FCDC-3 - Backwards compatibility
From Zenitel Wiki
The FCDC-3 is fully compatible with FCDC-1, FCDC-2 (including TFIX stations and Exigo Ex Access Panels) after these devices have been upgraded to software version 4.1.3.13 or newer.
- There is no compatibility if these devices are running version 4.1.3.12 or older. No connection can be established between the Flowire units.
If you mix software version 4.1.2.12 (or older) and version 4.1.2.13 (or newer) on the same Flowire network, there will be limited compatibility. You can do software upgrade, but regular operations will not work.