modbus_tcp.h File Reference

Modbus/TCP common function definitions. More...

#include <stdbool.h>
#include <stdint.h>
#include <modbus_core/modbus.h>
#include <modbus_core/modbus_exceptions.h>
#include <modbus_core/modbus_types.h>
#include <modbus_core/modbus_rtos.h>

Data Structures
union	ip_addr_t
	This structure represents an IP address. More...
struct	mb_tcp_adu_t
	This structure represents a Modbus/TCP Application Data Unit. More...
struct	mb_tcp_connection_t
	This structure represents a Modbus/TCP connection. More...
struct	mb_tcp_transaction_t
	This structure represents a Modbus/TCP transaction. More...

Macros
#define	MB_MODBUS_PROTOCOL_ID   (0)
	Identification number of the modbus protocol.
#define	MB_DEFAULT_TCP_PORT   (502)
	Registered TCP port of the modbus protocol.
#define	MB_TCP_DEFAULT_KEEP_ALIVE   (120)
	Default keep-alive for TCP sockets.
#define	MB_TCP_TRANS_IDLE   (0)
	Status of a transaction that is idle.
#define	MB_TCP_TRANS_BUSY   (1)
	Status of a transaction that is not ready to be processed.
#define	MB_TCP_TRANS_START   (2)
	Status of a transaction that is ready to be processed.
#define	MB_TCP_TRANS_WAITING   (3)
	Status of a transaction waiting for response.
#define	MB_TCP_TRANS_COMPLETED   (4)
	Status of a completed transaction.
#define	MB_TCP_MAX_ADU_SIZE   (260)
	Maxiumum size of the Modbus/TCP ADU in bytes.
#define	MB_TCP_NO_ERROR   (0)
	No error.
#define	MB_TCP_QUEUE_EMPTY   (-1)
	Queue is empty.
#define	MB_TCP_NOT_FOUND   (-2)
	The specified object was not found.
#define	MB_TCP_INVALID   (-3)
	The provided date is invalid (e.g.
#define	MB_TCP_ALLOC_ERROR   (-4)
	Error while allocating an object.
#define	MB_TCP_NOT_AUTH   (-5)
	Not authorized.
#define	MB_TCP_NETWORK_ERROR   (-6)
	A network error occurred (e.g.

Functions
void	mb_tcp_fill_adu (mb_tcp_adu_t *adu, const uint8_t *buf, uint32_t len)
	Fills the provided Modbus/TCP ADU with data.
void	mb_tcp_fill_hdr_buf (uint8_t *buf, mb_tcp_adu_t *adu)
	Fills the provided buffer with the header data from the provided Modbus/TCP ADU.
void	mb_tcp_fill_buf (uint8_t *buf, mb_tcp_adu_t *adu)
	Fills the provided buffer with header and payload data from the provided Modbus/TCP ADU.
void	mb_tcp_init_tx_adu (mb_tcp_adu_t *adu, uint16_t trans_id, uint8_t unit_id, uint8_t func_code)
	Initializes a Modbus/TCP ADU to be transmitted.

Detailed Description

Modbus/TCP common function definitions.

Author

Tecnologix, 2014

Macro Definition Documentation

MB_TCP_INVALID

#define MB_TCP_INVALID   (-3)

The provided date is invalid (e.g.

ADU length not correct).

MB_TCP_NETWORK_ERROR

#define MB_TCP_NETWORK_ERROR   (-6)

A network error occurred (e.g.

socket is disconnected).

Function Documentation

mb_tcp_fill_adu()

void mb_tcp_fill_adu	(	mb_tcp_adu_t *	adu,
		const uint8_t *	buf,
		uint32_t	len )

Fills the provided Modbus/TCP ADU with data.

This function is generally used to copy raw data from a TCP packet to a Modbus/TCP ADU structure and takes care of byte reordering.

Parameters

adu	Modbus/TCP ADU to be filled.
buf	buffer containing raw data.
len	size of buf.

mb_tcp_fill_buf()

void mb_tcp_fill_buf	(	uint8_t *	buf,
		mb_tcp_adu_t *	adu )

Fills the provided buffer with header and payload data from the provided Modbus/TCP ADU.

This function takes care of byte reordering is generally used to copy data from a Modbus/TCP ADU to a raw buffer before sending it.

Parameters

buf	buffer to store the header data into.
adu	Modbus/TCP ADU to read the header data from.

mb_tcp_fill_hdr_buf()

void mb_tcp_fill_hdr_buf	(	uint8_t *	buf,
		mb_tcp_adu_t *	adu )

Fills the provided buffer with the header data from the provided Modbus/TCP ADU.

This function takes care of byte reordering and is generally used to copy data from a Modbus/TCP ADU to a raw buffer before sending it.

Parameters

buf	buffer to store the header data into.
adu	Modbus/TCP ADU to read the header data from.

mb_tcp_init_tx_adu()

void mb_tcp_init_tx_adu	(	mb_tcp_adu_t *	adu,
		uint16_t	trans_id,
		uint8_t	unit_id,
		uint8_t	func_code )

Initializes a Modbus/TCP ADU to be transmitted.

Parameters

adu	Modbus/TCP ADU to be initialized.
trans_id	transaction id.
unit_id	unit id.
func_code	Modbus function code.