To possess the input-output control system null control control equipment

摘要

PROBLEM TO BE SOLVED: To allow a controller to properly transmit data to all input/output devices within one transmission unit even when a malfunction occurs in a line of systems different from each other in a plurality of input/output devices respectively connected to one controller by a multiplexed line.;SOLUTION: When a malfunction occurs in the multiplexed line between each of the input-output devices 12 and 14 and the controller 50, the controller 50 writes information showing that data cannot be transmitted to input/output devices connected to the line in a transmittable information table 28a and updates the information by an updating part 26c. When the controller 50 separately transmits data to all the input/output devices 12 and 13 within one transmission unit, the controller 50 uses a confirming part 26b to transmit the data through a transmittable line, while referring to the transmittable information table 28a, whenever data is transmitted.;COPYRIGHT: (C)2005,JPO&NCIPI