Issue
Can a BACnet device instance number be changed from the UNC or ENC?
Environment
I/A Series, Niagara R2 and G3
Cause
Some third party BACnet devices come with a fixed instance number based on their model and address on an MSTP trunk. Having them on multiple trunks will cause duplicate instance numbers in the system.
Resolution
The R2 software does not have capability to do this. If the device instance number is changed in the shadow object communications to the device is lost before the new instance number is written to the device. The G3 software has a button at the bottom of the BACnet Device Manager page called "DeviceID" specifically for this purpose.