| 摘要 |
PURPOSE:To ensure that the function of each functional unit can be easily expanded without changing hardware by allowing any functional unit to intervene between a control means and each functional unit in an optically communicable state for light shielding. CONSTITUTION:An arrangement means 17, which arranges for intervention any functional unit which can receive light by shielding light information to each functional unit from a control means, that is, an option board 21 on a light path, is installed between a main control part 11 and each functional unit in an optically communicable state. In this case, the processing of the functional unit 14 to which light information is shielded funk the main control part 11 is forcibly restricted, and the process by the option board 21 allowed to intervene can be performed preferentially. |
