Abstract: An optical data is transmitted from station to station through an optical T-coupler attached to each station. The optical T-coupler splits the data signals into two paths with identical data being transmitted to the attached station and also the succeeding station. An optical to electronic conversion takes place as the data enters the station. Electronic digital switching within each station selects a "normal" mode of receiving data from the preceding station when data is valid or a "bypass" mode of receiving data from the station which precedes the preceding station. Switching from normal to bypass mode is performed by electronic switching and requires no optical switches.