Omron CS1W-DRM21 Memory Access Errors, Bus Off Detected, Bus Off condition was detected

Troubleshooting with the DeviceNet Unit Indicators Section 9-1

DeviceNet Unit Response

Records the error in the error log.

•The Unit will go off–line and communications will be disabled. Error responses will be returned to all communications requests.

•The exchange of data with the CPU Unit will continue.

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

Bit 14 (Error Flag) and bit 01 (the Node Address Duplicated/Bus Off Flag) will be ON.

CIO Area Flags Allocated to DeviceNet Unit

Bits 00 and 06 of n+10 (the Unit Error Flag and Duplicated Node Address

Flag) will be ON.

Correction

Check the node addresses set on other nodes in the network. Correct the set- tings to eliminate the duplication and restart the DeviceNet Units.

Bus Off Detected

7-segment	MS indicator	NS indicator	Error log (Hex)
F1	---	Red (lit)	0340

Memory Access Errors

Message Monitoring Timer List Logic Error

Likely Cause

A Bus Off condition was detected.

DeviceNet Unit Response

Records the error in the error log.

•The Unit will go off–line and communications will be disabled. Error responses will be returned to all communications requests.

•The exchange of data with the CPU Unit will continue.

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

Bit 14 (Error Flag) and bit 01 (the Node Address Duplicated/Bus Off Flag) will be ON.

CIO Area Flags Allocated to DeviceNet Unit

Bits 00 and 05 of n+10 (the Unit Error Flag and Bus Off Flag) will be ON.

Correction

Check the following:

•Matching master and slave baud rates

•Proper cable lengths (trunk and branch lines)

•Broken or loose cables

•Installation of terminators at both ends of the trunk line

•Excessive noise

7-segment	MS indicator		NS indicator	Error log (Hex)
E6	Red (flashing)	---		021A

Likely Cause

There is an error in the contents of the message monitoring timer list stored in non-volatile memory.

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