IRT Electronics AMS-4170T Instruction Book

4170t-ams.ib.rev0.doc Page 1 of 14 17/10/2007

IRT Eurocard

Type AMS-4170T

2 x 2 relay switcher

for SDI, G.703 or analogue video

&

AES, RS422 or stereo audio signals

Designed and manufactured in Australia

IRT can be found on the Internet at:

http://www.irtelectronics.com

I R T Electronics Pty Ltd A.B.N. 35 000 832 575

26 Hotham Parade, ARTARMON N.S.W. 2064 AUSTRALIA
National: Phone: [phone] Fax: [phone]
International: [phone] [phone]
Email: [e-mail]
Web: www.irtelectronics.com

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IRT Eurocard

AMS-4170T

2 x 2 relay switcher

for SDI, G.703 or analogue video

&

AES, RS422 or stereo audio signals

Instruction Book

Table of Contents

Section Page

General Description 3
Technical Specifications 4
Configuration 5
Operation 6
SNMP 7

AMS-4170 SNMP Functions 9

Installation 10

SMU-4000 Installation 11

Figure 1: SMU-4000 module 11

Front & rear panel connector diagrams 12
Maintenance & Storage 13
Warranty & Service 13

Equipment return 13
Drawing index 14

This instruction book applies to units later than S/N 0504001.

Operational Safety:

WARNING

Operation of electronic equipment involves the use of voltages and currents that
may be dangerous to human life. Note that under certain conditions dangerous
potentials may exist in some circuits when power controls are in the OFF position.
Maintenance personnel should observe all safety regulations.

Do not make any adjustments inside equipment with power ON unless proper
precautions are observed. All internal adjustments should only be made by suitably
qualified personnel. All operational adjustments are available externally without the
need for removing covers or use of extender cards.

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IRT Eurocard

AMS-4170T

2 x 2 relay switcher

for SDI, G.703 or analogue video

&

AES, RS422 or stereo audio signals

General Description

The AMS-4170T consists of one “video” and two “balanced audio” switches. Each switch is arranged as a
changeover set with two inputs and two outputs. No terminations are provided on the board allowing the switcher to
be used in a wide variety of applications and with signals of various types and impedances.

The “video” path uses enhanced performance relays to provide switching cap abilities for high- speed data signals up
to 270 Mb/s and may be used with analogue video, SDI, MPEG or RF signals. When used with SDI and high-speed
data signals all cable lengths should be kept to a minimum. For best performance the outputs should be connected to
inputs with automatic cable equalisation.

The “audio” path may be used for balanced or unbalanced audio or control signals (RS232, RS422, RS485 etc).
The AMS-4170T is ideally suited to applications where a simple choice between two inputs or outputs is required

and may be easily driven by audio, video or other detector circuits for automatic path selection.
Each switch is equipped with its own transistor driver circuit, which may be bypassed for direct operation of the

relay if desired. Links allow any of the three driver circuits to operate more than one of the sets of relays.
Front panel LED indicators are used to indicate the status of each relay circuit.
Front panel switches allow a choice of local or remote control operation.
An optional SNMP (Simple Network Management Protocol) plug-in module is available for remote monitoring and

control when used in conjunction with IRT’s 4000 series frame fitted with SNMP capability.
The AMS-4170T is designed to fit IRT’s standard Eurocard frames as well as IRT’s 4000 series frame for use with

IRT’s SNMP system and may be used alongside any other of IRT’s analogue or digital Eurocards.

Standard features:

• One video and two balanced audio changeover switches in one package.

• Video path suitable for SDI (270 Mb/s), analogue video, MPEG data streams @ 2, 8, 34, 45, 144 Mb/s.

• Audio path suitable for 2 balanced audio or data signals or 4 unbalanced audio or data signals.

• Married or independent operation

• Default path on power fail.

• Local or remote control.

• Optional plug in SNMP monitoring and control module.

• Front panel LED status indicators.

VIDEO A I/P

AMS-4170T FUNCTIONAL BLOCK DIAGRAM

VIDEO B I/P

VIDEO A O/P

VIDEO B O/P

AUDIO B (L) O/P

AUDIO A (L) O/P

AUDIO B (L) I/P

AUDIO A (L) I/P

AUDIO B (R) O/P

AUDIO A (R) O/P

AUDIO B (R) I/P

A

UDIO A (R) I/P

SNMP

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Technical Specifications

IRT Eurocard module

Type AMS-4170T

Video:

Video crosstalk between channels < -70 dB to 10 MHz.
< -60 dB 10 MHz to 100 MHz.
< -50 dB 100 MHz to 300 MHz.
(With measured channel input terminated by 75 Ω.)

Audio:

Audio Crosstalk Between channels with measured channel input terminated by 600 Ohms.
Less than -90 dB (20 Hz - 20 KHz).

Control:

Inputs Ground active control to TTL level interface circuit, or
if interface circuit bypassed, to the relay coil with the common of the coil

circuit connected to +12 Volts.

Connectors:

Audio:

3 pin plug in screw termination sockets.

Control: 4 pin plug in screw termination socket.

Other:

Relay contact rating 24 Vdc - 1 A
100 Vac - 0.3 A
Power requirements: 28 Vac CT (14-0-14) or ± 16 Vdc
Power consumption 1 VA.
Temperature range 0 - 50° C ambient
Mechanical Suitable for mounting in IRT 19" rack chassis with input, output and

power connections on the rear panel.
Finish: Front panel Grey background, black lettering & red IRT logo.
Rear assembly Detachable silk-screened PCB with direct mount connectors to Eurocard

and external signals.
Dimensions 6 HP x 3 U x 220 mm IRT Eurocard.

Supplied accessories Rear connector assembly with matching connectors for control inputs.

Optional accessories SNMP plug-in module for use with 4000 series frame fitted with SNMP

“Agent”.

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Configuration

Transistor drive to relays:

The AMS-4170T comes standard with links LK2, 4 & 6 installed. This allows TTL logic to directly drive the relays
via transistor drive circuits. It is not necessary to use TTL logic to drive the transistor drive circuits, however,
grounding on the control port is all that is needed.

Direct drive to relays:

Provision has been made for bypassing the transistor relay drivers if required. This may be desirable in situations
where switching is to be initiated by alarm circuits with relay outputs.

The relay driver circuit can be bypassed as follows:

1. Remove links LK 2, 4 & 6.

2. Hard wire shorting links in positions LK 3, 5 & 7.

Ensure that only one link is installed of each pair so that the circuit is set for either TTL or direct operation, but not
both.

Relay grouping:

Each video and audio channel is equipped with its own driver circuit. However each circuit is capable of driving all
three sets of relays if required. Links LK 8, 9 & 10 provide a means of inter-connecting the relay sets so that only
one or two control inputs are required.
Some useful configurations are:

Unison operation: All three circuits switch from one control signal.

1. Remove links LK 2, 4 & 6.

2. Connect links LK 8, 9 & 10.

3. Control is via SK 5 pin 1 to ground (SK 5 pin 4).

In order for the front panel switches to work as intended, AMS-4170T should be run in unison operation.

Separate video & stereo audio operation:

1. One control signal for video, and separate control signal for stereo audio.

2. Connect LK 9 & 10.

3. Control for video is via SK 5 pin 1.

4. Control for stereo audio is via either SK 5 pin 2, or SK 5 pin 3.

If controlling video and audio separately the front panel switches will only work on the video part of the circuit.

Input termination:

No terminations are provided on the module so that the switcher can function in changeover mode. For 2 x 1
switcher applications the following terminations should be installed.

Video:

Output A only is used and should be terminated at connected equipment.
Output B should be terminated in 75 Ohms (or 50 Ohms if being used for 50 Ohm RF signals) using a BNC
termination plug.

Audio:

Outputs A only are used and should be terminated at connected equipment.
Output B may be terminated if desired by connecting termination resistors to the connector on the rear
assembly of the module. The resistor values should be chosen to match the characteristic impedance of the
rest of the connected audio system. For example for balanced 600 Ohms, two 300 Ohm resistors should be
used.
In most modern audio systems a low output impedance of approximately 40 Ohms and input impedances of
greater than 10 kOhms are used. If this is the case no termination of the unused audio output is required.

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Operation

See Configuration section for relevant link settings.

Control connections:

Control connections are via SK 5 plug in screw terminating connector located on the rear assembly.
Connecting the appropriate control input to ground will cause the relays to operate and the output state to cross over
as follows:

Control Input Output
High (or O/C

*

) A ↔ A

B ↔ B

Low (Gnd) A ↔ B
B ↔ A

Control input connector SK 5 pin configuration is as follows:

Pin Description

1 Video control

2 Left audio control

3 Right audio control

4 Gnd.

Note: * O/C = Open Circuit.

Front Panel Switches:

The AMS-4170T has two front panel switches – a local/remote switch and an activate/de-activate switch.

With the local/remote switch set to ‘remote’, the AMS-4170T behaves, and is controlled, as described above.

With the local/remote switch set to ‘local’, control connection via SK 5 on the rear assembly is bypassed. Control is
via the front panel activate/de-activate switch. Note that to fully function in the local mode, the AMS-4170T needs
to be run in unison operation as described in the Configuration section.

Note: SNMP control is disabled if the local/remote switch is set to local.