If you agree, I believe at this point it would be best to discuss this over email in order to provide and gather more specific information about your particular setup.
I thank you very much for your understanding and look forward to your response.
It was never resolved, tracked it down to the device doing an unexpected USB reset, which temporarily removed and recreated all the COM ports from the windows device manager. The devices do it very intermittently with no identifiable cause. We are replacing them with Moxa units instead.
I would recommend you to please contact our Technical Support in order to get assistance with your device. This will be the best way for us to better analyze your particular situation and find the right solution or alternative (as in Rhona’s case) to match your needs.
I thank you very much for your understanding and look forward to hearing back from you.