Protocol
Control
System
Users
Manual
2/12/01
12. Appendix B- Troubleshooting
12.1 PCS Troubleshooting
Below are some typical problems that may be encountered in the installation and use of the PCS.
Problem
Cause
Solution
Boot BIOS screen displayed on power
up or Board offline alarm
Problem with expansion board communi Check the wiring of the
communications between the
Controller and the expansion boards.
Also check the addressing of the
expansion boards.
Defrosts are not happening
Expansion board communications
Check Expansion board addressing and
communications (try forcing a defrost
and see if the appropriate relay on the
expansion board closes) also check for
board off line alarms.
Termination problem
Check the termination (either digital or
temperature) to insure that the sensor is
not shorted causing the controller to
terminate a defrost early
Temperature Probe bad
Temperature probe reads –623F (or a
very low value)
Probe is open
Temperature probe reads +687 (or a
very high value)
Probe is shorted
Pressure probe bad
Bad offset value
Check to insure that there is no offset
entered for the probe
Reads –90 lbs
Probe is open
Reads 400 or 401 lbs
Hardware failure
12.2 Supervisory System Troubleshooting
Below are some typical problems that may be encountered in the installation and use of the supervisory system.
Problem
Cause
Solution
Unable To Install PlantVisor
Do not have Administrator Privileges
on the PC
Log on as an administrator of the PC
before installing
The following message appears
“SmartKey Not Found. Running
Demo”
The supervisor does not recognize the
supervisory key.
Reinstall the Key on the USB port of
the PC.
Reinstall the PlantVisor Software
No data to the supervisor
The wrong serial port is being used
Check the com port assigned for the
supervisor
Addressing of the units is not correct
Check that all units have a different
address
Wiring problem
Check all wiring and insure that proper
termination is installed
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