Class for defining the structure of the Modbus-RTU-Frame. Can be constructed by a given modbus-frame and extracts payload, device-id and function-code (additionally checking CRC) or by providing payload, device-id and function-code (additionally calculating CRC). More...

#include <Frame_modbusRTU.h>

Inheritance diagram for Frame_modbusRTU:

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Collaboration diagram for Frame_modbusRTU:

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Public Member Functions
	Frame_modbusRTU (String pdu, char slaveId, char *functionCode)
	Construct a new Frame_modbusRTU object by PDU, modbus-slave-ID and modus-function-code. Object calculates and adds the CRC16, the Modbus-Slave-ID and the Modbus-Function-Code and concatenates them to the modbus-frame (representation) by calling content_to_rep during construction. Allocate heap-memory (buffer) to the frame-representation and let the Content's representation (parent-class-template) point to that buffer on heap.

	Frame_modbusRTU (CharArray *frame)
	Construct Modbus-RTU-Frame from given Byte-Frame (Representation). Copy the representation, the argument is pointing to, to heap-memory and let by calling copy_to_heap and let Content's representation (parent-class-template) point to that buffer on heap. Extract Payload, device-ID and function-Code. Check the CRC16 for plausibility by checking rest = 0.

	Frame_modbusRTU ()
	Construct empty Modbus-RTU-Frame.

	~Frame_modbusRTU ()
	Destroy the Frame_modbusRTU object.

bool	checkCRC16 ()
	Verifies the CRC16 checksum of the current Modbus RTU frame.

uint8_t	getServiceId () override
	Get the Service-ID (Modbus-RTU-function-code) of the frame-instance.

Public Member Functions inherited from Frame
	Frame ()
	Construct a new empty Frame object.

	~Frame ()
	Destroy the Frame object.

	Frame (String *pdu)
	Constructor for creating Frame-instance from pdu (Content)

	Frame (CharArray *frame)
	Constructor for creating Frame-Object from byte-frame (Representation)

Public Member Functions inherited from Content< String, CharArray >
	Content (String content)
	Construct a new Content object from an instance from type content_type (content itself)

	Content (CharArray representation)
	Construct a new Content object from it's representation from type representation_type.

CharArray *	get_representation ()
	Get the address of the informations representation of type representation-type.

String *	get_content ()
	Get the address of the informations content of type content_type.

bool	isValid ()
	Representation and Content of the object are existent (not default)

Additional Inherited Members
Protected Member Functions inherited from Content< String, CharArray >
Protected Attributes inherited from Content< String, CharArray >
String	content
	Content of an information (view on information (content) closer to Service-Layer)

CharArray	representation
	Representation of an information (view on information (content) closer to physical layer)

Detailed Description

Class for defining the structure of the Modbus-RTU-Frame. Can be constructed by a given modbus-frame and extracts payload, device-id and function-code (additionally checking CRC) or by providing payload, device-id and function-code (additionally calculating CRC).

Because the frame-representation is stored as a reference, the representation has to be allocated on the heap-memory (buffer) The allocation is done during the conversion from "Content" (construction by PDU) within the content_to_rep-function or it has to be initiated by calling the function "copy_to_heap" (e.g. in copy-constructor or during construction by frame-representation)

Constructor & Destructor Documentation

◆ Frame_modbusRTU() [1/2]

Frame_modbusRTU::Frame_modbusRTU	(	String *	pdu,
		char *	slaveId,
		char *	functionCode )

Construct a new Frame_modbusRTU object by PDU, modbus-slave-ID and modus-function-code. Object calculates and adds the CRC16, the Modbus-Slave-ID and the Modbus-Function-Code and concatenates them to the modbus-frame (representation) by calling content_to_rep during construction. Allocate heap-memory (buffer) to the frame-representation and let the Content's representation (parent-class-template) point to that buffer on heap.

Parameters

pdu
slaveId
functionCode

◆ Frame_modbusRTU() [2/2]

Frame_modbusRTU::Frame_modbusRTU ( CharArray * frame )

Construct Modbus-RTU-Frame from given Byte-Frame (Representation). Copy the representation, the argument is pointing to, to heap-memory and let by calling copy_to_heap and let Content's representation (parent-class-template) point to that buffer on heap. Extract Payload, device-ID and function-Code. Check the CRC16 for plausibility by checking rest = 0.

Parameters

frame const char** to a modbus-rtu-frame to construct the Frame-object from

Member Function Documentation

◆ checkCRC16()

bool Frame_modbusRTU::checkCRC16 ( )

Verifies the CRC16 checksum of the current Modbus RTU frame.

This function calculates the CRC16 checksum of the frame's representation and checks whether it is correct.

Returns: true if the CRC16 checksum is correct, false otherwise.

The function creates a temporary buffer, copies the frame's representation to it, and then compares the calculated CRC16 checksum with the expected value. The temporary buffer is deleted after use.

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◆ getServiceId()

uint8_t Frame_modbusRTU::getServiceId ( )

overridevirtual

Get the Service-ID (Modbus-RTU-function-code) of the frame-instance.

Returns: uint8_t Service-ID (Modbus-RTU-function-code) of the frame-instance

Implements Frame.

The documentation for this class was generated from the following files:

/Users/felixschulke/Developement/Arduino/Modbus_RTU/Modbus_RTU/Modbus-RTU/lib/ModbusRTU/Frame_modbusRTU.h
/Users/felixschulke/Developement/Arduino/Modbus_RTU/Modbus_RTU/Modbus-RTU/lib/ModbusRTU/Frame_modbusRTU.cpp

Public Member Functions