/* * FreeModbus Libary: A portable Modbus implementation for Modbus ASCII/RTU. * Copyright (c) 2013 China Beijing Armink * 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