Troubleshooting/Service
316 UDC3500 Universal Digital Controller Product Manual 3/07
7.6 Controller Failure Symptoms
Introduction
In addition to the error message prompts, there are failure symptoms that can be
identified by noting how the controller displays and indicators are reacting.
Symptoms
Compare your symptoms with those shown in Table 7-4.
Table 7-4 Controller Failure Symptoms
Upper
Display
Lower
Display
Indicators Controller
Output
Probable
Cause
Trouble-
shooting
Procedure
Blank Blank Off None Power Failure 7.7.1
OK OK Current
Proportional Output
7.7.2
OK OK Position
Proportional or
TPSC Output
7.7.3
OK OK Time Proportional
Output
7.7.4
OK
Displayed
Output
disagrees
with Controller
Output
OK
Controller
Output
disagrees
with Displayed
Output
Current/Time
Proportional Output
7.7.5
OK OK OK External Alarm
function does
not operate
properly
Malfunction in
alarm output
7.7.6
OK Displayed
Output
disagrees with
First Current
Output
OK
Controller
Current Output
#1 disagrees
with Displayed
First Current
Output
First Current
Output
7.7.2
OK Displayed
Output
disagrees with
Second Current
Output
OK
Controller
Current Output
#2 disagrees
with Displayed
Second Current
Output
Second Current
Output
7.7.2
OK Displayed
Output
disagrees with
Third Current
Output
OK Controller
Output
disagrees with
Displayed Third
Current Output
Third Current
Output
7.7.2
Display does not change when a key is pressed Keyboard
Malfunction
7.7.7