Hi,

If you are using qextserialport just for windows I've a version that I re-wrote myself that gives the functions you need plus a few others. It's still a work in progress but everything so far works (without the bugs of qextserialport). If it would be any use post a note back on this thread and I will zip the current state of play as a reply (note - not many comments added yet that explain all the workings) .