ASL INTERCOM VAR4 Operation Manual page 76

7. 7. Move to, and toggle to the required surveillance tone detection option in the left field: Move to, and toggle to the required surveillance tone detection option in the left field:
[Mode=Off] Level(dB)=-40 [Mode=Off] Level(dB)=-40
• •
[Mode=Off] [Mode=Off]
Disables the surveillance tone detection and prevents faults from being raised, e.g. when the VAR Disables the surveillance tone detection and prevents faults from being raised, e.g. when the VAR
Router input is connected to an audio source other than an ASL microphone, e.g., background Router input is connected to an audio source other than an ASL microphone, e.g., background
music, PC/DVA system, non-ASL microphones, etc. music, PC/DVA system, non-ASL microphones, etc.
• •
[Mode=LF] [Mode=LF]
Enables the VAR Router to detect and report the loss of the surveillance tone. Enables the VAR Router to detect and report the loss of the surveillance tone.
Default value: Default value: 'Mode=LF' (Low Frequency) 'Mode=LF' (Low Frequency)
Note: Typically this feature would be enabled (set to LF) if any ASL proprietary microphone is used, in Note: Typically this feature would be enabled (set to LF) if any ASL proprietary microphone is used, in
order to provide monitoring of the audio cabling. order to provide monitoring of the audio cabling.
This should be set to LF on Network Audio Channels. This should be set to LF on Network Audio Channels.
For BS5839 compliance the input surveillance MUST be enabled on Fire Microphone For BS5839 compliance the input surveillance MUST be enabled on Fire Microphone
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inputs. inputs.
8. Move to, and scroll the possible detection threshold levels until the required level (right level) is
displayed:
Mode=Off [Level(dB)=-40]
Default value: '–40'
Possible values: –40dB to 0dB (1dB steps)
Note: The surveillance tone level adjustment for any ASL Microphone is described in the following
guideline. Note that after each setting the SELECT key should be pressed in order to save the
new configuration.
This should be set to '–40dB' on Network Audio Channels.
9. Save the changes by pressing the SELECT key, or cancel by pressing the BACK key.
Adjusting the Surveillance Tone Level of ASL Microphones
1. Set 'Mode=LF' and 'Level (dB)=–40'.
2. Clear any existing faults by pressing the FAULT CLEAR button on the system front panel.
3. Any fault reported by the microphone at this stage should be cleared, see Section
and Suggested Actions".
4. Raise the surveillance tone level slowly (1dB step) from –40dB until the "IPXX AUDIO INPUT" fault is
reported. Where XX is the Mic/Line input to which the microphone is connected.
5. Set the surveillance tone level to 4dB below the level that caused the fault to be reported.
E.g. if a –18dB level causes the fault, then set the surveillance tone level to –22dB.
6. Make sure that no fault is reported for the microphone.
VAR4 / VAR12 / VAR20 - Operation Manual
Is sue: 03 complete, approved
Page 76 of 308 Page 76 of 308
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"20.5 Fault Codes