lightmodbus.h

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/*
    liblightmodbus - a lightweight, multiplatform Modbus library
    Copyright (C) 2017 Jacek Wieczorek <mrjjot@gmail.com>

    This file is part of liblightmodbus.

    Liblightmodbus is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Liblightmodbus is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef LIGHTMODBUS_H
#define LIGHTMODBUS_H

// For C++
#ifdef __cplusplus
extern "C" {
#endif

//Include proper header files
#include <inttypes.h>
#include "libconf.h"

//Some protection
#if defined(LIGHTMODBUS_BIG_ENDIAN) && defined(LIGHTMODBUS_LITTLE_ENDIAN)
#error LIGHTMODBUS_BIG_ENDIAN and LIGHTMODBUS_LITTLE_ENDIAN cannot be used at once!
#endif

typedef enum modbusError
{
    MODBUS_ERROR_OK = 0, 

    MODBUS_ERROR_EXCEPTION = 1,
    MODBUS_ERROR_ALLOC, 
    MODBUS_ERROR_OTHER, 
    MODBUS_ERROR_NULLPTR, 

    MODBUS_ERROR_PARSE,
    MODBUS_ERROR_BUILD, 
    MODBUS_OK = MODBUS_ERROR_OK, 
} ModbusError;

typedef enum modbusFrameError
{
    MODBUS_FERROR_OK = MODBUS_OK, 
    MODBUS_FERROR_CRC, 
    MODBUS_FERROR_LENGTH, 
    MODBUS_FERROR_COUNT, 
    MODBUS_FERROR_VALUE, 
    MODBUS_FERROR_RANGE, 
    MODBUS_FERROR_NOSRC, 
    MODBUS_FERROR_NOREAD, 
    MODBUS_FERROR_NOWRITE, 
    MODBUS_FERROR_NOFUN, 
    MODBUS_FERROR_BADFUN, 
    MODBUS_FERROR_NULLFUN, 
    MODBUS_FERROR_MISM_FUN, 
    MODBUS_FERROR_MISM_ADDR, 
    MODBUS_FERROR_MISM_INDEX, 
    MODBUS_FERROR_MISM_COUNT, 
    MODBUS_FERROR_MISM_VALUE, 
    MODBUS_FERROR_MISM_MASK, 
    MODBUS_FERROR_BROADCAST 

} ModbusFrameError;

typedef enum modbusExceptionCode
{
    MODBUS_EXCEP_ILLEGAL_FUNCTION = 1, 
    MODBUS_EXCEP_ILLEGAL_ADDRESS = 2, 
    MODBUS_EXCEP_ILLEGAL_VALUE = 3, 
    MODBUS_EXCEP_SLAVE_FAILURE = 4, 
    MODBUS_EXCEP_ACK = 5, 
    MODBUS_EXCEP_NACK = 7 
} ModbusExceptionCode;

typedef enum modbusDataType
{
    MODBUS_HOLDING_REGISTER = 1, 
    MODBUS_INPUT_REGISTER = 2, 
    MODBUS_COIL = 4, 
    MODBUS_DISCRETE_INPUT = 8 
} ModbusDataType;

static inline uint16_t modbusBitsToBytes( uint16_t n )
{
    return n != 0 ? ( 1 + ( ( n - 1 ) >> 3 ) ) : 0;
}

static inline uint16_t modbusSwapEndian( uint16_t data ) { return ( data << 8 ) | ( data >> 8 ); }

#ifdef LIGHTMODBUS_BIG_ENDIAN
    static inline uint16_t modbusMatchEndian( uint16_t data ) { return data; }
#else
    static inline uint16_t modbusMatchEndian( uint16_t data ) { return modbusSwapEndian( data ); }
#endif

extern uint8_t modbusMaskRead( const uint8_t *mask, uint16_t maskLength, uint16_t bit );

extern uint8_t modbusMaskWrite( uint8_t *mask, uint16_t maskLength, uint16_t bit, uint8_t value );

extern uint16_t modbusCRC( const uint8_t *data, uint16_t length );

//For user convenience
#include "master.h"
#include "slave.h"

// For C++ (closes `extern "C"` )
#ifdef __cplusplus
}
#endif

#endif