Please see attachment. 

Master Honeywell already disable function write single/multiple coil ( If I enable them, link will be fail).

Only work holding register read and write.

Thanks and best regards,

Note: before not happen until when I upload program s7-300 and modify just insert one network and download so it happens fault write single/multiple coil.

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Split from Error FB80 Modbus slave .

Closed cause question posted twice.

The second thread with the subject CP341 Slave RTU S7 300: Honeywell master can't write single coil is published within the conference Communication / Networks.

Best regards
Min_Moderator