Improved error handling logic to connect

mtec/integrationpluginmtec.cpp

@@ -153,7 +153,7 @@ void IntegrationPluginMTec::update(Thing *thing)
     }
 }
 
-void IntegrationPluginMTec::onConnectedChanged(bool connected)
+void IntegrationPluginMTec::onConnectedChanged(MTecHelpers::ConnectionState state)
 {
     MTec *mtec = qobject_cast<MTec *>(sender());
     Thing *thing = m_mtecConnections.key(mtec);
@@ -163,7 +163,11 @@ void IntegrationPluginMTec::onConnectedChanged(bool connected)
     if (!thing)
         return;
 
-    thing->setStateValue(mtecConnectedStateTypeId, connected);
+    if (state == MTecHelpers::ConnectionState::Online) {
+        thing->setStateValue(mtecConnectedStateTypeId, true);
+    }
+
+    thing->setStateValue(mtecStatusStateTypeId, MTecHelpers::connectionStateToString(state));
 }
 
 void IntegrationPluginMTec::onStatusUpdated(const MTecInfo &info)

mtec/integrationpluginmtec.h

@@ -34,6 +34,7 @@
 #include "plugintimer.h"
 
 #include "mtec.h"
+#include "mtechelpers.h"
 
 #include <QUuid>
 
@@ -62,7 +63,7 @@ private:
     QHash<QUuid, ThingActionInfo *> m_asyncActions;
 
 private slots:
-    void onConnectedChanged(bool connected);
+    void onConnectedChanged(MTecHelpers::ConnectionState state);
     void onRefreshTimer();
     void onStatusUpdated(const MTecInfo &info);
 

mtec/mtec.cpp

@@ -41,7 +41,10 @@ MTec::MTec(const QHostAddress &address, QObject *parent) :
     m_modbusMaster = new ModbusTCPMaster(address, 502, this);
 
     qCDebug(dcMTec()) << "created ModbusTCPMaster";
-    m_connected = m_modbusMaster->connectDevice();
+
+    if (m_modbusMaster->connectDevice()) {
+        emit connectedChanged(MTecHelpers::ConnectionState::Connecting);
+    }
 
     connect(m_modbusMaster, &ModbusTCPMaster::receivedHoldingRegister, this, &MTec::onReceivedHoldingRegister);
     connect(m_modbusMaster, &ModbusTCPMaster::readRequestError, this, &MTec::onModbusError);
@@ -56,19 +59,22 @@ void MTec::onModbusError()
 {
     qCWarning(dcMTec()) << "MTec: Received modbus error";
 
-    emit connectedChanged(false);
+    /* Only emit connected changed signal, if a soft connection
+     * had already been established.
+     * This avoids a series of possibly fake connection state changes,
+     * while the modbus server in the heatpump is starting up. */
+    if (m_softConnection) {
+        m_softConnection = false;
+        emit connectedChanged(MTecHelpers::ConnectionState::Offline);
+    }
 }
 
 void MTec::onRequestStatus()
 {
-    if ((m_connected) && (!m_firstTimeout.isValid())) {
-        /* No timestamp for timeout of first telegram defined,
-         * -> first request has not yet been sent
-         * -> do it now */
+    if ((m_softConnection) ||
+            ((m_connected) && (m_requestsSent < MTec::ConnectionRetries))) {
 
-        /* Note: m_firstRequest is set to false in
-         * the onReceivedHoldingRegister function */
-        if (m_firstRequest == true) {
+        if (m_requestsSent < MTec::ConnectionRetries) {
             m_firstTimeout = QDateTime::currentDateTime();
             m_firstTimeout = m_firstTimeout.addSecs(MTec::FirstConnectionTimeout);
 
@@ -83,17 +89,14 @@ void MTec::onRequestStatus()
             /* Set back original modbus timeout */
             m_modbusMaster->setTimeout(m_modbusTimeout);
         }
+        
     } else {
-        QDateTime now = QDateTime::currentDateTime();
-
-        if (m_firstTimeout.msecsTo(now) < MTec::FirstConnectionTimeout) {
-            /* Timeout of first request not yet reached
-             * -> return without sending another request */
-            return;
-        }
+        qCDebug(dcMTec()) << "Max number of modbus connects reached, giving up";
+        return;
     }
 
     m_modbusMaster->readHoldingRegister(MTec::ModbusUnitID, MTec::ActualPowerConsumption, 1);
+    m_requestsSent ++;
 }
 
 void MTec::onReceivedHoldingRegister(int slaveAddress, int modbusRegister, const QVector<quint16> &value)
@@ -102,7 +105,8 @@ void MTec::onReceivedHoldingRegister(int slaveAddress, int modbusRegister, const
 
     /* Some response was received, so the modbus communication is
      * established. */
-    m_firstRequest = false;
+    m_softConnection = true;
+    emit connectedChanged(MTecHelpers::ConnectionState::Online);
 
     switch (modbusRegister) {
     case ActualPowerConsumption:

mtec/mtec.h

@@ -37,6 +37,7 @@
 #include "../modbus/modbustcpmaster.h"
 
 #include "mtecinfo.h"
+#include "mtechelpers.h"
 
 class MTec : public QObject
 {
@@ -62,6 +63,9 @@ private:
     /** Modbus Unit ID (undocumented, guessing 1 for now) */
     static const quint16 ModbusUnitID = 1;
 
+    /** Number of retries to establish a modbus connection with the heat pump */
+    static const int ConnectionRetries = 3;
+
     /** The following modbus addresses can be read: */
     enum RegisterList {
         /**
@@ -108,15 +112,16 @@ private:
     /** This structure is filled by the receivedStatus... functions */
     MTecInfo m_info ;
 
-    bool m_firstRequest = true;
+    int m_requestsSent = 0;
     bool m_connected = false;
+    bool m_softConnection = false;
 
     QDateTime m_firstTimeout;
 
     int m_modbusTimeout;
 
 signals:
-    void connectedChanged(bool connected);
+    void connectedChanged(MTecHelpers::ConnectionState state);
     void statusUpdated(const MTecInfo &info);
 
 public slots:

mtec/mtechelpers.cpp

@@ -44,19 +44,41 @@ void MTecHelpers::convertFloatToRegister(quint16 &reg, float value)
     reg = qRound(value * 100.0);
 }
 
-QString MTecHelpers::externalHeatSourceRequestToString(quint16 value)
+QString MTecHelpers::connectionStateToString(ConnectionState state)
 {
     QString str{};
 
-    switch (value) {
-    case 0:
-        str = "No request, external heat source must be turned off";
+    switch (state) {
+    case Offline:
+        str = QT_TR_NOOP("Off");
         break;
-    case 1:
-        str = "External heat source is released and can be switched on";
+    case Connecting:
+        str = QT_TR_NOOP("Connecting");
         break;
-    case 2:
-        str = "External heat source is required and must be turned on";
+    case Online:
+        str = QT_TR_NOOP("Connected");
+        break;
+    case Error:
+        str = QT_TR_NOOP("Error");
+        break;
+    }
+
+    return str;
+}
+
+QString MTecHelpers::externalHeatSourceRequestToString(quint16 value)
+{
+    QString str{};
+
+    switch (value) {
+    case 0:
+        str = QT_TR_NOOP("No request, external heat source must be turned off");
+        break;
+    case 1:
+        str = QT_TR_NOOP("External heat source is released and can be switched on");
+        break;
+    case 2:
+        str = QT_TR_NOOP("External heat source is required and must be turned on");
         break;
     }
 

mtec/mtechelpers.h

@@ -32,13 +32,23 @@
 #define MTECHELPERS_H
 
 #include <QtGlobal>
+#include <QObject>
 #include <QString>
 
-class MTecHelpers {
+class MTecHelpers : public QObject {
 public:
+    enum ConnectionState {
+        Offline,
+        Connecting,
+        Online,
+        Error
+    };
+    Q_ENUM(ConnectionState);
+
     static float    convertRegisterToFloat(quint16 reg);
     static void     convertFloatToRegister(quint16 &reg, float value);
 
+    static QString  connectionStateToString(ConnectionState state);
     static QString  externalHeatSourceRequestToString(quint16 value);
 };