Thanks so much for your nice reply!
I tried to follow the suggestions from that page step by step carefully. Neither solution worked. The ‘State’ in the SCADA-Communicator was ‘error’. I tried in 3 computers in win10, win7 and xp. None of them worked. It’s so wired.
I tried to test the OPC server using other OPC client. They worked well. It means the OPC server has no problem. As you know, in the last time, I wrote a demo to communicate with the OPC server using codes from kpopc. It did work well when I did not use window service.
Therefore, I think the problem should be related to the window service. Could somebody advise how to solve this problem?