TLELECOMMUNICATION SYSTEM

摘要

Each of terminals connected to a center device supplies an information signal to the center device through a B channel of an ISDN. Displays indicative of both shot pictures at the terminals and whether the shot picture corresponds to a shot picture at any terminal, are made to a television monitor of the center device. Upon detection of an abnormal state by another terminal, a connection request signal and an abnormal state discrimination signal are supplied to the center device through a D channel of the ISDN. A terminal that has detected an abnormal state, and the contents of its abnormal state are displayed on the television monitor. A terminal connected to the center device through the B channel is switched to the terminal having detected the abnormal state, automatically or based on a user's operation. The terminal having detected the abnormal state transmits an information signal to the center device. A display indicative of a shot or photographed picture at the terminal having detected the abnormal state, a display indicative of the terminal having detected the abnormal state, and a display of the contents of its abnormal state are made. One center device is capable of performing monitoring by using a plurality of terminals. <IMAGE>