Contemporary Control Systems BASrouter Application Guide - Manual (Page 3)

AG-BASRTB00-BD0 Page 3
Application Guide — BASrouters
C
ONTR LS O
®
CONTEMPORARY
Application #2 — Connecting Together BACnet’s Automation and Field Levels
One advantage of BACnet is that the same protocol
can operate at both the automation level, and the
field level where the field controllers are operating.
The automation devices are BACnet/IP compatible
operator workstations (B-OWS) and building controllers
(B-BC) while the field devices are application specific
controllers (B-ASCs). In order to interconnect these
two levels, a BASrouter is needed. On the BACnet/
IP side, the BASrouter can operate up to 100 Mbps
while supporting both auto-negotiation and Auto-MDIX.
On the MS/TP side, baud rates up to 76.8 kbps are
supported — 115.2 kbps on the BASrouterLX. Notice
that multiple BASrouters can reside within the same
BACnet internetwork. A cluster of MS/TP devices
located at distant parts of a building can be connected
to the same BACnet/IP network but at different
locations using separate BASrouters. This could be a
more convenient solution than using EIA-485 repeaters
to extend MS/TP networks especially if the MS/TP
devices cannot all operate at the same baud rate.
Using repeaters with auto-bauding MS/TP devices can
also be tricky.
BACnet MS/TP Network 1 BACnet MS/TP Network 2
BACnet/IP Network 3
PC
Configuration
Router 1
Configuration
Router 2
Configuration