A connection equipment (IJB 200) for connected to a control system (205) via a cable (206) and a field device (201) via a terminal port (306), comprising: a processor (300) configured to determine the terminal port corresponding to the field device reference included in a communication signal received from the control system and to instruct a transmitter/receiver (304) to transmit the communication signal to the terminal port determined, and an isolator (305B) configured to electrically isolate the communication signal to be transmitted to the field device via the terminal port and the electric power signal to be provided to the field device via the terminal port, from the other terminal ports.