Technician Troubleshooting Guide Model 478 (D-15)2
Figure 1. Operating Controls
Key ControlName Function
1 PowerSwitch Controlsa pplication of powerto the system.
PowerIndicator Light Indicatespower is applied to the system.
2 VolumeControl Adjuststhe internal speaker (listen) audio level.
3 StandbyT ouch Switch Silencesinterco maudio to eliminate pickup of undesired
background noise and reconnects optional music/message
sourceto theexternal speaker when unit is not in use. The
systemautomatically exits the standb y mode with vehicle
detection or when the Touch/Talk switch is pressed.
4 Touch/Talk Switch Controls talk/listen communications. Operator touches switch
to talk and cancel alert tone. Operator releases switchto
listen.
5 IndicatorLights Red indicates TALK mode.
Greenindicates LISTEN mode.
Yellowindicates vehicle presence.
Yellowlight abo ve STANDBY lights and all other lights are
extinguished whenthe system is placed in the standby mode.