What does a CNF fault mean on the ATV61 and ATV71 drives?


21 July 2022

CNF fault on the ATV61/ATV71 drives.

Product Line:
Altivar 61 and 71


Drive is not connecting to the network.

CNF means communication network fault.
Check to make sure that if the drive is programmed for NET control that you are writing or reading a command to talk to the drive. 
Check your wiring. Make sure the network cables are isolated from any power leads or motor leads.
Check timeout settings as the command timeout may have passed to cause this fault.
Check the network set up parameters.
Check the option card for issue or try swapping out the option card.
For troubleshooting purposes if you need to temporarily disable the CNF fault, you can do so in the FLT menu.