E F Johnson Company 2425M80 Benutzerhandbuch

Draft 02 - Sep 1 2015

4-7

The radio can be installed so that the vehicle ignition switch as well as the front panel 
power switch of the radio control power. This is done by connecting the accessory cable 
ignition switch input to the vehicle ignition switch. Refer to the Viking Mobile Radio 
Installation Manual for more information. A Power Down Duration of up to 1,440 
minutes can then be programmed, or this feature can be disabled by programming 
“Infinite” delay so that there is no automatic power-off.

Both the ignition switch and the power switch must then be on for radio power to turn on. 
The delay can be overridden at any time by turning power OFF using the front panel 
power switch or turning the ignition switch back ON.

This power down delay can allow calls to be received or the horn alert to be active for a 
time after the ignition switch is turned OFF. At the same time, advantages of ignition 
switch control are used such as preventing the battery discharge that may occur if the radio 
is left ON for an extended period.

The horn alert feature sounds an external alert such as the vehicle horn when certain calls 
are received. It is available if a Horn option switch is programmed and the proper 
connection has been made to the external alert. The horn alert output is pin 4 of the 
accessory cable, and an external driver circuit of some type is usually required. Refer to 
the Viking Mobile Radio Installation Guide for more information on how to install this 
feature.

Additional information on the horn alert feature follows:

• It activates when receiving any Unit Call or Call Alert in the P25 conventional, 

SMARTNET/SmartZone, and P25 Trunking modes. It does not sound when receiving 
standard Group or telephone calls, and is not programmable on a per call basis.

• It must be manually enabled and disabled by the Horn option switch. It is not controlled 

by the vehicle ignition switch. When it is enabled, “HORN ON” is briefly displayed, 
and when it is disabled, “HORN OFF” is briefly displayed. It defaults to the OFF mode 
whenever power is turned on.

• If a power down duration is programmed as just described, it is functional during that 

delay.

• When activated, it can be programmed to sound for three 1-second beeps or 

continuously for 2 to 255 seconds. It then turns OFF until another Unit call or Call alert 
is received.