Honeywell UMC800 - Manual (Page 91)

Diagnostics and Troubleshooting
Fault Detection and Troubleclearing
Release F UMC800 Controller Installation and User Guide 83
4/01
Controller
Diagnostic Summary
(In the User Utility and Operator
Interface)
Controller
LED on CPU
Fault Detection / Troubleclearing
Menu
Item
Status Possible Cause Controller Action User Action
CPU ADDRESS
ERROR POWER
LED flashes
4 times. Address Error
Detected. Executes normally. 1. Force a cold
start. (Toggle
controller mode
switch from
PGM to RUN.)
2. Isolate system
from noise and
force a cold
start.
3. Replace CPU
board.
CPU INSTRUCTION
ERROR POWER
LED flashes
4 times. Bad Instruction
Detected. Executes normally. 1. Force a cold
start. (Toggle
controller mode
switch from
PGM to RUN.)
2. Isolate system
from noise and
force a cold
start.
3. Replace CPU
board.
CPU VECTOR
ERROR POWER
LED flashes
4 times. Bad Vector
Interrupt. Executes normally. 1. Force a cold
start. (Toggle
controller mode
switch from
PGM to RUN.)
2. Isolate system
from noise and
force a cold
start.
3. Replace CPU
board.