Usually , it will be the these probablities for this issue.
1. This IP has already exited in this network,
We can modify the IP of the computer into the relative . after you modified successfully, you can connect the same cable connecting the PC before. You can ping it. if you can reach it. it means this IP exits. If you can`t reach it. you can go 2 or 3.
How to check the MAC of the terminal. Telnet the terminal. Enter the command:Main macaddr
2. Network loopback
There are many ways to check whether it exists network loopback. Such as the monitor port, it can detect the port. Here it`s not the important point.
3. Set the IP.addr into 192.168.x.x.(the newest terminal has been modified into 202.168.x.x)
The inner communication IP.addr is the same lP group for the old terminals. If we the IP.addr we designed before is the same. It will have this error. So we suggest the customer redesign the IP.addr.
Such as this case is a strange situation. Such as the abnormal service-operation. Strange to our facility etc.