E F Johnson Company 2425M70 Manual Do Utilizador

6-18

that option is enabled). If talkgroup selection has been disabled on the channel by 
programming, the talkgroup does not change, “NO LIST” is displayed, and a tone 
sounds.

Unit calls (also called Individual Calls) can be placed to a specific radio on Project 25 
channels using the Unit Call option switch (if programmed) or by menu selection. Only 
the individual ID of the target radio is sent (a talkgroup ID is not sent). The radios that can 
be called are preprogrammed in the Unit Call list.

To receive a unit call, the RF channel of the call must be selected or scanned and the 
correct NAC and unit ID must be detected. The ID of the calling radio is then transmitted 
back. To respond to the call, the radio must be programmed with the Unit Call option 
switch, and have a Unit Call programmed with the ID of the calling radio.

Place and receive a Unit Call as follows:

1 To transmit a unit call, press the Unit Call option switch (or select the menu option). 

The alias (tag) of the last Unit Call is displayed.

2 If required, rotate the Select switch to display the desired alias/ID. The alias and ID of 

the unit calls that have been programmed are alternately displayed.

3 Press and then release the PTT switch. Ringing is then heard and “WAIT” displayed to 

indicate that the radio is being rung. To disable this ringing but not the call, briefly 
press the PTT switch again. Ringing occurs for 20 seconds or until the call is answered, 
whichever occurs first.

4 When a unit ID call is received, two beeps sound (if tones are enabled), and “CALL 

RCVD” and the alias of the Unit ID are alternately flashed.

5 To respond, select the Unit Call mode by pressing the Unit Call option key. 

- If the call timer times out (set by programming) or the channel is changed before a 

response is made, the unit call mode is exited.

Telephone calls can be placed and received on P25 conventional channels. Telephone calls 
to be placed and received over the public telephone system using your radio require a 
Network Interface Unit (NIU). Telephone calls are programmed to operate in one of the 
following modes:

• Disabled

• Answer-only capability