Control system

A control system comprising:

• one or more control devices;
• and
• an information processing device, wherein
• the information processing device and the one or more control devices are communicatively connected over a first network,
• each of the one or more control devices and a field device are communicatively connected over a second network different from the first network,
• the information processing device includes (i) a first timer, (ii) a processor configured to perform control calculation processing of calculating control data in accordance with control calculation based on data received from each of the one or more control devices, and (iii) a storage for storing a server program configured to be executed by the processor,
• each of the one or more control devices includes a second timer, and a controller configured to perform input/output processing of transferring incoming data from the field device to the information processing device and outputting the control data received from the information processing device to the field device,
• the field device includes a third timer,
• the control system is configured to perform a synchronization management to time- synchronize the first timer, the second timer, and the third timer with each other, and
• the control calculation processing and the input/output processing are performed within a period of time based on the time synchronization and shared between each of the one or more control devices and the information processing device,
• wherein the shared period of time includes a control period,
• wherein the processing to be performed by the processor further includes processing of changing the shared the control period by M (M>1) times when a part of the shared control period in which the control calculation processing is performed is insufficient, and notifying the one or more control devices that the shared control period is changed by M times, and
• wherein the input/output processing includes processing of starting, in response to the notification from the information processing device, to collect the incoming data from the field device for M control periods (M>1) and transmit the collected the incoming data to the information processing device.