Pickering 20-534A User manual

Page (1)
HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering
Issue 6.1 July 2019
User Manual
GPIB High Density Switching
Matrix Module with Self-Test
(Model No. 20-534A)
pickeringtest.com pickering
SYSTEM 10/20
*Please contact Pickering for alternative
PXI/LXI/USB solutions
*

Page (II) HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering
Page (II) REED RELAY MODULE 40-110/115/120/125
pickering
© COPYRIGHT (2019) PICKERING INTERFACES. ALL RIGHTS RESERVED.
No part of this publication may be reproduced, transmitted, transcribed, translated or stored in any form, or by
any means without the written permission of Pickering Interfaces.
Technical details contained within this publication are subject to change without notice.
ISO 9001
Reg No. FM38792

Page (III)
HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering
Page (III)
REED RELAY MODULE 40-110/115/120/125
pickering
TECHNICAL SUPPORT
For Technical Support please contact Pickering Interfaces either by phone, the website or via e-mail.
WARRANTY
All products manufactured by Pickering Interfaces are warranted against defective materials and workmanship for a period of
three years, excluding programmable power supplies, from the date of delivery to the original purchaser. Any product found to be
defective within this period will, at the discretion of Pickering Interfaces be repaired or replaced.
Products serviced and repaired outside of the warranty period are warranted for ninety days.
Extended warranty and service are available. Please contact Pickering Interfaces by phone, the website or via e-mail.
ENVIRONMENTAL POLICY
Pickering Interfaces operates under an environmental management system similar to ISO 14001.
Pickering Interfaces strives to full all relevant environmental laws and regulations and reduce wastes and releases to the
environment. Pickering Interfaces aims to design and operate products in a way that protects the environment and the health and
safety of its employees, customers and the public. Pickering Interfaces endeavours to develop and manufacture products that can
be produced, distributed, used and recycled, or disposed of, in a safe and environmentally friendly manner.
Worldwide Technical Support and Product Information
pickeringtest.com
Germany
Tel: [phone]
E-mail: [email protected]
Sweden
Tel: [phone]
E-mail: [email protected]
USA
Tel: (West) [phone]
Tel: (East) [phone]
E-mail: [email protected]
Czech Republic
Tel: [phone]
E-mail: [email protected]
France
Tel [phone]
E-mail [email protected]
Pickering Interfaces Headquarters
Stephenson Road Clacton-on-Sea CO15 4NL United Kingdom
Tel: [phone]
E-Mail: [email protected]
China
Tel: [phone]
E-mail: [email protected]

Page (IV) HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering
Page (IV) GENERAL PURPOSE REED RELAY MODULE 10-110/115/120/125
pickering
Page (IV) REED RELAY MODULE 40-110/115/120/125
pickering
MEANING / DESCRIPTION SYMBOL
PROTECTIVE EARTH (GROUND)
To identify any terminal which is intended for connection to an external conductor for
protection against electric shock in case of a fault, or the terminal of a protective earth
(ground) electrode.
DANGEROUS VOLTAGE
To indicate hazards arising from dangerous voltages.
WARNING / CAUTION
An appropriate safety instruction should be followed or caution to a potential hazard
exists.
Refer to the relevant instructions detailed within the product manual.
HEAVY
If this product is heavy reference should be made to the safety instructions for
provisions of lifting and moving.
STATIC SENSITIVE
To indicate that static sensitive devices are present and handling precautions should
be followed.
!
kg
SAFETY SYMBOLS
PRODUCT SAFETY
The following safety symbols may be used on the product and throughout the product documentation.

Page (V)
HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering
Copyright Statement ...................................................................II
Technical Support and Warranty................................................III
Product Safety .............................................................................IV
Contents (this page)....................................................................V
Warnings and Cautions ..............................................................VII
Section 1
Technical Specication...............................................................1.1
Section 2
Technical Description .................................................................2.1
Functional Description..........................................................2.1
Section 3
Installation....................................................................................3.1
Pre-Operation Checks...........................................................3.1
Hardware Installation ............................................................3.1
Software Installation .............................................................3.3
Self-Test..................................................................................3.4
Section 4
Programming Guide....................................................................4.1
Programming the Module .....................................................4.1
Section 5
Connector Information................................................................5.1
Section 6
Trouble Shooting .........................................................................6.1
Installation Problems ...........................................................6.1
Section 7
Maintenance Information............................................................7.1
Relay Lookup Tables.............................................................7.1
PCB and Component Layout................................................7.6
CONTENTS
Please use the hyperlinked text to navigate to the page required

Page (VI) HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering
THIS PAGE INTENTIONALLY BLANK

Page (VII)
HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering
Page (VII)
GENERAL PURPOSE REED RELAY MODULE 10-110/115/120/125
pickering
WARNINGS AND CAUTIONS
WARNING - HAZARDOUS ENVIRONMENTS SYMBOL
This product is not specically designed for use in hazardous environments, for example in explosive
atmospheres. If the product is to be used in hazardous environments we recommend that the user
ensures suitable protective measures are taken.
!
WARNING - DANGER OF ELECTRIC SHOCK SYMBOL
This module may contain hazardous voltages. Before removing the module from the rack remove all
supplies and disconnect user I/O signals.
Unused slots in the System 10/20 chassis are populated with blanking plates to prevent access
to user I/O signals that may be present. Blanking panels are available to order from Pickering in a
variety of slot widths. If the product is not used in this manner for example by using an extender card
then additional care must be taken to avoid contact with exposed signals.
CAUTION - HANDLING OF ELECTROSTATIC-SENSITIVE DEVICES SYMBOL
Certain semiconductor devices used in this equipment are liable to damage due to static voltage.
Observe the following precautions when handling these devices in their unterminated state, or
sub-assemblies containing these devices:
1. Persons removing sub-assemblies from equipment using these devices must be earthed by a
wrist strap and a resistor at the point provided on the equipment.
2. Soldering irons used during the repair operations must be low voltage types with earthed tips and
isolated from the mains voltage by a double insulated transformer.
3. Outer clothing worn must be unable to generate static charges.
4. Printed Circuit Boards (PCBs) tted with these devices must be stored and transported in
anti-static bags.
CAUTION - PRODUCT DOCUMENTATION SYMBOL
Suitably qualied & trained users should ensure that the accompanying documentation is fully read
and understood before attempting to install or operate the product.
!
SAFETY INSTRUCTIONS
SAFETY INSTRUCTIONS
All cleaning and servicing requires the equipment to be isolated and disconnected from the power source and user I/O
signals (refer to the Maintenance Section).
• Appropriate manual handling procedures should be followed as dictated by the weight of the individual module or
the combined weight of the modules & chassis.
• Should a fault occur with the module or chassis, immediately isolate and disconnect the incoming power to the
chassis and the user I/O signals.
• Ensure the equipment is installed, operated and maintained by trained and authorised personnel.

Page (VIII) HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering
THIS PAGE INTENTIONALLY BLANK

Page 1.1
HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering SECTION 1 - TECHNICAL SPECIFICATION
SECTION 1 - TECHNICAL SPECIFICATION
pickeringtest.com
GPIB Very High Density Switching Matrix 20-534A/535A
ISSUE 5.2 JUL 2019
• Very High Density Matrix Modules
• 32 x 8 Single Or Double Pole Matrix Format
• 64 x 4 Single Or Double Pole Matrix Format
• Modules Cascadable to Any Size Using
Internal 24 Pole Analogue Bus
• Automatic Isolation Switching for Maximized
Performance
• Built-In Switch Self Test with Fault Diagnosis
to Component Level
• Switch up to 100 Volts DC, 0.5 Amps (1.2A
carry), 20W Max Power
• Ruthenium Reed Relays For Maximum
Switching Performance
Switching Diagram for the 20-535A
32 x 8 Matrix, Available as Single or
Double Pole
Switching Diagram for the
20-534A 64 x 4 Matrix, Available
as Single or Double Pole
Y 2Y4
X 1
X 4
Isolation
Switch
Y 1Y3
X 2
X 3
X 5
X 6
X 7
X 62
X 8
Matrix
Crosspoint
X 63
X 64
Isolation
Switch
Y 2Y4
X 1
X 4
Y 1Y3
X 2
X 3
X 5
X 6
X 7
X 30
X 8
X 31
X 32
Y 8Y 5 7
Isolation
Switch
Matrix
Crosspoint
6YY
The highest density System 20 double pole matrices currently
available from Pickering Interfaces. The 20-534A range of 64 x 4 and
20-535A range of 32 x 8 matrix modules include automatic isolation
switching, plug-in expansion and built-in self-test to give complete
switching condence.
Models 20-534A (64x4) and 20-535A (32x8) now give the highest
density 1 or 2 pole matrices available in any Pickering Interfaces
System 20 switching module. They are intended for easy construction
and use of large matrix systems; modules may be easily expanded to
form matrices of almost any size, e.g. 64 x 4, 128 x 4, 256 x 8 ....512 x
16 using model 20-534; and 32 x 8, 64 x 8, 128 x 16....256 x 32 using
model 20-535A.
Main applications are for signal routing in ATE systems: between the
device under test and the measurement and stimulus instruments.
Connections are made via front panel mounted connectors. Larger
matrices may be constructed using the internal 24 pole analogue bus.
Isolation Switches on each module remove
all unused columns and rows from the system,
hence keeping interconnection capacitance,
leakage and crosstalk to an absolute
minimum.
Creating Larger Matrices - Easily!
Each System 20 interface can directly support
matrices with over 10 000 crosspoints. Larger
sizes are supported using multiple System
20 interface modules. Large matrices are
constructed by interconnecting two or more
matrix modules. All such matrix modules must
have the same primary address. Their position
within the matrix is determined by their bank
address, this is set on an additional 5 way dip
switch.
Both the X and Y axes have on-board
automatic isolation switches.In large
matrix systems the parasitic capacitance
and leakage associated with each crosspoint
switch can result in a signicant degradation
if several matrix modules are interconnected. The isolation switches
connect only those columns and rows on a module that contain an
active relay. Thereby keeping matrix capacitance to a minimum. These
isolation switches are also used to remove the matrix from the external
circuit when performing self-test.
A shielded 24 pole analogue bus is provided on the System 20
Analogue Backplane so constructing large matrices is very straight
forward, no time consuming daisy-chained wiring harnesses etc.
Pickering can build large Matrix systems constructed and tested to
your exact requirements, please contact sales ofce for further details.
*Please contact Pickering for alternative
PXI/LXI/USB solutions
*

Page 1.2 HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering
SECTION 1 - TECHNICAL SPECIFICATION
Very High Density Switching Matrix – 20-534A/535A
pickeringtest.com
Specifications
Specification
Switch Type: Ruthenium Reed
Max Voltage:
Max Power:
Max Switch Current:
Max Carry Current:
100V DC
20W
0.5A
1.2A
On Path Resistance:
Off Path Resistance:
Differential Thermal Offset:
<500mΩ
>108Ω
<20µV
Capacitance
Open Channel to Ground:
Selected Channel to Ground:
Open Input to Output:
<60pF
<100pF
<4pF
Bandwidth:
Isolation (at 1MHz):
Crosstalk (at 1MHz):
5MHz
>55dB
>55dB
Switching Time: 15ms
Expected Life (Low power):
Expected Life (Full power):
>1x108operations
>5x106 operations Operating/Storage Conditions
Operating Conditions
Operating Temperature:
Humidity:
Altitude:
0°C to +55°C
Up to 95% non-condensing
5000m
Storage and Transport Conditions
Storage Temperature:
Humidity:
Altitude:
-20°C to +75°C
Up to 95% non-condensing
15000m
Programming
The matrix module is very easy to program using the Intelligent
IEEE-488.2/RS-232-C Interface:
ARESET a Open all switches on device a
DIAGNOSTIC? Report any Self Test errors
DELAY t Force a minimum delay of tmilliseconds
between two instructions
MCLOSE a,x,y Close switch at coordinates x,y on matrix
a
MOPEN a,x,y Open switch at coordinates x,y on matrix
a
RESET Open all switches on all modules
VIEW? a View status of device a
Reed Switch Type
Ruthenium Electro-Plated Reed Relays offer maximum
performance, they are hermetically sealed and offer a very stable,
long life relay contact (over 108operations) with fast operate time.
Alternative types such as electro-mechanical armature relays are
lower cost but do not offer the consistent contact resistance, long
life, fast switching speed and low level switching capability of a
Ruthenium reed relay.
All reed relays are manufactured by our sister company Pickering
Electronics: pickeringrelay.com
Self Test Details
Self-Test is invoked at power on (taking up to 60 seconds) and
may also be operated under software (*TST?) or via a recessed
push button. Self-Test pass is indicated on a front panel LED with
a full pass/fail description available using the DIAGNOSTIC?
command. Self-Test comprises 3 levels:
1. Logic Test
2. Relay Coil Test
3. Full Contact Test
20-534A/535A matrix modules are
constructed using 400 Series 109 Reed
Relays manufactured by our sister
company Pickering Electronics Ltd.
These are the smallest double pole reed
relays currently available (the picture
shows two 109-2-A-12/2D reed relays
together with a British 1 pence coin,
shown actual size).
Mixed Matrix/Multiplexers Configurations
For some users requiring very large matrix systems the cost of a
“full” matrix may prove prohibitive, in many instances a combination
of multiplexer input/output and partially lled matrix may prove quite
acceptable and could prove to be more effective in terms of both
cost and performance. Please contact Pickering to discuss your
application in detail.
Automatic Self-Test
Full Self-Test is performed at power up and at any other time
either manually or under program control. Self-Test is of particular
importance in large systems where relay contact integrity is a very
major consideration. In the unlikely event of relay failure (either
high on-state or low off-state resistance) the front panel will indicate
a fault. The exact fault description is available via the IEEE-488/
RS-232 bus.
Mechanical Characteristics & Connectors
All 20-534A/535A model versions are housed in a shielded 6U
height (262mm) Eurocard module and are 160mm deep. Panel
width for all versions is 1.8 Inches.
The connector type used is 2 x 96-Pin Rectangular (ZIF type).
Other connector types are available e.g. BNC, Cannon, please
contact factory for details.

Page 1.3
HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering SECTION 1 - TECHNICAL SPECIFICATION
Very High Density Switching Matrix – 20-534A/535A
pickeringtest.com
Ordering Information
© Copyright (2019) Pickering Interfaces. All Rights Reserved Pickering Interfaces maintains a commitment to continuous product development, consequently we reserve the right to vary from the description given in this data sheet.
Product Customization
Pickering System 20 modules are designed and manufactured
on our own exible manufacturing lines, giving complete product
control and enabling simple customization to meet very specic
requirements.
Customization can include:
• Alternative relay types
• Mixture of relay types
• Alternative number of relays
• Different performance specications
All customized products are given a unique part number, fully
documented and may be ordered at any time in the future. Please
contact your local sales ofce to discuss.
Product Order Codes
64x4 Matrix, Ruthenium Reed, 1-Pole
64x4 Matrix, Ruthenium Reed, 2-Pole
20-534A-021
20-534A-022
32x8 Matrix, Ruthenium Reed, 1-Pole
32x8 Matrix, Ruthenium Reed, 2-Pole
20-535A-121
20-535A-122
Limiting Resistors
Built in limiting resistors on each row and column may be tted,
useful in preventing high current inrushes which may damage the
reed switch. Please specify option -R.
Safety & CE Compliance
All modules are fully CE compliant and meet applicable EU
directives: Low-voltage safety EN61010-1:2010, EMC Immunity
EN61326-1:2013, Emissions EN55011:2009+A1:2010.
Mating Connectors & Cabling
96-Pin ZIF Connector
ZIF Connector Pins, 100 off
10-964A-001
10-964A-801

Page 1.4 HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering
SECTION 1 - TECHNICAL SPECIFICATION
Former Products
Please note that manufacture has now ceased for the related product versions listed below. Should you require
any additional information related to them not contained in this manual please contact the factory.
Product Order Codes
32 x 10 Matrix, Ruthenium Reed, 1-Pole 20-535A-021
32 x 10 Matrix, Ruthenium Reed, 2-Pole 20-535A-022
Electrical & Mechanical Specications
Voltage Supplies
Logic Supply 5Vdc ±5%
Relay Supply 12Vdc ±10%
† Approx. dimensions. Standard 160mm Eurocard.
Model 20-534A
Approx. Weight 0.6kg
Dimensions (mm) 6U Eurocard as specied in
DIN41494
Front Panel Width 45.6
Height 268
Overall Length † 189
Power /Current Consumption
Max 5V 250mA
12V 800mA
Min. 5V 150mA
12V 0mA
To Self Test
Circuit
Y 1 Y 2 Y 4
lanoitpO
seireS
srotsiseR
tseT fleS oT
tiucriC
X 1
X 64
X 2
Figure 1.1 - Full Schematic of a 64 x 4 Single Pole Matrix Module
Schematic:

Page 2.1
HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering SECTION 2 - TECHNICAL DESCRIPTION
SECTION 2 - TECHNICAL DESCRIPTION
FUNCTIONAL DESCRIPTION
Figure 2.1 - High Density Switching Matrix Module 20-534A
Functional Block Diagram
STATUS LEDs
RELAY BOARD
SIMM CONTROLLER
PCB ASSY
FRONT PANEL CONNECTORS
RELAY
COILS
RELAY
CONTACTS
TO FRONT
PANEL
Y1-4
X1-64
CONNECTOR J1
DRIVER
ICs
CONNECTOR J4
A functional block diagram is provided in Figure 2.1. The module is powered via chassis connectors J1 and J4
with +12V relay and +5V logic supplies. The interface to the user test equipment is via the front panel mounted
connectors. The module comprises a SIMM Controller PCB Assy and a Relay PCB Assy populated with electro-
mechanical relays. Additional driver ICs are tted on the Relay PCB. The 20-534A module is available as a 64 x 4
Matrix utilising either SPST or DPST Normally Open relays. The drivers on the Relay PCB are fed with serial data
from the SIMM Controller PCB. General status LEDs are provided on the front panel. Relay switching is determined
by operator programming.

Page 2.2 HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering
SECTION 2 - TECHNICAL DESCRIPTION
Creating Large Matrices
Each System 20 interface can directly support cascaded matrices up to 160x48 or 80x96, i.e. up to 31 modules per
matrix and larger sizes can be supported using multiple System 20 interface modules mounted in separate cases.
Forming larger matrices is usually only a question of plugging in additional matrix modules, a 24 pole guarded
analogue bus is provided on the System 20 Analogue Backplane. So constructing large matrices is very straight
forward, no time consuming daisy-chained wiring harnesses. Further expansion is simply a matter of adding
additional matrix modules.
All matrix modules in a cascaded matrix must have the same primary address, their position within the matrix is
determined by their bank address (see Section 4), this is set on an additional 5 way dip switch. The cascaded matrix
is then programmed as a whole, the programmer does not need to address each matrix module individually, only a
pair of coordinates for the required crosspoint need be sent.
Isolation Switches
Both the X and Y axes have on-board automatic isolation switches. In large matrix systems the parasitic capacitance
associated with each crosspoint switch can result in a large capacitance if several matrix modules are interconnected.
The isolation switches only switch in those columns and rows on a module that contain an active switch. Thereby
keeping matrix capacitance to a minimum., this may be important for applications requiring high isolation and
crosstalk as well as good insulation resistance.
NB. These isolation switches are also used to remove the matrix from the external circuit when performing self-test.
“Partially Filled” Matrices
For users requiring very large matrix systems the cost of a fully populated matrix may prove prohibitive, in many
instances a combination of multiplexer input/output and small “core” matrix may prove quite acceptable. This
approach may prove to be more effective in terms of both cost and performance, the main draw backs being
additional programming complexity and restricted matrix versatility (particularly for future unforeseen requirements).
Please contact Pickering if you wish to discuss your matrix application in greater detail.
Pickering can build large Matrix systems constructed and tested to your exact requirements, (especially if your
application involves switching RF or very high isolation signals), please contact the sales ofce for further details.
Y 3
X 3
X 64
X 4
X 2
Y 4Y 2Y 1
X 1
Crosspoints Closed are at
x = 2, y = 2 & x = 2, y = 4.
Figure 2.2 - Typical 64 x 4 Matrix using Automatic Isolation Switching

Page 2.3
HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering SECTION 2 - TECHNICAL DESCRIPTION
12 3 4 5 20
21 32154
6 7
21 32154
12 3 4 5 20
21 32154
6 7
21 32154
12 3 4 5 20
21 32154
6 7
21 32154
12 3 4 5 20
21 32154
6 7
21 32154
SUB EUGOLANA ELOP 42 LANRETNI
20 x 12 Matrix
20 x 12 Matrix
20 x 12 Matrix
20 x 12 Matrix
stuptuO 21
stupnI 08
Figure 2.3 - Example: 80 x 12 Matrix Switch
(The 64 x 4 Modules (20-534A) can be expanded similarly)
12 Poles of the internal Screened Analogue Bus are used to interconnect the 4 matrix modules.
Additional matrix modules may be simply plugged in to give further expansion.

Page 2.4 HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering
SECTION 2 - TECHNICAL DESCRIPTION
THIS PAGE INTENTIONALLY BLANK

Page 3.1
HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering SECTION 3 - INSTALLATION
Page 3.1
GENERAL PURPOSE REED RELAY MODULE 20-110/115/120/125
pickering SECTION 3 - INSTALLATION
SECTION 3 - INSTALLATION
Power Supply
with
Interface Module
above
6U System 20 Modules
(Not position dependent)
3U System 10 Modules
(Not position dependent)
kg
PRE-OPERATION CHECKS (UNPACKING)
1. Check the module for transport damage and report any damage immediately to Pickering Interfaces.
Do not attempt to install the product if any damage is evident.
2. Position the chassis relative to any other equipment the module(s) will connect with. Ensure the chassis is not
connected to the electrical supply.
3. Ensure that the designated area for the chassis containing the module is of at and solid construction to
withstand and support the combined weight of the module(s) and chassis.
!
Refer to the Warnings and Cautions at the front of this manual
Modular products require installation in a suitable System 10/20 chassis.
The module is designed for indoor use only.
!
HARDWARE INSTALLATION
ELECTRICAL CONNECTION (CHASSIS)
1. The chassis must be electrically installed in accordance with local regional electrical codes by a qualied
engineer.
2. Ensure the power supply lead provides the necessary integrity of chassis ground.
Electrostatic discharge can damage the components on the module. To avoid such damage in handling the
board refer to page VII.
Ensure that there is adequate ventilation.
Figure 3.1 - System 10/20 Front Access Case Split 24/60 with Various Modules Fitted.

Page 3.2 HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering
SECTION 3 - INSTALLATION
Page 3.2 GENERAL PURPOSE REED RELAY MODULE 20-110/115/120/125
pickering
SECTION 3 - INSTALLATION
Figure 3.2 - Module Guide Rail Position
Figure 3.3 - A Partially Built System 20 Front Access Chassis
!
MODULE INSTALLATION
The module should be installed in accordance with the following procedure:
1. Ensure that the system is turned OFF but still connected to mains so that it remains grounded.
2. If the module has address switches ensure they are set to the appropriate position. (See Section 4).
Note individual modules are not sent out with a system drawing detailing their address.
3. Choose an appropriate slot in the rack and remove the blanking plate (if tted).
(See the Pickering 10-910M IEEE-488 GPIB System 10/20 Ancillaries manual for further details).
(When tted, additional modules will be automatically recognised by the interface card. See Figure 3.1).
4. If necessary t the module guide rails as supplied with the module to both the top and bottom of the chassis
in that slot position. One guide rail slot should be to the left of the connector as shown in Figure 3.2.
5. Align the module with the backplane and screw holes at the front of the chassis.
Hold the handle whilst slowly sliding the module into the card guides until the module seats rmly into the
backplane. See Figure 3.4. The front panel of the module should be ush with the front or rear panel of the
chassis.
6. Screw the front panel of the module to the chassis front panel mounting rails.
7. Ensure all necessary modules including the power supply are tted to the rack and other slots blanked off
before powering up.
To achieve the correct initialisation of the sytem, ensure any slave chassis are powered up before the master
chassis.

Page 3.3
HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering SECTION 3 - INSTALLATION
Page 3.3
GENERAL PURPOSE REED RELAY MODULE 20-110/115/120/125
pickering SECTION 3 - INSTALLATION
Figure 3.4 - Module Insertion in a Pickering 20-935A-001 Front Access Chassis
SOFTWARE INSTALLATION
Refer to the Pickering manual 10-921M.
For the latest version of the driver please refer to our web site pickeringtest.com where links to our Software
Download page will provide the driver software for the various programming environments encountered.

Page 3.4 HIGH DENSITY SWITCHING MATRIX MODULE 20-534A
pickering
SECTION 3 - INSTALLATION
SELF-TEST FUNCTION
Self-Test is invoked at power on (taking up to 60 seconds) and may also be operated under software control (*TST?).
Self-Test pass is indicated on a front panel LED with a full pass/fail description available using the DIAGNOSTIC?
command.
Self-Test comprises 3 levels, see Figure 3.5:
1. Logic Test: Checks all logic including on-board microprocessor, relay drivers etc.
2. Relay Coil Test: All reed relay coils are checked for continuity.
3. Full Contact Test: Tests all the relay contacts in the matrix block. Two test are undertaken:
(i) On-state resistance failure test. Fails if switch has on-state > 2Ω.
(ii) Off-state resistance test. A switch fails if it’s isolation resistance is < 106Ω.
The threshold for contact resistance is preset to approximately 2Ω at the factory. However this threshold may set
to customers precise requirements (from 200mΩ to 10Ω). If a very low threshold is selected, the self test could be
used to detect switches which are not failing to operate but which have reached an end of life condition, where the
contact resistance is starting to rise, indicating that the relay is due for replacement.
NB. The contact self test will only check the relay contacts in the core matrix block, isolation switches and self test
switches are not tested, please refer below.
Note: Spare reed relays are mounted onto the relay circuit board for fast repair, additional reed relays are available
from Pickering Interfaces.
Self-Test Operation
Self Test is always run at power on, taking approximately 60 seconds.
If self test is run under software control it will rstly clear the whole matrix (Manual Test will only function when the
module is in a clear state). So it is very important to prepare your external instruments and U.U.T. for this! During
self-test all isolation switches are opened so your external circuitry will see only very high resistance inputs.
When the self-test has nished the matrix will be returned to an all clear state (i.e. the previous state will not be
remembered!).
Please note that because of the long self-test time that your computer may time out waiting for the test result (many
PC's have default timeouts set to low values).
Detailed Self Test Reporting using the DIAGNOSTIC? Query
The DIAGNOSTIC? query will give an ASCII string detailing any self test failures. These will include:
Logic: Microprocessor, RAM, EPROM, Relay Drivers, Invalid Link Settings etc.
Relay Coils: Open Circuit Coil.
Switch Contacts: High On Resistance, Low Off Resistance.
This string is not intended to be processed by the user’s software, it is suitable for copying directly onto the screen
of your control computer. This information will then indicate maintenance required (please contact Pickering for
further help).
Self Test Limitations
Self Test covers all aspects of the Matrix Module which are liable to fail in normal use. The only exceptions to this
are the following:
“Isolation Relays”: These switches are used to isolate the matrix from the users external circuitry, for this reason
they cannot be included in the contact self test routine. These relays always “cold switch” (i.e. they are always
operated without any load, as opposed to the matrix switches which always “hot switch”), therefore they should have
an expected life in excess of 108 operations. These switches will only fail if a very heavy current is passed through
the contacts (greater than around 3-4A for 10's of milliseconds), this may result in switch weld to either an isolation
or matrix switch. Please note that all relays including isolation and self test relays are included in the coil test, so an
open circuit coil or faulty driver IC will be picked up and reported.
“Self Test Relays”: There are self test relays on every x and y axis on the matrix board, if one of these contacts
fails (very unlikely) then all relays on that axis will appear to fail self test.