Bacnet addressing mstp through ip router

I am developing a ui for a bacnet network on a single subnet: is the ip of the bacnet ip mstp router. I have 1 mstp device on mac address 1, mstp network number 3, mac address of router is 0, router device instance is 0.

I send a whois through node-red-contrib-bacnet, returns the objects and properties for the router, I can see its instance number etc. I can also view the roomsimulator running on my local machine, with the client set at I can use node red to read and write properties when that address is set as my device in the bacnet read and write nodes, respectively.

I am trying to figure out what to put in the device section of the bacnet read or write nodes to reflect the mstp address of network 3, device 1.

I can view the connected sensor on yabe, connected to the router, I use yabe to see its device instance 1176856, and subscribe to the analog inputs/values. This tells me that the router is storing the mstp address somewhere.

I have probably read every bacnet publication on the internet, and before delving into bacpypes I thought it would be prudent to check here first. This is also my first post so forgive me if it is in the wrong section, I've searched every topic here under term "bacnet" and "mstp".

I've attached screenshots of the configurations used.

It appears as if node red is sending a global broadcast address on instead of my local broadcast address of also on the whois request. Possibly willing to contribute cash, beer, bacnet testing lab fees.

I think you will ned to contact the author of that node directly as it's not one of the core ones and not often used by most of the folk here.

I was figuring that would be the way to go after posting, I have implemented the bacpypes application on my pi and will use the exec command to run a script. Was having trouble in the past with it because my loop back address was nonstandard.


Hi I was curious if you ever got this to work on reading an sensor value from a BACnet controller through an MSTP router on node red??? OR are you just going all Python bacpypes method?

Could you please let us know if it was successful. Were you able to read MSTP over node-red.

I was able to detect and write to / read from the mstp device through a router, using route aware notation of the python bacpypes commands using an exec node in node red.


could you provide this as an example flow?


Could you please share your solution

Since this node is based on bacstack there is an open issue, but someone in the thread got it to work by specifying the network number. Worked me also.

Look here: Using with MSTP Router · Issue #140 · fh1ch/node-bacstack · GitHub

And here: Using with MS/TP Router · Issue #28 · BiancoRoyal/node-bacstack · GitHub