E.F. Johnson Company 53SL ES Series, Руководство по эксплуатации

Страница: 61 / 190

53SL ES Series Mobile Radio Operating Manual April 2009 4-13
Operating Modes Section 4 - General Operation
4.2 Operating Modes
Each selectable channel can be programmed for the conventional (analog or Project 25
digital), SMARTNET/SmartZone, or Project 25 digital trunked operating mode. For
example, Zone 1/Channel 1 could be a conventional channel, Zone 1/Channel 2 a
SMARTNET channel, and so on. More information on these modes follows.
Note
All operating modes utilize certain functions that are activated/deactivated by pressing
and holding a particular button or switch. The “hold” interval is preset. When instructed
to “press and hold”, do so until the desired action occurs. For other operations (not
specified “press and hold”) only momentary pressing is required.
4.2.1 Conventional Mode
This is a non-trunked operating mode which accesses independent radio channels. There is
no automatic access to trunked channels. Selecting a conventional channel selects a
transmit and receive frequency and other channel parameters such as squelch control
coding.
Conventional channels can be either standard (analog) or Project 25 (digital). With digital
operation, the DSP (Digital Signal Processor) converts the audio signal to digital data
packets. Another difference is that analog channels use Call Guard (CTCSS/DCS) squelch
control and Project 25 channels use a NAC (Network Access Code) and talkgroup ID
codes.
With Project 25 operation, a NAC is transmitted which match the NAC programmed in
the repeater or base station equipment and the mobile(s) being called for communication
to occur. In addition, to receive standard group calls, the receiving mobile must be
programmed to detect the transmitted talkgroup ID code.
With conventional operation, a busy channel condition is detected automatically if the
busy channel lockout (transmit disable on busy) feature is programmed. Otherwise, it must
be detected manually. An out-of-range condition is not indicated by special tones or
messages as with SMARTNET operation because there is no initial data exchange with
the repeater that allows this condition to be detected. Operating features unique to
conventional channels are described in Section 6.
4.2.2 SMARTNET / SmartZone Mode
This is a trunked operating mode in which automatic access is provided to several RF
channels. ID codes are used to select what mobiles are being called and what calls are
received. Monitoring is performed automatically and special messages and tones indicate
busy and out-of-range conditions.