A control device, comprising: a user application processing part configured to detect slave devices (211, 212, 213), which are communication targets of control data having been set using a setting tool, and the slave devices are connected to a field bus; and a communication management part configured to perform communication management conforming to a control cycle of the control data, a control part configured to execute operation control of the communication management part and the user application processing part, the communication management part comprises a control cycle determination part configured to determine the control cycle using a pre-stored propagation delay time for each of the slave devices (211, 212, 213) that are the communication targets of the control data, the control part configured to execute a process of generating transmission data by the user application processing part, a process of communication by the communication management part, and a process of analyzing received data in the control data by the user application processing part in this order, on the basis of a process of generating the transmission data in the control data by the user application processing part, the control device and the slave devices (211, 212, 213) are connected to one other by a field network and the control device and the slave devices (211, 212, 213) perform communication of control data using the field bus via the field network, the communication management part comprises a propagation delay time measurement part configured to measure the propagation delay time, the propagation delay time is stored in association with a type of a slave device, and that the propagation delay time includes an outbound propagation delay time and a return propagation delay time. a user application processing part configured to detect slave devices (211, 212, 213), which are communication targets of control data having been set using a setting tool, and the slave devices are connected to a field bus; and a communication management part configured to perform communication management conforming to a control cycle of the control data, a control part configured to execute operation control of the communication management part and the user application processing part, the communication management part comprises a control cycle determination part configured to determine the control cycle using a pre-stored propagation delay time for each of the slave devices (211, 212, 213) that are the communication targets of the control data, the control part configured to execute a process of generating transmission data by the user application processing part, a process of communication by the communication management part, and a process of analyzing received data in the control data by the user application processing part in this order, on the basis of a process of generating the transmission data in the control data by the user application processing part, the control device and the slave devices (211, 212, 213) are connected to one other by a field network and the control device and the slave devices (211, 212, 213) perform communication of control data using the field bus via the field network, the communication management part comprises a propagation delay time measurement part configured to measure the propagation delay time, the propagation delay time is stored in association with a type of a slave device, and that the propagation delay time includes an outbound propagation delay time and a return propagation delay time.