/*
* Copyright © Stéphane Raimbault <stephane.raimbault@gmail.com>
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*/
#ifndef MODBUS_H
#define MODBUS_H
// clang-format off
/* Add this for macros that defined unix flavor */
#if (defined(__unix__) || defined(unix)) && !defined(USG)
# include <sys/param.h>
#endif
#ifndef _MSC_VER
# include <stdint.h>
#else
# include "stdint.h"
#endif
#include "modbus-version.h"
#if defined(_MSC_VER)
# if defined(DLLBUILD)
/* define DLLBUILD when building the DLL */
# define MODBUS_API __declspec(dllexport)
# else
# define MODBUS_API __declspec(dllimport)
# endif
#else
# define MODBUS_API
#endif
#ifdef __cplusplus
# define MODBUS_BEGIN_DECLS extern "C" {
# define MODBUS_END_DECLS }
#else
# define MODBUS_BEGIN_DECLS
# define MODBUS_END_DECLS
#endif
// clang-format on
MODBUS_BEGIN_DECLS
#ifndef FALSE
#define FALSE 0
#endif
#ifndef TRUE
#define TRUE 1
#endif
#ifndef OFF
#define OFF 0
#endif
#ifndef ON
#define ON 1
#endif
/* Modbus function codes */
#define MODBUS_FC_READ_COILS 0x01
#define MODBUS_FC_READ_DISCRETE_INPUTS 0x02
#define MODBUS_FC_READ_HOLDING_REGISTERS 0x03
#define MODBUS_FC_READ_INPUT_REGISTERS 0x04
#define MODBUS_FC_WRITE_SINGLE_COIL 0x05
#define MODBUS_FC_WRITE_SINGLE_REGISTER 0x06
#define MODBUS_FC_READ_EXCEPTION_STATUS 0x07
#define MODBUS_FC_WRITE_MULTIPLE_COILS 0x0F
#define MODBUS_FC_WRITE_MULTIPLE_REGISTERS 0x10
#define MODBUS_FC_REPORT_SLAVE_ID 0x11
#define MODBUS_FC_MASK_WRITE_REGISTER 0x16
#define MODBUS_FC_WRITE_AND_READ_REGISTERS 0x17
#define MODBUS_BROADCAST_ADDRESS 0
/* Modbus_Application_Protocol_V1_1b.pdf (chapter 6 section 1 page 12)
* Quantity of Coils to read (2 bytes): 1 to 2000 (0x7D0)
* (chapter 6 section 11 page 29)
* Quantity of Coils to write (2 bytes): 1 to 1968 (0x7B0)
*/
#define MODBUS_MAX_READ_BITS 2000
#define MODBUS_MAX_WRITE_BITS 1968
/* Modbus_Application_Protocol_V1_1b.pdf (chapter 6 section 3 page 15)
* Quantity of Registers to read (2 bytes): 1 to 125 (0x7D)
* (chapter 6 section 12 page 31)
* Quantity of Registers to write (2 bytes) 1 to 123 (0x7B)
* (chapter 6 section 17 page 38)
* Quantity of Registers to write in R/W registers (2 bytes) 1 to 121 (0x79)
*/
#define MODBUS_MAX_READ_REGISTERS 125
#define MODBUS_MAX_WRITE_REGISTERS 123
#define MODBUS_MAX_WR_WRITE_REGISTERS 121
#define MODBUS_MAX_WR_READ_REGISTERS 125
/* The size of the MODBUS PDU is limited by the size constraint inherited from
* the first MODBUS implementation on Serial Line network (max. RS485 ADU = 256
* bytes). Therefore, MODBUS PDU for serial line communication = 256 - Server
* address (1 byte) - CRC (2 bytes) = 253 bytes.
*/
#define MODBUS_MAX_PDU_LENGTH 253
/* Consequently:
* - RTU MODBUS ADU = 253 bytes + Server address (1 byte) + CRC (2 bytes) = 256
* bytes.
* - TCP MODBUS ADU = 253 bytes + MBAP (7 bytes) = 260 bytes.
* so the maximum of both backend in 260 bytes. This size can used to allocate
* an array of bytes to store responses and it will be compatible with the two
* backends.
*/
#define MODBUS_MAX_ADU_LENGTH 260
/* Random number to avoid errno conflicts */
#define MODBUS_ENOBASE 112345678
/* Protocol exceptions */
enum {
MODBUS_EXCEPTION_ILLEGAL_FUNCTION = 0x01,
MODBUS_EXCEPTION_ILLEGAL_DATA_ADDRESS,
MODBUS_EXCEPTION_ILLEGAL_DATA_VALUE,
MODBUS_EXCEPTION_SLAVE_OR_SERVER_FAILURE,
MODBUS_EXCEPTION_ACKNOWLEDGE,
MODBUS_EXCEPTION_SLAVE_OR_SERVER_BUSY,
MODBUS_EXCEPTION_NEGATIVE_ACKNOWLEDGE,
MODBUS_EXCEPTION_MEMORY_PARITY,
MODBUS_EXCEPTION_NOT_DEFINED,
MODBUS_EXCEPTION_GATEWAY_PATH,
MODBUS_EXCEPTION_GATEWAY_TARGET,
MODBUS_EXCEPTION_MAX
};
#define EMBXILFUN (MODBUS_ENOBASE + MODBUS_EXCEPTION_ILLEGAL_FUNCTION)
#define EMBXILADD (MODBUS_ENOBASE + MODBUS_EXCEPTION_ILLEGAL_DATA_ADDRESS)
#define EMBXILVAL (MODBUS_ENOBASE + MODBUS_EXCEPTION_ILLEGAL_DATA_VALUE)
#define EMBXSFAIL (MODBUS_ENOBASE + MODBUS_EXCEPTION_SLAVE_OR_SERVER_FAILURE)
#define EMBXACK (MODBUS_ENOBASE + MODBUS_EXCEPTION_ACKNOWLEDGE)
#define EMBXSBUSY (MODBUS_ENOBASE + MODBUS_EXCEPTION_SLAVE_OR_SERVER_BUSY)
#define EMBXNACK (MODBUS_ENOBASE + MODBUS_EXCEPTION_NEGATIVE_ACKNOWLEDGE)
#define EMBXMEMPAR (MODBUS_ENOBASE + MODBUS_EXCEPTION_MEMORY_PARITY)
#define EMBXGPATH (MODBUS_ENOBASE + MODBUS_EXCEPTION_GATEWAY_PATH)
#define EMBXGTAR (MODBUS_ENOBASE + MODBUS_EXCEPTION_GATEWAY_TARGET)
/* Native libmodbus error codes */
#define EMBBADCRC (EMBXGTAR + 1)
#define EMBBADDATA (EMBXGTAR + 2)
#define EMBBADEXC (EMBXGTAR + 3)
#define EMBUNKEXC (EMBXGTAR + 4)
#define EMBMDATA (EMBXGTAR + 5)
#define EMBBADSLAVE (EMBXGTAR + 6)
extern const unsigned int libmodbus_version_major;
extern const unsigned int libmodbus_version_minor;
extern const unsigned int libmodbus_version_micro;
typedef struct _modbus modbus_t;
/*! Memory layout in tab_xxx arrays is processor-endianness.
When receiving modbus data, it is converted to processor-endianness,
see read_registers().
*/
typedef struct _modbus_mapping_t {
int nb_bits;
int start_bits;
int nb_input_bits;
int start_input_bits;
int nb_input_registers;
int start_input_registers;
int nb_registers;
int start_registers;
uint8_t *tab_bits;
uint8_t *tab_input_bits;
uint16_t *tab_input_registers;
uint16_t *tab_registers;
} modbus_mapping_t;
typedef enum {
MODBUS_ERROR_RECOVERY_NONE = 0,
MODBUS_ERROR_RECOVERY_LINK = (1 << 1),
MODBUS_ERROR_RECOVERY_PROTOCOL = (1 << 2)
} modbus_error_recovery_mode;
typedef enum {
MODBUS_QUIRK_NONE = 0,
MODBUS_QUIRK_MAX_SLAVE = (1 << 1),
MODBUS_QUIRK_REPLY_TO_BROADCAST = (1 << 2),
MODBUS_QUIRK_ALL = 0xFF
} modbus_quirks;
MODBUS_API int modbus_set_slave(modbus_t *ctx, int slave);
MODBUS_API int modbus_get_slave(modbus_t *ctx);
MODBUS_API int modbus_set_error_recovery(modbus_t *ctx,
modbus_error_recovery_mode error_recovery);
MODBUS_API int modbus_set_socket(modbus_t *ctx, int s);
MODBUS_API int modbus_get_socket(modbus_t *ctx);
MODBUS_API int
modbus_get_response_timeout(modbus_t *ctx, uint32_t *to_sec, uint32_t *to_usec);
MODBUS_API int
modbus_set_response_timeout(modbus_t *ctx, uint32_t to_sec, uint32_t to_usec);
MODBUS_API int
modbus_get_byte_timeout(modbus_t *ctx, uint32_t *to_sec, uint32_t *to_usec);
MODBUS_API int modbus_set_byte_timeout(modbus_t *ctx, uint32_t to_sec, uint32_t to_usec);
MODBUS_API int
modbus_get_indication_timeout(modbus_t *ctx, uint32_t *to_sec, uint32_t *to_usec);
MODBUS_API int
modbus_set_indication_timeout(modbus_t *ctx, uint32_t to_sec, uint32_t to_usec);
MODBUS_API int modbus_get_header_length(modbus_t *ctx);
MODBUS_API int modbus_connect(modbus_t *ctx);
MODBUS_API void modbus_close(modbus_t *ctx);
MODBUS_API void modbus_free(modbus_t *ctx);
MODBUS_API int modbus_flush(modbus_t *ctx);
MODBUS_API int modbus_set_debug(modbus_t *ctx, int flag);
MODBUS_API const char *modbus_strerror(int errnum);
MODBUS_API int modbus_read_bits(modbus_t *ctx, int addr, int nb, uint8_t *dest);
MODBUS_API int modbus_read_input_bits(modbus_t *ctx, int addr, int nb, uint8_t *dest);
MODBUS_API int modbus_read_registers(modbus_t *ctx, int addr, int nb, uint16_t *dest);
MODBUS_API int
modbus_read_input_registers(modbus_t *ctx, int addr, int nb, uint16_t *dest);
MODBUS_API int modbus_write_bit(modbus_t *ctx, int coil_addr, int status);
MODBUS_API int modbus_write_register(modbus_t *ctx, int reg_addr, const uint16_t value);
MODBUS_API int modbus_write_bits(modbus_t *ctx, int addr, int nb, const uint8_t *data);
MODBUS_API int
modbus_write_registers(modbus_t *ctx, int addr, int nb, const uint16_t *data);
MODBUS_API int
modbus_mask_write_register(modbus_t *ctx, int addr, uint16_t and_mask, uint16_t or_mask);
MODBUS_API int modbus_write_and_read_registers(modbus_t *ctx,
int write_addr,
int write_nb,
const uint16_t *src,
int read_addr,
int read_nb,
uint16_t *dest);
MODBUS_API int modbus_report_slave_id(modbus_t *ctx, int max_dest, uint8_t *dest);
MODBUS_API modbus_mapping_t *
modbus_mapping_new_start_address(unsigned int start_bits,
unsigned int nb_bits,
unsigned int start_input_bits,
unsigned int nb_input_bits,
unsigned int start_registers,
unsigned int nb_registers,
unsigned int start_input_registers,
unsigned int nb_input_registers);
MODBUS_API modbus_mapping_t *modbus_mapping_new(int nb_bits,
int nb_input_bits,
int nb_registers,
int nb_input_registers);
MODBUS_API void modbus_mapping_free(modbus_mapping_t *mb_mapping);
MODBUS_API int
modbus_send_raw_request(modbus_t *ctx, const uint8_t *raw_req, int raw_req_length);
MODBUS_API int modbus_send_raw_request_tid(modbus_t *ctx,
const uint8_t *raw_req,
int raw_req_length,
int tid);
MODBUS_API int modbus_receive(modbus_t *ctx, uint8_t *req);
MODBUS_API int modbus_receive_confirmation(modbus_t *ctx, uint8_t *rsp);
MODBUS_API int modbus_reply(modbus_t *ctx,
const uint8_t *req,
int req_length,
modbus_mapping_t *mb_mapping);
MODBUS_API int
modbus_reply_exception(modbus_t *ctx, const uint8_t *req, unsigned int exception_code);
MODBUS_API int modbus_enable_quirks(modbus_t *ctx, unsigned int quirks_mask);
MODBUS_API int modbus_disable_quirks(modbus_t *ctx, unsigned int quirks_mask);
/**
* UTILS FUNCTIONS
**/
#define MODBUS_GET_HIGH_BYTE(data) (((data) >> 8) & 0xFF)
#define MODBUS_GET_LOW_BYTE(data) ((data) & 0xFF)
#define MODBUS_GET_INT64_FROM_INT16(tab_int16, index) \
(((int64_t) tab_int16[(index)] << 48) | ((int64_t) tab_int16[(index) + 1] << 32) | \
((int64_t) tab_int16[(index) + 2] << 16) | (int64_t) tab_int16[(index) + 3])
#define MODBUS_GET_INT32_FROM_INT16(tab_int16, index) \
(((int32_t) tab_int16[(index)] << 16) | (int32_t) tab_int16[(index) + 1])
#define MODBUS_GET_INT16_FROM_INT8(tab_int8, index) \
(((int16_t) tab_int8[(index)] << 8) | (int16_t) tab_int8[(index) + 1])
#define MODBUS_SET_INT16_TO_INT8(tab_int8, index, value) \
do { \
((int8_t *) (tab_int8))[(index)] = (int8_t) ((value) >> 8); \
((int8_t *) (tab_int8))[(index) + 1] = (int8_t) (value); \
} while (0)
#define MODBUS_SET_INT32_TO_INT16(tab_int16, index, value) \
do { \
((int16_t *) (tab_int16))[(index)] = (int16_t) ((value) >> 16); \
((int16_t *) (tab_int16))[(index) + 1] = (int16_t) (value); \
} while (0)
#define MODBUS_SET_INT64_TO_INT16(tab_int16, index, value) \
do { \
((int16_t *) (tab_int16))[(index)] = (int16_t) ((value) >> 48); \
((int16_t *) (tab_int16))[(index) + 1] = (int16_t) ((value) >> 32); \
((int16_t *) (tab_int16))[(index) + 2] = (int16_t) ((value) >> 16); \
((int16_t *) (tab_int16))[(index) + 3] = (int16_t) (value); \
} while (0)
MODBUS_API void modbus_set_bits_from_byte(uint8_t *dest, int idx, const uint8_t value);
MODBUS_API void modbus_set_bits_from_bytes(uint8_t *dest,
int idx,
unsigned int nb_bits,
const uint8_t *tab_byte);
MODBUS_API uint8_t modbus_get_byte_from_bits(const uint8_t *src,
int idx,
unsigned int nb_bits);
MODBUS_API float modbus_get_float(const uint16_t *src);
MODBUS_API float modbus_get_float_abcd(const uint16_t *src);
MODBUS_API float modbus_get_float_dcba(const uint16_t *src);
MODBUS_API float modbus_get_float_badc(const uint16_t *src);
MODBUS_API float modbus_get_float_cdab(const uint16_t *src);
MODBUS_API void modbus_set_float(float f, uint16_t *dest);
MODBUS_API void modbus_set_float_abcd(float f, uint16_t *dest);
MODBUS_API void modbus_set_float_dcba(float f, uint16_t *dest);
MODBUS_API void modbus_set_float_badc(float f, uint16_t *dest);
MODBUS_API void modbus_set_float_cdab(float f, uint16_t *dest);
#include "modbus-rtu.h"
#include "modbus-tcp.h"
MODBUS_END_DECLS
#endif /* MODBUS_H */