Rockwell Automation 1746-NT4 Series B,D17466.6.1 SLC 500 4-Channel Thermocouple/mV Input Module User Manual - Manual (Page 79)

1 Publication 1746-UM007C-EN-P - July 2004
Chapter
7
Module Diagnostics and Troubleshooting
This chapter describes troubleshooting using the channel status LEDs
as well as the module status LED. It explains the types of conditions
that might cause an error to be reported and gives suggestions on
how to resolve the problem. This chapter includes:
•
Module Operation vs. Channel Operation
•
Power-up Diagnostics
•
Channel Diagnostics
•
LED Indicators
•
Troubleshooting Flowchart
•
Replacement Parts
•
Contacting Rockwell Automation
Module Operation vs
Channel Operation The thermocouple module performs operations at two levels:
•
module level operations
•
channel level operations
Module level operations include functions such as power–up
configuration and communication with the SLC processor.
Channel level operations describe channel-related functions, such as
data conversion and open-circuit detection.
Internal diagnostics are performed at both levels of operation and any
error conditions detected are immediately indicated by the module’s
LEDs.
Power-up Diagnostics At module powerup, a series of internal diagnostic tests is performed.
These diagnostic tests must be successfully completed or a module
error results and the module status LED remains off.