内容

• 公共函数
• 静态公共成员
• 相关非成员
• 详细描述

QModbusResponse Class

QModbusResponse is a container class containing the function code and payload that is stored inside a Modbus ADU. 更多...

头：	#include <QModbusResponse>
qmake:	QT += serialbus
Since:	Qt 5.8
继承：	QModbusPdu
继承者：	QModbusExceptionResponse

• 所有成员列表，包括继承成员

公共函数

	QModbusResponse () = default
	QModbusResponse (const QModbusPdu & pdu )
	QModbusResponse (FunctionCode code , const QByteArray & data = QByteArray())
	QModbusResponse (FunctionCode code , Args... data )

• 11 公共函数继承自 QModbusPdu

静态公共成员

int	calculateDataSize (const QModbusResponse & response )
int	minimumDataSize (const QModbusResponse & response )
void	registerDataSizeCalculator (FunctionCode fc , CalcFuncPtr calculator )

• 1 静态公共成员继承自 QModbusPdu

相关非成员

QDataStream &

operator>> (QDataStream & stream , QModbusResponse & pdu )

额外继承成员

• 1 保护函数继承自 QModbusPdu

详细描述

QModbusResponse is a container class containing the function code and payload that is stored inside a Modbus ADU.

A typical Modbus response can looks like this:

QModbusResponse response(QModbusResponse::ReadCoils, QByteArray::fromHex("02cd01"));
					

注意： When using the constructor taking the QByteArray , please make sure to convert the containing data to big-endian byte order before creating the request.

The same response can be created like this, if the values are know at compile time:

quint8 payloadInBytes = 2, outputHigh = 0xcd, outputLow = 0x01;
QModbusResponse response(QModbusResponse::ReadCoils, payloadInBytes, outputHigh, outputLow);
					

成员函数文档编制

[default] QModbusResponse:: QModbusResponse ()

构造无效 QModbusResponse .

QModbusResponse:: QModbusResponse (const QModbusPdu & pdu )

构造副本为 pdu .

QModbusResponse:: QModbusResponse ( FunctionCode code , const QByteArray & data = QByteArray())

构造 QModbusResponse with function code set to code and payload set to data . The data is expected to be stored in big-endian byte order already.

QModbusResponse:: QModbusResponse ( FunctionCode code , Args ... data )

构造 QModbusResponse with function code set to code and payload set to data . The data is converted and stored in big-endian byte order.

注意： Usage is limited quint8 and quint16 only. This is because QDataStream stream operators will not only append raw data, but also e.g. size, count etc. for complex types.

[static] int QModbusResponse:: calculateDataSize (const QModbusResponse & response )

Calculates the expected data size for response , based on the response's function code and data. Returns the full size of the response's data part; -1 if the size could not be properly calculated.

另请参阅 minimumDataSize and registerDataSizeCalculator .

[static] int QModbusResponse:: minimumDataSize (const QModbusResponse & response )

Returns the expected minimum data size for response based on the response's function code; -1 if the function code is not known.

[static] void QModbusResponse:: registerDataSizeCalculator ( FunctionCode fc , CalcFuncPtr calculator )

This function registers a user-defined implementation to calculate the response data size for function code fc . It can be used to extend or override the implementation inside QModbusResponse::calculateDataSize ().

The CalcFuncPtr is a typedef for a pointer to a custom calculator function with the following signature:

int myCalculateDataSize(const QModbusResponse &pdu);
					

相关非成员

QDataStream & operator>> ( QDataStream & stream , QModbusResponse & pdu )

读取 pdu 从 stream 并返回流引用。

注意： The function might fail to properly stream PDU's with function code QModbusPdu::Diagnostics or QModbusPdu::EncapsulatedInterfaceTransport because of the missing size indicator inside the PDU. In particular this may happen when the PDU is embedded into a stream that doesn't end with the diagnostic/encapsulated request itself.