Sequence controller

A sequence controller comprising:

• a memory configured to hold a plurality of irregular processing function blocks;
• and
• a processor configured with:
• a periodic execution type sequence control module that executes periodically a regular processing function block in a predetermined control period;
• and
• a time-sharing execution type sequence control module that executes at least one of the plurality of irregular processing function blocks called from the memory by time-sharing in a free time of the control period in-between a time the processor executes periodically,
• wherein the plurality of irregular processing function blocks include time-sharing execution type irregular processing function blocks to be executed by the time-sharing execution type sequence control module, and a periodic execution type irregular processing function block to be used when periodically determined processing is performed,
• wherein the processor is further configured with an execution link generating module that generates a periodic execution link and a time-sharing execution link, the periodic execution link defining an execution order of only the regular processing function block and the periodic execution type irregular processing function block to be executed only by the periodic execution type sequence control module, the time-sharing execution link defining an execution order of only the time-sharing execution type irregular processing function blocks to be executed only by the time-sharing execution type sequence control module,
• wherein the periodic execution type sequence control module is configured to execute sequence control based on the periodic execution link,
• wherein the irregular processing function block called and executed by the periodic execution type sequence control module in the control period is formed so that repeated processing of the irregular processing function block is limited to one loop in the predetermined control period, and
• wherein the irregular processing function block called and executed by the periodic execution type sequence control module in the control period continues until completion even when there is no time left in the predetermined control period.