ModBus master, GUI code?

Question

Qt

How to organize the algorithm for the master (ModBus ASCii)? for example, I form a request ":....." and send it to the slave device, how can I wait for a response then? using QtSerialPort

Answer 1

You need to read response with timeout.
Something like:

serial->write(msg, len);
if (serial->waitForReadyRead(timeout_ms))
{
    serial->read(buffer, 1);
    ....
} else //timeout error

why are you writing? there is also libmodbus