Via the relay modules, outputs can be switched. A relay module has no specific function but can handle any switch functions: monostable (eg a doorbell), bistable (on / off), timer, interval, thermostat output. Some relays can also control motors of blinds, curtains, gates.

In a Qbus system, motor control (for shutters, screens,…) can be done centrally (from the electrical distribution board) or decentrally (with a module on the bus closeby the motor).