A bus is the system for data transmission between two or more units (actuators, sensors, ...). In a building automation system, a BUS adapted to the electrical installation (e.g. according to DIN EN 50090-5-1) is usually used for switching, reporting, measuring, controlling, regulating, displaying and monitoring. Data is transmitted wired (e.g. twisted pair, powerline) or wirelessly (e.g. radio, W-LAN, IR).
Source: bauwion
