Troubleshooting/Service
318 UDC3500 Universal Digital Controller Product Manual 3/07
7.7.1 Procedure #1 – Power
Table 7-5 explains how to troubleshoot power failure symptoms.
Table 7-5 Troubleshooting Power Failure Symptoms
Step What to do How to do it
1
Check the AC or DC line
voltage.
Use a voltmeter to measure the AC or DC
voltage across terminals L1 and L2 on the rear
terminal panel of the controller.
Check the earth ground connection.
2
Make sure the chassis plugs
into the rear of the case
properly.
Withdraw the chassis and visually inspect the
controller board and the inside of the case.
Reseat the boards into the Chassis if
necessary.
3
Check the system for
Brownouts, heavy load
switching, etc., and
conformance to installation
instructions.
Refer to Section
2 – Installation.
4
Change Power board.
Installation instructions supplied with new
board.
7.7.2 Procedure #2 – Current Outputs
Table 7-6 explains how to troubleshoot Current Output failure symptoms.
Table 7-6 Troubleshooting Current Output Failure
Step What to do How to do it
1
Make sure that the controller is
configured correctly and that the
proper range (4 to 20 or 0 to 20)
is configured.
Refer to Section
3 – Configuration.
Configuration incorrect: Fix configuration
Configuration correct: Go to Step 2.
2
Check the field wiring. Output impedance must be less than or equal
to 1000 ohms.
3a
First Current Output: Test for
operation.
Change Output Set Up group function prompt
OUT ALG = CUR.
Make the Output Set up group function prompt
CO RANGE = 4–20
Go to Step 4
3b
Second Current Output: Test for
operation.
Change Options Set Up group function prompt
CUR2 OUT = OUTPUT
Make the Current #2 Options Set up group
function prompt CO RANGE = 4–20
Go to Step 4