PURPOSE: To complete works in a short time, by installing line concentration frames where subscriber units and control connection units mounted with plural subscriber circuit modules at each subscriber, for the number of frames corresponding to the scale of final state at the opening of a station and having only to plug in the subscriber circuit modules corresponding to the increase in the subscribers after the opening.
CONSTITUTION: At the start of the station, subscriber circuit modules equal to the number of subscribers 110 at the start of station are mounted on line concentration frames 101, 102, 103... selectively and the amount of calls are made adequate. Subscribers 111, 121... after the station start are connected to the frames 101, 102, 103... selectively and the subscriber circuit modules are mounted corresponding to the new subscribers 111, 121,.... Thus, the subscriber modules are mounted selectively, allowing to make the amount of calls adequate without rewiring jumpers as conventional systems.
ABE TOSHIO
SHINJIYOU MAMORU
