424 lines
19 KiB
C
424 lines
19 KiB
C
/*
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* FreeModbus Libary: A portable Modbus implementation for Modbus ASCII/RTU.
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* Copyright (c) 2006 Christian Walter <wolti@sil.at>
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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: mb.h,v 1.17 2006/12/07 22:10:34 wolti Exp $
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*/
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#ifndef _MB_H
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#define _MB_H
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#include "port.h"
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#ifdef __cplusplus
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PR_BEGIN_EXTERN_C
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#endif
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#include "mbport.h"
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#include "mbproto.h"
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/*! \defgroup modbus Modbus
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* \code #include "mb.h" \endcode
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*
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* This module defines the interface for the application. It contains
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* the basic functions and types required to use the Modbus protocol stack.
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* A typical application will want to call eMBInit() first. If the device
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* is ready to answer network requests it must then call eMBEnable() to activate
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* the protocol stack. In the main loop the function eMBPoll() must be called
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* periodically. The time interval between pooling depends on the configured
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* Modbus timeout. If an RTOS is available a separate task should be created
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* and the task should always call the function eMBPoll().
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*
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* \code
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* // Initialize protocol stack in RTU mode for a slave with address 10 = 0x0A
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* eMBInit( MB_RTU, 0x0A, 38400, MB_PAR_EVEN );
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* // Enable the Modbus Protocol Stack.
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* eMBEnable( );
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* for( ;; )
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* {
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* // Call the main polling loop of the Modbus protocol stack.
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* eMBPoll( );
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* ...
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* }
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* \endcode
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*/
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/* ----------------------- Defines ------------------------------------------*/
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/*! \ingroup modbus
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* \brief Use the default Modbus TCP port (502)
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*/
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#define MB_TCP_PORT_USE_DEFAULT 0
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#define MB_FUNC_CODE_MAX 127
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/* ----------------------- Type definitions ---------------------------------*/
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#ifndef _MB_M_H
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#define MB_FUNC_CODE_MAX 127
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/*! \ingroup modbus
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* \brief Modbus serial transmission modes (RTU/ASCII).
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*
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* Modbus serial supports two transmission modes. Either ASCII or RTU. RTU
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* is faster but has more hardware requirements and requires a network with
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* a low jitter. ASCII is slower and more reliable on slower links (E.g. modems)
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*/
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typedef enum
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{
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MB_RTU, /*!< RTU transmission mode. */
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MB_ASCII, /*!< ASCII transmission mode. */
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MB_TCP /*!< TCP mode. */
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} eMBMode;
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/*! \ingroup modbus
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* \brief If register should be written or read.
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*
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* This value is passed to the callback functions which support either
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* reading or writing register values. Writing means that the application
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* registers should be updated and reading means that the modbus protocol
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* stack needs to know the current register values.
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*
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* \see eMBRegHoldingCB( ), eMBRegCoilsCB( ), eMBRegDiscreteCB( ) and
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* eMBRegInputCB( ).
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*/
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typedef enum
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{
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MB_REG_READ, /*!< Read register values and pass to protocol stack. */
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MB_REG_WRITE /*!< Update register values. */
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} eMBRegisterMode;
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/*! \ingroup modbus
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* \brief Errorcodes used by all function in the protocol stack.
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*/
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typedef enum
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{
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MB_ENOERR, /*!< no error. */
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MB_ENOREG, /*!< illegal register address. */
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MB_EINVAL, /*!< illegal argument. */
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MB_EPORTERR, /*!< porting layer error. */
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MB_ENORES, /*!< insufficient resources. */
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MB_EIO, /*!< I/O error. */
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MB_EILLSTATE, /*!< protocol stack in illegal state. */
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MB_ETIMEDOUT /*!< timeout error occurred. */
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} eMBErrorCode;
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#endif
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/* ----------------------- Function prototypes ------------------------------*/
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/*! \ingroup modbus
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* \brief Initialize the Modbus protocol stack.
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*
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* This functions initializes the ASCII or RTU module and calls the
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* init functions of the porting layer to prepare the hardware. Please
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* note that the receiver is still disabled and no Modbus frames are
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* processed until eMBEnable( ) has been called.
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*
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* \param eMode If ASCII or RTU mode should be used.
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* \param ucSlaveAddress The slave address. Only frames sent to this
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* address or to the broadcast address are processed.
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* \param ucPort The port to use. E.g. 1 for COM1 on windows. This value
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* is platform dependent and some ports simply choose to ignore it.
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* \param ulBaudRate The baudrate. E.g. 19200. Supported baudrates depend
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* on the porting layer.
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* \param eParity Parity used for serial transmission.
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*
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* \return If no error occurs the function returns eMBErrorCode::MB_ENOERR.
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* The protocol is then in the disabled state and ready for activation
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* by calling eMBEnable( ). Otherwise one of the following error codes
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* is returned:
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* - eMBErrorCode::MB_EINVAL If the slave address was not valid. Valid
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* slave addresses are in the range 1 - 247.
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* - eMBErrorCode::MB_EPORTERR IF the porting layer returned an error.
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*/
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eMBErrorCode eMBInit( eMBMode eMode, UCHAR ucSlaveAddress,
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UCHAR ucPort, ULONG ulBaudRate, eMBParity eParity );
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/*! \ingroup modbus
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* \brief Initialize the Modbus protocol stack for Modbus TCP.
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*
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* This function initializes the Modbus TCP Module. Please note that
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* frame processing is still disabled until eMBEnable( ) is called.
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*
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* \param usTCPPort The TCP port to listen on.
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* \return If the protocol stack has been initialized correctly the function
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* returns eMBErrorCode::MB_ENOERR. Otherwise one of the following error
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* codes is returned:
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* - eMBErrorCode::MB_EINVAL If the slave address was not valid. Valid
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* slave addresses are in the range 1 - 247.
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* - eMBErrorCode::MB_EPORTERR IF the porting layer returned an error.
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*/
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eMBErrorCode eMBTCPInit( USHORT usTCPPort );
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/*! \ingroup modbus
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* \brief Release resources used by the protocol stack.
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*
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* This function disables the Modbus protocol stack and release all
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* hardware resources. It must only be called when the protocol stack
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* is disabled.
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*
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* \note Note all ports implement this function. A port which wants to
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* get an callback must define the macro MB_PORT_HAS_CLOSE to 1.
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*
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* \return If the resources where released it return eMBErrorCode::MB_ENOERR.
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* If the protocol stack is not in the disabled state it returns
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* eMBErrorCode::MB_EILLSTATE.
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*/
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eMBErrorCode eMBClose( void );
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/*! \ingroup modbus
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* \brief Enable the Modbus protocol stack.
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*
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* This function enables processing of Modbus frames. Enabling the protocol
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* stack is only possible if it is in the disabled state.
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*
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* \return If the protocol stack is now in the state enabled it returns
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* eMBErrorCode::MB_ENOERR. If it was not in the disabled state it
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* return eMBErrorCode::MB_EILLSTATE.
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*/
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eMBErrorCode eMBEnable( void );
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/*! \ingroup modbus
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* \brief Disable the Modbus protocol stack.
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*
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* This function disables processing of Modbus frames.
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*
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* \return If the protocol stack has been disabled it returns
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* eMBErrorCode::MB_ENOERR. If it was not in the enabled state it returns
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* eMBErrorCode::MB_EILLSTATE.
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*/
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eMBErrorCode eMBDisable( void );
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/*! \ingroup modbus
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* \brief The main pooling loop of the Modbus protocol stack.
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*
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* This function must be called periodically. The timer interval required
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* is given by the application dependent Modbus slave timeout. Internally the
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* function calls xMBPortEventGet() and waits for an event from the receiver or
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* transmitter state machines.
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*
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* \return If the protocol stack is not in the enabled state the function
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* returns eMBErrorCode::MB_EILLSTATE. Otherwise it returns
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* eMBErrorCode::MB_ENOERR.
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*/
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eMBErrorCode eMBPoll( void );
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/*! \ingroup modbus
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* \brief Configure the slave id of the device.
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*
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* This function should be called when the Modbus function <em>Report Slave ID</em>
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* is enabled ( By defining MB_FUNC_OTHER_REP_SLAVEID_ENABLED in mbconfig.h ).
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*
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* \param ucSlaveID Values is returned in the <em>Slave ID</em> byte of the
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* <em>Report Slave ID</em> response.
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* \param xIsRunning If TRUE the <em>Run Indicator Status</em> byte is set to 0xFF.
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* otherwise the <em>Run Indicator Status</em> is 0x00.
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* \param pucAdditional Values which should be returned in the <em>Additional</em>
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* bytes of the <em> Report Slave ID</em> response.
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* \param usAdditionalLen Length of the buffer <code>pucAdditonal</code>.
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*
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* \return If the static buffer defined by MB_FUNC_OTHER_REP_SLAVEID_BUF in
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* mbconfig.h is to small it returns eMBErrorCode::MB_ENORES. Otherwise
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* it returns eMBErrorCode::MB_ENOERR.
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*/
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eMBErrorCode eMBSetSlaveID( UCHAR ucSlaveID, BOOL xIsRunning,
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UCHAR const *pucAdditional,
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USHORT usAdditionalLen );
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/*! \ingroup modbus
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* \brief Registers a callback handler for a given function code.
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*
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* This function registers a new callback handler for a given function code.
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* The callback handler supplied is responsible for interpreting the Modbus PDU and
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* the creation of an appropriate response. In case of an error it should return
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* one of the possible Modbus exceptions which results in a Modbus exception frame
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* sent by the protocol stack.
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*
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* \param ucFunctionCode The Modbus function code for which this handler should
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* be registers. Valid function codes are in the range 1 to 127.
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* \param pxHandler The function handler which should be called in case
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* such a frame is received. If \c NULL a previously registered function handler
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* for this function code is removed.
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*
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* \return eMBErrorCode::MB_ENOERR if the handler has been installed. If no
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* more resources are available it returns eMBErrorCode::MB_ENORES. In this
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* case the values in mbconfig.h should be adjusted. If the argument was not
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* valid it returns eMBErrorCode::MB_EINVAL.
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*/
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eMBErrorCode eMBRegisterCB( UCHAR ucFunctionCode,
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pxMBFunctionHandler pxHandler );
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/* ----------------------- Callback -----------------------------------------*/
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/*! \defgroup modbus_registers Modbus Registers
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* \code #include "mb.h" \endcode
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* The protocol stack does not internally allocate any memory for the
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* registers. This makes the protocol stack very small and also usable on
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* low end targets. In addition the values don't have to be in the memory
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* and could for example be stored in a flash.<br>
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* Whenever the protocol stack requires a value it calls one of the callback
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* function with the register address and the number of registers to read
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* as an argument. The application should then read the actual register values
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* (for example the ADC voltage) and should store the result in the supplied
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* buffer.<br>
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* If the protocol stack wants to update a register value because a write
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* register function was received a buffer with the new register values is
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* passed to the callback function. The function should then use these values
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* to update the application register values.
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*/
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/*! \ingroup modbus_registers
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* \brief Callback function used if the value of a <em>Input Register</em>
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* is required by the protocol stack. The starting register address is given
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* by \c usAddress and the last register is given by <tt>usAddress +
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* usNRegs - 1</tt>.
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*
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* \param pucRegBuffer A buffer where the callback function should write
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* the current value of the modbus registers to.
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* \param usAddress The starting address of the register. Input registers
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* are in the range 1 - 65535.
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* \param usNRegs Number of registers the callback function must supply.
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*
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* \return The function must return one of the following error codes:
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* - eMBErrorCode::MB_ENOERR If no error occurred. In this case a normal
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* Modbus response is sent.
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* - eMBErrorCode::MB_ENOREG If the application can not supply values
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* for registers within this range. In this case a
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* <b>ILLEGAL DATA ADDRESS</b> exception frame is sent as a response.
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* - eMBErrorCode::MB_ETIMEDOUT If the requested register block is
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* currently not available and the application dependent response
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* timeout would be violated. In this case a <b>SLAVE DEVICE BUSY</b>
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* exception is sent as a response.
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* - eMBErrorCode::MB_EIO If an unrecoverable error occurred. In this case
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* a <b>SLAVE DEVICE FAILURE</b> exception is sent as a response.
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*/
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eMBErrorCode eMBRegInputCB( UCHAR * pucRegBuffer, USHORT usAddress,
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USHORT usNRegs );
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/*! \ingroup modbus_registers
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* \brief Callback function used if a <em>Holding Register</em> value is
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* read or written by the protocol stack. The starting register address
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* is given by \c usAddress and the last register is given by
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* <tt>usAddress + usNRegs - 1</tt>.
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*
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* \param pucRegBuffer If the application registers values should be updated the
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* buffer points to the new registers values. If the protocol stack needs
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* to now the current values the callback function should write them into
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* this buffer.
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* \param usAddress The starting address of the register.
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* \param usNRegs Number of registers to read or write.
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* \param eMode If eMBRegisterMode::MB_REG_WRITE the application register
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* values should be updated from the values in the buffer. For example
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* this would be the case when the Modbus master has issued an
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* <b>WRITE SINGLE REGISTER</b> command.
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* If the value eMBRegisterMode::MB_REG_READ the application should copy
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* the current values into the buffer \c pucRegBuffer.
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*
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* \return The function must return one of the following error codes:
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* - eMBErrorCode::MB_ENOERR If no error occurred. In this case a normal
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* Modbus response is sent.
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* - eMBErrorCode::MB_ENOREG If the application can not supply values
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* for registers within this range. In this case a
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* <b>ILLEGAL DATA ADDRESS</b> exception frame is sent as a response.
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* - eMBErrorCode::MB_ETIMEDOUT If the requested register block is
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* currently not available and the application dependent response
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* timeout would be violated. In this case a <b>SLAVE DEVICE BUSY</b>
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* exception is sent as a response.
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* - eMBErrorCode::MB_EIO If an unrecoverable error occurred. In this case
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* a <b>SLAVE DEVICE FAILURE</b> exception is sent as a response.
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*/
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eMBErrorCode eMBRegHoldingCB( UCHAR * pucRegBuffer, USHORT usAddress,
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USHORT usNRegs, eMBRegisterMode eMode );
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/*! \ingroup modbus_registers
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* \brief Callback function used if a <em>Coil Register</em> value is
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* read or written by the protocol stack. If you are going to use
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* this function you might use the functions xMBUtilSetBits( ) and
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* xMBUtilGetBits( ) for working with bitfields.
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*
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* \param pucRegBuffer The bits are packed in bytes where the first coil
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* starting at address \c usAddress is stored in the LSB of the
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* first byte in the buffer <code>pucRegBuffer</code>.
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* If the buffer should be written by the callback function unused
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* coil values (I.e. if not a multiple of eight coils is used) should be set
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* to zero.
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* \param usAddress The first coil number.
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* \param usNCoils Number of coil values requested.
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* \param eMode If eMBRegisterMode::MB_REG_WRITE the application values should
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* be updated from the values supplied in the buffer \c pucRegBuffer.
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* If eMBRegisterMode::MB_REG_READ the application should store the current
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* values in the buffer \c pucRegBuffer.
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*
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* \return The function must return one of the following error codes:
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* - eMBErrorCode::MB_ENOERR If no error occurred. In this case a normal
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* Modbus response is sent.
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* - eMBErrorCode::MB_ENOREG If the application does not map an coils
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* within the requested address range. In this case a
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* <b>ILLEGAL DATA ADDRESS</b> is sent as a response.
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* - eMBErrorCode::MB_ETIMEDOUT If the requested register block is
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* currently not available and the application dependent response
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* timeout would be violated. In this case a <b>SLAVE DEVICE BUSY</b>
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* exception is sent as a response.
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* - eMBErrorCode::MB_EIO If an unrecoverable error occurred. In this case
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* a <b>SLAVE DEVICE FAILURE</b> exception is sent as a response.
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*/
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eMBErrorCode eMBRegCoilsCB( UCHAR * pucRegBuffer, USHORT usAddress,
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USHORT usNCoils, eMBRegisterMode eMode );
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/*! \ingroup modbus_registers
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* \brief Callback function used if a <em>Input Discrete Register</em> value is
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* read by the protocol stack.
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*
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* If you are going to use his function you might use the functions
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* xMBUtilSetBits( ) and xMBUtilGetBits( ) for working with bitfields.
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*
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* \param pucRegBuffer The buffer should be updated with the current
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* coil values. The first discrete input starting at \c usAddress must be
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* stored at the LSB of the first byte in the buffer. If the requested number
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* is not a multiple of eight the remaining bits should be set to zero.
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* \param usAddress The starting address of the first discrete input.
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* \param usNDiscrete Number of discrete input values.
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* \return The function must return one of the following error codes:
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* - eMBErrorCode::MB_ENOERR If no error occurred. In this case a normal
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* Modbus response is sent.
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* - eMBErrorCode::MB_ENOREG If no such discrete inputs exists.
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* In this case a <b>ILLEGAL DATA ADDRESS</b> exception frame is sent
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* as a response.
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* - eMBErrorCode::MB_ETIMEDOUT If the requested register block is
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* currently not available and the application dependent response
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* timeout would be violated. In this case a <b>SLAVE DEVICE BUSY</b>
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* exception is sent as a response.
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* - eMBErrorCode::MB_EIO If an unrecoverable error occurred. In this case
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* a <b>SLAVE DEVICE FAILURE</b> exception is sent as a response.
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*/
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eMBErrorCode eMBRegDiscreteCB( UCHAR * pucRegBuffer, USHORT usAddress,
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USHORT usNDiscrete );
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#ifdef __cplusplus
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PR_END_EXTERN_C
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#endif
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#endif
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