Rockwell Automation 1762-IR4 RTD/Resistance Input Module - Manual (Page 71)

Publication 1762-UM003A-EN-P - February 2003
Diagnostics and Troubleshooting 4-3
Internal diagnostics are performed at both levels of operation. When
detected, module error conditions are immediately indicated by the
module status LED. Both module hardware and channel configuration
error conditions are reported to the controller. Channel over-range or
under-range conditions are reported in the module’s input data table.
Module hardware errors are reported in the controller’s I/O status file.
Refer to your controller manual for details.
Power-up Diagnostics At module power-up, a series of internal diagnostic tests are
performed. These diagnostic tests must be successfully completed or
the module status LED remains off and a module error results and is
reported to the controller.
Channel Diagnostics When an input channel is enabled, the module performs a diagnostic
check to see that the channel has been properly configured. In
addition, the channel is tested on every scan for configuration errors,
over-range and under-range, and broken input conditions.
Invalid Channel Configuration Detection
Whenever a channel configuration word is improperly defined, the
module reports an error. See pages 4-4 to 4-7 for a description of
module errors.
Out-of-Range Detection
When the input signal data received at the channel word is out of the
defined operating range, an over-range or under-range error is
indicated in input data word 5.
If module
status LED is: Indicated
condition: Corrective action:
On Proper Operation No action required.
Off Module Fault Cycle power. If condition persists, replace the
module. Call your local distributor or Rockwell
Automation for assistance.
IMPORTANT
There is no under-range error for direct resistance
inputs because 0 is a valid number.