can easily insert these plug-ins into the 1256 Switching
System to meet the needs of nearly any switching application.
Figure 1-1 shows a picture of the 1256.
Figure 1-1, 1256 Switching System

1256E User Manual
Introduction 1-2 Racal Instruments ©2002
Features
Ease Of Use The 1256 Switching System has many design features to make it
easy and convenient to use:
•Fast Setup. There are no configuration jumpers or switches
to be set. The 1256 is ready to use as soon as the plug-ins
have been inserted.
•Flexible Controller Interface. The controller (host
computer) may communicate with the 1256 using Ethernet,
IEEE-488 (GPIB), or RS-232 interfaces. This allows an
external computer to automate the operation of the 1256.
•Front-Panel Controls. The front-panel controls provide an
intuitive user interface for manually controlling the plug-ins
and setting user preferences. The front-panel controls also
provide access to all interface parameters, such as Ethernet
IP address, GPIB address, and RS-232 baud rates. These
controls are often helpful during system setup.
•Command Set Commonality. The 1256 supports the
Standard Commands for Programmable Instruments (SCPI)
Language. This command set is used in other Racal
Instruments switching platforms such as 1260-Series VXI.
For an introduction to the SCPI command set and its usage,
see Chapter 5, SCPI COMMAND BASICS. For a complete
description of all SCPI commands for the 1256, see Chapter
6, SCPI COMMAND REFERENCE.
Front and Rear
Panels Figures 1-2 and 1-3 show the features of the front and rear panels,
respectively. Figure 1-4 gives the physical dimensions of the 1256
chassis.
Figure 1-2, 1256 Features, Front Panel
1256
SWITCHING SYSTEM
Display
Keypad and LEDs
Speaker
Knob

1256E User Manual
Racal Instruments ©2002 Introduction 1-3
Figure 1-3, 1256 Features, Rear Panel
Figure 1-4, Dimensions
2.3711.63
16.38
3.468
8.74
1.73
2.10 9.50
10.961.33
1.75
.53
2.3711.63
16.38
3.468
8.74
1.73
2.10 9.50
10.961.33
1.75
.53
.39
15.60
Plug-In Slots AC Input
Power Switch
Fuse Cover RS-232
Trigger In
Trigger Out
GPIB
Ethernet
Note
Earlier versions may not be equipped with Ethernet
capability, and may have different connector layout.

1256E User Manual
Introduction 1-4 Racal Instruments ©2002
Powerful Software The 1256 provides extensive software capabilities, including:
•Exclude Lists. Allows you to prevent simultaneous closure
of switches in a specified group. The switches are then
mutually exclusive.
•Equate Lists. Reduces programming effort. When two or
more modules are on an equate list, they respond
simultaneously to a command sent to any of them.
•External Trigger Input. Allows an external device to trigger
switching operations. The external device connects to the
External Trigger In connector.
•External Trigger Output. Provides a pulse on the External
Trigger Out connector to trigger an external device, such as
a DMM, after the relay states have changed.
•Scan Lists. Allows you to specify a sequence of relay
closures to step through in response to an external trigger
source. A scan list may include relays on one module or
multiple modules.
•Programmable Delay. Allows you to specify the amount of
time delay from a relay state change to an external trigger
pulse.
•Verification. Allows you to verify the status of all switches.
•Path-Level Switching. Allows complex paths to be
defined with open and close elements, stored in non-
volatile memory, and be controlled remotely or through the
front-panel display.
•Confidence Mode. Automatically verifies correct
application of voltage to relay coils.
•Non-Volatile Memory. Stores and recalls switch
configurations and 1256 user preferences (such as GPIB
address and RS-232 baud rate).
•Power-Up Recall. Automatically recalls a complete
switching system configuration from non-volatile memory at
power-up.
•Self-Test. Ensures that critical system components are
functioning correctly. This test executes automatically at
power-up.

1256E User Manual
Racal Instruments ©2002 Introduction 1-5
Items Shipped
with the 1256 The following items are shipped with each 1256 Switching System:
ITEM RACAL PART
NUMBER QUANTITY
1256 Enclosure Assembly 407837 1
Instruction Manual 980873 1
AC Power Mains Cable 600620 1
Blanking Plates (to cover
empty plug-in slots) 407667 4
Software Driver 921678 1
The following accessories may be ordered separately:
•Option 60: Rack Mount Kit P/N 407731
•Option 04: European Power Cord P/N 407730
(unterminated)
•GPIB Cable, 1-meter P/N 500310-001
•GPIB Cable, 2-meter P/N 500310-002
•RS-232 Cable, 10 ft., P/N 602248
9-pin female D-Sub to
9-pin male D-Sub

1256E User Manual
Introduction 1-6 Racal Instruments ©2002
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