444 lines
14 KiB
C
444 lines
14 KiB
C
/*
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* FreeModbus Libary: A portable Modbus implementation for Modbus ASCII/RTU.
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* Copyright (c) 2013 China Beijing Armink <armink.ztl@gmail.com>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* File: $Id: mbrtu_m.c,v 1.60 2013/08/17 11:42:56 Armink Add Master Functions $
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*/
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/* ----------------------- System includes ----------------------------------*/
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#include "stdlib.h"
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#include "string.h"
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/* ----------------------- Platform includes --------------------------------*/
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#include "port.h"
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/* ----------------------- Modbus includes ----------------------------------*/
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#include "mb.h"
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#include "mb_m.h"
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#include "mbrtu.h"
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#include "mbframe.h"
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#include "mbcrc.h"
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#include "mbport.h"
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#if MB_MASTER_RTU_ENABLED > 0
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/* ----------------------- Defines ------------------------------------------*/
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#define MB_SER_PDU_SIZE_MIN 4 /*!< Minimum size of a Modbus RTU frame. */
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#define MB_SER_PDU_SIZE_MAX 256 /*!< Maximum size of a Modbus RTU frame. */
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#define MB_SER_PDU_SIZE_CRC 2 /*!< Size of CRC field in PDU. */
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#define MB_SER_PDU_ADDR_OFF 0 /*!< Offset of slave address in Ser-PDU. */
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#define MB_SER_PDU_PDU_OFF 1 /*!< Offset of Modbus-PDU in Ser-PDU. */
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/* ----------------------- Type definitions ---------------------------------*/
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typedef enum
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{
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STATE_M_RX_INIT, /*!< Receiver is in initial state. */
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STATE_M_RX_IDLE, /*!< Receiver is in idle state. */
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STATE_M_RX_RCV, /*!< Frame is beeing received. */
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STATE_M_RX_ERROR, /*!< If the frame is invalid. */
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} eMBMasterRcvState;
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typedef enum
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{
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STATE_M_TX_IDLE, /*!< Transmitter is in idle state. */
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STATE_M_TX_XMIT, /*!< Transmitter is in transfer state. */
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STATE_M_TX_XFWR, /*!< Transmitter is in transfer finish and wait receive state. */
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} eMBMasterSndState;
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/* ----------------------- Static variables ---------------------------------*/
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static volatile eMBMasterSndState eSndState;
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static volatile eMBMasterRcvState eRcvState;
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static volatile UCHAR ucMasterRTUSndBuf[MB_PDU_SIZE_MAX];
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static volatile UCHAR ucMasterRTURcvBuf[MB_SER_PDU_SIZE_MAX];
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static volatile USHORT usMasterSendPDULength;
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static volatile UCHAR *pucMasterSndBufferCur;
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static volatile USHORT usMasterSndBufferCount;
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static volatile USHORT usMasterRcvBufferPos;
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static volatile BOOL xFrameIsBroadcast = FALSE;
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static volatile eMBMasterTimerMode eMasterCurTimerMode;
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/* ----------------------- Start implementation -----------------------------*/
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eMBErrorCode
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eMBMasterRTUInit(UCHAR ucPort, ULONG ulBaudRate, eMBParity eParity )
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{
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eMBErrorCode eStatus = MB_ENOERR;
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ULONG usTimerT35_50us;
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ENTER_CRITICAL_SECTION( );
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/* Modbus RTU uses 8 Databits. */
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if( xMBMasterPortSerialInit( ucPort, ulBaudRate, 8, eParity ) != TRUE )
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{
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eStatus = MB_EPORTERR;
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}
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else
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{
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/* If baudrate > 19200 then we should use the fixed timer values
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* t35 = 1750us. Otherwise t35 must be 3.5 times the character time.
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*/
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if( ulBaudRate > 19200 )
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{
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usTimerT35_50us = 35; /* 1800us. */
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}
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else
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{
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/* The timer reload value for a character is given by:
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*
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* ChTimeValue = Ticks_per_1s / ( Baudrate / 11 )
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* = 11 * Ticks_per_1s / Baudrate
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* = 220000 / Baudrate
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* The reload for t3.5 is 1.5 times this value and similary
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* for t3.5.
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*/
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usTimerT35_50us = ( 7UL * 220000UL ) / ( 2UL * ulBaudRate );
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}
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if( xMBMasterPortTimersInit( ( USHORT ) usTimerT35_50us ) != TRUE )
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{
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eStatus = MB_EPORTERR;
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}
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}
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EXIT_CRITICAL_SECTION( );
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return eStatus;
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}
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void
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eMBMasterRTUStart( void )
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{
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ENTER_CRITICAL_SECTION( );
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/* Initially the receiver is in the state STATE_M_RX_INIT. we start
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* the timer and if no character is received within t3.5 we change
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* to STATE_M_RX_IDLE. This makes sure that we delay startup of the
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* modbus protocol stack until the bus is free.
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*/
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eRcvState = STATE_M_RX_INIT;
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vMBMasterPortSerialEnable( TRUE, FALSE );
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vMBMasterPortTimersT35Enable( );
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EXIT_CRITICAL_SECTION( );
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}
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void
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eMBMasterRTUStop( void )
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{
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ENTER_CRITICAL_SECTION( );
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vMBMasterPortSerialEnable( FALSE, FALSE );
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vMBMasterPortTimersDisable( );
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EXIT_CRITICAL_SECTION( );
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}
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eMBErrorCode
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eMBMasterRTUReceive( UCHAR * pucRcvAddress, UCHAR ** pucFrame, USHORT * pusLength )
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{
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eMBErrorCode eStatus = MB_ENOERR;
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ENTER_CRITICAL_SECTION( );
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RT_ASSERT( usMasterRcvBufferPos < MB_SER_PDU_SIZE_MAX );
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/* Length and CRC check */
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if( ( usMasterRcvBufferPos >= MB_SER_PDU_SIZE_MIN )
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&& ( usMBCRC16( ( UCHAR * ) ucMasterRTURcvBuf, usMasterRcvBufferPos ) == 0 ) )
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{
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/* Save the address field. All frames are passed to the upper layed
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* and the decision if a frame is used is done there.
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*/
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*pucRcvAddress = ucMasterRTURcvBuf[MB_SER_PDU_ADDR_OFF];
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/* Total length of Modbus-PDU is Modbus-Serial-Line-PDU minus
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* size of address field and CRC checksum.
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*/
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*pusLength = ( USHORT )( usMasterRcvBufferPos - MB_SER_PDU_PDU_OFF - MB_SER_PDU_SIZE_CRC );
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/* Return the start of the Modbus PDU to the caller. */
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*pucFrame = ( UCHAR * ) & ucMasterRTURcvBuf[MB_SER_PDU_PDU_OFF];
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}
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else
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{
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eStatus = MB_EIO;
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}
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EXIT_CRITICAL_SECTION( );
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return eStatus;
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}
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eMBErrorCode
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eMBMasterRTUSend( UCHAR ucSlaveAddress, const UCHAR * pucFrame, USHORT usLength )
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{
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eMBErrorCode eStatus = MB_ENOERR;
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USHORT usCRC16;
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if ( ucSlaveAddress > MB_MASTER_TOTAL_SLAVE_NUM ) return MB_EINVAL;
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ENTER_CRITICAL_SECTION( );
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/* Check if the receiver is still in idle state. If not we where to
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* slow with processing the received frame and the master sent another
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* frame on the network. We have to abort sending the frame.
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*/
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if( eRcvState == STATE_M_RX_IDLE )
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{
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/* First byte before the Modbus-PDU is the slave address. */
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pucMasterSndBufferCur = ( UCHAR * ) pucFrame - 1;
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usMasterSndBufferCount = 1;
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/* Now copy the Modbus-PDU into the Modbus-Serial-Line-PDU. */
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pucMasterSndBufferCur[MB_SER_PDU_ADDR_OFF] = ucSlaveAddress;
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usMasterSndBufferCount += usLength;
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/* Calculate CRC16 checksum for Modbus-Serial-Line-PDU. */
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usCRC16 = usMBCRC16( ( UCHAR * ) pucMasterSndBufferCur, usMasterSndBufferCount );
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ucMasterRTUSndBuf[usMasterSndBufferCount++] = ( UCHAR )( usCRC16 & 0xFF );
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ucMasterRTUSndBuf[usMasterSndBufferCount++] = ( UCHAR )( usCRC16 >> 8 );
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/* Activate the transmitter. */
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eSndState = STATE_M_TX_XMIT;
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vMBMasterPortSerialEnable( FALSE, TRUE );
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}
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else
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{
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eStatus = MB_EIO;
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}
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EXIT_CRITICAL_SECTION( );
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return eStatus;
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}
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BOOL
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xMBMasterRTUReceiveFSM( void )
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{
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BOOL xTaskNeedSwitch = FALSE;
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UCHAR ucByte;
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RT_ASSERT(( eSndState == STATE_M_TX_IDLE ) || ( eSndState == STATE_M_TX_XFWR ));
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/* Always read the character. */
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( void )xMBMasterPortSerialGetByte( ( CHAR * ) & ucByte );
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switch ( eRcvState )
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{
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/* If we have received a character in the init state we have to
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* wait until the frame is finished.
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*/
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case STATE_M_RX_INIT:
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vMBMasterPortTimersT35Enable( );
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break;
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/* In the error state we wait until all characters in the
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* damaged frame are transmitted.
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*/
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case STATE_M_RX_ERROR:
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vMBMasterPortTimersT35Enable( );
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break;
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/* In the idle state we wait for a new character. If a character
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* is received the t1.5 and t3.5 timers are started and the
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* receiver is in the state STATE_RX_RECEIVCE and disable early
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* the timer of respond timeout .
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*/
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case STATE_M_RX_IDLE:
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/* In time of respond timeout,the receiver receive a frame.
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* Disable timer of respond timeout and change the transmiter state to idle.
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*/
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vMBMasterPortTimersDisable( );
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eSndState = STATE_M_TX_IDLE;
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usMasterRcvBufferPos = 0;
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ucMasterRTURcvBuf[usMasterRcvBufferPos++] = ucByte;
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eRcvState = STATE_M_RX_RCV;
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/* Enable t3.5 timers. */
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vMBMasterPortTimersT35Enable( );
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break;
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/* We are currently receiving a frame. Reset the timer after
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* every character received. If more than the maximum possible
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* number of bytes in a modbus frame is received the frame is
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* ignored.
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*/
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case STATE_M_RX_RCV:
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if( usMasterRcvBufferPos < MB_SER_PDU_SIZE_MAX )
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{
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ucMasterRTURcvBuf[usMasterRcvBufferPos++] = ucByte;
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}
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else
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{
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eRcvState = STATE_M_RX_ERROR;
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}
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vMBMasterPortTimersT35Enable();
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break;
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}
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return xTaskNeedSwitch;
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}
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BOOL
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xMBMasterRTUTransmitFSM( void )
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{
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BOOL xNeedPoll = FALSE;
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RT_ASSERT( eRcvState == STATE_M_RX_IDLE );
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switch ( eSndState )
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{
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/* We should not get a transmitter event if the transmitter is in
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* idle state. */
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case STATE_M_TX_IDLE:
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/* enable receiver/disable transmitter. */
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vMBMasterPortSerialEnable( TRUE, FALSE );
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break;
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case STATE_M_TX_XMIT:
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/* check if we are finished. */
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if( usMasterSndBufferCount != 0 )
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{
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xMBMasterPortSerialPutByte( ( CHAR )*pucMasterSndBufferCur );
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pucMasterSndBufferCur++; /* next byte in sendbuffer. */
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usMasterSndBufferCount--;
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}
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else
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{
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xFrameIsBroadcast = ( ucMasterRTUSndBuf[MB_SER_PDU_ADDR_OFF] == MB_ADDRESS_BROADCAST ) ? TRUE : FALSE;
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/* Disable transmitter. This prevents another transmit buffer
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* empty interrupt. */
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vMBMasterPortSerialEnable( TRUE, FALSE );
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eSndState = STATE_M_TX_XFWR;
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/* If the frame is broadcast ,master will enable timer of convert delay,
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* else master will enable timer of respond timeout. */
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if ( xFrameIsBroadcast == TRUE )
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{
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vMBMasterPortTimersConvertDelayEnable( );
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}
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else
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{
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vMBMasterPortTimersRespondTimeoutEnable( );
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}
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}
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break;
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}
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return xNeedPoll;
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}
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BOOL
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xMBMasterRTUTimerExpired(void)
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{
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BOOL xNeedPoll = FALSE;
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switch (eRcvState)
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{
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/* Timer t35 expired. Startup phase is finished. */
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case STATE_M_RX_INIT:
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xNeedPoll = xMBMasterPortEventPost(EV_MASTER_READY);
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break;
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/* A frame was received and t35 expired. Notify the listener that
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* a new frame was received. */
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case STATE_M_RX_RCV:
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xNeedPoll = xMBMasterPortEventPost(EV_MASTER_FRAME_RECEIVED);
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break;
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/* An error occured while receiving the frame. */
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case STATE_M_RX_ERROR:
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vMBMasterSetErrorType(EV_ERROR_RECEIVE_DATA);
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xNeedPoll = xMBMasterPortEventPost( EV_MASTER_ERROR_PROCESS );
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break;
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/* Function called in an illegal state. */
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default:
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RT_ASSERT(
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( eRcvState == STATE_M_RX_INIT ) || ( eRcvState == STATE_M_RX_RCV ) ||
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( eRcvState == STATE_M_RX_ERROR ) || ( eRcvState == STATE_M_RX_IDLE ));
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break;
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}
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eRcvState = STATE_M_RX_IDLE;
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switch (eSndState)
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{
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/* A frame was send finish and convert delay or respond timeout expired.
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* If the frame is broadcast,The master will idle,and if the frame is not
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* broadcast.Notify the listener process error.*/
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case STATE_M_TX_XFWR:
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if ( xFrameIsBroadcast == FALSE ) {
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vMBMasterSetErrorType(EV_ERROR_RESPOND_TIMEOUT);
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xNeedPoll = xMBMasterPortEventPost(EV_MASTER_ERROR_PROCESS);
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}
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break;
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/* Function called in an illegal state. */
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default:
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RT_ASSERT(
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( eSndState == STATE_M_TX_XFWR ) || ( eSndState == STATE_M_TX_IDLE ));
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break;
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}
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eSndState = STATE_M_TX_IDLE;
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vMBMasterPortTimersDisable( );
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/* If timer mode is convert delay, the master event then turns EV_MASTER_EXECUTE status. */
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if (eMasterCurTimerMode == MB_TMODE_CONVERT_DELAY) {
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xNeedPoll = xMBMasterPortEventPost( EV_MASTER_EXECUTE );
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}
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return xNeedPoll;
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}
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/* Get Modbus Master send RTU's buffer address pointer.*/
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void vMBMasterGetRTUSndBuf( UCHAR ** pucFrame )
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{
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*pucFrame = ( UCHAR * ) ucMasterRTUSndBuf;
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}
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/* Get Modbus Master send PDU's buffer address pointer.*/
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void vMBMasterGetPDUSndBuf( UCHAR ** pucFrame )
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{
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*pucFrame = ( UCHAR * ) &ucMasterRTUSndBuf[MB_SER_PDU_PDU_OFF];
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}
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/* Set Modbus Master send PDU's buffer length.*/
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void vMBMasterSetPDUSndLength( USHORT SendPDULength )
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{
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usMasterSendPDULength = SendPDULength;
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}
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/* Get Modbus Master send PDU's buffer length.*/
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USHORT usMBMasterGetPDUSndLength( void )
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{
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return usMasterSendPDULength;
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}
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/* Set Modbus Master current timer mode.*/
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void vMBMasterSetCurTimerMode( eMBMasterTimerMode eMBTimerMode )
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{
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eMasterCurTimerMode = eMBTimerMode;
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}
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/* The master request is broadcast? */
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BOOL xMBMasterRequestIsBroadcast( void ){
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return xFrameIsBroadcast;
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}
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#endif
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