Absolutely do not have administrator rights on the development of computer problems, there will be a lot of accidents, debugging OPC is somehow always connected state sometimes returns 3, suggesting that not configuration, the problem is:
Do not run with administrator privileges OPCConfig.exe, resulting in PLC parameter CODESYS.ini configuration file is not written down codesys2.3 CODESYS2.3 installation directory folder, please pay attention to see C: \ Program Files (x86) \ XXX \ CoDeSys V2 .3 \ under CoDeSys.ini whether to update.
