Allen-Bradley 1756 Series, User Manual, Page: 104 / 136

104 Rockwell Automation Publication 1756-UM013B-EN-P - October 2019
Appendix A Troubleshoot Your Module
OK Status Indicators
The OK status indicator shows the module status.
Table 2 describes the I/O Status (ST) and Fault Status (FLT) status indicators.
Table 1 - Module OK Status Indicator
Indicator State Description
Off There is no module power applied.
Green The device is operating in a normal condition. At least one IO connection is in the established
state.
Flashing Green The device is OK, but it does not have a connection.
A connection may be established, but the Validator has not completed an initial Time
Coordination exchange.
Red The device has an unrecoverable fault.
Minimum recovery is to cycle power. It may be necessary to replace the device.
Flashing red • The device has a recoverable fault. The fault can be read from the device through the bus
or network.
• An IO connection time-out.
• Recoverable NVS Fault.
• A firmware update is being performed on the module.
Flashing Red/Green • Indicates that you must commission the UNID on the device.
Table 2 - Module ST/FLT Status Indicator
Indicator State Description
Off The digital I/O point is Off.
Channel is not configured or enabled.
Yellow The digital I/O point is On.
Flashing red • Open wire / open load
• Input/output Off
• Short circuit
Red Internal Malfunction
Flashing Red/Yellow • Open load
• Output ON / Open wire
• Input ON