| 摘要 |
PURPOSE:To easily extend interphone sets, by adding an adaptor to the system. CONSTITUTION:When a hook switch HS of an interphone A1 is turned on, transmission/reception switches SW1, SW2 are selected to the transmission side, and when a channel selection switch CSW is depressed, a pulse signal is transmitted and received at a channel selection signal section SC of other systems A2-An. Further, the pulse signal is transmitted to a channel selection signal section SC1 of an adaptor AD, and when the pulse and the set number of the station are coincident, the call with the station to be called can be attained. Interphones B1, Bn of the other system are constituted similarly with the system A, a pulse is transmitted to the SC and when it is coincident with the set number of the station itself, an inter-station call can be attained. |
