'How to customize QModbusDataUnit to send hex values in modbus?

I would need to customize the QModbusDataUnit by sending custom hex via modbus, below my code, I'm trying to customize the post but I do not understand how to do it.

I should send the following values: 0x01,0x08,0x00,0x00,0x00,0x00,0xE0,0x0B

   void connessione::clickButton(){

  QModbusDataUnit readUnit(QModbusDataUnit::HoldingRegisters, 1, QVector<quint16>({0x01,0x08,0x00,0x00,0x00,0x00,0xE0,0x0B}));
        qDebug() << "readUnit" << clientX->state();

        if (auto *reply = clientX->sendReadRequest(readUnit, 255)) // client id 255
        {
            if (!reply->isFinished())
            {
                // connect the finished signal of the request to your read slot
                qDebug() << "connected" << reply->errorString();
                connect(reply, &QModbusReply::finished, this, &connessione::readReady);
            }
            else
            {
                qDebug() << "Errore" << reply->errorString();
                delete reply; // broadcast replies return immediately
            }
        }
        else
        {
            qDebug() << "Errore" << reply->errorString();
            // request error
        }
    }

but my response is:

D/libmodbusMobile.so(15006): (null):0 ((null)): qt.modbus: (TCP client) Sent TCP PDU: 0x0300080008 with tId: 0

where set 0x03 ? this is not right, it's not equal to my QVector send, how to solve ?

c++qttcpqt-creatormodbus


Solution 1:[1]

Try to test a QModbusDataUnit as follows:

QModbusDataUnit myUnit;
QModbusDataUnit::RegisterType myType;
myType = static_cast<QModbusDataUnit::RegisterType>(0x04);
myUnit = QModbusDataUnit(myType,0x0c,0x03);
cout << hex;
cout << myUnit.registerType() << endl;
cout << myUnit.startAddress() << endl;

Notes:

To use “cout” in a console QT application;

#include <iostream>
using namespace std;

To create a QT Modbus console application include the following in the .pro file;

QT += serialbus widgets
qtConfig(modbus-serialport): QT += serialport

TARGET = modbusserver

Sources

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Source: Stack Overflow

Solution Source
Solution 1

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