METHOD FOR CHECKING IP ADDRESS COLLISION OF ETHERNET COMMUNICATION MODULE OF PLC

摘要

The present invention relates to an Internet Protocol (IP) address collision checking method, and more particularly to an IP address collision checking method in which a Programmable Logic Controller (PLC) Ethernet communication module can check an IP address collision occurring in a network. The IP address collision checking method comprises the steps of: transmitting an Access Resolution Protocol (ARP) request message, in which an IP address of an Ethernet communication module has been set as a destination, to a counterpart communication module when an IP address collision checking request has been received; receiving an ARP response message transmitted by the counterpart communication module; determining whether an IP address of the counterpart communication module included in the ARP response message is identical to the IP address of the Ethernet communication module; and determining that IP address collision does not occur when it is determined that the IP address of the counterpart communication module included in the ARP response message is not identical to the IP address of the Ethernet communication module.