| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a plant controller inexpensively duplicating PIO modules. Ž<P>SOLUTION: When using a PIO module 3 of a system A, a system-A DI/DO control signal S8 is output from a duplicated PIO switching logic circuit 5 to a first CPU 1, and a DI signal S1 of a DI module 31b is used as an input signal by selection logic in the first CPU 1. Further, the first CPU 1 sets a DO module device 42 to standby, outputs an output signal S14 to a DO module device 32 of the system A, and outputs a DO signal S3 from a DO module 32b. When a failure occurs in the DI module device 31 or the DO module device 32 in the system A, the failure is recognized by the first CPU 1 via a PIO bus 9 and control is performed by a PIO module 4 in a system B. Thus, the PIO modules can be inexpensively duplicated only by using one CPU and the duplicated PIO switching logic circuit 5. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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