Abstract: A data transmission system having a plurality of stations and bus structure connected among the stations for sending an information data or an answer back data in a packet from one station to another station through the bus structure. Each station has a receiver which receives the packet and detects that the packet of information data is directed to the station by identifying the address data. If it is so detected that the packet is directed to this station, an acknowledge signal is produced. A carrier sensor is provided for producing a presence signal indicative of the presence of the packet on the bus structure. A counter starts to count time when the presence signal disappears, and produces first and second time-up signals after the lapse of first and second predetermined times, respectively, provided that the first predetermined time is shorter than the second predetermined time.

Abstract: A noise elimination circuit for eliminating noise signals from data given by a binary form includes a modulo in up/down counter having a first input for receiving binary data, a second input for receiving clock pulses and output for producing a counted signal. The counter is effected to count up in response to the clock pulses when the binary data is a HIGH, and to count down in response to said clock pulses when the binary data is a LOW. A decoder is provided which has inputs for receiving the counted signal, a first output for producing an indication signal when the counted signal corresponds to a first predetermined number i, and a second output for producing an indication signal when the counted signal corresponds to a second predetermined number j, in which i is equal to or greater than zero, j is greater than i and n is equal to or greater than j.