Indeed, thank you for the pointer to the timeout section of the manual. I did not need the timeouts when using Device::SerialPort so I completely overlooked them. I changed my code and my "blocking" forever problem in Windows has been solved.

For some reason my program does not appear to be writing when running under Windows. It writes correctly under Linux, but my embedded controller does not see any activity when run under Windows. I'm not sure of the problem; however, I will read the Win32::SerialPort documentation more carefully.

Thank you for your suggestions and response.