GB1143746A - Data transmission system for more than two subscribers - Google Patents

Abstract

1,143,746. Data transmission systems. TELEFUNKEN PATENTVERWERTUNGS G.m.b.H. 15 March, 1966 [17 March, 1965], No. 11263/66. Heading H4P. In a system in which the same data is transmitted to at least two receivers E and in which errors are corrected by repetition, the receivers E are connected to the transmitter S by one or more transmission lines L which are returned to the transmitter. There may be a plurality of receivers in series on each transmission line loop. Errors in transmission are detected by returning to the transmitter the data from the final receiver on each loop for comparison with the data as originally sent on that loop. Alternatively, the return signal may comprise signals derived from the final receiver, e.g. redundancy signals. Each receiver may correct errors prior to passing the corrected data to the following receiver. If the errors cannot be so corrected the data is deliberately mutilated, to ensure that repetition occurs. The receiving unit of the transmitter may have means to detect correct data on a loop and itself to transmit such correct data to any other loop containing a receiver which detected error in that data, the transmitter being stopped during this action, or may have means to compare corresponding data on each loop and to determine, by majority decision, which loops transmitted correctly.