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Momentum M1E Ethernet Port Lockup Caution

Goals and Symptoms

The purpose of this resolution is to inform users of Momentum M1E Processor of a potential problem of the Ethernet port locking up under certain conditions.

Facts and Changes

The M1E Processor Ethernet port will lock up if the Constant Sweep function is enabled and the PLC scan time exceeds the user configured Constant Sweep time. This will occur regardless of which 984LL or IEC Exec is used. When the fault occurs, the unit will produce a stopped error code 80 and the user is not able to log back in and an error: "Illegal Modbus function code. Error Id: OL9-21581" will be displayed.

  • The processors affected are:
    • 171CCC96020
    • 171CCC98020
    • 171CCC96030
    • 171CCC98030

Causes and Fixes

This issue is under investigation by Engineering. An update to this Resolution will be made available when new information from engineering is received.

Recovery from this fault requires user intervention. To recover, power cycling alone will not clear the fault, but removing the battery and leaving the unit powered down for 5 minutes, will allow access through the Ethernet port once power is restored.

To avoid this issue, the constant sweep function in the PLC should be disabled.

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