To facilitate ensuring a space for wirings and reduce required expenses for the wirings in a security system for condominiums by eliminating the need of a high-price line exchange and making the intercom wiring and the telephone wiring common to a LAN wiring.
The intercom system comprises an interphone IF 12 for making a D/A or A/D conversion process of input/output data between an IP telephone 13 and an assembled intercom 11, and an SIP server 61 for converting received room number data from the assembled intercom 11 to IP address data of the IP telephone 13 to send a calling signal to the IP address. This establishes a call between the fixed IP telephone 13 and the analog type assembled intercom 11 without the intermediate of a line exchange. A door 15 at the common entrance can be unlocked, using the IP telephone 13, and the intercom wiring and the IP telephone wiring are made common to a LAN wiring.
OSAWA TAKUYA
MIYASHITA HIROYUKI
SHODA NORIMITSU
IWATSU ELECTRIC CO LTD