Specifications

Remote Field Bus
The Remote Field Bus uses a BACnet Router to connect remote BACnet MS/TP devices such as FECs and VMA16s
to the Metasys network. These devices include FACs, FECs, VMA16s, IOMs, TEC26xx Series thermostats, and
other BACnet MS/TP field devices. Although several routers from different manufacturers are available, the
recommended device is the LIP-ME201™ BACnet Router from Loytec Electronics GmbH. Do not use any
USB-powered MS/TP to IP converter, including the Johnson Controls® BACnet to MS/TP Router (TL-BRTRP-0).
Use a Remote Field Bus for applications where routing an RS-485 network directly to an NxE supervisory engine
is not practical because of distance, cost, or poor accessibility. In many cases, an IP network connection is available
at both the NxE supervisory engine and at some point near the BACnet MS/TP devices. By leveraging the Metasys
Remote Field Bus capability with installing the BACnet Router near the BACnet MS/TP devices, you can reduce
system cost. Also, when you choose MS/TP device integration with a router rather than BACnet Integration, access
to proprietary attributes, message types, and objects from Metasys field controllers is available. This functionality
provides you with more information and more capability than the standard BACnet attributes, services, and object
types. For example, at the Site Management Portal you can view proprietary attributes such as communication
statistics from mapped FEC Family devices. Also, remote MS/TP device integration supports the CCT Pass Through
option for downloading devices directly connected to the Remote Field Bus (but not to devices connected to the
sensor bus).
Figure 2 shows an example of a Metasys network with a Remote Field Bus.
Figure 2: Example of a Remote Field Bus
7MS/TP Communications Bus Technical Bulletin