Network layer base class (backend) More...

#include <netlayer.h>

Inheritance diagram for Modbus::NetLayer:

Public Member Functions
const std::string &	connection () const
	Returns the connection used. More...

modbus_t *	context ()
	libmodbus context More...

const modbus_t *	context () const

uint16_t	maxAduLength () const
	Returns the maximum ADU length.

Net	net () const
	Underlying layer used (backend) More...

	NetLayer ()
	Constructor.

virtual bool	prepareToSend (Message &msg)
	Prepare the message msg before sending. More...

virtual int	sendRawMessage (const Message *msg)
	Send a request/response msg via the socket of the context() More...

const std::string &	settings () const
	Returns the connection settings. More...

virtual	~NetLayer ()
	Destructor.

Static Public Member Functions
static bool	checkMessage (const Message &msg)
	Return true if the message is valid for this backend.

static std::string	lastError ()
	last error message More...

Detailed Description

Network layer base class (backend)

Author: Pascal JEAN, aka epsilonrt

Copyright: GNU Lesser General Public License

Member Function Documentation

◆ connection()

const std::string& Modbus::NetLayer::connection ( ) const

Returns the connection used.

Serial port or host depending on the backend.

◆ context() [1/2]

modbus_t* Modbus::NetLayer::context ( )

libmodbus context

context is an opaque structure containing all necessary information to establish a connection with other Modbus devices according to the selected variant.

◆ context() [2/2]

const modbus_t* Modbus::NetLayer::context ( ) const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

◆ lastError()

static std::string Modbus::NetLayer::lastError ( )

static

last error message

This function shall return the error message corresponding to the last error. This function must be called right after the instruction that triggered an error.

◆ net()

Net Modbus::NetLayer::net ( ) const

Underlying layer used (backend)

This function allows to know the underlying layer used.

◆ prepareToSend()

virtual bool Modbus::NetLayer::prepareToSend ( Message & msg )

virtual

Prepare the message msg before sending.

This function updates the ADU header or adds the CRC at the end depending on the network used..

Reimplemented in Modbus::RtuLayer, and Modbus::TcpLayer.

◆ sendRawMessage()

virtual int Modbus::NetLayer::sendRawMessage ( const Message * msg )

virtual

Send a request/response msg via the socket of the context()

This function can be used to send message not handled by the library. The message is transmitted "raw", without any modification.

Returns: The function shall return the full message length, if successful. Otherwise it shall return -1 and set errno.

Reimplemented in Modbus::RtuLayer, and Modbus::TcpLayer.

◆ settings()

const std::string& Modbus::NetLayer::settings ( ) const

Returns the connection settings.

IP port or speed, parity and stop bit depending on the backend

Public Member Functions

Static Public Member Functions