Motion controller device and communication method therein

A motion controller device and a communication method for the motion controller device are provided to reduce the large number of man-hours that are required for making communication settings and wiring design in large-scale systems. The motion controller device and communication method improve the degree of freedom for communication line connections by switching the two transmission paths on the transmitting and receiving sides of the communication ports contained within a central communication device and a terminal communication devices for full duplex communications. The motion controller device and communication also ensure the response performance required in the devices being controlled by way of the terminal communication device that autonomously and dynamically switches the communication paths according to the volume of communication data on the communication line along this type of network.