modbus_tcp_slave.h File Reference

Modbus/TCP slave 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>
#include <modbus_tcp/modbus_tcp.h>

Data Structures
struct	mb_tcp_config_t
	This structure represents the configuration of a Modbus/TCP slave. 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)

Typedefs
typedef struct mb_tcp_transactions_queue	mb_tcp_transactions_queue_t
	This structure represents a queue of transactions.

Functions
void	mb_tcp_set_secure_addrs (const ip_addr_t *auth_addrs, uint8_t auth_addrs_count, mb_tcp_config_t *conf)
	Sets the secure addresses for a modbus node.
void	mb_tcp_set_priority_conns (ip_addr_t *priority_conn_addrs, uint8_t priority_conn_addrs_count, mb_tcp_config_t *conf)
	Sets the addresses for the priority connection pool.
mb_tcp_config_t *	mb_tcp_init (uint8_t jbus, mb_data_handlers_t *handlers, uint16_t port, uint8_t socket_count, uint16_t keep_alive, uint8_t trans_count, uint8_t non_priority_conns_max)
	Initializes a modbus node.
void	mb_tcp_close (mb_tcp_config_t *conf)
	Releases all the connections of the node.
uint8_t	mb_tcp_slave_loop (mb_tcp_config_t *conf, uint32_t timeout)
	Function that processes modbus requests.

Detailed Description

Modbus/TCP slave function definitions.

Author

Tecnologix, 2021

Function Documentation

mb_tcp_close()

void mb_tcp_close

(

mb_tcp_config_t *

conf

)

Releases all the connections of the node.

The configuration structure is deallocated.

Parameters

conf	configuration structure of the modbus node to close.

mb_tcp_init()

mb_tcp_config_t * mb_tcp_init	(	uint8_t	jbus,
		mb_data_handlers_t *	handlers,
		uint16_t	port,
		uint8_t	socket_count,
		uint16_t	keep_alive,
		uint8_t	trans_count,
		uint8_t	non_priority_conns_max )

Initializes a modbus node.

Parameters

jbus	0 if the jbus mode is disabled.
handlers	pointer to the data handlers structure containing the function pointers to use to process modbus requests.
port	TCP port to listen on.
socket_count	number of socket to use for listening for incoming connections.
keep_alive	TCP keep alive for the established connections.
trans_count	maximum number of transactions to process simultaneously.
non_priority_conns_max	maximum number of connections of the non-priority pool.

Returns

the configuration of the modbus node.

mb_tcp_set_priority_conns()

void mb_tcp_set_priority_conns	(	ip_addr_t *	priority_conn_addrs,
		uint8_t	priority_conn_addrs_count,
		mb_tcp_config_t *	conf )

Sets the addresses for the priority connection pool.

Connections from these addresses will not be rejected if they are authorized addresses.

Parameters

priority_conn_addrs	array of ip addresses.
priority_conn_addrs_count	number of elements of the specified array.
conf	configuration of the modbus node.

mb_tcp_set_secure_addrs()

void mb_tcp_set_secure_addrs	(	const ip_addr_t *	auth_addrs,
		uint8_t	auth_addrs_count,
		mb_tcp_config_t *	conf )

Sets the secure addresses for a modbus node.

Parameters

auth_addrs	array of IP addresses that are secure.
auth_addrs_count	number of IP addresses that are secure.
conf	configuration of the modbus node.

mb_tcp_slave_loop()

uint8_t mb_tcp_slave_loop	(	mb_tcp_config_t *	conf,
		uint32_t	timeout )

Function that processes modbus requests.

It has to be invoked in a loop.

Parameters

conf	configuration of the node.
timeout	time to wait for incoming requests to process.

Returns

MSG_RECEIVED if a request has been processed, MSG_TIMEOUT otherwise.