
Installing the MPC Open XP
MPC Open XP
MPC Open XP IO48/816
Carrier Proprietary and Confidential
CARRIER CORPORATION ©2017
Installation and Start-up Guide
All rights reserved
9
Wiring for communications
The MPC Open XP communicates using BACnet on the following types of network segments:
•
MS/TP communicating at 9600 bps, 19.2 kbps, 38.4 kbps, or 76.8 kbps
•
ARC156 communicating at 156 kbps
NOTE
For more networking details, see the
Open Controller Network Wiring Installation Guide
.
Wiring specifications for BACnet MS/TP and ARC156
Cable:
22 AWG or 24 AWG, low-capacitance, twisted, stranded, shielded copper wire
Maximum length:
2000 feet (610 meters)
WARNING
Do not apply line voltage (mains voltage) to the controller's ports and terminals.
To wire the controller to the network
1
Pull the screw terminal connector from the controller's power terminals labeled
24 Vac/26 Vdc
and
Return
(Ground).
2
Check the communications wiring for shorts and grounds.
3
Connect the communications wiring to the controller’s screw terminals labeled
Net +
,
Net -
, and
Shield
.
NOTE
Use the same polarity throughout the network segment.
4
Set the communication type and baud rate.
For...
Set BACnet Mode jumper to...
Set DIP switches 7 and 8 to...
MS/TP
BACnet MS/TP
The appropriate baud rate. See the BACnet
MS/TP
Baud
diagram on the controller.
ARC156
BACnet ARC156
N/A. Baud rate will be 156 kbps regardless of the DIP
switch settings.
NOTE
Use the same baud rate for all controllers on the network segment.
5
Wire the controllers on a BACnet MS/TP or BACnet ARC156 network segment in a daisy-chain configuration.
6
Install a BT485 on the first and last controller on a network segment to add bias and prevent signal
distortions due to echoing.