| 摘要 |
<p>A communication relaying device and a communication relaying method are comprised of plurality of production device connected with an IP network, a production monitoring and control device connected with the IP network for monitoring and controlling operations of the production devices, and a working state monitoring device for monitoring working states of the production devices from information included in an IP packet, to relay the IP packet sent to, and received from, the production devices, the production monitoring and control device, or the working state monitoring device. The communication relaying device holds IP address information and MAC address information granted in advance to the production devices and the production monitoring and control device, sends an ARP packet in which a MAC address granted to the communication relaying device is granted to the IP address information granted in advance to the production devices and the production monitoring and control device, and receives the IP packet sent from either the production devices or the production monitoring and control device. Further, the communication relaying device holds sequence numbers included in this IP packet, changes to sequence numbers which each of the IP packet addressed devices must receive, and relays the IP packet.</p> |
