Cam Marshall
Port of the FreeModbus Libary for mbed
mbfuncdisc.cpp@0:0453a0a7e500, 2010-04-15 (annotated)
- Committer:
- cam
- Date:
- Thu Apr 15 12:10:34 2010 +0000
- Revision:
- 0:0453a0a7e500
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| cam | 0:0453a0a7e500 | 1 | /* |
| cam | 0:0453a0a7e500 | 2 | * FreeRTOS Modbus Libary: A Modbus serial implementation for FreeRTOS |
| cam | 0:0453a0a7e500 | 3 | * Copyright (C) 2006 Christian Walter <wolti@sil.at> |
| cam | 0:0453a0a7e500 | 4 | * |
| cam | 0:0453a0a7e500 | 5 | * This library is free software; you can redistribute it and/or |
| cam | 0:0453a0a7e500 | 6 | * modify it under the terms of the GNU Lesser General Public |
| cam | 0:0453a0a7e500 | 7 | * License as published by the Free Software Foundation; either |
| cam | 0:0453a0a7e500 | 8 | * version 2.1 of the License, or (at your option) any later version. |
| cam | 0:0453a0a7e500 | 9 | * |
| cam | 0:0453a0a7e500 | 10 | * This library is distributed in the hope that it will be useful, |
| cam | 0:0453a0a7e500 | 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| cam | 0:0453a0a7e500 | 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| cam | 0:0453a0a7e500 | 13 | * Lesser General Public License for more details. |
| cam | 0:0453a0a7e500 | 14 | * |
| cam | 0:0453a0a7e500 | 15 | * You should have received a copy of the GNU Lesser General Public |
| cam | 0:0453a0a7e500 | 16 | * License along with this library; if not, write to the Free Software |
| cam | 0:0453a0a7e500 | 17 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| cam | 0:0453a0a7e500 | 18 | */ |
| cam | 0:0453a0a7e500 | 19 | |
| cam | 0:0453a0a7e500 | 20 | |
| cam | 0:0453a0a7e500 | 21 | |
| cam | 0:0453a0a7e500 | 22 | /* ----------------------- System includes ----------------------------------*/ |
| cam | 0:0453a0a7e500 | 23 | #include "stdlib.h" |
| cam | 0:0453a0a7e500 | 24 | #include "string.h" |
| cam | 0:0453a0a7e500 | 25 | |
| cam | 0:0453a0a7e500 | 26 | /* ----------------------- Platform includes --------------------------------*/ |
| cam | 0:0453a0a7e500 | 27 | #include "port.h" |
| cam | 0:0453a0a7e500 | 28 | |
| cam | 0:0453a0a7e500 | 29 | /* ----------------------- Modbus includes ----------------------------------*/ |
| cam | 0:0453a0a7e500 | 30 | #include "mb.h" |
| cam | 0:0453a0a7e500 | 31 | #include "mbframe.h" |
| cam | 0:0453a0a7e500 | 32 | #include "mbproto.h" |
| cam | 0:0453a0a7e500 | 33 | #include "mbconfig.h" |
| cam | 0:0453a0a7e500 | 34 | |
| cam | 0:0453a0a7e500 | 35 | /* ----------------------- Defines ------------------------------------------*/ |
| cam | 0:0453a0a7e500 | 36 | #define MB_PDU_FUNC_READ_ADDR_OFF ( MB_PDU_DATA_OFF ) |
| cam | 0:0453a0a7e500 | 37 | #define MB_PDU_FUNC_READ_DISCCNT_OFF ( MB_PDU_DATA_OFF + 2 ) |
| cam | 0:0453a0a7e500 | 38 | #define MB_PDU_FUNC_READ_SIZE ( 4 ) |
| cam | 0:0453a0a7e500 | 39 | #define MB_PDU_FUNC_READ_DISCCNT_MAX ( 0x07D0 ) |
| cam | 0:0453a0a7e500 | 40 | |
| cam | 0:0453a0a7e500 | 41 | /* ----------------------- Static functions ---------------------------------*/ |
| cam | 0:0453a0a7e500 | 42 | eMBException prveMBError2Exception( eMBErrorCode eErrorCode ); |
| cam | 0:0453a0a7e500 | 43 | |
| cam | 0:0453a0a7e500 | 44 | /* ----------------------- Start implementation -----------------------------*/ |
| cam | 0:0453a0a7e500 | 45 | |
| cam | 0:0453a0a7e500 | 46 | #if MB_FUNC_READ_COILS_ENABLED > 0 |
| cam | 0:0453a0a7e500 | 47 | |
| cam | 0:0453a0a7e500 | 48 | eMBException |
| cam | 0:0453a0a7e500 | 49 | eMBFuncReadDiscreteInputs( UCHAR * pucFrame, USHORT * usLen ) |
| cam | 0:0453a0a7e500 | 50 | { |
| cam | 0:0453a0a7e500 | 51 | USHORT usRegAddress; |
| cam | 0:0453a0a7e500 | 52 | USHORT usDiscreteCnt; |
| cam | 0:0453a0a7e500 | 53 | UCHAR ucNBytes; |
| cam | 0:0453a0a7e500 | 54 | UCHAR *pucFrameCur; |
| cam | 0:0453a0a7e500 | 55 | |
| cam | 0:0453a0a7e500 | 56 | eMBException eStatus = MB_EX_NONE; |
| cam | 0:0453a0a7e500 | 57 | eMBErrorCode eRegStatus; |
| cam | 0:0453a0a7e500 | 58 | |
| cam | 0:0453a0a7e500 | 59 | if( *usLen == ( MB_PDU_FUNC_READ_SIZE + MB_PDU_SIZE_MIN ) ) |
| cam | 0:0453a0a7e500 | 60 | { |
| cam | 0:0453a0a7e500 | 61 | usRegAddress = ( USHORT )( pucFrame[MB_PDU_FUNC_READ_ADDR_OFF] << 8 ); |
| cam | 0:0453a0a7e500 | 62 | usRegAddress |= ( USHORT )( pucFrame[MB_PDU_FUNC_READ_ADDR_OFF + 1] ); |
| cam | 0:0453a0a7e500 | 63 | usRegAddress++; |
| cam | 0:0453a0a7e500 | 64 | |
| cam | 0:0453a0a7e500 | 65 | usDiscreteCnt = ( USHORT )( pucFrame[MB_PDU_FUNC_READ_DISCCNT_OFF] << 8 ); |
| cam | 0:0453a0a7e500 | 66 | usDiscreteCnt |= ( USHORT )( pucFrame[MB_PDU_FUNC_READ_DISCCNT_OFF + 1] ); |
| cam | 0:0453a0a7e500 | 67 | |
| cam | 0:0453a0a7e500 | 68 | /* Check if the number of registers to read is valid. If not |
| cam | 0:0453a0a7e500 | 69 | * return Modbus illegal data value exception. |
| cam | 0:0453a0a7e500 | 70 | */ |
| cam | 0:0453a0a7e500 | 71 | if( ( usDiscreteCnt >= 1 ) && |
| cam | 0:0453a0a7e500 | 72 | ( usDiscreteCnt < MB_PDU_FUNC_READ_DISCCNT_MAX ) ) |
| cam | 0:0453a0a7e500 | 73 | { |
| cam | 0:0453a0a7e500 | 74 | /* Set the current PDU data pointer to the beginning. */ |
| cam | 0:0453a0a7e500 | 75 | pucFrameCur = &pucFrame[MB_PDU_FUNC_OFF]; |
| cam | 0:0453a0a7e500 | 76 | *usLen = MB_PDU_FUNC_OFF; |
| cam | 0:0453a0a7e500 | 77 | |
| cam | 0:0453a0a7e500 | 78 | /* First byte contains the function code. */ |
| cam | 0:0453a0a7e500 | 79 | *pucFrameCur++ = MB_FUNC_READ_DISCRETE_INPUTS; |
| cam | 0:0453a0a7e500 | 80 | *usLen += 1; |
| cam | 0:0453a0a7e500 | 81 | |
| cam | 0:0453a0a7e500 | 82 | /* Test if the quantity of coils is a multiple of 8. If not last |
| cam | 0:0453a0a7e500 | 83 | * byte is only partially field with unused coils set to zero. */ |
| cam | 0:0453a0a7e500 | 84 | if( ( usDiscreteCnt & 0x0007 ) != 0 ) |
| cam | 0:0453a0a7e500 | 85 | { |
| cam | 0:0453a0a7e500 | 86 | ucNBytes = ( UCHAR ) ( usDiscreteCnt / 8 + 1 ); |
| cam | 0:0453a0a7e500 | 87 | } |
| cam | 0:0453a0a7e500 | 88 | else |
| cam | 0:0453a0a7e500 | 89 | { |
| cam | 0:0453a0a7e500 | 90 | ucNBytes = ( UCHAR ) ( usDiscreteCnt / 8 ); |
| cam | 0:0453a0a7e500 | 91 | } |
| cam | 0:0453a0a7e500 | 92 | *pucFrameCur++ = ucNBytes; |
| cam | 0:0453a0a7e500 | 93 | *usLen += 1; |
| cam | 0:0453a0a7e500 | 94 | |
| cam | 0:0453a0a7e500 | 95 | eRegStatus = |
| cam | 0:0453a0a7e500 | 96 | eMBRegDiscreteCB( pucFrameCur, usRegAddress, usDiscreteCnt ); |
| cam | 0:0453a0a7e500 | 97 | |
| cam | 0:0453a0a7e500 | 98 | /* If an error occured convert it into a Modbus exception. */ |
| cam | 0:0453a0a7e500 | 99 | if( eRegStatus != MB_ENOERR ) |
| cam | 0:0453a0a7e500 | 100 | { |
| cam | 0:0453a0a7e500 | 101 | eStatus = prveMBError2Exception( eRegStatus ); |
| cam | 0:0453a0a7e500 | 102 | } |
| cam | 0:0453a0a7e500 | 103 | else |
| cam | 0:0453a0a7e500 | 104 | { |
| cam | 0:0453a0a7e500 | 105 | /* The response contains the function code, the starting address |
| cam | 0:0453a0a7e500 | 106 | * and the quantity of registers. We reuse the old values in the |
| cam | 0:0453a0a7e500 | 107 | * buffer because they are still valid. */ |
| cam | 0:0453a0a7e500 | 108 | *usLen += ucNBytes;; |
| cam | 0:0453a0a7e500 | 109 | } |
| cam | 0:0453a0a7e500 | 110 | } |
| cam | 0:0453a0a7e500 | 111 | else |
| cam | 0:0453a0a7e500 | 112 | { |
| cam | 0:0453a0a7e500 | 113 | eStatus = MB_EX_ILLEGAL_DATA_VALUE; |
| cam | 0:0453a0a7e500 | 114 | } |
| cam | 0:0453a0a7e500 | 115 | } |
| cam | 0:0453a0a7e500 | 116 | else |
| cam | 0:0453a0a7e500 | 117 | { |
| cam | 0:0453a0a7e500 | 118 | /* Can't be a valid read coil register request because the length |
| cam | 0:0453a0a7e500 | 119 | * is incorrect. */ |
| cam | 0:0453a0a7e500 | 120 | eStatus = MB_EX_ILLEGAL_DATA_VALUE; |
| cam | 0:0453a0a7e500 | 121 | } |
| cam | 0:0453a0a7e500 | 122 | return eStatus; |
| cam | 0:0453a0a7e500 | 123 | } |
| cam | 0:0453a0a7e500 | 124 | |
| cam | 0:0453a0a7e500 | 125 | #endif |