esp-idf/components/freemodbus/modbus/tcp/mbtcp.c
Alex Lisitsyn f0eb9985b9 examples: freemodbus port slave basic implementation
This example adds functionality to support basic communication in RS485 networks using Modbus protocol.
This example uses FreeModbus stack and regular UART driver API to communicate in RS485 half duplex mode.
Added initial support of modbus controller pure C api to access device parameters over Modbus transport.
Move freemodbus stack and port files into components folder
Move the modbus_controller interface into components idf folder
Source files updated after review.
Add modbus interface documentation docs/en/api-reference/protocols/modbus.rst
porttimer.c: fix bug with timer1 selected in the Kconfig
Add support of cmake system (added cmake files)

Closes https://github.com/espressif/esp-idf/issues/858
2018-10-17 12:47:12 +02:00

159 lines
5.4 KiB
C

/*
* 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 "stdlib.h"
#include "string.h"
/* ----------------------- Platform includes --------------------------------*/
#include "port.h"
/* ----------------------- Modbus includes ----------------------------------*/
#include "mb.h"
#include "mbconfig.h"
#include "mbtcp.h"
#include "mbframe.h"
#include "mbport.h"
#if MB_TCP_ENABLED > 0
/* ----------------------- 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( USHORT 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( UCHAR * pucRcvAddress, UCHAR ** ppucFrame, USHORT * pusLength )
{
eMBErrorCode eStatus = MB_EIO;
UCHAR *pucMBTCPFrame;
USHORT usLength;
USHORT 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( UCHAR _unused, const UCHAR * pucFrame, USHORT usLength )
{
eMBErrorCode eStatus = MB_ENOERR;
UCHAR *pucMBTCPFrame = ( UCHAR * ) pucFrame - MB_TCP_FUNC;
USHORT 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