Originally Posted by Cavalier
Andy's suggestion should work.
If you're using the Prolific USB to RS232
converter you may be running out of luck. I've had quite a few bits of software
become unable to talk properly through the Prolific chipset since a driver update was released and auto-installed around 8months ago.
Unfortunately, most of the USB/RS232 converters you'll find in the shops nowadays are based upon the Prolific chipset. The only solution I've found in some cases is to find an older laptop
with a serial
port and go direct.
Sent from my Windows Phone
I had the same problem with a USB radio
programming cable. It suddenly stopped working and after a little head
scratching, I discovered it was after a windows update. I did a google
search for an older driver, re-installed it over the newer driver and it started working again.
Check your hardware
devices list in control panel
and see if the prolific usb-serial device has a warning next to it. If it has a comm error, like device unable t ostart, just do a google
search for old prolific driver. If there's no error and it has a comm ort assigned, take note of the comm port number and enter it into the opencpn program.