BACKUP SYSTEM OF INTERFACE

摘要

PURPOSE:To smplify the constitution of a circuit, and to reduce the cost by using a stand-by input or output interface unit in common with each existing input or output interface unit. CONSTITUTION:M pieces of existing input/output interface units 20a-20m and one stand-by input/output interface unit 20s are provided on the inside of an input/output interface 20. A switching circuit 22 connects the stand-by input/output interface unit 20s in common and in parallel to each existing input/output interface units 20a-20m. When a fault is generated in one of the input/output interface units of the existing side, the input/output interface unit 20s of the stand-by side constituted so as to be connected in parallel on a matrix circuit is switched and connected to the faulty existing input/output interface unit by a selecting signal from a switching operating part 30.