Patent ID: 8570557

Claim:
An electronic equipment system provided with an apparatus main body and a plurality of optional apparatuses connected to the apparatus main body through a bus line which is capable of transmitting and receiving a signal, the bus line including a select line and a serial line, the electronic equipment system comprising: a main body side controller which is provided in the apparatus main body, the main body side controller outputting a command signal through the serial line and selectively outputting one of a signal indicating an optional apparatus as a destination or a signal instructing all of the optional apparatus to perform simultaneous communication through the select line as a select signal, to each of the optional apparatuses; an option side controller which is provided in each of the optional apparatuses, the option side controller which is provided in an optional apparatus indicated by the select signal accepting the command signal; a storage section which is provided in each of the optional apparatuses, the storage section storing the accepted command signal under a control executed by the option side controller; and a command executing section which is provided in each of the optional apparatuses, the command executing section executing a processing in accordance with the accepted command signal under a control executed by the option side controller, wherein when a command-save-bit which is a predetermined bit among bits constituting the accepted command signal is in a predetermined state, the option side controller controls the storage section to store the command signal and prohibits the command executing section from executing a processing in accordance with the command signal, when the command-save-bit is not in the predetermined state, the option side controller prohibits the storage section from storing the command signal and controls the command executing section to execute a processing in accordance with the command signal, and when the accepted select signal is a signal indicating the simultaneous communication, the option side controller reads the command signal stored in the storage section in advance and controls the command executing section to execute a processing in accordance with the command signal.