Bus master device for a hazard alarming system and a hazard alarming system using the same

摘要

The invention concerns a bus master device for controlling the operation of at least one hazard alarming device (3) comprising: a first interface (15) for connecting a first bus (1) coupled with the least one hazard alarming device (3); a second interface (5) for connecting a second bus (7) coupled with a central control device (9); and an internal time determining device (11) for determining a local time signal to be used to control an alarm operation of the at least one hazard alarming device (3); characterized by comprising synchronisation means (13) for receiving a master time signal from the central control device (9) via the second bus (7) and for controlling the local time signal based on the master time signal.