Patent ID: 6941179

Claim:
A device control system in which at least one host device and at least one target device are connected to each other via a communications network, the target device including: a storage unit operable to store a plurality of pieces of program code required for control of the target device; and a managing unit operable to manage program code information associated with the pieces of program code, wherein the pieces of program code stored in the storage unit correspond to possible system environments of the host device, and two or more pieces of program code of different data sizes correspond to at least one of the possible system environments, and the host device including: an obtaining unit operable to obtain the program code information from the target device; a predetermined memory area operable to store one of the pieces of program code; an information parser for checking a system environment of the host device and a free space in the memory area, parsing the program code information, and determining, from out of the pieces of program code stored in the target device, a piece of program code that is suitable for the system environment and is storable in the memory area; a reading unit operable to read the piece of program code determined by the information parser from the target device, and to cause the read piece of program code to be stored in the memory area; and a controller for controlling the target device by using the piece of program code stored in the memory area.