root / freemodbus / modbus / functions / mbfuncinput.c @ 20e5429c
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1 | 20e5429c | Tom Mullins | /*
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2 | * FreeModbus Libary: A portable Modbus implementation for Modbus ASCII/RTU.
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3 | * Copyright (c) 2006 Christian Walter <wolti@sil.at>
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4 | * All rights reserved.
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5 | *
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6 | * Redistribution and use in source and binary forms, with or without
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7 | * modification, are permitted provided that the following conditions
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8 | * are met:
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9 | * 1. Redistributions of source code must retain the above copyright
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10 | * notice, this list of conditions and the following disclaimer.
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11 | * 2. Redistributions in binary form must reproduce the above copyright
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12 | * notice, this list of conditions and the following disclaimer in the
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13 | * documentation and/or other materials provided with the distribution.
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14 | * 3. The name of the author may not be used to endorse or promote products
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15 | * derived from this software without specific prior written permission.
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16 | *
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17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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27 | *
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28 | * File: $Id: mbfuncinput.c,v 1.10 2007/09/12 10:15:56 wolti Exp $
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29 | */
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30 | |||
31 | /* ----------------------- System includes ----------------------------------*/
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32 | #include "stdlib.h" |
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33 | #include "string.h" |
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34 | |||
35 | /* ----------------------- Platform includes --------------------------------*/
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36 | #include "port.h" |
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37 | |||
38 | /* ----------------------- Modbus includes ----------------------------------*/
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39 | #include "mb.h" |
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40 | #include "mbframe.h" |
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41 | #include "mbproto.h" |
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42 | #include "mbconfig.h" |
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43 | |||
44 | /* ----------------------- Defines ------------------------------------------*/
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45 | #define MB_PDU_FUNC_READ_ADDR_OFF ( MB_PDU_DATA_OFF )
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46 | #define MB_PDU_FUNC_READ_REGCNT_OFF ( MB_PDU_DATA_OFF + 2 ) |
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47 | #define MB_PDU_FUNC_READ_SIZE ( 4 ) |
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48 | #define MB_PDU_FUNC_READ_REGCNT_MAX ( 0x007D ) |
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49 | |||
50 | #define MB_PDU_FUNC_READ_RSP_BYTECNT_OFF ( MB_PDU_DATA_OFF )
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51 | |||
52 | /* ----------------------- Static functions ---------------------------------*/
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53 | eMBException prveMBError2Exception( eMBErrorCode eErrorCode ); |
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54 | |||
55 | /* ----------------------- Start implementation -----------------------------*/
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56 | #if MB_FUNC_READ_INPUT_ENABLED > 0 |
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57 | |||
58 | eMBException |
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59 | eMBFuncReadInputRegister( UCHAR * pucFrame, USHORT * usLen ) |
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60 | { |
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61 | USHORT usRegAddress; |
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62 | USHORT usRegCount; |
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63 | UCHAR *pucFrameCur; |
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64 | |||
65 | eMBException eStatus = MB_EX_NONE; |
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66 | eMBErrorCode eRegStatus; |
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67 | |||
68 | if( *usLen == ( MB_PDU_FUNC_READ_SIZE + MB_PDU_SIZE_MIN ) )
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69 | { |
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70 | usRegAddress = ( USHORT )( pucFrame[MB_PDU_FUNC_READ_ADDR_OFF] << 8 );
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71 | usRegAddress |= ( USHORT )( pucFrame[MB_PDU_FUNC_READ_ADDR_OFF + 1] );
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72 | usRegAddress++; |
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73 | |||
74 | usRegCount = ( USHORT )( pucFrame[MB_PDU_FUNC_READ_REGCNT_OFF] << 8 );
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75 | usRegCount |= ( USHORT )( pucFrame[MB_PDU_FUNC_READ_REGCNT_OFF + 1] );
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76 | |||
77 | /* Check if the number of registers to read is valid. If not
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78 | * return Modbus illegal data value exception.
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79 | */
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80 | if( ( usRegCount >= 1 ) |
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81 | && ( usRegCount < MB_PDU_FUNC_READ_REGCNT_MAX ) ) |
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82 | { |
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83 | /* Set the current PDU data pointer to the beginning. */
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84 | pucFrameCur = &pucFrame[MB_PDU_FUNC_OFF]; |
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85 | *usLen = MB_PDU_FUNC_OFF; |
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86 | |||
87 | /* First byte contains the function code. */
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88 | *pucFrameCur++ = MB_FUNC_READ_INPUT_REGISTER; |
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89 | *usLen += 1;
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90 | |||
91 | /* Second byte in the response contain the number of bytes. */
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92 | *pucFrameCur++ = ( UCHAR )( usRegCount * 2 );
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93 | *usLen += 1;
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94 | |||
95 | eRegStatus = |
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96 | eMBRegInputCB( pucFrameCur, usRegAddress, usRegCount ); |
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97 | |||
98 | /* If an error occured convert it into a Modbus exception. */
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99 | if( eRegStatus != MB_ENOERR )
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100 | { |
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101 | eStatus = prveMBError2Exception( eRegStatus ); |
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102 | } |
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103 | else
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104 | { |
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105 | *usLen += usRegCount * 2;
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106 | } |
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107 | } |
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108 | else
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109 | { |
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110 | eStatus = MB_EX_ILLEGAL_DATA_VALUE; |
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111 | } |
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112 | } |
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113 | else
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114 | { |
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115 | /* Can't be a valid read input register request because the length
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116 | * is incorrect. */
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117 | eStatus = MB_EX_ILLEGAL_DATA_VALUE; |
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118 | } |
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119 | return eStatus;
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120 | } |
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121 | |||
122 | #endif
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