GTT Opticom GPS System Installation Manual page 52

Intersection Equipment Installation Instructions
Table 9-1. Troubleshooting Symptoms, Possible Causes, and Solutions (continued)
Symptom
Call LED lights and controller
responds, but green light not
granted in time.
Call LED lights, but intersection
displays all red lights.
Call to controller will not drop.
Times in log are incorrect.
GPS will not acquire.
(GPS LED is amber.)
Possible Cause
Phase selector timing.
Controller not programmed
correctly.
Range and ETA set too short.
Approach map is not long enough,
or is drawn incorrectly.
Call was placed, but then dropped.
Radio/GPS unit is obstructed
preventing constant radio
reception.
Controller preemption input is not
programmed.
Long call hold time or lost signal
hold time programmed.
Vehicle is not in disable mode
Phase selector failed.
Controller input failed.
Time localization not set or set
incorrectly.
Initial start-up may take up to 15
minutes.
Radio/GPS unit's view of sky is
obstructed.
Garage GPS repeater not operating.
RF interference.
Incorrect wiring.
Radio/GPS cable connector
(terminal block) plugged in
backwards.
Radio/GPS unit failed.
Phase selector failed.
No power to GPS receiver.
Solution
Verify that there is no call delay in
phase selector and controller.
Program preemption routines to
respond as quickly and safely as
possible.
Increase range and/or ETA.
Redraw approach map.
Move unit or increase lost signal
timeout.
Program preemption inputs to
display green light as quickly and
safely as possible.
Reduce hold time.
Activate vehicle disable switch
Replace phase selector.
Replace controller.
Set correct offset for your area.
Wait 15 minutes.
Move unit or remove obstructions.
Repair or replace GPS repeater.
Turn off phase selector for 15
minutes, then try again.
Check wiring at both ends of
radio/GPS cable.
Plug in terminal block correctly.
Return unit to GTT for service.
Return unit to GTT for service.
Check voltage between brown (+)
and brown/white (–) wires at both
ends. It should be about 8.3 VDC.
49