PROGRAMMABLE CONTROLLER AND CONTROLLING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To continue a proper control at a low cost even when power interruption is generated. SOLUTION: In this programmable controller executing a control processing based on a user program with a described timer instruction 101, a time measuring state by the timer instruction 101 in a user program area 100 is maintained when the power interruption is generated and the timer instruction 101 is continued based on the time measuring state by the maintained timer instruction 101 when recovering power supply.