BACnet
BACnet — Building Automation and Control Networks — is the open protocol most of the building-controls world speaks. Standardized as ASHRAE 135 (and, internationally, ISO 16484-5), it models every sensor, setpoint, and command as a self-describing object: a point carries its own name, units, and value, so a workstation can browse a controller it has never seen and read what each point is. That object model, the services that act on it, and the networks that carry them are what these pages cover.
New to it? Work through the five lessons in order — they build from the object model up to the wire and out across the network. Already have a device on the bench? Jump to the tools: paste the number a controller reported and get its meaning. Everything here is open, needs no login, and tracks nothing.
Start here — the lessons, in order
1 Basics → 2 Services → 3 Networking → 4 MS/TP → 5 vs Modbus
The tools
Six field utilities — each one a table or resolver that turns a number a device reported into something you can read. No login, nothing to install.