5
Volume Control Override Relays
It is important that announcements and/or
alarm signals come through at full volume,
regardless of the volume settings of
individual loudspeakers. The processor can
be programmed to switch in a series of relays
mounted on the Control Relay Card, which
correspond to the loudspeaker zones
selected. These in turn activate individual
volume control override relays in the
loudspeaker enclosures.
Using the Function Keys to Make a Call
Using the four Function Keys (mounted on
the Call Station) to make a call is done in
the same way as using the Keypad.
The main difference being that instead of
the operator selecting the zones using the
Numeric Keypad, the Function Keys route
the call to a pre-programmed selection of
zones.
This of course saves a great amount of time
when an operator has to frequently call the
same selection of zones, or when an “ALL
CALL” must be made in emergencies.
The Function Keys can also be used to select
and broadcast an alarm or attention tone, or
activate a pre-recorded message, without any
microphone generated call being made.
Whenever the function key is pressed its
Function Key LED illuminates, along with
any Zone Selection Indicators activated by
the routing of the Function Key. When the
call is completed the LEDs are extinguished.
Microphone and Control Input Calls
Calls, signals and/or pre-recorded messages,
can also be activated by means of a
microphone switch connected to the
Microphone Input Module, and a remote
switch wired to the Control Input Module
(The last of course without a “live” call).
Power on delay
In order to conserve power for battery
operated systems, the amplifier can be
switched on only when a call is made.
It causes a time delay (programmable from
2-9 seconds) between pressing an activation
key and the actual activation moment of the
call. Relay 3 of the Control Relay Module is
dedicated to switching the power to the
amplifier(s).
Alarm interrupt
In order to conform with certain European
military requirements an alarm call
generated by a contact on a Control Input
Module can be interrupted by a call with a
higher priority. After releasing the relevant
call key, the alarm signal will return for the
programmed duration. Selection of the non-
interrupted or interrupted mode is
programmable in the “CTL ALARM
MODE” program of the Installer Mode.
3 ATTENTION AND ALARM
SIGNALS
Built into the SM30 Control Centre is a
signal generator, programmed with more
than 40 attention tones and alarm signals.
These can be programmed, via the User
Menu, to proceed a call or pre-recorded
message, or to be activated independently.
As noted in the list below, some of these
signals are terminated when the Call Station
key, Control Input Relay, etc. is released.
Other signals stop after about 1 minute, or
when the Call Station activation key is
pressed again. In order to confirm with
STANAG (Standard Nato Agreement)
requirements, an alarm signal can be
interrupted by a call with higher priority.
After releasing the call key, the alarm signal
will return for the programmed duration.
Along with the list below, chapter 6 (Call
GB/SM 30 user manual 5/26/98 10:17 AM Page 5