Rockwell Automation 1746-NI8 SLC 500 Analog Input Modules User Manual - Manual (Page 63)

7–4 Module Diagnostics and Troubleshooting
Publication 1746Ć6.8 - April 1997
Module Status LED (Green)
The module status LED is used to indicate module-related diagnostic
or operating errors. These non-recoverable errors may be detected
at power-up or during module operation. Once in a module error
state, the 1746-NI8 module no longer communicates with the SLC
processor. Channel states are disabled, and data words are cleared.
Failure of any diagnostic test results in a non-recoverable error and
requires the assistance of your local distributor or Allen-Bradley.