With one thing and another, I decided that it was necessary to knock the rust off my Java skills. What better way to do it that create a PLC client in Java?
In just a few hours I had created the application and made it talk with the server, the communications object spins a thread to handle the asynchronous messages from the server, and for each message it generates a command object that is then sent to the main thread for processing. At the moment the only command that is handled is "DEVICE". This is usually in response to "GET DEVICES" from the client at login.
This evening I will be building out the UI in each tab so that devices can be seen and controlled. It wont take long, and then I can add additional command handling, both incoming and outgoing and make this a full featured client. Perhaps it will replace the wxWidgets client in the near future.