Qt Modbus TCP C++

Roman111

#include <QCoreApplication>
#include <QModbusDevice>
#include <QModbusTcpClient>
#include <QVariant>
#include <iostream>
#include <QDebug>

using namespace std;
int main(int argc, char *argv[])

{
QCoreApplication a(argc, argv);
const QVariant adress("192.168.1.100");
qDebug() << "Start";

QModbusTcpClient* m_modbusDevice = new QModbusTcpClient;
// initial parameters
qDebug() << (m_modbusDevice->connectionParameter(QModbusDevice::NetworkAddressParameter));
qDebug() << (m_modbusDevice->connectionParameter(QModbusDevice::NetworkPortParameter));

//set parameters
m_modbusDevice->setConnectionParameter(QModbusDevice::NetworkPortParameter,502); // Порт Modbus на устройстве
m_modbusDevice->setConnectionParameter(QModbusDevice::NetworkAddressParameter,adress); // IP-адрес устройства

//check the status
qDebug() << int(m_modbusDevice->state());

//check the parameters
qDebug() << (m_modbusDevice->connectionParameter(QModbusDevice::NetworkAddressParameter));
qDebug() << (m_modbusDevice->connectionParameter(QModbusDevice::NetworkPortParameter));

m_modbusDevice->setTimeout(250);

//let's check the status again
 qDebug() << int(m_modbusDevice->state());


 m_modbusDevice->connectDevice();

 if (m_modbusDevice->state()==QModbusDevice::ConnectedState)
     qDebug() << "Connect";
 else    qDebug() << "Disconnect";

qDebug() << int(m_modbusDevice->state());


//always status 1 (QModbusDevice::Connecting State),
//need 2  (QModbusDevice::Connected State)

m_modbusDevice->disconnectDevice();

qDebug() << int(m_modbusDevice->state());

if (m_modbusDevice->state()==QModbusDevice::ConnectedState)
    qDebug() << "Connect";
else    qDebug() << "Disconnect";

return a.exec();

}

does not establish a connection...
what am I doing wrong?

Christian Ehrlicher

@Roman111 said in Qt Modbus TCP C++:

what am I doing wrong?

All this stuff can only work when the Qt event loop is running (so after a.exec()) - put your stuff into a proper class and use signals/slots to do something e.g. after the device is really connected ( m_modbusDevice->connectDevice();)

And please format your code with proper <code> - tags so anyone can read you code.