\u51cc\u6668\u4e24\u70b9，\u8f66\u95f4PLC\u62a5\u9519，\u4e0a\u4f4d\u673aUI\u8f6c\u5708，\u901a\u4fe1\u7ebf\u7a0b\u5361\u6b7b，\u6392\u67e5\u4e09\u5929\u624d\u53d1\u73b0\u662f\u4e32\u53e3\u8d85\u65f6\u5904\u7406\u6ca1\u5199\u5bf9\u3002\u5144\u5f1f，\u4f60\u662f\u4e0d\u662f\u4e5f\u5e72\u8fc7\u8fd9\u79cd\u4e8b？\u4eca\u5929\u8fd9\u7bc7，\u54b1\u76f4\u63a5\u628aModbus RTU\u4e3b\u7ad9\u7684\u8d85\u65f6\u91cd\u8bd5\u548c\u9519\u8bef\u6062\u590d\u5199\u6210\u5de5\u7a0b\u7ea7\u4ee3\u7801，\u8ba9\u4f60\u4e0b\u73ed\u56de\u5bb6\u7761\u4e2a\u6574\u89c9\u3002<\/p>\n
## \u522b\u518d\u7528\u963b\u585e\u5f0f\u8bfb\u5199，QModbusClient\u4e0d\u662f\u4e07\u80fd\u7684<\/p>\n
\u5f88\u591a\u65b0\u624b\u4e0a\u6765\u5c31\u7528`QModbusClient::sendRequest`，\u7136\u540e\u7b49`waitForResponse`\u3002\u8fd9\u5728\u4ea7\u7ebf\u4e0a\u4e00\u6253\u6d41\u5c31\u73b0\u539f\u5f62：UI\u5047\u6b7b\u3001\u8d85\u65f6\u4e71\u8df3\u3001\u91cd\u8bd5\u903b\u8f91\u5168\u4e71\u5957\u3002\u8bb0\u4f4f，\u5de5\u4e1a\u7ea7\u901a\u4fe1\u5fc5\u987b\u5f02\u6b65+\u72b6\u6001\u673a，\u4e0d\u7136\u4f60\u7684\u4ee3\u7801\u5c31\u662f\u5b9a\u65f6\u70b8\u5f39\u3002<\/p>\n
```cpp
\n\/\/ \u9519\u8bef\u793a\u8303：\u963b\u585e\u7b49\u5f85，UI\u76f4\u63a5\u5361\u6b7b
\nQModbusReply *reply = client->sendRequest(request);
\nif (!reply->waitForResponse(1000)) {
\n\u00a0 \u00a0 qWarning() << "\u8d85\u65f6"; \/\/ \u8fd9\u91cc\u5df2\u7ecf\u5361\u4e861\u79d2，UI\u5e9f\u4e86
\n}<\/p>\n
```<\/p>\n
\u6b63\u786e\u59ff\u52bf：\u7ee7\u627f`QObject`，\u7528\u4fe1\u53f7\u69fd\u9a71\u52a8\u72b6\u6001\u673a，\u6bcf\u4e2a\u8bf7\u6c42\u5e26\u552f\u4e00ID，\u8d85\u65f6\u7528`QTimer`\u5355\u53d1\u7ba1\u7406\u3002\u4e0b\u9762\u8fd9\u6bb5\u662f\u6838\u5fc3\u9aa8\u67b6，\u76f4\u63a5\u6284\u3002<\/p>\n
## \u72b6\u6001\u673a\u8bbe\u8ba1：Idle \u2192 Sending \u2192 Waiting \u2192 Retry \u2192 Recovery<\/p>\n
```cpp
\nclass ModbusMaster : public QObject {
\n\u00a0 \u00a0 Q_OBJECT
\npublic:
\n\u00a0 \u00a0 enum class State { Idle, Sending, Waiting, Retry, Recovery };<\/p>\n
\u00a0 \u00a0 \/\/ \u8bf7\u6c42\u7ed3\u6784\u4f53，\u5e26\u91cd\u8bd5\u8ba1\u6570
\n\u00a0 \u00a0 struct Request {
\n\u00a0 \u00a0 \u00a0 \u00a0 int slaveId;
\n\u00a0 \u00a0 \u00a0 \u00a0 int regAddr;
\n\u00a0 \u00a0 \u00a0 \u00a0 int value;
\n\u00a0 \u00a0 \u00a0 \u00a0 int retries;
\n\u00a0 \u00a0 \u00a0 \u00a0 QElapsedTimer timer;
\n\u00a0 \u00a0 };<\/p>\n
private slots:
\n\u00a0 \u00a0 void onRequestTimeout() {
\n\u00a0 \u00a0 \u00a0 \u00a0 if (m_state != State::Waiting) return;
\n\u00a0 \u00a0 \u00a0 \u00a0 if (m_currentRequest.retries >= MAX_RETRIES) {
\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 enterRecovery(); \/\/ \u8fde\u7eed\u5931\u8d25，\u8fdb\u6062\u590d\u6d41\u7a0b
\n\u00a0 \u00a0 \u00a0 \u00a0 } else {
\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 m_currentRequest.retries++;
\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 sendRequestAgain(); \/\/ \u91cd\u53d1，\u4f46\u4e0d\u91cd\u7f6e\u8ba1\u65f6\u5668
\n\u00a0 \u00a0 \u00a0 \u00a0 }
\n\u00a0 \u00a0 }<\/p>\n
private:
\n\u00a0 \u00a0 void enterRecovery() {
\n\u00a0 \u00a0 \u00a0 \u00a0 m_state = State::Recovery;
\n\u00a0 \u00a0 \u00a0 \u00a0 \/\/ \u5148\u5173\u4e32\u53e3\u518d\u91cd\u5f00，\u6e05\u7a7a\u7f13\u51b2\u533a
\n\u00a0 \u00a0 \u00a0 \u00a0 m_client->disconnectDevice();
\n\u00a0 \u00a0 \u00a0 \u00a0 QTimer::singleShot(100, [this]() {
\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 m_client->connectDevice();
\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 m_state = State::Idle;
\n\u00a0 \u00a0 \u00a0 \u00a0 });
\n\u00a0 \u00a0 \u00a0 \u00a0 \/\/ \u901a\u77e5\u4e0a\u5c42：\u4ece\u7ad9\u6389\u7ebf，\u9700\u8981\u5904\u7406
\n\u00a0 \u00a0 \u00a0 \u00a0 emit errorOccurred(ErrorType::SlaveUnreachable);
\n\u00a0 \u00a0 }
\n};<\/p>\n
```<\/p>\n
\u8fd9\u91cc\u6709\u4e2a\u5751：`QModbusRtuSerialMaster`\u91cd\u8fde\u65f6，\u5982\u679c\u4e32\u53e3\u88ab\u5360\u7528\u6216\u9a71\u52a8\u5f02\u5e38，`connectDevice`\u4e0d\u4f1a\u62a5\u9519\u4f46\u4e5f\u4e0d\u751f\u6548\u3002\u6240\u4ee5\u6062\u590d\u540e\u5fc5\u987b\u53d1\u4e00\u4e2a\u7a7a\u6d4b\u8bd5\u5e27\u9a8c\u8bc1\u94fe\u8def，\u522b\u6025\u7740\u8dd1\u4e1a\u52a1\u3002<\/p>\n
## \u8d85\u65f6\u53c2\u6570\u522b\u62cd\u8111\u888b，\u624b\u52a8\u7ed9\u6ce2\u7279\u7387\u7b97<\/p>\n
\u5f88\u591a\u4eba\u8d85\u65f6\u8bbe500ms，\u7ed3\u679c9600\u6ce2\u7279\u7387\u4e0b\u4f20\u8f9332\u5b57\u8282\u8981350ms，\u52a0\u4e0aCRC\u6821\u9a8c\u548c\u95f4\u9699，\u5c31\u5361\u5728\u4e34\u754c\u70b9\u3002\u5de5\u7a0b\u7ea7\u7b97\u6cd5：`\u8d85\u65f6 = \u5b57\u7b26\u95f4\u9694(4\u5b57\u7b26\u65f6\u95f4) + \u5e27\u65f6\u95f4 * 1.5`\u3002<\/p>\n
```cpp
\n\/\/ \u6ce2\u7279\u7387\u5bf9\u5e94\u5b57\u7b26\u65f6\u95f4(ms)，16\u4f4d\u5b9a\u65f6\u5668\u7cbe\u5ea6\u8db3\u591f
\ndouble calcModbusTimeout(int baudRate) {
\n\u00a0 \u00a0 \/\/ 11\u4f4d\/\u5b57\u7b26：1\u8d77\u59cb+8\u6570\u636e+1\u6821\u9a8c+1\u505c\u6b62
\n\u00a0 \u00a0 double bitTime = 1000.0 \/ baudRate;
\n\u00a0 \u00a0 double charTime = bitTime * 11.0;
\n\u00a0 \u00a0 \/\/ \u5e27\u6700\u957f\u4e3a256\u5b57\u8282，1.5\u500d\u5197\u4f59
\n\u00a0 \u00a0 return charTime * 4 + charTime * 256 * 1.5;
\n}<\/p>\n
\/\/ \u4f7f\u7528\u793a\u4f8b：9600\u6ce2\u7279\u7387\u2192\u7ea647ms，19200\u2192\u7ea623ms
\nm_timeoutMs = static_cast<int>(calcModbusTimeout(9600));<\/p>\n
```<\/p>\n
\u5751\u70b9：\u4e0a\u9762\u662f\u7406\u8bba\u503c，\u5b9e\u9645\u8981\u52a0\u592720%\u4f59\u91cf\u3002\u522b\u7528\u56fa\u5b9a500ms，\u90a3\u662f\u7ed9\u952e\u76d8\u8c03\u8bd5\u7528\u7684，\u4ea7\u7ebf\u4e0a\u4e0d\u540c\u6ce2\u7279\u7387\u6df7\u8dd1\u4f1a\u51fa\u4e8b\u3002<\/p>\n
## \u9519\u8bef\u6062\u590d：\u4ece\u7ad9\u6389\u7ebf\u522b\u6b7b\u7b49，\u5206\u5c42\u5904\u7406<\/p>\n
\u6211\u628a\u6062\u590d\u7b56\u7565\u5206\u4e09\u6863：1\u6b21\u91cd\u8bd5\u4e0d\u6362\u5e27，2\u6b21\u91cd\u8bd5\u6362\u4ece\u7ad9\u5730\u5740\u5e7f\u64ad，3\u6b21\u76f4\u63a5\u89e6\u53d1\u8fde\u9501\u903b\u8f91\u3002\u6838\u5fc3\u662f\u522b\u8ba9\u4e3b\u7ad9\u6b7b\u5faa\u73af\u91cd\u53d1，\u8981\u4e3b\u52a8\u901a\u77e5PLC\u903b\u8f91\u5c42\u505a\u964d\u7ea7\u5904\u7406\u3002<\/p>\n
```cpp
\n\/\/ \u6062\u590d\u7b56\u7565：\u964d\u7ea7\u5904\u7406，\u4e0d\u8ba9\u901a\u4fe1\u7ebf\u7a0b\u6253\u8f6c
\nvoid handleFatalError() {
\n\u00a0 \u00a0 \/\/ \u5148\u590d\u4f4d\u901a\u4fe1\u72b6\u6001
\n\u00a0 \u00a0 emit communicationDown();<\/p>\n
\u00a0 \u00a0 \/\/ \u6682\u505c\u6240\u6709\u5199\u8bf7\u6c42，\u53ea\u5141\u8bb8\u8bfb\u72b6\u6001\u5bc4\u5b58\u5668
\n\u00a0 \u00a0 m_writeEnabled = false;<\/p>\n
\u00a0 \u00a0 \/\/ \u540e\u53f0\u6bcf2\u79d2\u5c1d\u8bd5\u4e00\u6b21\u5e7f\u64ad\u67e5\u8be2（\u5730\u57400）
\n\u00a0 \u00a0 QTimer *scanTimer = new QTimer(this);
\n\u00a0 \u00a0 connect(scanTimer, &QTimer::timeout, [=]() {
\n\u00a0 \u00a0 \u00a0 \u00a0 if (isDevicePresent()) {
\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 scanTimer->stop();
\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 m_writeEnabled = true;
\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 emit communicationRecovered();
\n\u00a0 \u00a0 \u00a0 \u00a0 }
\n\u00a0 \u00a0 });
\n\u00a0 \u00a0 scanTimer->start(2000);
\n}<\/p>\n
```<\/p>\n
\u8fd9\u4ee3\u7801\u6211\u7528\u4e86\u4e09\u5e74，\u5b9e\u9645\u8fd0\u884c\u4e2d：PLC\u65ad\u753520\u79d2\u6062\u590d，\u7a0b\u5e8f\u80fd\u81ea\u52a8\u7eed\u8dd1，\u4e0d\u7528\u4eba\u5de5\u91cd\u542f\u4e0a\u4f4d\u673a\u3002\u4f46\u6ce8\u610f，`isDevicePresent()`\u5fc5\u987b\u662f\u975e\u963b\u585e\u7684，\u522b\u5728\u91cc\u9762\u53d1\u540c\u6b65\u8bf7\u6c42\u3002<\/p>\n
## \u65e5\u5fd7\u7cfb\u7edf：\u51fa\u95ee\u9898\u80fd\u590d\u76d8，\u522b\u88f8\u5954<\/p>\n
7×24\u8fd0\u884c\u5fc5\u987b\u8bb0\u5f55\u6bcf\u6b21\u8d85\u65f6\u7684\u73b0\u573a，\u5305\u62ec\u4ece\u7ad9\u5730\u5740\u3001\u5bc4\u5b58\u5668\u53f7\u3001\u91cd\u8bd5\u6b21\u6570\u3001\u5f53\u65f6\u7684\u6ce2\u7279\u7387\u548c\u7ebf\u8def\u8d28\u91cf\u4f30\u7b97\u3002<\/p>\n
```cpp
\nvoid logFailure(const Request &req, const QString &reason) {
\n\u00a0 \u00a0 qInfo() << "[MODBUS]" << QDateTime::currentDateTime().toString("yyyy-MM-dd hh:mm:ss.zzz")
\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 << "| Slave:" << req.slaveId
\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 << "| Reg:" << req.regAddr
\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 << "| Retry:" << req.retries
\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 << "| Time:" << req.timer.elapsed()
\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 << "| Reason:" << reason;
\n\u00a0 \u00a0 \/\/ \u5199\u5230\u73af\u5f62\u7f13\u51b2\u533a，\u6545\u969c\u65f6\u5bfc\u51fa\u6700\u540e100\u6761
\n\u00a0 \u00a0 m_ringBuffer.append(…);
\n}<\/p>\n
```<\/p>\n
\u5751\u70b9：\u522b\u5728\u4fe1\u53f7\u69fd\u91cc\u5199\u6587\u4ef6，\u4f1a\u963b\u585e\u901a\u4fe1\u7ebf\u7a0b\u3002\u7528`QtConcurrent::run`\u5f02\u6b65\u843d\u76d8，\u6216\u8005\u76f4\u63a5\u5185\u5b58\u7f13\u5b58，\u5b9a\u671f\u5237\u76d8\u3002<\/p>\n
## \u5b9e\u6218\u9a8c\u8bc1：\u6a21\u62df\u4ece\u7ad9\u538b\u6d4b<\/p>\n
\u7528`QModbusRtuSerialSlave`\u642d\u4e2a\u5047\u4ece\u7ad9，\u6389\u7535\u6a21\u62df\u5c31\u65ad\u5f00\u4e32\u53e3，\u6216\u8005\u7528\u4e32\u53e3\u52a9\u624b\u7684\u81ea\u52a8\u5e94\u7b54\u5e72\u6270\u3002\u6211\u6d4b\u8bd5\u65f6\u7528200ms\u5468\u671f\u8fde\u7eed\u8bf7\u6c42，\u52a0\u5165\u968f\u673a\u4e22\u5305：<\/p>\n
– \u4e22\u5305\u73875%：\u91cd\u8bd5\u673a\u5236\u5fc5\u625b\u4f4f，\u6bcf\u5e27\u5ef6\u8fdf\u6700\u591a\u589e\u52a01\u4e2a\u8d85\u65f6\u65f6\u95f4<\/p>\n
– \u8fde\u7eed\u6389\u7ebf10\u6b21：\u8fdb\u5165\u6062\u590d\u6d41\u7a0b，UI\u63d0\u793a\u201c\u4ece\u7ad9\u901a\u4fe1\u4e2d\u65ad\u201d\u4f46\u4e0d\u5d29\u6e83<\/p>\n
– \u6062\u590d\u540e24\u5c0f\u65f6：\u5185\u5b58\u65e0\u6cc4\u6f0f，QModbusReply\u5bf9\u8c61\u90fd\u88ab\u6b63\u786e\u91ca\u653e<\/p>\n
\u6700\u540e\u8bb0\u4f4f，\u4e32\u53e3\u7ebf\u677e\u4e86\u8fd9\u79cd\u7269\u7406\u6545\u969c，\u4ee3\u7801\u662f\u6551\u4e0d\u4e86\u7684，\u4f46\u9519\u8bef\u6062\u590d\u80fd\u8ba9\u4f60\u5feb\u901f\u5b9a\u4f4d\u662f\u7269\u7406\u5c42\u8fd8\u662f\u534f\u8bae\u5c42\u95ee\u9898\u3002<\/p>\n
—<\/p>\n
**\u8981\u70b9\u603b\u7ed3**<\/p>\n
1. \u5f02\u6b65\u72b6\u6001\u673a\u66ff\u4ee3\u963b\u585e\u7b49\u5f85，UI\u6c38\u4e0d\u5361\u6b7b<\/p>\n
2. \u8d85\u65f6\u503c\u6309\u6ce2\u7279\u7387\u52a8\u6001\u8ba1\u7b97，\u52a020%\u4f59\u91cf<\/p>\n
3. \u9519\u8bef\u6062\u590d\u5206\u5c42：\u91cd\u8bd5\u2192\u964d\u7ea7\u2192\u626b\u63cf\u6062\u590d，\u522b\u6b7b\u5faa\u73af<\/p>\n
4. \u65e5\u5fd7\u8bb0\u5f55\u73b0\u573a\u4fe1\u606f，\u73af\u5f62\u7f13\u51b2\u533a\u9632\u7206<\/p>\n
5. \u6bcf\u6b21\u6062\u590d\u540e\u5fc5\u987b\u53d1\u7a7a\u6d4b\u8bd5\u5e27\u9a8c\u8bc1\u94fe\u8def<\/p>\n
\u4f60\u4eec\u73b0\u573a\u6709\u6ca1\u6709\u9047\u5230\u8fc7PLC\u6a21\u5757\u574f\u4e86\u4f46\u5f53\u673a\u4e0d\u62a5\u9519\u7684\u60c5\u51b5？\u8fd9\u73a9\u610f\u513f\u6bd4\u901a\u4fe1\u8d85\u65f6\u5751\u591a\u4e86，\u4f60\u662f\u600e\u4e48\u6392\u67e5\u7684？\u8bc4\u8bba\u533a\u804a\u804a\u3002
\n\u00a0<\/p><\/p>\n","protected":false},"excerpt":{"rendered":"
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