E F Johnson Company 2425770 사용자 설명서

Viking Portable 600 Radio Operating Manual

6-15

• Scanning is turned on and off by the Scan option button or menu parameter. Talkgroups 

(channels) can be programmed so that scanning automatically starts when the talkgroup 
is selected (Autoscan).

• When responding to calls in the scan mode, the programming of the Talkback Scan 

parameter determines if a response always occurs on the talkgroup of the call (Active 
Group) or the Selected Group if they are different. Transmissions at other times always 
occur on the selected talkgroup.

• Each talkgroup can be programmed to select one of the programmed scan lists or “No 

List” (scanning is disabled). If scanning is enabled and the selected channel does not 
permit scanning, it is automatically enabled again when a channel is selected that 
permits scanning.

• Up to 255 scan lists, each with up to 255 talkgroups from the same system can be 

programmed. The selected scan list can be temporarily changed and edited as described 
in Section 4.11.5.1, Group / Priority Scan Lists.

• In addition to calls on channels in the scan list, pages, private/unit calls, and telephone 

calls are received while scanning. Private and telephone calls are not interrupted by 
priority messages.

Every radio on the system has to register with the Zone or Site Controller so that the 
system knows where everyone is and if traffic from one site needs to be sent to another 
site. This is determined by the list of talkgroups associated with the radio.

When a call needs to be passed to a radio at another site, the traffic from one site to 
another is sent out over the control channel to the radios. When a radio is scanning, it is 
monitoring the call information being sent out over the control channel. The radio 
compares the call information (talkgroup and voice channel handling the talkgroup) to the 
scan list to see if any of the talkgroups it is scanning are receiving a call. If it finds a 
match, the radio moves to the voice channel for this call. If no one is registered on a 
talkgroup on the site being scanned, the call information for the call is not sent out by the 
Control Channel (because the Zone or Site Controller did not see a requirement to pass the 
information for this call) and the call will not be received.

For example: Radio 1 is on a call on talkgroup 1 on Site 1, Radio 2 is on talkgroup 2 on 
Site 2 and scanning. The call on talkgroup 1 from radio 1 is not heard by radio 2. Then, if 
radio 3 registers on talkgroup 1 on site 2, the call from radio 1 on site 1 will go to site 2. 
Radio 2, radio 3, and any other radios on site 2 and scanning, will hear the call.

The Viking Portable 600 radio supports Dual Priority talkgroups in all trunking and 
conventional formats.