Ильнур

portCOM->write(ba);
portCOM->waitForReadyRead(200);

QByteArray data = portCOM->readAll();
while (portCOM->waitForReadyRead(10))
data += portCOM->readAll();

class ClassLA
{
private:
    float result_float;
    int i_test=0;

public:
    float getFloat(){

        result_float = (float)i_test++;
        return result_float;
    }
};
ClassLA la[5];


float getFloat(int number_of_device){
    return la[number_of_device].getFloat();
}

QLibrary lib ( LIB_NAME );
        typedef float ( *outputFloat )(int);
        outputFloat outputFloatd;
        for (int i=0; i<14; i++)
        {
            outputFloatd = ( outputFloat ) lib.resolve( "getFloat" );
            if( outputFloatd ) {
                qDebug() << outputFloatd(number_of_device);
            }
        }

connect( devices1, SIGNAL(sendData(int)), plot, SLOT(draw_a_point(int)) );