Changing The Priority Channel; Standard Conventional Calls - E.F. Johnson 5100 SERIES Operating Manual

NOTE: Priority channel sampling (both analog and
P25 channels) currently does not occur when
receiving encrypted calls, and also when receiving
P25 calls if equipped with Flash code 1.10 or earlier.
In addition, the priority channel is not scanned if the
active channel is an analog channel on the same
frequency programmed with CTCSS/DCS squelch
control.
Either a single or dual priority* channels can be
programmed if desired. With dual priority, a call on
the second priority channel is interrupted by a call on
the first priority channel but not vice versa. When
scanning and the selected channel is a single or first
priority channel, is indicated in the display. This
indication is displayed regardless of whether the
priority channel is fixed or always the selected
channel. When it is a second priority channel,
displayed.
The priority channel sampling frequency is deter-
mined by the programmed Priority Lookback Time A
(see description which follows). For example, if 2.0
seconds is programmed, the priority channel is
sampled every 2.0 seconds when listening to a
message on a non-priority channel. When not listening
to a message, the priority channels are scanned in the
normal scan sequence. With dual priority, the first and
second priority channels are alternately sampled at the
Lookback Time.
Priority channel sampling occurs only with stan-
dard conventional scanning. It does not occur with
radio-wide scanning, when listening to any type of
SMARTNET/SmartZone/P25 trunked call, encrypted
call, or when transmitting (see preceding note). A
series of "ticks" may be heard when the priority
channel is sampled while listening to a message on
some other conventional 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
* This feature requires 51xx operating (Flash) software
1.5.0 or later and PCConfigure 1.17 or later.
Guard (CTCSS/DCS) or NAC 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
difficult to understand. Times of 0.5-8.0 seconds can
be programmed in 0.5-second steps.

5.11.4 CHANGING THE PRIORITY CHANNEL

If a fixed priority channel is associated with the
current scan list, it can be changed if the Priority
option switch or menu parameter is programmed. With
dual priority, this function changes only the first
priority channel. To change both priority channels, use
the Scan List Edit function described in Section 4.9.5.
is Proceed as follows to change the priority channel
2
using the Priority option switch/menu parameter:
1. Make sure scanning is disabled (
displayed) and the desired scan list is selected (see
Section 4.9).
2. Select the channel you want to be the priority
channel and then press the Priority option switch or
select that menu parameter. "Priority" is then
flashed to indicate that the current channel is now
the priority channel when scanning that list. Other
indications that may occur are as follows:
•
If "No Priority" is displayed, priority sampling
may not be enabled on the scan list.
•
If "Sel Chan" is displayed, the priority channel is
always the selected channel and cannot be
changed.
•
If no indication displayed, the scan list may not be
user editable or the channel may not be in the scan
list.

5.12 STANDARD CONVENTIONAL CALLS

Standard conventional calls are placed to other
mobile units monitoring the selected channel. The
proper coded Call Guard squelch tone or code or P25
NAC may need to be transmitted by your radio for
them to receive a call (see Sections 5.5 and 5.16.3).
29
CONVENTIONAL MODE FEATURES
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