【经验分享】STM32移植FreeModbus实现ModBusRTU协议

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STMCU小助手发布时间：2022-4-23 15:41

文章
文章封面:
文章简介:	STM32移植FreeModbus实现ModBusRTU协议

首先将FreeModbus移植到自己工程中，如下图所示：

然后修改portserial.c和porttimer.c文件：
portserial.c

/*
* FreeModbus Libary: BARE Port
* Copyright (C) 2006 Christian Walter
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* File: $Id: portserial.c,v 1.1 2006/08/22 21:35:13 wolti Exp $
*/
#include "port.h"
#include "stm32f10x.h"
#include "modbus.h"
/* ----------------------- Modbus includes ----------------------------------*/
#include "mb.h"
#include "mbport.h"
/* ----------------------- static functions ---------------------------------*/
static void prvvUARTTxReadyISR( void );
static void prvvUARTRxISR( void );
/* ----------------------- Start implementation -----------------------------*/
void
vMBPortSerialEnable( BOOL xRxEnable, BOOL xTxEnable )
{
/* If xRXEnable enable serial receive interrupts. If xTxENable enable
* transmitter empty interrupts.
*/
if(xRxEnable == TRUE)
{
USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);
}
else
{
USART_ITConfig(USART2, USART_IT_RXNE, DISABLE);
}
if(xTxEnable == TRUE)
{
USART_ITConfig(USART2, USART_IT_TC, ENABLE);
}
else
{
USART_ITConfig(USART2, USART_IT_TC, DISABLE);
}
}
BOOL
xMBPortSerialInit( UCHAR ucPORT, ULONG ulBaudRate, UCHAR ucDataBits, eMBParity eParity )
{
modbus_uart_init((uint16_t)ulBaudRate);
return TRUE;
}
BOOL
xMBPortSerialPutByte( CHAR ucByte )
{
/* Put a byte in the UARTs transmit buffer. This function is called
* by the protocol stack if pxMBFrameCBTransmitterEmpty( ) has been
* called. */
USART_SendData(USART2, ucByte);
return TRUE;
}
BOOL
xMBPortSerialGetByte( CHAR * pucByte )
{
/* Return the byte in the UARTs receive buffer. This function is called
* by the protocol stack after pxMBFrameCBByteReceived( ) has been called.
*/
*pucByte = USART_ReceiveData(USART2);
return TRUE;
}
/* Create an interrupt handler for the transmit buffer empty interrupt
* (or an equivalent) for your target processor. This function should then
* call pxMBFrameCBTransmitterEmpty( ) which tells the protocol stack that
* a new character can be sent. The protocol stack will then call
* xMBPortSerialPutByte( ) to send the character.
*/
static void prvvUARTTxReadyISR( void )
{
pxMBFrameCBTransmitterEmpty( );
}
/* Create an interrupt handler for the receive interrupt for your target
* processor. This function should then call pxMBFrameCBByteReceived( ). The
* protocol stack will then call xMBPortSerialGetByte( ) to retrieve the
* character.
*/
static void prvvUARTRxISR( void )
{
pxMBFrameCBByteReceived( );
}
/**
* @brief This function handles usart1 Handler.
* @param None
* @retval None
*/
void USART2_IRQHandler(void)
{
//发生接收中断
if(USART_GetITStatus(USART2, USART_IT_RXNE) == SET)
{
prvvUARTRxISR();
//清除中断标志位
USART_ClearITPendingBit(USART2, USART_IT_RXNE);
}
if(USART_GetITStatus(USART2, USART_IT_ORE) == SET)
{
USART_ClearITPendingBit(USART2, USART_IT_ORE);
prvvUARTRxISR();
}
//发生完成中断
if(USART_GetITStatus(USART2, USART_IT_TC) == SET)
{
prvvUARTTxReadyISR();
//清除中断标志
USART_ClearITPendingBit(USART2, USART_IT_TC);
}
}

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porttimer.c

```c
/*
* FreeModbus Libary: BARE Port
* Copyright (C) 2006 Christian Walter <<a href="mailto:wolti@sil.at">wolti@sil.at</a>>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* File: $Id: porttimer.c,v 1.1 2006/08/22 21:35:13 wolti Exp $
*/
/* ----------------------- Platform includes --------------------------------*/
#include "port.h"
#include "modbus.h"
/* ----------------------- Modbus includes ----------------------------------*/
#include "mb.h"
#include "mbport.h"
/* ----------------------- static functions ---------------------------------*/
static void prvvTIMERExpiredISR( void );
/* ----------------------- Start implementation -----------------------------*/
BOOL
xMBPortTimersInit( USHORT usTim1Timerout50us )
{
modbus_timer_init(usTim1Timerout50us);
return TRUE;
}
void
vMBPortTimersEnable( )
{
/* Enable the timer with the timeout passed to xMBPortTimersInit( ) */
TIM_ClearITPendingBit(TIM3, TIM_IT_Update);
TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);
TIM_SetCounter(TIM3,0x0000);
TIM_Cmd(TIM3, ENABLE);
}
void
vMBPortTimersDisable( )
{
/* Disable any pending timers. */
TIM_ClearITPendingBit(TIM3, TIM_IT_Update);
TIM_ITConfig(TIM3, TIM_IT_Update, DISABLE);
TIM_SetCounter(TIM3,0x0000);
TIM_Cmd(TIM3, DISABLE);
}
/* Create an ISR which is called whenever the timer has expired. This function
* must then call pxMBPortCBTimerExpired( ) to notify the protocol stack that
* the timer has expired.
*/
static void prvvTIMERExpiredISR( void )
{
( void )pxMBPortCBTimerExpired( );
}
void TIM3_IRQHandler(void)
{
if(TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET)
{
prvvTIMERExpiredISR();
TIM_ClearITPendingBit(TIM3, TIM_IT_Update);
}
}

复制代码

然后主函数中调用

int main(void)
{
delay_init(); //延时函数初始化
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); //设置NVIC中断分组2:2位抢占优先级，2位响应优先级
uart_init(115200);
eMBInit(MB_RTU, 0x01, 0x01, 9600, MB_PAR_NONE);
eMBEnable();
while(1)
{
(void)eMBPoll();
delay_ms(5);
}
}

复制代码

其次还要实现读线圈、写线圈、读离散输入、写保持寄存器、读保持寄存器、读输入寄存器等功能，如下：

#define REG_INPUT_START 0x0001 //输入寄存器起始地址
#define REG_INPUT_NREGS 8 //输入寄存器数量
#define REG_HOLDING_START 0x0001 //保持寄存器起始地址
#define REG_HOLDING_NREGS 8 //保持寄存器数量
#define REG_COILS_START 0x0001 //线圈起始地址
#define REG_COILS_SIZE 16 //线圈数量
#define REG_DISCRETE_START 0x0001 //开关寄存器其实地址
#define REG_DISCRETE_SIZE 16 //开关寄存器数量
//输入寄存器内容
uint16_t usRegInputBuf[REG_INPUT_NREGS] = {0x1000,0x1001,0x1002,0x1003,0x1004,0x1005,0x1006,0x1007};
//保持寄存器内容
uint16_t usRegHoldingBuf[REG_HOLDING_NREGS] = {0x2000,0x2001,0x2002,0x2003,0x2004,0x2005,0x2006,0x2007};
//线圈状态
uint8_t ucRegCoilsBuf[REG_COILS_SIZE] = {0x01,0x01,0x00,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00};
//离散寄存器内容
uint8_t ucRegDiscreteBuf[REG_DISCRETE_SIZE] = {0x01,0x01,0x00,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x01};
/****************************************************************************
* 名称：eMBRegInputCB
* 功能：读取输入寄存器，对应功能码是 04 eMBFuncReadInputRegister
* 入口参数：pucRegBuffer: 数据缓存区，用于响应主机
* usAddress: 寄存器地址
* usNRegs: 要读取的寄存器个数
* 出口参数：
* 注意：上位机发来的帧格式是: SlaveAddr(1 Byte)+FuncCode(1 Byte)
* +StartAddrHiByte(1 Byte)+StartAddrLoByte(1 Byte)
* +LenAddrHiByte(1 Byte)+LenAddrLoByte(1 Byte)+
* +CRCAddrHiByte(1 Byte)+CRCAddrLoByte(1 Byte)
* 3 区
****************************************************************************/
eMBErrorCode
eMBRegInputCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNRegs )
{
eMBErrorCode eStatus = MB_ENOERR;
int iRegIndex;
if( ( usAddress >= REG_INPUT_START )
&& ( usAddress + usNRegs <= REG_INPUT_START + REG_INPUT_NREGS ) )
{
iRegIndex = ( int )( usAddress - REG_INPUT_START );
while( usNRegs > 0 )
{
*pucRegBuffer++ = ( UCHAR )( usRegInputBuf[iRegIndex] >> 8 );
*pucRegBuffer++ = ( UCHAR )( usRegInputBuf[iRegIndex] & 0xFF );
iRegIndex++;
usNRegs--;
}
}
else
{
eStatus = MB_ENOREG;
}
return eStatus;
}
/****************************************************************************
* 名称：eMBRegHoldingCB
* 功能：对应功能码有：06 写保持寄存器 eMBFuncWriteHoldingRegister
* 16 写多个保持寄存器 eMBFuncWriteMultipleHoldingRegister
* 03 读保持寄存器 eMBFuncReadHoldingRegister
* 23 读写多个保持寄存器 eMBFuncReadWriteMultipleHoldingRegister
* 入口参数：pucRegBuffer: 数据缓存区，用于响应主机
* usAddress: 寄存器地址
* usNRegs: 要读写的寄存器个数
* eMode: 功能码
* 出口参数：
* 注意：4 区
****************************************************************************/
eMBErrorCode
eMBRegHoldingCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNRegs, eMBRegisterMode eMode )
{
eMBErrorCode eStatus = MB_ENOERR;
int iRegIndex;
if((usAddress >= REG_HOLDING_START)&&\
((usAddress+usNRegs) <= (REG_HOLDING_START + REG_HOLDING_NREGS)))
{
iRegIndex = (int)(usAddress - REG_HOLDING_START);
switch(eMode)
{
case MB_REG_READ://读 MB_REG_READ = 0
while(usNRegs > 0)
{
*pucRegBuffer++ = (u8)(usRegHoldingBuf[iRegIndex] >> 8);
*pucRegBuffer++ = (u8)(usRegHoldingBuf[iRegIndex] & 0xFF);
iRegIndex++;
usNRegs--;
}
break;
case MB_REG_WRITE://写 MB_REG_WRITE = 0
while(usNRegs > 0)
{
usRegHoldingBuf[iRegIndex] = *pucRegBuffer++ << 8;
usRegHoldingBuf[iRegIndex] |= *pucRegBuffer++;
iRegIndex++;
usNRegs--;
}
break;
}
}
else//错误
{
eStatus = MB_ENOREG;
}
return eStatus;
}
/****************************************************************************
* 名称：eMBRegCoilsCB
* 功能：对应功能码有：01 读线圈 eMBFuncReadCoils
* 05 写线圈 eMBFuncWriteCoil
* 15 写多个线圈 eMBFuncWriteMultipleCoils
* 入口参数：pucRegBuffer: 数据缓存区，用于响应主机
* usAddress: 线圈地址
* usNCoils: 要读写的线圈个数
* eMode: 功能码
* 出口参数：
* 注意：如继电器
* 0 区
****************************************************************************/
eMBErrorCode
eMBRegCoilsCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNCoils, eMBRegisterMode eMode )
{
eMBErrorCode eStatus = MB_ENOERR;
int iRegIndex;
u8 i;
USHORT readNumber=usNCoils;
USHORT coilValue=0x0000;
if((usAddress >= REG_COILS_START)&&\
((usAddress+usNCoils) <= (REG_COILS_START + REG_COILS_SIZE)))
{
iRegIndex = (int)(usAddress + usNCoils-REG_COILS_START);
switch(eMode)
{
case MB_REG_READ://读 MB_REG_READ = 0
for(i=0;i<usNCoils;i++)
{
readNumber--;
iRegIndex--;
coilValue|=ucRegCoilsBuf[iRegIndex]<<readNumber;
}
if(usNCoils<=8)
{
* pucRegBuffer=coilValue;
}
else
{
* pucRegBuffer++ = (coilValue)&0x00ff;
* pucRegBuffer++ = (coilValue>>8)&0x00ff;
}
break;
case MB_REG_WRITE://写 MB_REG_WRITE = 1
while(usNCoils > 0)
{
// usRegHoldingBuf[iRegIndex] = *pucRegBuffer++ << 8;
// usRegHoldingBuf[iRegIndex] |= *pucRegBuffer++;
iRegIndex++;
usNCoils--;
}
break;
}
}
else//错误
{
eStatus = MB_ENOREG;
}
return eStatus;
}
/****************************************************************************
* 名称：eMBRegDiscreteCB
* 功能：读取离散寄存器，对应功能码有：02 读离散寄存器 eMBFuncReadDiscreteInputs
* 入口参数：pucRegBuffer: 数据缓存区，用于响应主机
* usAddress: 寄存器地址
* usNDiscrete: 要读取的寄存器个数
* 出口参数：
* 注意：1 区
****************************************************************************/
eMBErrorCode
eMBRegDiscreteCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNDiscrete )
{
eMBErrorCode eStatus = MB_ENOERR;
int iRegIndex;
u8 i;
USHORT readNumber=usNDiscrete;
USHORT coilValue=0x0000;
iRegIndex = (int)(usAddress + usNDiscrete-REG_DISCRETE_START);
if((usAddress >= REG_DISCRETE_START)&&\
((usAddress+usNDiscrete) <= (REG_DISCRETE_START + REG_DISCRETE_SIZE)))
{
for(i=0;i<usNDiscrete;i++)
{
readNumber--;
iRegIndex--;
coilValue|=ucRegDiscreteBuf[iRegIndex]<<readNumber;
}
if(usNDiscrete<=8)
{
* pucRegBuffer=coilValue;
}
else
{
* pucRegBuffer++ = (coilValue)&0x00ff;
* pucRegBuffer++ = (coilValue>>8)&0x00ff;
}
}
else
{
eStatus = MB_ENOREG;
}
return eStatus;
}