Com port

The com port does not send interruptions to OS, because of its logic. So if you have a device on com port you should write program that periodically asks incoming buffer on com port, if it got anything in it. Otherwise, when you buffer is full there can be problems with periferial device.

We are under some project for cash machines. So we talk to this cash machine we have via com port, sending it commands and listening to output. We had issues in validation module, that was created by third-party, so we decided to rewrite the validation driver using protocol, it uses. We sent a few command and our program showed, there was nothing recieved. If only we knew from the beginning, that we should try to read from the comport we wouldn’t losthalf of a day.