Programmable controller and synchronization control program

摘要

A programmable controller periodically controls a plurality of external devices. The programmable controller includes a temporary memory, a working memory, and a control unit. The control unit transmits request packets to each of the external devices, the request packets requesting transmission of device data to be used in control of the external devices, the external devices being targets to be subjected to synchronization control, acquires the device data from response packets received from the external devices in response to the request packets, and stores the acquired device data into the temporary memory, and writes the device data stored in the temporary memory into the working memory on the condition that the respective response packets in response to the request packets transmitted within the same control period are received from the external devices.