E F Johnson Company 2425M70 Benutzerhandbuch

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4-13
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 several 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 must match the NAC programmed 
in the Repeater or Base Station equipment and the radio(s) being called for 
communication to occur. In addition, to receive standard group calls, the receiving radio 
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 radios are being called and what calls are 
received. Monitoring is performed automatically and special messages and tones indicate 
busy and out-of-range conditions.
Draft 4/29/2014