| 摘要 |
PROBLEM TO BE SOLVED: To prevent system resources from unnecessarily being occupied by deleting a port for communication and assigning a port for communication newly when a connection request is detected and a port number for communication is assigned to a controller, and establishing a connection with the controller. SOLUTION: An arbitrary controller sends a connection request to a standby port number of a system control unit 10 when the power source is ON or when there is no status request from the system control unit 10 for a given time. The system control unit 10 checks the IP address of the request when the connection request to the specific standby port number is detected and checks whether or not the port number for communication is assigned to the controller having the IP address. When the port number for communication is assigned, the thread of the port number for communication is deleted and a port number for communication is assigned to the controller to establish a connection. |
