Pickering SYSTEM 10 User manual

Page (1)
LOW NOISE HIGH ISOLATION MULTIPLEXER 20-620-322
pickering
Issue 4.1 July 2019
User Manual
GPIB Low Noise High Isolation
Multiplexer Module
(Model No. 20-620-322)
pickeringtest.com pickering
SYSTEM 10/20
*Please contact Pickering for alternative
PXI/LXI/USB solutions
*

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Page (II) REED RELAY MODULE 40-110/115/120/125
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© 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

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LOW NOISE HIGH ISOLATION MULTIPLEXER 20-620-322
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REED RELAY MODULE 40-110/115/120/125
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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) LOW NOISE HIGH ISOLATION MULTIPLEXER 20-620-322
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Page (IV) GENERAL PURPOSE REED RELAY MODULE 10-110/115/120/125
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Page (IV) REED RELAY MODULE 40-110/115/120/125
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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.

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LOW NOISE HIGH ISOLATION MULTIPLEXER 20-620-322
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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................................................7.3
CONTENTS
Please use the hyperlinked text to navigate to the page required

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Page (VII)
LOW NOISE HIGH ISOLATION MULTIPLEXER 20-620-322
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Page (VII)
GENERAL PURPOSE REED RELAY MODULE 10-110/115/120/125
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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.

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Page 1.1
LOW NOISE HIGH ISOLATION MULTIPLEXER 20-620-322
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SECTION 1 - TECHNICAL SPECIFICATION
pickeringtest.com
GPIB Low Noise High Isolation Multiplexer 20-620
ISSUE 5.2 JUL 2019
• High Isolation Low Noise Multiplexer
Switching 1 Pole Plus Switched Shield
• Single or Dual Multiplexer Operation
• Uses High Quality Ruthenium Reed Relays For
Maximum Reliability
• Built-In Self Test
• Choice of Shielded Connectors: BNC or XLR
A High Isolation Very Low Noise Multiplexer, available as either
Single 16 to 1 or dual 8 to 1 with a choice of connector types. This
module is intended for high quality multiplexing of low frequency
signals up to 1MHz.
20-620 Multiplexer - For the highest quality switching applications
Applications will be found where general purpose multiplexers
have inadequate isolation and crosstalk performance. These
include: high quality data acquisition (usually 2-pole with
frequencies < 1MHz), audio broadcast/studio, low noise high
isolation instrumentation and very high quality signal routing in ATE
systems.
1
2
3
4
15
16
1
2
3
4
7
8
MU
X Bank 1
1
2
3
4
7
8
MUX Bank 2
The 20-620 is Available as Either a 16 to 1 or
Dual 8 to 1 Multiplexer
0 dB
-0.8 dB
-1.2 dB
-1.6 dB
-2.0 dB
-2.4 dB
-2.8 dB
-0.4 dB
10MHz 20MHz 30MHz
20-620 INSERTION LOSS
-3.2 dB
40MHz
Insertion Loss Plot For The 20-620 Multiplexer
-85 dB
-90 dB
-95 dB
-100 dB
25kHz 50kHz 75kHz
20-620 CROSSTALK – Channel to Channel
--105 dB
100kHz
--110 dB
Crosstalk Plot For The 20-620 Multiplexer
-40 dBm
250kHz 500kHz 750kHz
-80 dBm
1000kHz
-120 dBm
0 dBm
Unguarded noise is approx 5dB's Higher
Note: Measuring System Noise Floor = -120dBm
20-620 NOISE
Noise Performance For The 20-620 Multiplexer
*Please contact Pickering for alternative
PXI/LXI/USB solutions
*

Page 1.2 LOW NOISE HIGH ISOLATION MULTIPLEXER 20-620-322
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SECTION 1 - TECHNICAL SPECIFICATION
Low Noise High Isolation Multiplexer – 20-620
pickeringtest.com
Specifications
Electrical Specification
Maximum Switch Voltage:
Maximum High to Low Voltage:
Maximum Guard Voltage (Relative to Hi/Lo):
200V d.c.
100V d.c.
±100V d.c.
Maximum Power:
Maximum Switch Current:
Maximum Carry Current:
10W
0.5A
1.2A
On Path Resistance:
Off Path Resistance:
Differential Thermal Offset:
<300mΩ
>1x1010Ω
<5µV
Maximum Frequency (3dB in 50Ω system):
Capacitance, unselected channel to guard:
Capacitance, selected channel to guard:
Capacitance, unselected channel to common:
40MHz
<40pF
<70pF
<5pF
Expected Life (low power):
Expected Life (high power):
>1x108ops
>5x106ops
Switching Time: <15ms
Noise Level/dBm (0 to 1MHz in 50Ωsystem)
With Passive Guard:
With No Guard:
<-105dBm
<-100dBm
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.
Operating/Storage Conditions
Operating Conditions
Operating Temperature:
Humidity:
Altitude:
0°C to +55°C
Up to 90% non-condensing
5000m
Storage and Transport Conditions
Storage Temperature:
Humidity:
Altitude:
-20°C to +75°C
Up to 90% non-condensing
15000m
Programming
The 20-620 Multiplexer module is simple to program:
ARESET a Open all channels on device a
CHAN a,c Select channel con multiplexer a
When in dual 8 to 1 mode the address is
prexed by 1 or 2.
DELAY t Force a minimum delay of tmilliseconds
between two instructions
DIAGNOSTIC? Report any Self Test errors
RESET Open all switches on all modules
VIEW? a View status of device a
AC Performance (50Ω) 10kHz 100kHz 1MHz
Isolation, channel to common:
Isolation, channel to channel:
Isolation, bank to bank:
Isolation, module to module
>90dB
>90dB
>100dB
>100dB
>85dB
>78dB
>90dB
>100dB
>68dB
>70dB
>80dB
>90dB
Mechanical Characteristics
All modules conform to the 6U height (262mm) Eurocard standard
and are 160mm deep. Panel width is 2.4 Inches for the BNC
version and 3.6 Inches for the XLR type.
Connectors
Connection to the module front panel is via 18 screened
connectors. The screen for each connector is isolated from the
analogue common except when that channel is selected.
Relay Type
The modules are tted with Ruthenium Reed Relays.
All reed relays are manufactured by our sister company Pickering
Electronics: pickeringrelay.com

Page 1.3
LOW NOISE HIGH ISOLATION MULTIPLEXER 20-620-322
pickering SECTION 1 - TECHNICAL SPECIFICATION
Low Noise High Isolation Multiplexer – 20-620
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
Single 16-Chan MUX, BNC Coaxial
(
Single pole + switched shield) 20-620-021-S/16/1
Dual 8 Channel MUX, XLR Audio
(Two pole + switched shield) 20-620-322

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SECTION 1 - TECHNICAL SPECIFICATION
Product Order Codes
Dual 8-Channel MUX, BNC Coaxial 20-620-021-D/8/1
Former Products
Please note that manufacture has now ceased for the related product versions listed below. Should you require
any additional information regarding them not contained in the 20-620-021 manual please contact the factory.

Page 2.1
LOW NOISE HIGH ISOLATION MULTIPLEXER 20-620-322
pickering SECTION 2 - TECHNICAL DESCRIPTION
SECTION 2 - TECHNICAL DESCRIPTION
FUNCTIONAL DESCRIPTION
Figure 2.1 - Low Noise High Isolation Multiplexer Module: Functional Block Diagram
GND
SIG 1
SIG 2
1
GND
SIG 1
SIG 2
2
GND
SIG 1
SIG 2
3
GND
SIG 1
SIG 2
4
GND
SIG 1
SIG 2
5
GND
SIG 1
SIG 2
6
GND
SIG 1
SIG 2
7
GND
SIG 1
SIG 2
8
GND
SIG 1
SIG 2
9
GND
SIG 1
SIG 2
10
GND
SIG 1
SIG 2
11
GND
SIG 1
SIG 2
12
GND
SIG 1
SIG 2
13
GND
SIG 1
SIG 2
14
GND
SIG 1
SIG 2 15
GND
SIG 1
SIG 2
16
16 TO 1
OR
DUAL 8 TO 1
MULTIPLEXER
RELAY
DRIVER
U1
RELAY
DRIVER
U2
UNIVERSAL CONTROL PCB
CONTROL
FROM
SYSTEM 20
BACKPLANE
GND
SIG 1
SIG 2 C1
GND
SIG 1
SIG 2
C2
TO FRONT
PANEL
STATUS LEDs
The 20-620 Module is powered by +5VDC and +12VDC supplies from the variable input power supply.
A functional block diagram is provided in Figure 2.1. Sixteen balanced signals, or two banks of eight balanced
signals are applied to the module via the front panel mounted XLR Audio connectors. The relays to switch those
signals are energised via control signals from relay drivers U1 and U2 on the Relay board, the relay drivers being
addressed via signals from the Universal Control PCB.
Status LEDs and a Manual Self-Test button are also provided on the Front Panel.

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SECTION 2 - TECHNICAL DESCRIPTION
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Page 3.1
LOW NOISE HIGH ISOLATION MULTIPLEXER 20-620-322
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Page 3.1
GENERAL PURPOSE REED RELAY MODULE 20-110/115/120/125
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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.

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SECTION 3 - INSTALLATION
Page 3.2 GENERAL PURPOSE REED RELAY MODULE 20-110/115/120/125
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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.

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LOW NOISE HIGH ISOLATION MULTIPLEXER 20-620-322
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Page 3.3
GENERAL PURPOSE REED RELAY MODULE 20-110/115/120/125
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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.

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SECTION 3 - INSTALLATION
SELF -TEST FUNCTION
Self-Test is invoked at power on and may also be operated under software control using the *TST? command. If
the Self-Test fails the Error LED on the front panel will be turned on. A full pass/fail description is available using the
DIAGNOSTIC? command.
The Self-Test for the 20-620-322 Module comprises 2 levels (see Figure 3.5):
1. Logic Test: Checks all logic including on-board microprocessor RAM, ROM, and EEPROM, relay drivers etc.
2. Relay Coil Test: The resistance of all reed relay coils are checked.
Note: In the unlikely event of a relay needing replacement Spare Reed Relays are built onto the module circuit
board to facilitate easy maintenance with minimum downtime. Additional reed relays are available from Pickering
Interfaces.
Self-Test Operation
Self-Test is always run at power on, taking approximately 5 seconds.
If Self-test is run under software control it will rstly clear the whole module. So it is very important to prepare your
external instruments and U.U.T. for this. During self-test all switches are opened so your external circuitry will see
only very high resistance inputs.
When the self-test has nished the relays 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 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.
Analogue: 5 Volt supply low etc. (Not applicable for this module)
Relay Coils: Open Circuit Coil.
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).
Note:
If the interface module locks up while running high speed programs check the setting of the SPI bus. Refer to
Section 4.

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LOW NOISE HIGH ISOLATION MULTIPLEXER 20-620-322
pickering SECTION 3 - INSTALLATION
Figure 3.5 - Self-Test Basic Flow Diagram: 20-620-322
SELF TEST INITIATED BY:
. POWER ON
. *TST? INTERFACE CMND
. TS 1 RS232 COMMAND
CLEAR MODULE
MEMORY and LOGIC
TEST
ANALOGUE TEST
LOGIC TEST
FAIL ?
ANALOGUE
TEST FAIL ?
RELAY COIL
TEST FAIL ?
RELAY COIL TEST
SELF TEST PASS
SELF TEST FAILURE
ERROR LED ON
USE DIAGNOSTIC? COMMAND
Yes
No
Yes
No
Yes
No
NOT
APPLICABLE

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