Rockwell Automation 1746-NT4 Series B,D17466.6.1 SLC 500 4-Channel Thermocouple/mV Input Module User Manual - Manual (Page 84)

Publication 1746-UM007C-EN-P - July 2004
7-6 Module Diagnostics and Troubleshooting
Troubleshooting Flowchart
End
Check LEDs
on module.
Module Channel
blinking
Module fault
condition
Normal module
operation
Channel is
not enabled.
Channel enabled
and working
properly
Is problem
Check to see
that module is
seated properly
in chassis.
Cycle power. .
corrected?
Contact your local
distributor or
Rockwell
Automation.
Yes
No
Check channel
status word
bits 12 15.
Bit 12
set (1)
Bit 13
set (1)
Bit 14
set (1)
Bit 15
set (1)
Enable channel if
desired by setting
channel config.
word (bit 11 = 1).
Retry.
End
End
CJC fault
has occurred
Check that wiring is secure at
both CJC assemblies and that
the temperature within the
enclosure is in the range limits
of the CJC sensor. Retry.
Fault
condition
Are
faulted channel(s)
configured for mV or
thermocouple
input?
mV
thermocouple
Is more than one
LED blinking?
No
Yes
Configuration error. Check
configuration word bits 0-3
for valid input type
configuration as well as bits
6 and 7 for valid
configuration setting.
Retry.
Over-range condition
exists. The input signal is
greater than the high scale
limit for the channel or the
CJC connections. Correct
and Retry.
Under-range condition
exists. The input signal is
less than the low scale limit
for the channel or the CJC
connections. Correct and
Retry.
An open-circuit condition is
present. Check channel and
CJC wiring for open or loose
connections. Retry. .
Is problem
corrected?
No
Channel
Status LED
on.
Channel
Status LED
off.
Yes
Is problem
corrected?
Yes
No
Status LED off
Module
Status LED on Status LED(s)
_
.
Contact your local
distributor or
Rockwell
Automation.
Contact your local
distributor or
Rockwell
Automation.