COMMUNICATION CONTROL METHOD FOR FAST DIGITAL BRANCH LINE

PURPOSE:To prevent a time division multiplexer(TDM) at a reception side from being become impossible to receive a data signal from an-other TDM at a transmission side when the power source of the TDM at the transmission side is applied by performing the all-space control of the control progressive status bit of a fast port for constant time when the power source of the TDM is applied. CONSTITUTION:As shown in figure (e), the control signal status bit(S bit) of the fast port is controlled so as to be set at (0) (namely, all-space control is applied) during a time T3 after applying the power source to the TDM 5. As a result, the data signal B sent from the TDM 5 to a line 7 goes to the one shown in figure b' and an abnormal state in the period of time T1 can be solved. In such a way, the TDM 8 at the reception side can receive the data signal from another TDMs 4 and 6 at the transmission side correctly regardless of the data signal B.