Trane BACnet MS/TP - Page 14

14 BAS-SVX51L-EN
Best Practices
Meet requirements when adding zone sensor communication stubs to a Tracer
®
UC400/Symbio™ 500.
The wire that runs from a zone sensor to a unit controller is commonly referred to as a communication stub.
Figure 8 shows an example of communication stub-wiring to a BACnet
®
device. The stub is not part of
the BACnet
®
link; it is a wire that runs from the Tracer
®
UC400 IMC link down to the zone sensor. Ensure
that the zone sensor includes the optional communication module.
Any or all unit controllers on a link can be wired with a communication stub. Unlike LonTalk
®
links, there
is no limit on the number of unit controller communication stubs. Polarity must be maintained and the
length limit is 600 ft (183 m).
For ease of use, the wire for the communication stub can be the same as that used for BACnet
®
communication link wiring as described in “Configuring and Wiring the BACnet® MS/TP Link,” p. 8.
Note: UC400 is shown, but this applies to Symbio™ 500 as well.
Figure 8. Zone sensor communication stubs on Tracer
®
UC400/Symbio™ 500
BI LINK IMC
+
VDC
AI
AIAI AI AI
P P
TX
RX
LINK IM
SERVI
SERVICE TOOL
IM
BI LINK IMC
+
VDC
AI
AIAI AI AI
P P
TX
RX
LINK IM
SERVI
SERVICE TOOL
IM
+
Tracer
®
UC400
Zone sensors
Tracer
®
SC+
The zone sensors are wired into
the IMC terminals on the Tracer
®
UC400/Symbio™ 500 controller
BACnet
®
Terminator
Trace
®
r UC400