Single transmission bus data network employing an expandable daisy-chained bus assignment control line

摘要

This disclosure relates to a network of stations having a single transmission bus. A bus assignment control line is daisy-chained to all of the stations to form a closed loop such that an assignment signal will circulate through the loop and return to the originating station after each station has been given an equal chance to be serviced. Stations of a lower priority can be attached to the bus in such a manner that the preceding station will direct the bus assignment control signal to the lower priority stations with a frequency less than the transmission of the assignment control signal to a succeeding higher priority station.