TRANSCEIVER OPERATION
2-12
November 1999
Part No. 001-7780-500
channel is sampled while listeningto 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 checkedonce an incorrect Call
Guard (CTCSS/DCS) code is detected. Since it takes
much longer to detect an incorrectCall Guard signal
than a carrier, this time should be relativelylong to
prevent the interruptionsfrom making a message diffi-
cult to understand. Times of 0.5-8.0 secondscan be
programmedin0.5-secondsteps.
Changing The Priority Channel
If a specific priority channel is associat ed with
the current scan list, itcan be changed if the Priority
option switch is programmed.Proceed as follows:
1. Make sure all scanning is off (neither th e standard
scan “S” icon nor radio-wide scan icon
displayed).
2. Select the channel that you want to be the priority
channel using the channelselector 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”iconis
displayed to indicate that the selected channel is
now the priority channel.
2.4.13 STANDARD CONVENTIONAL CALLS
Standard conventional callsare calls to or from
other mobile units on the selectedchannel. The proper
coded Call Guard signaling (see Section 2.4.6) may
need to be transmitted forthem to receive your call
and also for you to receive their calls. Procee d as
follows to place and receivethese calls:
Placing a Standard Conventional Call
1. Turn power on andset the volume as described in
Section 2.3.2. Select the channel programmed for
the mobile you want to call (seeSection 2.3.7).
2. Monitor the channel automaticallyor manually as
described in Section 2.4.3.
3. Press the PTTswitch and the call proceeds as
follows:
•If the Busy Channel Lockout featureis
programmed on the channel, the transm itter is
automatically disabledif the channel is busy (see
Section 2.4.5).
•Otherwise, busy and out-of-rangeconditions are
not indicated and speaking can beginafter moni-
toring the channel.
4. Press (and hold) the PTTswitch to talk and release
it to listen.
Receiving a Standard Conventional Call
1. Select or scan the channelprogrammed for the call
you want to receive (refer to Sections2.3.11 and
2.4.11 for more scanning information).
2. When the call is received, press the PTTswitch to
talk and release it to listen.If scanning, you may
have to respond before scanning resumesto ensure
that the response occurs onthe channel of the call.
2.4.14 DTMF/ANI SIGNALING
DTMF (Dual Tone Multi-Frequency)tones can
be generated manually or automaticallyfor ANI
(Automatic Number Identificatio n) 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, pressing0-9, , or # on the keypad while
holding the PTT switchtransmits the corresponding
tone until the key is released.
Pre-Tx ANI - A preprogrammed ANI sequence is
automatically sent when you pressthe PTT switch.
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