i have a big problem!

I assigned the IP address to the PLC 192.168.0.1 and 192.168.0.2 for the computer. After that, i set PC/PC Interface for Step 7 to the network card. In WinCC i set the parameters connection to use S7Online (the same network card).

It was working until yesterday ... now there is no connection neither Step 7 nor WinCC. I don't know why.

The firewall is deactivated.

If I use the profibus interface with a notebook i can see the CPU diagnostic and there is no error, and i see the ethernet interface is connected.

In the computer if use the accesible stations menu, the CPU appears.

Then, the PLC see the computer, the computer see the PLC but Step 7 and WinCC are not connecting.

Any idea ?

Thanks in advance.

Miguel

we are using TPC/IP, it was working some days ago.

We had Norton AV installed, but it was uninstalled and the problem was not solved.

The firewall is deactivated.

In HW Config, if I use the menu PLC / Ethernet / Edit Ethernet Node in the option Browse... I can see the CPU with the right MAC address and IP address then the computer can reach the CPU using ethernet but something is blocking the communication in a higher level.

Any idea ?

Thanks

Miguel

we have discovered that the problem is in the netwok interface.

When the communication between the PLC and the computer is not working, if I disable and enable the network interface the communication start working again. 

When the comm fails if I restart the computer, the problem is not solved. I don't understand the diference between disable and enable the interface, and the computer complete restart.

I have a "manual" solution, now I need an automatic solution for this problem.

Any suggestion ?

Miguel