JACE-645-R2 Fails to Learn BACnet Devices on MSTP Trunk – Error in Application Director

[Product_Support]

Issue

The JACE-645-R2 controller does not learn BACnet devices on its MSTP trunk and displays the following error in the Application Director:

devctl rx frame failed: No error  
java.lang.RuntimeException: mstp rcv failed  
at tridium.nre.qnx.mstp.QnxMstpDriver.rcvFrameJNI(Native Method)  
at tridium.nre.qnx.mstp.QnxMstpDriver.access$0(QnxMstpDriver.java)  
at tridium.nre.qnx.mstp.QnxMstpDriver$MstpTrunkListener.run(QnxMstpDriver.java:287)  
at java.lang.Thread.run(Unknown Source)

Product Line

TAC IA Series

Environment

• JACE-645-R2 retrofit board (TRD-RB-645)
• G3 version 3.8.37

Cause

The issue is caused by a problem with the platform drivers in G3 (version 3.8.37) that interface with R2, resulting in MSTP communication failure.

Resolution

Perform a clean installation using:

• G3 version: 3.6.47
• Commissioning tool: 3.6.406

This resolves the MSTP driver compatibility issue and restores BACnet device learning functionality.