qt中modbus串口和tcp协议源码

以下是在Qt中使用Modbus协议进行串口通信的示例代码：

#include <QtSerialPort/QSerialPort>
#include <QDebug>
#include "qmodbusrtuserialmaster.h"

QModbusRtuSerialMaster* modbus;

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QSerialPort serial;
    serial.setPortName("COM1");
    serial.setBaudRate(QSerialPort::Baud9600);
    serial.setDataBits(QSerialPort::Data8);
    serial.setParity(QSerialPort::NoParity);
    serial.setStopBits(QSerialPort::OneStop);

    if (!serial.open(QIODevice::ReadWrite)) {
        qDebug() << "Serial port open failed.";
        return -1;
    }

    modbus = new QModbusRtuSerialMaster(&serial);
    modbus->setConnectionParameter(QModbusDevice::SerialParity, QSerialPort::NoParity);
    modbus->setConnectionParameter(QModbusDevice::SerialDataBits, QSerialPort::Data8);
    modbus->setConnectionParameter(QModbusDevice::SerialStopBits, QSerialPort::OneStop);
    modbus->setTimeout(1000);

    if (!modbus->connectDevice()) {
        qDebug() << "Modbus connection failed.";
        return -1;
    }

    QModbusDataUnit request(QModbusDataUnit::HoldingRegisters, 0, 10);
    request.setValue(0, 123);
    request.setValue(1, 456);
    request.setValue(2, 789);

    if (modbus->sendWriteRequest(request, 1) == -1) {
        qDebug() << "Write failed:" << modbus->errorString();
        return -1;
    }

    while (modbus->state() != QModbusDevice::UnconnectedState) {
        QCoreApplication::processEvents();
    }

    modbus->disconnectDevice();
    delete modbus;

    return 0;
}

以下是在Qt中使用Modbus协议进行TCP通信的示例代码：

#include <QtNetwork/QHostAddress>
#include <QDebug>
#include "qmodbustcpclient.h"

QModbusTcpClient* modbus;

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    modbus = new QModbusTcpClient(&a);
    modbus->setConnectionParameter(QModbusDevice::NetworkPortParameter, 502);
    modbus->setConnectionParameter(QModbusDevice::NetworkAddressParameter, QHostAddress("192.168.0.1"));
    modbus->setTimeout(1000);

    if (!modbus->connectDevice()) {
        qDebug() << "Modbus connection failed.";
        return -1;
    }

    QModbusDataUnit request(QModbusDataUnit::HoldingRegisters, 0, 10);
    request.setValue(0, 123);
    request.setValue(1, 456);
    request.setValue(2, 789);

    if (modbus->sendWriteRequest(request, 1) == -1) {
        qDebug() << "Write failed:" << modbus->errorString();
        return -1;
    }

    while (modbus->state() != QModbusDevice::UnconnectedState) {
        QCoreApplication::processEvents();
    }

    modbus->disconnectDevice();
    delete modbus;

    return 0;
}

以上示例代码中，使用了QModbusRtuSerialMaster和QModbusTcpClient两个类来实现Modbus协议的串口和TCP通信。需要注意的是，这两个类都需要通过setConnectionParameter函数来设置连接参数，如串口的波特率、数据位、校验位、停止位等，TCP的IP地址和端口号等。同时，还需要设置超时时间，以避免通信超时导致程序崩溃。在发送数据时，需要创建QModbusDataUnit对象，设置数据类型、起始地址和数据值等，然后调用sendWriteRequest函数发送数据。在等待响应时，可以使用QCoreApplication::processEvents函数处理事件循环。最后，在程序退出前需要调用disconnectDevice函数和delete操作符来释放资源。