Fault Detection And Troubleclearing; Table 20 Details Of The Diagnostic Summary Display - Honeywell UMC800 Installation And User Manual

Fault Detection and Troubleclearing

Interpreting the controller status and determining if any corrective action is necessary can be done by
referring to Table 20 and Table 21. Actions to clear fault conditions usually consist of restarting the
controller, and if the fault reoccurs, replacing the suspected faulty component. It is recommended that you
replace controller components only after performing all other actions listed for that fault condition.
NOTE: The controller status POWER LED is used to indicate a number of faults. A diagnostic fault
causes the POWER LED to flash. The LED will flash a number of times to indicate the type of fault
detected. (See the column "Controller LED on CPU" in Table 20.) The LED flashes quickly a number of
times followed by a long off period. This is similar to a telephone answering machine which uses a
flashing LED to indicate the number of messages. This indication is helpful when the operator interface or
PC is not connected or is not communicating with the controller.
ATTENTION
When replacement of a controller component is necessary, refer to procedures in
Maintenance section.
Controller
Diagnostic Summary
(In the User Utility and Operator
Interface)
Menu Status
Item
SYSTEM
GOOD
SYSTEM
OFFLINE MODE
SYSTEM PROGRAM
MODE
SYSTEM INVALID
CONFIG.
Release F
4/01

Table 20 Details of the diagnostic summary display

Controller
LED on CPU
Possible Cause
POWER RAM failed on
LED flashes power-up.
1 time.
RUN LED on Controller is in
RUN mode.
RUN LED Controller is in
flashes. OFFLINE mode.
RUN LED Controller is in
off. PROGRAM mode.
RUN LED A configuration
off. with more than 8
loops was
And
downloaded to an
8 loop controller.
POWER
LED strobes
Incomplete
12 times.
download of
configuration files.
UMC800 Controller Installation and User Guide
Diagnostics and Troubleshooting
Fault Detection and Troubleclearing
Fault Detection / Troubleclearing
Controller Action
Executes an infinite
loop that toggles
the LED.
Communications
and control are
disabled.
Executes the run
mode.
Executes the
Offline mode.
Function blocks are
not executed.
Empty database
created.
User Action
Cycle power;
If fault reappears,
replace CPU.
None
None
None
Download
previous valid
configuration.
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