A control system comprising: a control device configured to execute a control arithmetic for controlling a control target; and a support device configured to set content of the control arithmetic which is executed by the control device, wherein the control device includes a first arithmetic unit configured for cyclically executing a first task to which one or a plurality of processes is allocated in a first control cycle and a second arithmetic unit configured for cyclically executing a second task to which one or a plurality of processes is allocated in a second control cycle that is N times of the first control cycle, wherein N is an integer greater than 1, the control arithmetic includes a data collection process of collecting input data that is capable of being referred to by the control device and a data processing process of processing the collected input data to generate new data, a first data collection process with first input data as a target and a corresponding first data processing process are allocated to the first task, and a second data collection process with second input data as a target and a corresponding second data processing process are allocated to either of the first task and the second task in accordance with a setting via the support device, the control system being characterized in that when the second data collection process and the corresponding second data processing process are allocated to the second task, the first arithmetic unit is configured for not cyclically executing the second data collection process and the corresponding second data processing process in the first control cycle, and the second arithmetic unit is configured for cyclically executing the second data collection process and the corresponding second data processing process in the second control cycle, wherein both the first task cyclically executed by the first arithmetic unit and the second task cyclically executed by the second arithmetic unit comprise a motion control process. a control device configured to execute a control arithmetic for controlling a control target; and a support device configured to set content of the control arithmetic which is executed by the control device, wherein the control device includes a first arithmetic unit configured for cyclically executing a first task to which one or a plurality of processes is allocated in a first control cycle and a second arithmetic unit configured for cyclically executing a second task to which one or a plurality of processes is allocated in a second control cycle that is N times of the first control cycle, wherein N is an integer greater than 1, the control arithmetic includes a data collection process of collecting input data that is capable of being referred to by the control device and a data processing process of processing the collected input data to generate new data, a first data collection process with first input data as a target and a corresponding first data processing process are allocated to the first task, and a second data collection process with second input data as a target and a corresponding second data processing process are allocated to either of the first task and the second task in accordance with a setting via the support device, the control system being characterized in that when the second data collection process and the corresponding second data processing process are allocated to the second task, the first arithmetic unit is configured for not cyclically executing the second data collection process and the corresponding second data processing process in the first control cycle, and the second arithmetic unit is configured for cyclically executing the second data collection process and the corresponding second data processing process in the second control cycle, wherein both the first task cyclically executed by the first arithmetic unit and the second task cyclically executed by the second arithmetic unit comprise a motion control process.