DATA COMMUNICATION SYSTEM USING PHOTO COUPLERS

摘要

A data communication system comprising a master station and n number of substations, each substation comprising a receiving photocoupler and a transmission photocoupler, and wherein a particular substation may be connected into a transmission line leading to the master station by connecting the receiving photocoupler in series in parallel circuit to the transmission line and wherein data transmission from the master station to the substation is accomplished by means of a current supplied forward with respect to the receiving photocoupler of the substation, and data transmission from the substation to the master station is done by means of a current supplied reverse with respect to the transmission photocoupler of the substation.