QModbusTcpClient类，可读取保存寄存器数据

#include "widget.h" #include "ui_widget.h" Widget::Widget(QWidget *parent) : QWidget(parent), ui(new Ui::Widget) { ui->setupUi(this); } Widget::~Widget() { delete ui; } void Widget::on_mConBtn_clicked() { QString strText= ui->mConBtn->text(); if(strText == QStringLiteral("连接"))//**若点击了连接按钮 { //Modbus TCP //new 主站对象 master = new QModbusTcpClient(); //走的网络,设置IP与端口 master->setConnectionParameter( QModbusDevice::NetworkAddressParameter, "192.168.31.45" ); master->setConnectionParameter( QModbusDevice::NetworkPortParameter, "502"); //**设置连接超时时间50ms master->setTimeout(50); //失败后禁用重发 master->setNumberOfRetries(0); //连接信号槽 connect(master, &QModbusDevice::stateChanged ,this ,[this]() { //成连接状态了 if(master->state() == QModbusDevice::ConnectedState) { ui->mConBtn->setText(QStringLiteral("断开")); //ui->statusbar->showMessage("Connect Success!",3000); Flag_Connect=1;//已连接了 qDebug()<<"设备已连接了"; } else { ui->mConBtn->setText(QStringLiteral("连接")); Flag_Connect=0;//已断开了 qDebug()<<"设备已断开了"; } }); // 设备发生错误时信号、槽 connect(master, &QModbusClient::errorOccurred, [this](QModbusDevice::Error) { //statusBar()->showMessage(master->errorString(), 3000); ui->mConBtn->setText(QStringLiteral("连接")); Flag_Connect=0;//已断开了 qDebug()<<"设备已断开了"; }); //连接设备 master->connectDevice(); qDebug()<<QDateTime::currentDateTime().toString("yyyy-MM-dd HH:mm:ss:zzz"); //打开定时轮询的定时器 Timer=new QTimer(); Timer->setTimerType(Qt::PreciseTimer); Timer->setInterval(500); Timer->start(); connect(Timer, &QTimer::timeout, this, [=]() { qDebug()<<"MODBUS TCP定时器在运行"; qDebug()<<"Flag_Connect"<<Flag_Connect; //发现问题，大概要50s-60s才能重连上？ 但是我用modbus助手，10s左右就能重连 if(Flag_Connect==0) {master->connectDevice();qDebug()<<"触发一次MODBUS TCP重连";return;} else if(Flag_Connect==1) { QModbusDataUnit Data(QModbusDataUnit::HoldingRegisters,0,10); QModbusReply* reply=master->sendReadRequest(Data,1); if (!reply->isFinished()) connect(reply, &QModbusReply::finished, this, &Widget::readReady); else delete reply; } }); } else { if(master) { //断开连接 Timer->stop(); master->disconnectDevice(); delete master; master = nullptr; } } } void Widget::readReady() { auto reply = qobject_cast<QModbusReply *>(sender()); qDebug()<<reply->result().values(); qDebug()<<QDateTime::currentDateTime().toString("yyyy-MM-dd HH:mm:ss:zzz"); }