TRANSCEIVER OPERATION
2-12
November 1999
Part No. 001-7780-500
channel is sampled while listening to a message on
some other channel.
The priority sampling times are programmed by
the following parameters:
Lookback Time A - This time determines how often
the priority channel is checked for activity. Times of
0.25-4.00 seconds in 0.25-second steps can be
programmed.
Lookback Time B - This time determines how often
the priority channel is checked once an incorrect Call
Guard (CTCSS/DCS) code is detected. Since it takes
much longer to detect an incorrect Call Guard signal
than a carrier, this time should be relatively long to
prevent the interruptions from making a message diffi-
cult to understand. Times of 0.5-8.0 seconds can be
programmed in 0.5-second steps.
Changing The Priority Channel
If a specific priority channel is associated with
the current scan list, it can be changed if the Priority
option switch is programmed. Proceed as follows:
1. Make sure all scanning is off (neither the standard
scan “
S
” icon nor radio-wide scan
icon
displayed).
2. Select the channel that you want to be the priority
channel using the channel selector switch on the top
panel. If the channel is in a different zone, also select
the appropriate zone.
3. Press the Priority option switch and the “
P
” icon is
displayed to indicate that the selected channel is
now the priority channel.
2.4.13 STANDARD CONVENTIONAL CALLS
Standard conventional calls are calls to or from
other mobile units on the selected channel. The proper
coded Call Guard signaling (see Section 2.4.6) may
need to be transmitted for them to receive your call
and also for you to receive their calls. Proceed as
follows to place and receive these calls:
Placing a Standard Conventional Call
1. Turn power on and set the volume as described in
Section 2.3.2. Select the channel programmed for
the mobile you want to call (see Section 2.3.7).
2. Monitor the channel automatically or manually as
described in Section 2.4.3.
3. Press the PTT switch and the call proceeds as
follows:
•
If the Busy Channel Lockout feature is
programmed on the channel, the transmitter is
automatically disabled if the channel is busy (see
Section 2.4.5).
•
Otherwise, busy and out-of-range conditions are
not indicated and speaking can begin after moni-
toring the channel.
4. Press (and hold) the PTT switch to talk and release
it to listen.
Receiving a Standard Conventional Call
1. Select or scan the channel programmed for the call
you want to receive (refer to Sections 2.3.11 and
2.4.11 for more scanning information).
2. When the call is received, press the PTT switch to
talk and release it to listen. If scanning, you may
have to respond before scanning resumes to ensure
that the response occurs on the channel of the call.
2.4.14 DTMF/ANI SIGNALING
DTMF (Dual Tone Multi-Frequency) tones can
be generated manually or automatically for ANI
(Automatic Number Identification) and other
purposes. The following options may be enabled by
dealer programming for each conventional channel:
DTMF Keypad - With full keypad (15-key) models
only, pressing 0-9,
, or # on the keypad while
holding the PTT switch transmits the corresponding
tone until the key is released.
Pre-Tx ANI - A preprogrammed ANI sequence is
automatically sent when you press the PTT switch.
*
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