A2FV70D-A411000/HKU includes the /HKU cabinet interface, so an HKU signal or wiring condition can alarm while the CP471 controllers continue running. Check the cabinet sensor and HKU circuit separately.

A2FV70D-A411000/HKU may remain online through the other path, but the degraded cable, switch port or interface should be diagnosed and restored before another network fault removes redundancy.

For A2FV70D-A411000/HKU, trace the /HKU READY contact, cabinet wiring and receiving status point separately from the CP471 control state; a contact-path fault does not by itself prove controller failure.

Do not drop /HKU from A2FV70D-A411000/HKU without reviewing the cabinet monitoring and READY connections. The base controller identity alone does not include that interface scope.

A2FV70D-A411000/HKU uses the 100 to 120 V AC configuration encoded in A411000. Verify cabinet supply before comparing it with another A2FV70D suffix.

For A2FV70D-A411000/HKU, confirm duplex status, project compatibility, processor revision, power isolation, Vnet/IP paths and the approved transfer procedure before removing either controller side.