Bi-directional controller area network communication system of multiple devices

A method of communication for a plurality of sub-devices from a first sub-device to an nth sub-device, which are connected to a main device through a communication line, the method comprising:

• providing a communication system, the communication system comprising a switch at each of both ends of the main device and at each of the plurality of sub-devices;
• opening and closing a first communication line between the main device and the plurality of sub-devices using the communication system;
• forming one termination end of the first communication line by opening the switch, wherein the communication system further comprises, at each of both ends of the main device and the plurality of sub-devices, a termination resistor and a termination switch;
• sequentially connecting the main device to each of the plurality of sub-devices to form the first communication line;
• directly connecting one end of the main device to one end of the nth sub-device to form a second communication line;
• and
• controlling, by a processor electrically connected to the switch and the termination switch, opening and closing operations of the switch and the termination switch.