Troubleshooting Bacnet Ms/Tp - Carrier RTU Open v3 Integration Manual

Communications wiring
The following example shows the DIP switches set for 76.8k (Carrier default), and MS/TP.
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Connect the MS/TP network to the controller's J19 port. Connect to Net+, Net-, and SHLD.
Wire specifications
A dedicated 22 AWG shielded twisted pair wire (EIA 485)
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Maximum wire length 2000 feet (610 meters) or 32 nodes
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Devices should be daisy-chained and not star-wired
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Attach the drain/shield wire to both ends of the network segment and through every controller
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NOTE Use the same polarity throughout the network segment.
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Turn on the RTU Open's power.

Troubleshooting BACnet MS/TP

Check the following to troubleshoot your RTU Open:
1
Verify that the BAS and controller are both set to speak the BACnet MS/TP protocol on the Comm Selector
DIP switches DS3 - DS6.
2
Verify that the BAS and the controller are both set for the same baud rate:
Baud rate DIP switches DS2 and DS1
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Obtain a Modstat of the controller. Scroll to the bottom of the page to Network Communications to view
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the active protocol and baud rate.
3
Verify that the BAS is configured to speak 2-wire EIA-485 to the controller. The BAS may have to configure
jumper or DIP switches on their end.
4
Verify that the BAS and the controller have the same communication settings (8 data bits, No Parity, and 1
stop bit).
5
Verify proper connection wiring between the BAS and the controller.
6
Verify that the controller has a unique MAC address on the MS/TP bus. The controller's MS/TP MAC address
is set by its rotary address switches.
RTU Open v3
Integration Guide
Carrier Proprietary and Confidential
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