BACnet IP Across Subnets
I have a few related questions with regard to using BACnet IP in the recent releases of Mango.
- How should the BACnet Local Devices be set up in a system operating across multiple subnets? Should there be a Local Device set up for each BBMD or is there no correlation between the two concepts? In the older versions of Mango I was able to discover a large number of our devices across multiple subnets with the data source set up with a Device ID of 0, a Broadcast Address of 255.255.255.255 and a Port of 47808. I have been unable to find a Local Device and Data Source setup under the newer versions that discovers nearly as many devices.
- Autodiscovery seems to work to a limited number of devices across subnets. Using a local Device of 0.0.0.0:47808 Mango always discovers exactly the same 115 devices almost instantly and then never discovers anything else. With all the other Autodiscovery tools we use (including the one in the older version of Mango) we find many more devices on our network but it takes several minutes for them all to report in. Does anybody know why this should be so different?
- How does the MAC relate to the older concepts of IP, Port, Network Number, Network Address and Instance Number. Working with our commercial BACnet providers, I was able to relate this older terminology to concepts they were familiar with. But, while I have found some references to a MAC in the literature, I have been unable to determine how that relates using real world BACnet systems from companies like Johnson Controls, Automated Logic, Delta, Siemens, etc.
Thanks for any help.