Installation guide

VAR4 / VAR12 / VAR20 - Product Description
3.2 Audio Inputs
Dependent on model, the VAR Router has 4,12 or 20 electronically balanced universal inputs, these have
switchable sensitivity to accept microphone or line level signals, and have digitally controlled adjustable
analogue gain prior to the DSP. These analogue gain settings are non-volatile and retained even after power
failure and/or processor failure.
Each of these inputs features a serial communications interface to allow any ASL microphone to be
connected.
The first two of these inputs can also be used for ASL emergency or Fireman’s Microphones in Voice Alarm
systems, this is because they have the facility for an analogue bypass mode in the event of processor
failure/mis-operation, as required by BS5839 Pt 8. In the event of processor failure or communication failure,
the operation reverts to All-Call mode. These two inputs also support DVA routing for triggering DVA
messages.
Two Music inputs are provided, Music A and Music B. These accept stereo phono connections which are
mixed to mono internally. It must be noted that these Music inputs are pre-selectable in the analogue domain
prior to DSP routing. This allows two alternative background music sources to be connected. Only one can
be routed at a time.
Each VAR Router provides a number (2, 4 or 6 dependent on model) of Long DVA messages (32 seconds)
and a matching number of Short DVA (16 seconds) messages. These are treated as additional inputs to the
routing matrix.
One additional input is provided on the Audio-CAN port, this is the Amplifier Audio Monitor Bus.
All inputs described above feed a DSP Audio Routing Matrix. Audio is soft-switched to prevent clicks, and
fade times can be assigned suitable for background music applications.
Issue: 03 complete, approved
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