modbus-tool: Introduce string endianess

libnymea-modbus/modbusdatautils.cpp

@@ -133,10 +133,12 @@ qint64 ModbusDataUtils::convertToInt64(const QVector<quint16> &registers, ByteOr
     return result;
 }
 
-QString ModbusDataUtils::convertToString(const QVector<quint16> &registers)
+QString ModbusDataUtils::convertToString(const QVector<quint16> &registers, ByteOrder characterByteOrder)
 {
     QByteArray bytes;
     QDataStream stream(&bytes, QIODevice::WriteOnly);
+    // Note: some devices use little endian within the register uint16 representation of the 2 characters.
+    stream.setByteOrder(characterByteOrder == ByteOrderBigEndian ? QDataStream::BigEndian : QDataStream::LittleEndian);
     for (int i = 0; i < registers.count(); i++) {
         stream << registers.at(i);
     }
@@ -239,11 +241,13 @@ QVector<quint16> ModbusDataUtils::convertFromInt64(qint64 value, ByteOrder byteO
     return values;
 }
 
-QVector<quint16> ModbusDataUtils::convertFromString(const QString &value, quint16 stringLength)
+QVector<quint16> ModbusDataUtils::convertFromString(const QString &value, quint16 stringLength, ByteOrder characterByteOrder)
 {
     Q_ASSERT_X(value.length() <= stringLength, "ModbusDataUtils", "cannot convert a string which is bigger than the desired register vector.");
     QByteArray data = value.toLatin1() + QByteArray('\0', stringLength - value.count());
     QDataStream stream(&data, QIODevice::ReadOnly);
+    // Note: some devices use little endian within the register uint16 representation of the 2 characters.
+    stream.setByteOrder(characterByteOrder == ByteOrderBigEndian ? QDataStream::BigEndian : QDataStream::LittleEndian);
     QVector<quint16> values;
     for (int i = 0; i < stringLength; i++) {
         quint16 registerValue = 0;

libnymea-modbus/modbusdatautils.h

@@ -88,7 +88,7 @@ public:
     static qint32 convertToInt32(const QVector<quint16> &registers, ByteOrder byteOrder = ByteOrderLittleEndian);
     static quint64 convertToUInt64(const QVector<quint16> &registers, ByteOrder byteOrder = ByteOrderLittleEndian);
     static qint64 convertToInt64(const QVector<quint16> &registers, ByteOrder byteOrder = ByteOrderLittleEndian);
-    static QString convertToString(const QVector<quint16> &registers);
+    static QString convertToString(const QVector<quint16> &registers, ByteOrder characterByteOrder = ByteOrderLittleEndian);
     static float convertToFloat32(const QVector<quint16> &registers, ByteOrder byteOrder = ByteOrderLittleEndian);
     static double convertToFloat64(const QVector<quint16> &registers, ByteOrder byteOrder = ByteOrderLittleEndian);
 
@@ -99,7 +99,7 @@ public:
     static QVector<quint16> convertFromInt32(qint32 value, ByteOrder byteOrder = ByteOrderLittleEndian);
     static QVector<quint16> convertFromUInt64(quint64 value, ByteOrder byteOrder = ByteOrderLittleEndian);
     static QVector<quint16> convertFromInt64(qint64 value, ByteOrder byteOrder = ByteOrderLittleEndian);
-    static QVector<quint16> convertFromString(const QString &value, quint16 stringLength);
+    static QVector<quint16> convertFromString(const QString &value, quint16 stringLength, ByteOrder characterByteOrder = ByteOrderLittleEndian);
     static QVector<quint16> convertFromFloat32(float value, ByteOrder byteOrder = ByteOrderLittleEndian);
     static QVector<quint16> convertFromFloat64(double value, ByteOrder byteOrder = ByteOrderLittleEndian);
 };

libnymea-modbus/tools/README.md

@@ -20,6 +20,7 @@ The basic structure of the modbus register JSON looks like following example:
     "className": "MyConnection",
     "protocol": "BOTH",
     "endianness": "BigEndian",
+    "stringEndianness": "BigEndian",
     "errorLimitUntilNotReachable": 10,
     "checkReachableRegister": "registerPropertyName",
     "enums": [
@@ -138,6 +139,19 @@ There are 2 possibilities:
 * `BigEndian`: default if not specified: register bytes come in following order `[0, 1, 2, 3]`: `ABCD`
 * `LittleEndian`: register bytes come in following order `[0, 1, 2, 3]`: `CDAB`
 
+
+## String endianness
+
+When converting multiple registers to a string, some modbus devices use a different endianess within a register.
+One register contains 2 bytes, miltiple registers in a row build up a string. The string endianess tells the generated class how to parse those strings. 
+
+There are 2 possibilities:
+
+* `BigEndian`: default if not specified: register bytes come in following order `[0, 1], [2, 3]`: `ABCD`
+* `LittleEndian`: register bytes come in following order `[1, 0] [3, 2]`: `BADC`
+
+Please not that the overall endianess of the device does not change the order of the register regarding strings since in modbus a normal register is definded as big endian. Only multiple registers combined to a numeric data type will be taken into account by the `endianess` property.
+
 ## Enums
 
 Many modbus devices provide inforation using `Enums`, indicating a special state trough a defined list of values. If a register implements an enum, you can define it in the `enums` section. The `name` property defines the name of the enum, and the script will generate a c++ enum definition from this section. Each enum value will then be generated using `<EnumName><EnumValueName> = <value>`.

libnymea-modbus/tools/connectiontool/toolcommon.py

@@ -277,7 +277,7 @@ def getConversionToValueMethod(registerDefinition):
     elif registerDefinition['type'] == 'float64':
         return ('ModbusDataUtils::convertFromFloat64(%s, m_endianness)' % propertyName)
     elif registerDefinition['type'] == 'string':
-        return ('ModbusDataUtils::convertFromString(%s)' % propertyName)    
+        return ('ModbusDataUtils::convertFromString(%s, m_stringEndianness)' % propertyName)
 
 
 def getValueConversionMethod(registerDefinition):
@@ -334,7 +334,7 @@ def getValueConversionMethod(registerDefinition):
     elif registerDefinition['type'] == 'float64':
         return ('ModbusDataUtils::convertToFloat64(values, m_endianness)')
     elif registerDefinition['type'] == 'string':
-        return ('ModbusDataUtils::convertToString(values)')
+        return ('ModbusDataUtils::convertToString(values, m_stringEndianness)')
 
 
 def writeBlockGetMethodDeclarations(fileDescriptor, registerDefinitions):

libnymea-modbus/tools/generate-connection.py

@@ -71,6 +71,9 @@ def writeTcpHeaderFile():
     writeLine(headerFile, '    ModbusDataUtils::ByteOrder endianness() const;')
     writeLine(headerFile, '    void setEndianness(ModbusDataUtils::ByteOrder endianness);')
     writeLine(headerFile)
+    writeLine(headerFile, '    ModbusDataUtils::ByteOrder stringEndianness() const;')
+    writeLine(headerFile, '    void setStringEndianness(ModbusDataUtils::ByteOrder stringEndianness);')
+    writeLine(headerFile)
     writeLine(headerFile, '    uint checkReachableRetries() const;')
     writeLine(headerFile, '    void setCheckReachableRetries(uint checkReachableRetries);')
     writeLine(headerFile)
@@ -117,6 +120,7 @@ def writeTcpHeaderFile():
     writeLine(headerFile, '    void updateFinished();')
     writeLine(headerFile)
     writeLine(headerFile, '    void endiannessChanged(ModbusDataUtils::ByteOrder endianness);')
+    writeLine(headerFile, '    void stringEndiannessChanged(ModbusDataUtils::ByteOrder stringEndianness);')
     writeLine(headerFile)
 
     writePropertyChangedSignals(headerFile, registerJson['registers'])
@@ -148,6 +152,7 @@ def writeTcpHeaderFile():
     # Private members
     writeLine(headerFile, 'private:')
     writeLine(headerFile, '    ModbusDataUtils::ByteOrder m_endianness = ModbusDataUtils::ByteOrder%s;' % endianness)
+    writeLine(headerFile, '    ModbusDataUtils::ByteOrder m_stringEndianness = ModbusDataUtils::ByteOrder%s;' % stringEndianness)
     writeLine(headerFile, '    quint16 m_slaveId = 1;')
     writeLine(headerFile)
     writeLine(headerFile, '    bool m_reachable = false;')
@@ -259,6 +264,22 @@ def writeTcpSourceFile():
     writeLine(sourceFile, '}')
     writeLine(sourceFile)
 
+    writeLine(sourceFile, 'ModbusDataUtils::ByteOrder %s::stringEndianness() const' % (className))
+    writeLine(sourceFile, '{')
+    writeLine(sourceFile, '    return m_stringEndianness;')
+    writeLine(sourceFile, '}')
+    writeLine(sourceFile)
+
+    writeLine(sourceFile, 'void %s::setStringEndianness(ModbusDataUtils::ByteOrder stringEndianness)' % (className))
+    writeLine(sourceFile, '{')
+    writeLine(sourceFile, '    if (m_stringEndianness == stringEndianness)')
+    writeLine(sourceFile, '        return;')
+    writeLine(sourceFile,)
+    writeLine(sourceFile, '    m_stringEndianness = stringEndianness;')
+    writeLine(sourceFile, '    emit stringEndiannessChanged(m_stringEndianness);')
+    writeLine(sourceFile, '}')
+    writeLine(sourceFile)
+
     # Property get methods
     writePropertyGetSetMethodImplementationsTcp(sourceFile, className, registerJson['registers'])
     if 'blocks' in registerJson:
@@ -445,6 +466,9 @@ def writeRtuHeaderFile():
     writeLine(headerFile, '    ModbusDataUtils::ByteOrder endianness() const;')
     writeLine(headerFile, '    void setEndianness(ModbusDataUtils::ByteOrder endianness);')
     writeLine(headerFile)
+    writeLine(headerFile, '    ModbusDataUtils::ByteOrder stringEndianness() const;')
+    writeLine(headerFile, '    void setStringEndianness(ModbusDataUtils::ByteOrder stringEndianness);')
+    writeLine(headerFile)
 
     # Write registers get method declarations
     writePropertyGetSetMethodDeclarationsRtu(headerFile, registerJson['registers'])
@@ -486,6 +510,7 @@ def writeRtuHeaderFile():
     writeLine(headerFile, '    void updateFinished();')
     writeLine(headerFile)
     writeLine(headerFile, '    void endiannessChanged(ModbusDataUtils::ByteOrder endianness);')
+    writeLine(headerFile, '    void stringEndiannessChanged(ModbusDataUtils::ByteOrder stringEndianness);')
     writeLine(headerFile)
     writePropertyChangedSignals(headerFile, registerJson['registers'])
     if 'blocks' in registerJson:
@@ -518,6 +543,7 @@ def writeRtuHeaderFile():
     writeLine(headerFile, 'private:')
     writeLine(headerFile, '    ModbusRtuMaster *m_modbusRtuMaster = nullptr;')
     writeLine(headerFile, '    ModbusDataUtils::ByteOrder m_endianness = ModbusDataUtils::ByteOrder%s;' % endianness)
+    writeLine(headerFile, '    ModbusDataUtils::ByteOrder m_stringEndianness = ModbusDataUtils::ByteOrder%s;' % stringEndianness)
     writeLine(headerFile, '    quint16 m_slaveId = 1;')
     writeLine(headerFile)
     writeLine(headerFile, '    bool m_reachable = false;')
@@ -645,6 +671,21 @@ def writeRtuSourceFile():
     writeLine(sourceFile, '    m_endianness = endianness;')
     writeLine(sourceFile, '    emit endiannessChanged(m_endianness);')
     writeLine(sourceFile, '}')
+
+    writeLine(sourceFile, 'ModbusDataUtils::ByteOrder %s::stringEndianness() const' % (className))
+    writeLine(sourceFile, '{')
+    writeLine(sourceFile, '    return m_stringEndianness;')
+    writeLine(sourceFile, '}')
+    writeLine(sourceFile)
+
+    writeLine(sourceFile, 'void %s::setStringEndianness(ModbusDataUtils::ByteOrder stringEndianness)' % (className))
+    writeLine(sourceFile, '{')
+    writeLine(sourceFile, '    if (m_stringEndianness == stringEndianness)')
+    writeLine(sourceFile, '        return;')
+    writeLine(sourceFile,)
+    writeLine(sourceFile, '    m_stringEndianness = stringEndianness;')
+    writeLine(sourceFile, '    emit stringEndiannessChanged(m_stringEndianness);')
+    writeLine(sourceFile, '}')
     writeLine(sourceFile)
 
     # Property get methods
@@ -828,6 +869,11 @@ endianness = 'BigEndian'
 if 'endianness' in registerJson:
     endianness = registerJson['endianness']
 
+stringEndianness = 'BigEndian'
+if 'stringEndianness' in registerJson:
+    stringEndianness = registerJson['stringEndianness']
+
+
 errorLimitUntilNotReachable = 10
 if 'errorLimitUntilNotReachable' in registerJson:
     errorLimitUntilNotReachable = registerJson['errorLimitUntilNotReachable']
@@ -875,6 +921,7 @@ logger.debug('Script path: %s' % scriptPath)
 logger.debug('Output directory: %s' % outputDirectory)
 logger.debug('Class name prefix: %s' % classNamePrefix)
 logger.debug('Endianness: %s' % endianness)
+logger.debug('String endianness: %s' % stringEndianness)
 logger.debug('Error limit until not reachable: %s' % errorLimitUntilNotReachable)
 logger.debug('Check reachable register: %s' % checkReachableRegister['id'])