Patent ID: 8341461

Claim:
An image forming apparatus comprising: a master control unit that controls a plurality of sub-master control units via a first communication line for forming an image on a printing material; said plurality of sub-master control units that respectively control any of a plurality of slave control units via a second communication line for implementing a function regarding an image formation, wherein each sub-master control unit controls different slave control units; said plurality of slave control units that controls a load for implementing the function; a third communication line that connects said master control unit with one of said sub-master control units; and a fourth communication line that connects one of said slave control units controlled by said one sub-master control unit with another slave control unit controlled by another sub-master control unit, wherein a connection bridge is formed by use of the second and third communication lines, and wherein in a case that an error occurs in the image forming apparatus, said master control unit determines a path, using at least one of the communication lines from among the first, second, third and fourth communication lines, for performing a communication of a diagnosis process based on a diagnosis result of a network, and performs the communication related to the diagnosis process via the determined path.