open_source / modbus

#pragma once

#include <stdint.h>
#include <termios.h>

#define _MODBUS_RTU_HEADER_LENGTH      1
#define _MODBUS_RTU_PRESET_REQ_LENGTH  6
#define _MODBUS_RTU_PRESET_RSP_LENGTH  2

#define _MODBUS_RTU_CHECKSUM_LENGTH    2

typedef struct _modbus_rtu
{
    /* Device: "/dev/ttyS0", "/dev/ttyUSB0" or "/dev/tty.USA19*" on Mac OS X. */
    char *device;
    /* Bauds: 9600, 19200, 57600, 115200, etc */
    int baud;
    /* Data bit */
    uint8_t data_bit;
    /* Stop bit */
    uint8_t stop_bit;
    /* Parity: 'N', 'O', 'E' */
    char parity;
    /* Save old termios settings */
    struct termios old_tios;

#if HAVE_DECL_TIOCSRS485
    int serial_mode;
#endif

    /* To handle many slaves on the same link */
    int confirmation_to_ignore;
} modbus_rtu_t;