There are a few places that have to match up for this to work.
It looks like perhaps you are not matching up the Edge Thing name "OPC DA" with the Thing based on the "Edge" Template "ElgaOPC". I recommend you try naming your Edge Thing "ElgaOPC" vs. "OPC DA" since spaces are not allowed in ThingWorx.
If that does not work for you, we may need to get some of the log files and perhaps schedule a call with you.
Pai, thanks for the quick response!
"OPC DA" is Edge Thing Type I choose in ThingWorx .NET Edge Thing Configuration Manager. It's not name of Edge Thing on ThingWorx Composer.
Do you have the opportunity to connect by Remote Desktop Connection to the server and watch my configuration?
I will tell you credentials to connect.