Communication control device

In a system made up of a plurality of devices, e.g., an image forming device such as a copier and additional devices such as a RDF and a sorter, each of the devices incorporates a communication-only control unit. This enables communications between the devices to be performed independently of the device control inherent to the devices. The communication control unit includes a dual port RAM which can be accessed by the host controller for controlling the device and by a remote controller. The host controller, the remote controller and the other communication control unit are synchronized when the dual port RAM is accessed. The data set in a predetermined area in the dual port RAM by the hot controller is transmitted to the remote controller, and the data transmitted from the remote controller is stored in a predetermined area in the dual port RAM. In this way, communication is performed independently of the device control inherent to the device, and highly accurate and high-speed system control is ensured.