COMMUNICATION SYSTEM, CONTROL DEVICE, SETTING DEVICE, SETTING METHOD AND PROGRAM

Reliability with which a control device at a transmission destination can receive data is improved. In a communication system in which a plurality of control devices for factory automation are connected to a network, a communication protocol among the control devices includes a publish/subscribe type. Each of the control devices includes: a data storage unit in which control data is stored; a publisher unit that transmits data including a state of the control device of the publisher unit itself to other control devices than the control device; and a subscriber unit that receives data from each of the other control devices. When a state of each of the other control devices that is received by the subscriber unit satisfies a reception allowing condition, the publisher unit transmits the control data of the control device of the publisher unit itself.