An FC bus connects a Metasys system NAE, NCE, SNC, or SNE to CGMs, CVMs, FACs, FECs, VMAs or TEC36xxs, IOMs and XPMs. Third-party BACnet MS/TP devices such as the TEC26xx series thermostats can also be connected to the FC bus.
Figure 1. Example of an MS/TP communications Bus
On an FC bus, the NAE, NCE, SNE, and SNC is the bus supervisor. An FC bus supports up to three bus segments that are connected with network repeaters (Figure 1). See Local FC Bus rules and specifications for more information.