DATA TRANSMISSION EQUIPMENT

PURPOSE:To eliminate the need for a transmission line supervisory device by selecting data from two ways depending on the priority of advanced order or simultaneous order, transmitting the data in a direction different from the reception direction, abolishing the data received from the other direction and transmitting data in two ways at the transmission from its own station. CONSTITUTION:In transmitting data from a station S1, a detection signal is outputted from a carrier detector 9c to an advanced order discriminating section 10 in a two-way transceiver 6 at the transmission of data, a discriminating signal selecting transmission data from a station master 1 is outputted to a relay control section 11 and the transmission data is transmitted at the same time to stations S2 and S4. Even when the reception data reaches the relay control section 11 during the transmission, the reception of the received data is abolished to eliminate the reception data. The transmitted transmission data collide with each other on a transmission line 5 between the stations S2 and S3, and since the succeeding data is abolished in the S2 and S3, the effect of signal interference due to multi-path caused in a ring transmission line is eliminated. If a faulty state takes place, an open loop is formed and the signal interference due to the multi-path is not generated.