User Manual

18
CHANNEL GUARD
Channel Guard is a method of reducing "channel chatter" by
equipping receivers with tone-responsive devices, which only allow
calls with the correct sub-audible tones to be heard by the user.
Channel Guard options and parameters are defined in the radio
personality.
The radio can be programmed on a per-channel basis to encode
and/or decode Channel Guard tones. Squelch Tail Elimination
(STE) can be enabled or disabled on a channel programmed with a
Channel Guard tone.
Channel Guard Monitor Function
The radio can be programmed, on a per-channel basis to transmit
with or without Channel Guard tones. STE can optionally be
enabled on a per-channel basis.
Ensure there is no activity on the channel by:
•
checking the
TX/RX LED
.
•
pressing and holding the
Monitor/Clear
button. Squelch noise
will be heard if the channel is clear of traffic.
Digital Channel Guard
Digital Channel Guard performs similar to Channel Guard except
sub-audible code words are decoded and/or encoded. STE is
standard with Digital Channel Guard operation.
SENDING DTMF WITH THE DTMF MICROPHONE
The optional DTMF microphone allows the radio to send DTMF
signaling. DTMF may be used in a radio system to access a
telephone line or to perform system control functions.
1. Select a channel. DTMF must be enabled on the channel.
2. Ensure there is no activity on the channel by:
•
checking the
TX/RX LED
.
•
pressing and holding the
Monitor/Clear
button. Squelch
noise will be heard if the channel is clear of traffic.
3. Remove the microphone from the hookswitch.
4. "Dial" the required DTMF digits from the telephone keypad on
the microphone. Do not hold the
PTT
button on the microphone