Omron CS1W-DRM21 Likely Cause CPU Unit Watchdog Timer Error, An error occurred in the CPU Unit

Troubleshooting with the DeviceNet Unit Indicators Section 9-1

CPU Unit Service Monitoring Error

CIO Area Flags Allocated to DeviceNet Unit

Bit 00 of n+10 (Unit Error Flag) will be ON together with one of the following combinations:

•Bit 05 of n+12 (the Master I/O Refresh Error Flag) and bit 01 of n+10 (the Master Function Error Flag) ON.

•Bit 05 of n+14 (Remote I/O Refresh Error Flag) and bit 03 of n+10 (the Slave Error Flag) ON.

Correction

Check the master scan list and slave scan list and reset with a correct alloca- tion.

7-segment	MS indicator		NS indicator	Error log (Hex)
HE	Red (flashing)	---		0002

Likely Cause

CPU Unit Watchdog Timer Error

Servicing from the CPU Unit is not at fixed intervals. Servicing is normally monitored at 11 s.

DeviceNet Unit Response

•Records the error in the error log.

•Stops master and slave remote I/O communications.

Performs the following processing if it receives FINS frames that must be passed along to the CPU Unit:

•Returns an error response (0302 Hex) to commands requiring a re- sponse.

•Discards other frames and stores an error record (010B Hex) in the er- ror log.

Note There is a possibility that this error will occur again. If it does occur again, restart remote I/O communications to return the system to normal operation.

Flags Allocated for C200H DeviceNet Master Unit (CIO n+24)

There is no status notification because communications with the CPU Unit are disabled.

CIO Area Flags Allocated to DeviceNet Unit

There is no status notification because communications with the CPU Unit are disabled.

Correction

Inspect the CPU Unit’s operating environment.

7-segment	MS indicator		NS indicator	Error log (Hex)
HF	Red (flashing)	---		0001

Likely Cause

An error occurred in the CPU Unit.

Note The CPU Unit’s watchdog timer error can occur during initialization.

DeviceNet Unit Response

•Records the error in the error log.

•Stops master and slave remote I/O communications.

Performs the following processing if it receives FINS frames that must be passed along to the CPU Unit:

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