Surveillance Tone Detection And Generation; Detection; Generation; Control - ASL INTERCOM VAR8-ACU 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 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.
The surveillance tone detection must be enabled on Network Channel inputs on the Slave Units
for recovery in case of network faults.
2.5.2

Generation

The Router emits a continuous 30 Hz surveillance tone, which is monitored by the Slaves Units for fault
reporting and recovery.
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 ASL Remote I/O Units (BMB01) to be configured in order to expand the Router's control
capabilities.
The additional functions include further digital contact inputs and outputs, analogue inputs, and ambient
noise sensing, remote volume and routing controls.
Each of the above functions is described in following sections.
VAR8-ACU and Variants - Product Description
Issue: 02 complete, approved
Page 13 of 44