Flowire CCo

From Zenitel Wiki

One of the Flowires in a cluster must be the CCo - Central Coordinator. CCo is essentially a bus master. By default, the Flowires automatically negotiate among themselves who is to be CCo.

By cluster we mean Flowires on a physical bus that share an NMK - Network Membership Key. If several NMKs are used, each "NMK-group" will be a cluster with its own CCo. (The Homeplug term for cluster is AVLN.)

But if there are more than two Flowires in a cluster, it can make a difference which Flowire is the CCo. If the CCo Flowire is lost, then the communication in the whole cluster will stop for several seconds until a new CCo is agreed upon. Therefore it is best that a network-side Flowire is CCo, so that an endpoint-side Flowire out in the field can be lost without affecting the rest of the cluster.

For point-to-point link between two Flowires, it does not matter.

Note icon In mixed cluster with both FCDC3 and FCDC1/2, FCDC1/2 should be set as "Not CCo", and one FCDC3 must be set as "CCo".

Configured PLC Role

Since Flowire SW version it is possible to configure CCo mode under the section "Configured PLC Role" in the device web interface.

There is a choice between three modes:

  • auto: Default - Negotiate who is to be CCo.
  • CCo: Force this Flowire to be CCo. Only one Flowire in the cluster can be forced to be CCo!
  • not CCo: This Flowire is never the CCo.

If you select one of the Flowires as forced CCo, then all the others in the cluster must be set as not CCo!


  • Set endpoint-side Flowires as not CCo
  • If there is only one Flowire in the cluster connecting to the network, set it as forced CCo
  • If there are two redundant Flowires connecting to the network (using RSTP), leave them as auto