DATA COMMUNICATION EQUIPMENT

摘要

PURPOSE:To always synchronize the operator of an active transmitter with that of a standby transmitter by connecting the two transmitters by a synchronizing pulse common line in a data communication equipment provided with the active/standby transmitters and allowing he active transmitter to send a synchronizing signal to the synchronizing pulse common line to synchronize both the transmitters. CONSTITUTION:A NAND gate circuit 15 is an open collector circuit, and in using the transmitter 1 as an active transmitter, the output of a synchronizing pulse generator 14 is outputted to the synchronizing pulse common line l3. The standby transmitter 2 generates a synchronizing pulse similarly and the output to the line l3 is inhibited by the NAND gate circuit. The NAND gate circuit 16 is an open collector circuit and in using the transmitter 1 as the active transmitter, the output of a parallel/serial shift register 13 is outputted to an output data line l4. The parallel/serial shift register 13 outputs a data in the standby transmitter 2 similarly but the output to the line l4 is inhibited by the NAND gate circuit. Thus, the synchronization is not lost in switching the active/standby transmitters.