35
BACnet
1
Communication Option Wiring
WIRING THE UPC OPEN CONTROLLER TO THE MS/TP
NETWORK
The UPC Open controller communicates using BACnet on an
MS/TP network segment communications at 9600 bps, 19.2 kbps,
38.4 kbps, or 76.8 kbps.
Wire the controllers on an MS/TP network segment in a daisy-
chain configuration. Wire specifications for the cable are 22 AWG
(American Wire Gage) or 24 AWG, low-capacitance, twisted,
stranded, shielded copper wire. The maximum length is 2000 ft.
Install a BT485 terminator on the first and last controller on a net
-
work segment to add bias and prevent signal distortions due to
To wire the UPC Open controller to the BAS network:
1. Pull the screw terminal connector from the controller’s BAS
Port.
2. Check the communications wiring for shorts and grounds.
3. Connect the communications wiring to the BAS port’s screw
terminals labeled Net +, Net -, and Shield.
NOTE: Use the same polarity throughout the network segment.
4. Insert the power screw terminal connector into the UPC
Open controller’s power terminals if they are not currently
connected.
5. Verify communication with the network by viewing a module
status report. Perform a Modstat using the i-Vu tools Field
Assistant.
To install a BT485 terminator, push the BT485 terminator on to
the BT485 connector located near the BACnet connector.
NOTE: The BT485 terminator has no polarity associated with it.
To order a BT485 terminator, consult Commercial Products i
-
Vu
®
Open Control System Master Prices.
MS/TP WIRING RECOMMENDATIONS
Recommendations are shown in Tables 11 and 12. The wire
jacket and UL temperature rating specifications list two accept
-
able alternatives. The Halar
2
specification has a higher tempera
-
ture rating and a tougher outer jacket than the SmokeGard
3
spec
-
ification, and it is appropriate for use in applications where the
user is concerned about abrasion. The Halar jacket is also less
likely to crack in extremely low temperatures.
NOTE: Use the specified type of wire and cable for maximum sig
-
nal integrity.
Fig. 47 —
UPC Open Controller
1. BACnet is a trademark of ASHRAE.
2. Halar is a registered trademark of Solvay Plastics.
3. SmokeGard is a trademark of AlphaGary-Mexichem Corp.
8
7
6
5
4
3
2
1
09
8
7
6
5
4
3
2
1
09
BACNET
BAUD RATE
DIP SWITCHES
ADDRESS
ROTARY
SWITCHES
POWER LED
RUN LED
ERROR LED
BACNET
CONNECTION
(BAS PORT)
BT485
TERMINATOR
Tx2 LED
Rx2 LED
Tx1 LED
Rx1 LED
EIA-485
JUMPERS
RNET
INPUT