Connection Opc server Moeller and Wincc explorer

[Ali_Reza]

Hello

I used Wincc 7.0 for visualization Moeller PLC data via Ethernet (TCP/IP) . I used Moeller OPC server and can connected to Wincc and  see tag value at first . but after few minutes tag can not be Update and be disconnect . (easy 800)
 


I use Moeller  OPC server . OPC server and client are at same PC

so what is Problem ?