Communications wiring
Unit Ventilator
CARRIER CORPORATION ©2019
Integration Guide
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10
3
Set communications selector for
EIA-485
.
4
Set both DIP switches
1
and
2
OFF for 9600 bps.
NOTE
Use the same baud rate for all devices on the network segment.
5
Set the DIP switches
3
ON and
4
OFF
for N2.
The following example is set for 9600 bps and N2.
6
Connect the communications wiring to the
Comm
port in the screw terminals labeled
Net +
,
Net -
, and
Shield
.
Wire specifications
○
A dedicated 22 AWG shielded twisted pair wire (EIA 485)
○
Maximum wire length 2000 feet (610 meters) or 32 nodes
○
Devices should be daisy-chained and not star-wired
○
Attach the drain/shield wire to both ends of the network segment and through every controller
NOTE
Use the same polarity throughout the network segment.
7
Turn on the power for the Unit Vent by connecting power terminals.
Troubleshooting N2 communication
The most common communication problems result from not properly following the configuration steps outlined
above in this manual. Review all of the steps and use the following list to check your settings.
Verify accuracy of the following:
Hardware settings
for N2 (8 Data bits, No Parity, and 1 Stop bit):
Baud rate DIP switches 1 and 2 set to 9600 bps
Protocol DIP switches 3 and 4
Jumper set to EIA-485
Proper connection wiring
