Actually i did not at all, it's the first time i'm doing C# (i need to open a SQL Ce Database to make a custom tool for a software and i don't want to learn the MS UI stuff ^^) Thanks for the clarification !

@suslucoder are you sure com4 is the correct name ? something seems of, I would suggest using https://doc.qt.io/qt-5/qserialportinfo.html to query for the correct port and port name

@SGaist Ok, I saw his user name is "china-Qter", so I used chinese.

Uzupełniając moje pytanie. Próba dodania obiektu takiego jak punkt czy koło kończy się takim komunikatem.: QAxBase: Error calling IDispatch member AddCircle: Exception thrown by server Code : -2147024809 Source : Description: Help : Connect to the exception(int,QString,QString,QString) signal to catch this exception Ktoś może wie gdzie sprawdzić ten kod? Dzięki za pomoc Adam

@mrjj thx,I am astonished and I will try it soon...:(

All works well now. Thank you!

Any Idea?

the problem is solved or not?

This might be the culprit: while (serial->waitForReadyRead(200)) This will put your thread to sleep until data has arrived or 200 ms has elapsed. QSerialPort seems to rely on the message loop to handle data so this might interfere with it (?). There is no guarantee that you will have 512 bytes of data back at once either. There is a signal (QSerialPort::readyRead() ) you can use when received data arrives. Connect this to a suitable slot and buffer what has arrived each time the signal is fired (I assume you will not get all the data at once). Do this until you have 512 bytes then process it. Keep the event loop active if you have some other 'heavy' function somewhere (QApplication::processEvents() ).

@Jeroen3 Thank you for your sharing!

now get_function it is ok now i want to call a function with two argument but ICAPLfunction::Call must have ten argument what should i do here my exemple: VARIANT p[10]; p[0].lVal=1;p[1].lVal=4;p[2].lVal=0;p[3].lVal=0;p[4].lVal=0;p[5].lVal=0;p[6].lVal=0;p[7].lVal=0;p[8].lVal=0;p[9].lVal=0; VARIANT r; result4=fn->Call( p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], p[8], p[9], &r);