Issue
In MNB-1000 (Plant Controller) firmware Revision 1.50E, the Spanning Tree Protocol is Disabled, by default.
All previous versions were shipped with the Spanning Tree Protocol enabled.
Product Line
TAC IA Series
Environment
I/A Series MNB-1000 (Plant Controller), firmware Revision 1.50E, and later.
Cause
In some cases where multiple BACnet routers (eg, MNB-1000, UNC, ENC, etc) were installed on the same BACnet-IP internetwork, having the Spanning Tree Protocol enabled in the MNB-1000 would allow a "router loop".
Resolution
Be aware that in MNB-1000s with firmware Revision 1.50E and later, the Spanning Tree protocol is disabled, by default.
Click here to see the Release Notes for firmware Revision 1.50E .
It is always recommended the highest firmware version available for the MNB-1000 be used. Many issues have been addressed for better functionality.
