diff options
Diffstat (limited to 'apps/modbus/tcp/mbtcp.c')
| -rw-r--r-- | apps/modbus/tcp/mbtcp.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/apps/modbus/tcp/mbtcp.c b/apps/modbus/tcp/mbtcp.c new file mode 100644 index 000000000..fb06144ae --- /dev/null +++ b/apps/modbus/tcp/mbtcp.c @@ -0,0 +1,158 @@ +/* + * 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 |