| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a duplex programmable controller and a synchronization method therefor which suppress an increase of program execution time due to an increase of synchronization time.SOLUTION: The duplex programmable controller comprises: a first control system CPU unit 11a in which a first CPU, a first program counter 16a and a first transmission and reception buffer 13a are provided; a second standby system CPU unit 11b in which a second CPU, a second program counter 16b, a second transmission and reception buffer 13b, and a comparison unit 17b are provided; and a two-way communication path 20 which transmits synchronization information from the first transmission and reception buffer 13a to the second transmission and reception buffer 13b. The second CPU unit 11b executes a synchronization program on the basis of a comparison result made by the comparison unit 17b comparing the synchronization information stored in the second transmission and reception buffer 13b with a value output by the second program counter 16b.</p> |
