Surveillance Tone Detection And Generation; Detection; Generation; Control - ASL INTERCOM VAR8 Product Description

2.5

Surveillance Tone Detection and Generation

2.5.1

Detection

The Router is able to detect the presence of a low frequency 20 Hz surveillance tone on the Mic/Line inputs.
ASL Microphones produce this tone as standard and, in a networked system, the network audio busses also
carry this signal.
Surveillance tone detection can be configured 'on' or 'off' per input. The detection threshold is adjustable per
input. With surveillance configured to 'on' then in the absence of a surveillance tone, or with the surveillance
tone below the detection threshold, then an input audio fault will be raised and logged.
2.5.2

Generation

The Router is capable of generating a low frequency 30 Hz surveillance tone, at each audio output.
Surveillance tone generation is configurable either continuous 'on', 'off', or 'pulsed' per output. The outgoing
tone level per Router output is also adjustable.
Pulsed surveillance tone uses less power than continuous 'on' surveillance.
If configured as 'pulsed', the pulse interval is 20 seconds, and the pulse 'on' time is 1 second. The 'on' and
'off' envelope of the pulsed surveillance is so shaped that no audible artefacts can be heard.
2.6

Control

The following Control Functions are provided by the Control Ports:
•
Contacts
Enables any of the control ports to be configured to control Latent Routes i.e. pre-programmed routes,
which are enabled by a contact closure.
Routes may be assigned as Non-Latching or Latching. In the latter case, a separate contact is assigned
as a 'reset' contact to terminate the route.
Contacts may also be assigned as fault status inputs from external equipment.
•
Permanent
Enables certain routes to be set up as permanent. Typically used for background music.
•
Remote
Enables remote I/O units (ASL product: BMB01, EFI01, or third party Fire Loop Interfaces) to be
configured in order to expand the Router's control capabilities.
The additional functions include further digital contact inputs and outputs, analogue inputs, ambient
noise sensing, remote volume and routing controls, and direct connection to fire system loops.
Each of the above functions is described in following sections.
VAR8 and Variants - Product Description
Issue: 02 complete, approved
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