/*
* FreeModbus Libary: A portable Modbus implementation for Modbus ASCII/RTU.
* Copyright (c) 2006 Christian Walter <wolti@sil.at>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* File: $Id: mbutils.c,v 1.6 2007/02/18 23:49:07 wolti Exp $
*/
/* ----------------------- System includes ----------------------------------*/
#include "stdlib.h"
#include "string.h"
/* ----------------------- Platform includes --------------------------------*/
#include "port.h"
/* ----------------------- Modbus includes ----------------------------------*/
#include "mb.h"
#include "mbproto.h"
/* ----------------------- Defines ------------------------------------------*/
#define BITS_UCHAR 8U
/* ----------------------- Start implementation -----------------------------*/
void
xMBUtilSetBits( UCHAR * ucByteBuf, USHORT usBitOffset, UCHAR ucNBits,
UCHAR ucValue )
{
USHORT usWordBuf;
USHORT usMask;
USHORT usByteOffset;
USHORT usNPreBits;
USHORT usValue = ucValue;
// assert( ucNBits <= 8 );
// assert( ( size_t )BITS_UCHAR == sizeof( UCHAR ) * 8 );
/* Calculate byte offset for first byte containing the bit values starting
* at usBitOffset. */
usByteOffset = ( USHORT )( ( usBitOffset ) / BITS_UCHAR );
/* How many bits precede our bits to set. */
usNPreBits = ( USHORT )( usBitOffset - usByteOffset * BITS_UCHAR );
/* Move bit field into position over bits to set */
usValue <<= usNPreBits;
/* Prepare a mask for setting the new bits. */
usMask = ( USHORT )( ( 1 << ( USHORT ) ucNBits ) - 1 );
usMask <<= usBitOffset - usByteOffset * BITS_UCHAR;
/* copy bits into temporary storage. */
usWordBuf = ucByteBuf[usByteOffset];
usWordBuf |= ucByteBuf[usByteOffset + 1] << BITS_UCHAR;
/* Zero out bit field bits and then or value bits into them. */
usWordBuf = ( USHORT )( ( usWordBuf & ( ~usMask ) ) | usValue );
/* move bits back into storage */
ucByteBuf[usByteOffset] = ( UCHAR )( usWordBuf & 0xFF );
ucByteBuf[usByteOffset + 1] = ( UCHAR )( usWordBuf >> BITS_UCHAR );
}
UCHAR
xMBUtilGetBits( UCHAR * ucByteBuf, USHORT usBitOffset, UCHAR ucNBits )
{
USHORT usWordBuf;
USHORT usMask;
USHORT usByteOffset;
USHORT usNPreBits;
/* Calculate byte offset for first byte containing the bit values starting
* at usBitOffset. */
usByteOffset = ( USHORT )( ( usBitOffset ) / BITS_UCHAR );
/* How many bits precede our bits to set. */
usNPreBits = ( USHORT )( usBitOffset - usByteOffset * BITS_UCHAR );
/* Prepare a mask for setting the new bits. */
usMask = ( USHORT )( ( 1 << ( USHORT ) ucNBits ) - 1 );
/* copy bits into temporary storage. */
usWordBuf = ucByteBuf[usByteOffset];
usWordBuf |= ucByteBuf[usByteOffset + 1] << BITS_UCHAR;
/* throw away unneeded bits. */
usWordBuf >>= usNPreBits;
/* mask away bits above the requested bitfield. */
usWordBuf &= usMask;
return ( UCHAR ) usWordBuf;
}
eMBException
prveMBError2Exception( eMBErrorCode eErrorCode )
{
eMBException eStatus;
switch ( eErrorCode )
{
case MB_ENOERR:
eStatus = MB_EX_NONE;
break;
case MB_ENOREG:
eStatus = MB_EX_ILLEGAL_DATA_ADDRESS;
break;
case MB_ETIMEDOUT:
eStatus = MB_EX_SLAVE_BUSY;
break;
default:
eStatus = MB_EX_SLAVE_DEVICE_FAILURE;
break;
}
return eStatus;
}
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