Issue
The purpose of this resolution is to inform users of Momentum M1E processors that the Ethernet port can lock up under certain circumstances.

The Ethernet port on Momentum M1E processors will lock up if the PLC scan exceeds Watchdog Timer (WDT) timeout value and the constant sweep function is enabled. This will occur using any version of 984LL or IEC Exec equal to or less than version 1.26.

When the fault occurs, the unit loses its RUN LED and produces a stopped error code 80. The user is not able to log back in using Concept and gets an error: "Illegal Modbus function code. Error Id: OL9-21581". Power cycling alone will not clear the fault but removing the battery and leaving the unit powered down for a few minutes will allow access back into the Ethernet port once it is powered back up.


Product Line
Momentum
   171CCC96020
   171CCC96030
   171CCC98020
   171CCC98030


Resolution
This problem has been resolved in IEC Exec version 1.27e. Reference Resolution 187847 for further details.

A temporary workaround to this issue is to disable the constant sweep function or increase the WDT timeout value.