A control system comprises a plurality of peripheral devices represented as objects, and a controller connectable to the plurality of peripheral devices via a common communication line for unitarily controlling the plurality of peripheral devices. The controller is arranged to be connected to an arbitrary number of peripheral devices selected from among the plurality of peripheral devices, read control information stored in the arbitrary number of peripheral devices via the communication line into a predetermined memory area of the controller in a predetermined format so that the controller can control the arbitrary number of peripheral devices. The controller is also arranged to issue a command and transmit the command to each of the arbitrary number of peripheral devices via the communication line.