There is disclosed an office communication system adapted to handle both bursty and continuous data transmission over a single transmission facility to a central switching network. A programmable station controller is used at each station location to interface a number of transmission inputs to the single communication link. The programmable station controller is arranged to statistically multiplex the inputs associated with the bursty data while allowing the continuous data to pass on dedicate time slots. Transmission compatibility between the types of data transmission received from the bursty and continuous data inputs is assured by subdividing the transmission on the single link into frames having four time slots. A fixed number of time slots of each frame are assigned by a central controller to active ones of the continuous data inputs while other time slots of each frame are assigned to the multiplexed bursty data inputs. One of the time slots of each frame is utilized for communicating control information between the programmable station controller and the central switching network controller.