REDUNDANT PROGRAMMABLE CONTROLLER FOR EQUALIZING CONTROL DATA AND EQUALIZATION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a programmable controller which has a mechanism for achieving equalization processing without disordering the fixed periodicity of a fixed-period task. SOLUTION: A task which performs equalization processing is divided into processing for gathering equalization data and processing for transmitting the gathered equalization data. The equalization data are transmitted to a standby- side CPU while divided into multiple equalization files. When the timing of the start of the fixed-period task is reached during the equalization processing, the fixed-period task is interposed. Frame No.s and serial No.s are put in the equated files to accurately perform the transmission and reception. An in- operation side CPU and a standby side CPU has the same transfer table and transfer systems for gathering and distribution are changed according to the arrangement of the data to be equalized.