A motor control system 1 includes a motor controller 20 to control a motor 30. An upper-level communication path 80 connects an upper-level communication port 24A of the motor controller 20 to an upper-level controller 10 that sends an instruction to the motor controller 20. A lower-level communication path 90 is connected to a lower-level communication port 24C of the motor controller 20 and connects a plurality of devices 40, 50, 60, 70 in series to each other. The devices 40, 50, 60, 70 include a rotational angle detector 40 and an output device 50, 60, 70. The rotational angle detector 40 detects a rotation angle of the motor 30. The output device 50, 60, 70 outputs associated information that is associated with the motor 20 and is different from the rotational angle or that is associated with an industrial device associated with the motor 30. The motor controller 20 performs a predetermined processing based on the rotational angle and the associated information, and sends a result of the predetermined processing to the upper-level controller 10.