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/*
* 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: mbtcp.c,v 1.3 2006/12/07 22:10:34 wolti Exp $
*/
/* ----------------------- System includes ----------------------------------*/
#include <nuttx/config.h>
#include <stdlib.h>
#include <string.h>
/* ----------------------- Platform includes --------------------------------*/
#include "port.h"
/* ----------------------- Modbus includes ----------------------------------*/
#include <apps/modbusmb.h>
#include <apps/modbusmbframe.h>
#include <apps/modbusmbport.h>
#include "mbtcp.h"
#ifdef CONFIG_MB_TCP_ENABLED
/* ----------------------- Defines ------------------------------------------*/
/* ----------------------- MBAP Header --------------------------------------*/
/*
*
* <------------------------ MODBUS TCP/IP ADU(1) ------------------------->
* <----------- MODBUS PDU (1') ---------------->
* +-----------+---------------+------------------------------------------+
* | TID | PID | Length | UID |Code | Data |
* +-----------+---------------+------------------------------------------+
* | | | | |
* (2) (3) (4) (5) (6)
*
* (2) ... MB_TCP_TID = 0 (Transaction Identifier - 2 Byte)
* (3) ... MB_TCP_PID = 2 (Protocol Identifier - 2 Byte)
* (4) ... MB_TCP_LEN = 4 (Number of bytes - 2 Byte)
* (5) ... MB_TCP_UID = 6 (Unit Identifier - 1 Byte)
* (6) ... MB_TCP_FUNC = 7 (Modbus Function Code)
*
* (1) ... Modbus TCP/IP Application Data Unit
* (1') ... Modbus Protocol Data Unit
*/
#define MB_TCP_TID 0
#define MB_TCP_PID 2
#define MB_TCP_LEN 4
#define MB_TCP_UID 6
#define MB_TCP_FUNC 7
#define MB_TCP_PROTOCOL_ID 0 /* 0 = Modbus Protocol */
/* ----------------------- Start implementation -----------------------------*/
eMBErrorCode
eMBTCPDoInit( uint16_t ucTCPPort )
{
eMBErrorCode eStatus = MB_ENOERR;
if( xMBTCPPortInit( ucTCPPort ) == false )
{
eStatus = MB_EPORTERR;
}
return eStatus;
}
void
eMBTCPStart( void )
{
}
void
eMBTCPStop( void )
{
/* Make sure that no more clients are connected. */
vMBTCPPortDisable( );
}
eMBErrorCode
eMBTCPReceive( uint8_t * pucRcvAddress, uint8_t ** ppucFrame, uint16_t * pusLength )
{
eMBErrorCode eStatus = MB_EIO;
uint8_t *pucMBTCPFrame;
uint16_t usLength;
uint16_t usPID;
if( xMBTCPPortGetRequest( &pucMBTCPFrame, &usLength ) != false )
{
usPID = pucMBTCPFrame[MB_TCP_PID] << 8U;
usPID |= pucMBTCPFrame[MB_TCP_PID + 1];
if( usPID == MB_TCP_PROTOCOL_ID )
{
*ppucFrame = &pucMBTCPFrame[MB_TCP_FUNC];
*pusLength = usLength - MB_TCP_FUNC;
eStatus = MB_ENOERR;
/* Modbus TCP does not use any addresses. Fake the source address such
* that the processing part deals with this frame.
*/
*pucRcvAddress = MB_TCP_PSEUDO_ADDRESS;
}
}
else
{
eStatus = MB_EIO;
}
return eStatus;
}
eMBErrorCode
eMBTCPSend( uint8_t _unused, const uint8_t * pucFrame, uint16_t usLength )
{
eMBErrorCode eStatus = MB_ENOERR;
uint8_t *pucMBTCPFrame = ( uint8_t * ) pucFrame - MB_TCP_FUNC;
uint16_t usTCPLength = usLength + MB_TCP_FUNC;
/* The MBAP header is already initialized because the caller calls this
* function with the buffer returned by the previous call. Therefore we
* only have to update the length in the header. Note that the length
* header includes the size of the Modbus PDU and the UID Byte. Therefore
* the length is usLength plus one.
*/
pucMBTCPFrame[MB_TCP_LEN] = ( usLength + 1 ) >> 8U;
pucMBTCPFrame[MB_TCP_LEN + 1] = ( usLength + 1 ) & 0xFF;
if( xMBTCPPortSendResponse( pucMBTCPFrame, usTCPLength ) == false )
{
eStatus = MB_EIO;
}
return eStatus;
}
#endif
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