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diff --git a/apps/modbus/functions/mbfuncinput.c b/apps/modbus/functions/mbfuncinput.c
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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: mbfuncinput.c,v 1.10 2007/09/12 10:15:56 wolti Exp $
+ */
+
+/* ----------------------- System includes ----------------------------------*/
+#include "stdlib.h"
+#include "string.h"
+
+/* ----------------------- Platform includes --------------------------------*/
+#include "port.h"
+
+/* ----------------------- Modbus includes ----------------------------------*/
+#include "mb.h"
+#include "mbframe.h"
+#include "mbproto.h"
+#include "mbconfig.h"
+
+/* ----------------------- Defines ------------------------------------------*/
+#define MB_PDU_FUNC_READ_ADDR_OFF ( MB_PDU_DATA_OFF )
+#define MB_PDU_FUNC_READ_REGCNT_OFF ( MB_PDU_DATA_OFF + 2 )
+#define MB_PDU_FUNC_READ_SIZE ( 4 )
+#define MB_PDU_FUNC_READ_REGCNT_MAX ( 0x007D )
+
+#define MB_PDU_FUNC_READ_RSP_BYTECNT_OFF ( MB_PDU_DATA_OFF )
+
+/* ----------------------- Static functions ---------------------------------*/
+eMBException prveMBError2Exception( eMBErrorCode eErrorCode );
+
+/* ----------------------- Start implementation -----------------------------*/
+#if MB_FUNC_READ_INPUT_ENABLED > 0
+
+eMBException
+eMBFuncReadInputRegister( UCHAR * pucFrame, USHORT * usLen )
+{
+ USHORT usRegAddress;
+ USHORT usRegCount;
+ UCHAR *pucFrameCur;
+
+ eMBException eStatus = MB_EX_NONE;
+ eMBErrorCode eRegStatus;
+
+ if( *usLen == ( MB_PDU_FUNC_READ_SIZE + MB_PDU_SIZE_MIN ) )
+ {
+ usRegAddress = ( USHORT )( pucFrame[MB_PDU_FUNC_READ_ADDR_OFF] << 8 );
+ usRegAddress |= ( USHORT )( pucFrame[MB_PDU_FUNC_READ_ADDR_OFF + 1] );
+ usRegAddress++;
+
+ usRegCount = ( USHORT )( pucFrame[MB_PDU_FUNC_READ_REGCNT_OFF] << 8 );
+ usRegCount |= ( USHORT )( pucFrame[MB_PDU_FUNC_READ_REGCNT_OFF + 1] );
+
+ /* Check if the number of registers to read is valid. If not
+ * return Modbus illegal data value exception.
+ */
+ if( ( usRegCount >= 1 )
+ && ( usRegCount < MB_PDU_FUNC_READ_REGCNT_MAX ) )
+ {
+ /* Set the current PDU data pointer to the beginning. */
+ pucFrameCur = &pucFrame[MB_PDU_FUNC_OFF];
+ *usLen = MB_PDU_FUNC_OFF;
+
+ /* First byte contains the function code. */
+ *pucFrameCur++ = MB_FUNC_READ_INPUT_REGISTER;
+ *usLen += 1;
+
+ /* Second byte in the response contain the number of bytes. */
+ *pucFrameCur++ = ( UCHAR )( usRegCount * 2 );
+ *usLen += 1;
+
+ eRegStatus =
+ eMBRegInputCB( pucFrameCur, usRegAddress, usRegCount );
+
+ /* If an error occured convert it into a Modbus exception. */
+ if( eRegStatus != MB_ENOERR )
+ {
+ eStatus = prveMBError2Exception( eRegStatus );
+ }
+ else
+ {
+ *usLen += usRegCount * 2;
+ }
+ }
+ else
+ {
+ eStatus = MB_EX_ILLEGAL_DATA_VALUE;
+ }
+ }
+ else
+ {
+ /* Can't be a valid read input register request because the length
+ * is incorrect. */
+ eStatus = MB_EX_ILLEGAL_DATA_VALUE;
+ }
+ return eStatus;
+}
+
+#endif