Honeywell UMC800 - Manual (Page 94)

Diagnostics and Troubleshooting
Fault Detection and Troubleclearing
86 UMC800 Controller Installation and User Guide Release F
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
COMM A GOOD − − − none
COMM A BOARD
FAILURE POWER
LED flashes
13 times. The COMM A port
hardware has a
serious failure. Executes normally. Replace Comm
board.
COMM A BOARD NOT
FOUND POWER
LED flashes
13 times The main CPU
board has a non-
default address
and no COMM
port installed. Executes normally. Install CPU with
optional RS 485
communications
(if not installed)
or set COMM A
station address to
255.
COMM B GOOD − − − none
COMM B BOARD
FAILURE POWER
LED flashes
13 times. The COMM B port
hardware has a
serious failure. Executes normally.
All Modbus read
block outputs are
frozen at their last
read values. Replace CPU.
COMM B BOARD NOT
FOUND POWER
LED flashes
13 times The control file
configuration
requires a master
port and no Comm
Port is installed. Executes normally.
All Modbus read
block outputs are
frozen at their last
read values. Install Comm
Board or
download a
configuration that
has no Modbus
slave blocks
PANEL
(OI) NORMAL − − − none