ASL INTERCOM MPS Series Configuration Manual Download

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MPS-Series – Configuration Guide

U-0664-0265.doc – Issue: 03 complete, approved

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If this surveillance is enabled, then in the absence of a surveillance tone, an Input Audio fault will be raised
and logged. This would indicate that the microphone audio connection is broken, or is a poor connection.

Note that on VAR4/12/20 the microphone input gain affects the surveillance tone. Therefore, the surveillance
tone detection should only be commissioned after configuring the microphone input gain; see Section “4.4.1
Microphone Input Gain” (page 25).

Enable the microphone surveillance tone detection and adjust the detection threshold level as follows:

Configure

Mode=LF

and

Level (dB)=

–

, enabling the Router to detect the presence of the low

frequency surveillance tone that is generated by ASL microphones.

On VAR8/DAU, set

Interval=005

Clear any existing faults by pressing the FAULT CLEAR button on the system front panel.

Make sure that no fault is reported for the microphone. Any fault reported by the microphone at this
stage should be cleared; see Section “4.4.1 Microphone Input Gain” (page 25).

Raise the surveillance tone level slowly (1 dB step) from –40 dB until “AUDIO INPUT” fault is reported
for the microphone.

Set the surveillance tone level to 4 dB below the level that caused the fault to be reported.

E.g. if a –18 dB level causes the fault, then set the surveillance tone level to –22 dB.

Clear faults and make sure that no faults are reported for the microphone.

4.4.3

Microphone Output Relative Gain

Menu:

Configuration

Config

System

Router

Inputs

Mic/Line

I/P #

–

input name

Paging Microphone

Audio

Gain

O/pGains

Possible values:

–40dB to 0dB (1dB steps)

System default configuration: ‘0dB’

Normally all input gains will be set to ‘balance’ each of the inputs, and the output gain will be set to give the
required level at each output. However, if any input is desired to have a different gain for a particular output
or outputs, then these inputs can be given a different gain relative to each appropriate output. This is the
‘Relative Output Gain’ setting, and can be used to e.g. avoid feedback for a microphone which is located in
one of its output zones.

Note that:

This setting is not used by the Control Node (VAR8-ACU).

Before carrying out this adjustment the input gains of all audio sources and the output gains for all zones
and other audio outputs must be set-up to ‘balance’ each input and output.

Ensure that the Relative Output Gain for each output is set to the default level (0 dB), and then for
each output in the system configure the Relative Output Gain as follows:

Disable any ANS for the output associated with the microphone, by setting it to ‘Off’:

Menu:

Configuration

Config

System

Router

Outputs

O/P #

–

output name

ANS

Where

is the output number and the

output name

is the configured output name, which may have

been changed to zone names.

Consult the system design documentation for zones associated with the microphone. These
associated zones are as programmed in Section “4.3.3 Microphone Priority” (page 23).