| 摘要 |
PURPOSE:To control a start of an automatically balanced connection network by a central control device, and to easily execute the maintenance and operation, by providing a means adjusted automatically by a ringing tone to a 2-wire-4-wire converting circuit of a 4-wire system exchange having an automatically balanced connection network. CONSTITUTION:Terminals A, B are signal lines of the 2-wire line side, and terminals C, D are terminals of the transmission side and ther receiving side of the 4-wire line side, respectively. A terminal E controls either operating an automatic balancing function Zn or locking the terminal by its value, and is controlled by a central control device of an exchange basically. As for a controlling method, a subscriber of the line for which readjustment of the balanced connection network is required is discriminated in advance, this subscriber calls, this terminal is made a nonlocked state temporarily only when a ringing tone is being received, and the balanced connection network is adjusted automatically by the ringing tone. The terminal is returned to its locked state by a response of the subscriber to be called. |
