esp-idf/components/freemodbus/modbus/rtu/mbrtu_m.c
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C

/*
* FreeModbus Libary: A portable Modbus implementation for Modbus ASCII/RTU.
* Copyright (c) 2013 China Beijing Armink <armink.ztl@gmail.com>
* 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: mbrtu_m.c,v 1.60 2013/08/17 11:42:56 Armink Add Master Functions $
*/
/* ----------------------- System includes ----------------------------------*/
#include "stdlib.h"
#include "string.h"
#include "stdio.h"
/* ----------------------- Platform includes --------------------------------*/
#include "port.h"
/* ----------------------- Modbus includes ----------------------------------*/
#include "mb_m.h"
#include "mbrtu.h"
#include "mbframe.h"
#include "mbcrc.h"
#include "mbport.h"
/* ----------------------- Defines ------------------------------------------*/
#define MB_RTU_SER_PDU_SIZE_MIN 4 /*!< Minimum size of a Modbus RTU frame. */
/* ----------------------- Type definitions ---------------------------------*/
typedef enum
{
STATE_M_RX_INIT, /*!< Receiver is in initial state. */
STATE_M_RX_IDLE, /*!< Receiver is in idle state. */
STATE_M_RX_RCV, /*!< Frame is beeing received. */
STATE_M_RX_ERROR, /*!< If the frame is invalid. */
} eMBMasterRcvState;
typedef enum
{
STATE_M_TX_IDLE, /*!< Transmitter is in idle state. */
STATE_M_TX_XMIT, /*!< Transmitter is in transfer state. */
STATE_M_TX_XFWR, /*!< Transmitter is in transfer finish and wait receive state. */
} eMBMasterSndState;
#if MB_MASTER_RTU_ENABLED > 0
/*------------------------ Shared variables ---------------------------------*/
extern volatile UCHAR ucMasterRcvBuf[];
extern volatile UCHAR ucMasterSndBuf[];
/* ----------------------- Static variables ---------------------------------*/
static volatile eMBMasterSndState eSndState;
static volatile eMBMasterRcvState eRcvState;
static volatile UCHAR *pucMasterSndBufferCur;
static volatile USHORT usMasterSndBufferCount;
static volatile USHORT usMasterRcvBufferPos;
static volatile UCHAR *ucMasterRTURcvBuf = ucMasterRcvBuf;
static volatile UCHAR *ucMasterRTUSndBuf = ucMasterSndBuf;
/* ----------------------- Start implementation -----------------------------*/
eMBErrorCode
eMBMasterRTUInit(UCHAR ucPort, ULONG ulBaudRate, eMBParity eParity )
{
eMBErrorCode eStatus = MB_ENOERR;
ULONG usTimerT35_50us;
ENTER_CRITICAL_SECTION( );
/* Modbus RTU uses 8 Databits. */
if( xMBMasterPortSerialInit( ucPort, ulBaudRate, 8, eParity ) != TRUE )
{
eStatus = MB_EPORTERR;
}
else
{
/* If baudrate > 19200 then we should use the fixed timer values
* t35 = 1750us. Otherwise t35 must be 3.5 times the character time.
*/
if( ulBaudRate > 19200 )
{
usTimerT35_50us = 35; /* 1800us. */
}
else
{
/* The timer reload value for a character is given by:
*
* ChTimeValue = Ticks_per_1s / ( Baudrate / 11 )
* = 11 * Ticks_per_1s / Baudrate
* = 220000 / Baudrate
* The reload for t3.5 is 1.5 times this value and similary
* for t3.5.
*/
usTimerT35_50us = ( 7UL * 220000UL ) / ( 2UL * ulBaudRate );
}
if( xMBMasterPortTimersInit( ( USHORT ) usTimerT35_50us ) != TRUE )
{
eStatus = MB_EPORTERR;
}
}
EXIT_CRITICAL_SECTION( );
return eStatus;
}
void
eMBMasterRTUStart( void )
{
ENTER_CRITICAL_SECTION( );
/* Initially the receiver is in the state STATE_M_RX_INIT. we start
* the timer and if no character is received within t3.5 we change
* to STATE_M_RX_IDLE. This makes sure that we delay startup of the
* modbus protocol stack until the bus is free.
*/
eRcvState = STATE_M_RX_IDLE; //STATE_M_RX_INIT (We start processing immediately)
vMBMasterPortSerialEnable( TRUE, FALSE );
vMBMasterPortTimersT35Enable( );
EXIT_CRITICAL_SECTION( );
}
void
eMBMasterRTUStop( void )
{
ENTER_CRITICAL_SECTION( );
vMBMasterPortSerialEnable( FALSE, FALSE );
vMBMasterPortTimersDisable( );
EXIT_CRITICAL_SECTION( );
}
eMBErrorCode
eMBMasterRTUReceive( UCHAR * pucRcvAddress, UCHAR ** pucFrame, USHORT * pusLength )
{
eMBErrorCode eStatus = MB_ENOERR;
ENTER_CRITICAL_SECTION( );
assert( usMasterRcvBufferPos < MB_SER_PDU_SIZE_MAX );
/* Length and CRC check */
if( ( usMasterRcvBufferPos >= MB_RTU_SER_PDU_SIZE_MIN )
&& ( usMBCRC16( ( UCHAR * ) ucMasterRTURcvBuf, usMasterRcvBufferPos ) == 0 ) )
{
/* Save the address field. All frames are passed to the upper layed
* and the decision if a frame is used is done there.
*/
*pucRcvAddress = ucMasterRTURcvBuf[MB_SER_PDU_ADDR_OFF];
/* Total length of Modbus-PDU is Modbus-Serial-Line-PDU minus
* size of address field and CRC checksum.
*/
*pusLength = ( USHORT )( usMasterRcvBufferPos - MB_SER_PDU_PDU_OFF - MB_SER_PDU_SIZE_CRC );
/* Return the start of the Modbus PDU to the caller. */
*pucFrame = ( UCHAR * ) & ucMasterRTURcvBuf[MB_SER_PDU_PDU_OFF];
}
else
{
eStatus = MB_EIO;
}
EXIT_CRITICAL_SECTION( );
return eStatus;
}
eMBErrorCode
eMBMasterRTUSend( UCHAR ucSlaveAddress, const UCHAR * pucFrame, USHORT usLength )
{
eMBErrorCode eStatus = MB_ENOERR;
USHORT usCRC16;
if ( ucSlaveAddress > MB_MASTER_TOTAL_SLAVE_NUM ) return MB_EINVAL;
ENTER_CRITICAL_SECTION( );
/* Check if the receiver is still in idle state. If not we where to
* slow with processing the received frame and the master sent another
* frame on the network. We have to abort sending the frame.
*/
if( eRcvState == STATE_M_RX_IDLE )
{
/* First byte before the Modbus-PDU is the slave address. */
pucMasterSndBufferCur = ( UCHAR * ) pucFrame - 1;
usMasterSndBufferCount = 1;
/* Now copy the Modbus-PDU into the Modbus-Serial-Line-PDU. */
pucMasterSndBufferCur[MB_SER_PDU_ADDR_OFF] = ucSlaveAddress;
usMasterSndBufferCount += usLength;
/* Calculate CRC16 checksum for Modbus-Serial-Line-PDU. */
usCRC16 = usMBCRC16( ( UCHAR * ) pucMasterSndBufferCur, usMasterSndBufferCount );
ucMasterRTUSndBuf[usMasterSndBufferCount++] = ( UCHAR )( usCRC16 & 0xFF );
ucMasterRTUSndBuf[usMasterSndBufferCount++] = ( UCHAR )( usCRC16 >> 8 );
/* Activate the transmitter. */
eSndState = STATE_M_TX_XMIT;
// The place to enable RS485 driver
vMBMasterPortSerialEnable( FALSE, TRUE );
}
else
{
eStatus = MB_EIO;
}
EXIT_CRITICAL_SECTION( );
return eStatus;
}
BOOL
xMBMasterRTUReceiveFSM( void )
{
BOOL xStatus = FALSE;
UCHAR ucByte;
assert(( eSndState == STATE_M_TX_IDLE ) || ( eSndState == STATE_M_TX_XFWR ));
/* Always read the character. */
xStatus = xMBMasterPortSerialGetByte( ( CHAR * ) & ucByte );
switch ( eRcvState )
{
/* If we have received a character in the init state we have to
* wait until the frame is finished.
*/
case STATE_M_RX_INIT:
vMBMasterPortTimersT35Enable( );
break;
/* In the error state we wait until all characters in the
* damaged frame are transmitted.
*/
case STATE_M_RX_ERROR:
vMBMasterPortTimersT35Enable( );
break;
/* In the idle state we wait for a new character. If a character
* is received the t1.5 and t3.5 timers are started and the
* receiver is in the state STATE_M_RX_RCV and disable early
* the timer of respond timeout .
*/
case STATE_M_RX_IDLE:
/* In time of respond timeout,the receiver receive a frame.
* Disable timer of respond timeout and change the transmiter state to idle.
*/
vMBMasterPortTimersDisable( );
eSndState = STATE_M_TX_IDLE;
usMasterRcvBufferPos = 0;
ucMasterRTURcvBuf[usMasterRcvBufferPos++] = ucByte;
eRcvState = STATE_M_RX_RCV;
/* Enable t3.5 timers. */
vMBMasterPortTimersT35Enable( );
break;
/* We are currently receiving a frame. Reset the timer after
* every character received. If more than the maximum possible
* number of bytes in a modbus frame is received the frame is
* ignored.
*/
case STATE_M_RX_RCV:
if( usMasterRcvBufferPos < MB_SER_PDU_SIZE_MAX )
{
if ( xStatus ) {
ucMasterRTURcvBuf[usMasterRcvBufferPos++] = ucByte;
}
}
else
{
eRcvState = STATE_M_RX_ERROR;
}
vMBMasterPortTimersT35Enable( );
break;
}
return xStatus;
}
BOOL
xMBMasterRTUTransmitFSM( void )
{
BOOL xNeedPoll = TRUE;
BOOL xFrameIsBroadcast = FALSE;
assert( eRcvState == STATE_M_RX_IDLE );
switch ( eSndState )
{
/* We should not get a transmitter event if the transmitter is in
* idle state. */
case STATE_M_TX_XFWR:
xNeedPoll = FALSE;
break;
case STATE_M_TX_IDLE:
break;
case STATE_M_TX_XMIT:
/* check if we are finished. */
if( usMasterSndBufferCount != 0 )
{
xMBMasterPortSerialPutByte( ( CHAR )*pucMasterSndBufferCur );
pucMasterSndBufferCur++; /* next byte in sendbuffer. */
usMasterSndBufferCount--;
}
else
{
xFrameIsBroadcast = ( ucMasterRTUSndBuf[MB_SER_PDU_ADDR_OFF] == MB_ADDRESS_BROADCAST ) ? TRUE : FALSE;
vMBMasterRequestSetType( xFrameIsBroadcast );
eSndState = STATE_M_TX_XFWR;
/* If the frame is broadcast ,master will enable timer of convert delay,
* else master will enable timer of respond timeout. */
if ( xFrameIsBroadcast == TRUE )
{
vMBMasterPortTimersConvertDelayEnable( );
}
else
{
vMBMasterPortTimersRespondTimeoutEnable( );
}
}
break;
}
return xNeedPoll;
}
BOOL MB_PORT_ISR_ATTR
xMBMasterRTUTimerExpired(void)
{
BOOL xNeedPoll = FALSE;
switch (eRcvState)
{
/* Timer t35 expired. Startup phase is finished. */
case STATE_M_RX_INIT:
xNeedPoll = xMBMasterPortEventPost(EV_MASTER_READY);
break;
/* A frame was received and t35 expired. Notify the listener that
* a new frame was received. */
case STATE_M_RX_RCV:
xNeedPoll = xMBMasterPortEventPost(EV_MASTER_FRAME_RECEIVED);
break;
/* An error occured while receiving the frame. */
case STATE_M_RX_ERROR:
vMBMasterSetErrorType(EV_ERROR_RECEIVE_DATA);
xNeedPoll = xMBMasterPortEventPost(EV_MASTER_ERROR_PROCESS);
break;
/* Function called in an illegal state. */
default:
assert(eRcvState == STATE_M_RX_IDLE);
break;
}
eRcvState = STATE_M_RX_IDLE;
switch (eSndState)
{
/* A frame was send finish and convert delay or respond timeout expired.
* If the frame is broadcast,The master will idle,and if the frame is not
* broadcast. Notify the listener process error.*/
case STATE_M_TX_XFWR:
if ( xMBMasterRequestIsBroadcast( ) == FALSE ) {
vMBMasterSetErrorType(EV_ERROR_RESPOND_TIMEOUT);
xNeedPoll = xMBMasterPortEventPost(EV_MASTER_ERROR_PROCESS);
}
break;
/* Function called in an illegal state. */
default:
assert( ( eSndState == STATE_M_TX_XMIT ) || ( eSndState == STATE_M_TX_IDLE ));
break;
}
eSndState = STATE_M_TX_IDLE;
vMBMasterPortTimersDisable( );
/* If timer mode is convert delay, the master event then turns EV_MASTER_EXECUTE status. */
if (xMBMasterGetCurTimerMode() == MB_TMODE_CONVERT_DELAY) {
xNeedPoll = xMBMasterPortEventPost(EV_MASTER_EXECUTE);
}
return xNeedPoll;
}
#endif