Control system for communications between driving units and control units

Abstract

An image forming apparatus including a status detecting unit for detecting a status of each portion of the apparatus, a driving unit for driving each portion of the apparatus, an input unit having an input data storing unit for storing input data detected by the status detecting unit, an output unit having an output data storing unit for storing data to be output for driving the driving unit, a controlling unit connected to the input data storing unit and the output data storing unit for controlling the whole image forming operation of the apparatus including a control of the driving unit, in accordance with a status detected with the status detecting unit or a predetermined rule, a network for transferring data between the controlling unit and a plurality of the input or output units, and a timing control unit for controlling the timing of data transfer over the network, wherein the timing control unit includes a plurality of timing control modes and selects one of the timing control modes in accordance with an instruction from the controlling unit. The plurality of timing control modes of the timing control unit includes a first timing mode of performing data transfer in accordance with a timing generated by the controlling unit and a second timing mode of performing data transfer independently from the timing generated by the controlling unit. The second timing mode is a mode of performing data transfer at a predetermined time interval.