Communications wiring
Unit Ventilator
CARRIER CORPORATION ©2019
Integration Guide
All rights reserved
16
Troubleshooting LonWorks 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 LonWorks (8 Data bits, No Parity, and 1 Stop bit):
Baud rate DIP switches 1 and 2 set to 38.4 kbps
LonWorks protocol DIP switches 3 and 4
Jumper set to EIA-485 when using the LonWorks Option Card
LON network terminated on LonWorks Option Card pins 1 and 2
NOTES
If RX LED is solid, then the terminations are incorrect.
If the network has greater than 32 devices or exceeds 2,000 feet, a Repeater should be installed.
If a controller begins or ends a network segment, a terminating resistor may be needed.
Start-up
Use one of the following interfaces to start up, access information, read sensor values, and test the controller.
This interface...
Provides a...
Field Assistant
application -
Runs on a laptop that connects to controller's Local Access port
1
Temporary interface
Equipment Touch
device -
Connects to controller's Rnet port
2
Temporary or permanent
interface
i-Vu®
application
Available for BACnet systems only
Permanent interface
System Touch
device
Available only for BACnet MS/TP systems.
Wire to a BACnet MS/TP network connector and a 24 Vac power supply
3
Temporary or permanent
interface
1
Requires a USB Link (Part #USB-L).
2
See the
Equipment Touch Installation and Setup Guide
for detailed instructions.
3
See the
System Touch Installation and Setup Guide
for detailed instructions.
CAUTION
If multiple controllers share power but polarity was not maintained when they were wired, the
difference between the controller's ground and the computer's AC power ground could damage the USB Link and
the controller. If you are not sure of the wiring polarity, use a USB isolator between the computer and the USB
Link. Purchase a USB isolator online from a third-party manufacturer.
