Operating Manual

March 2008 5100 ES Models II/III Portable Radio Operating Manual 5-11
Conventional Mode Features
Priority/Tx Selected - Priority sampling occurs and the priority channel or channels are
those programmed in the selected scan list. The radio transmits on the selected channel.
Priority/Tx Priority (1) - Priority sampling occurs and the priority channel or channels
are those programmed in the selected scan list. The radio transmits on the priority (1)
channel.
Priority (1) on Selected - The priority (1) channel is always the selected channel. The
radio transmits on the selected channel.
Talkback - No priority sampling occurs. The radio transmits on the channel of a call
while scanning is halted. Then once scanning resumes, it transmits on the selected
channel.
5.10.2 Priority Channel Sampling
The following describes priority sampling when scanning conventional channels.
Note Priority sampling when scanning SMARTNET/SmartZone/P25 Trunked channels is
described in Section 6.11.
The priority channel sampling feature ensures that when priority scanning, messages on
the priority channel are not missed while listening to a message on some other channel.
The radio can be programmed as just described so that the priority channel is a fixed
channel programmed in the current scan list, the currently selected channel, or not used.
Note Priority channel sampling is not available when receiving analog encrypted (DES) calls,
nor when receiving unit calls. In addition, the priority channel is not scanned if the active
channel is an analog channel on the same frequency as the priority channel and is
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, is displayed.
The priority channel sampling frequency is determined 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.
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