STM32F407和ucosIII移植FreeMODBUS RTU
1 FreeMODBUS是什么
FreeMODBUS 是针对通用的Modbus协议栈在嵌入式系统中应用的一个实现
。Modbus协议是一个在工业制造领域中得到广泛应用的一个网络协议。
一个Modbus通信协议栈包括两层：定义了数据结构和功能Modbus应用协议和网络层。
在FreeMODBUS的当前版本中，提供了Modbus Application Protocol v1.1a 的实现并且支持在Modbus over serial line specification 1.0中定义的RTU/ASCII传输模式。从0.7版本开始，FreeModbus也支持在TCP defined in Modbus Messaging on TCP/IP Implementation Guide v1.0a中定义的TCP传输。Freemodbus遵循BSD[1] ，这意味着本协议栈的实现代码可以应用于商业用途。目前版本的FreeModbus支持如下的功能码：
- 读输入寄存器 (0x04)
- 读保持寄存器 (0x03)
- 写单个寄存器 (0x06)
- 写多个寄存器 (0x10)
- 读/写多个寄存器 (0x17)
- 读取线圈状态 (0x01)
- 写单个线圈 (0x05)
- 写多个线圈 (0x0F)
- 读输入状态 (0x02)
- 报告从机标识 (0x11)
本实现基于最新的标准并且与标准完全兼容。
接收和传输Modbus RTU/ASCII数据帧是通过一个由硬件提取层的调用来驱动状态机来实现的
。这就使得该协议非常容易移植到其他的平台之上。当收到一个完整的数据帧后，该数据帧被传入Modbus应用层，数据帧的内容在该层得到解析。为例方便增加新的Modbus功能，Freemodbus在应用层通提供了Hooks。
如果用到了Modbus TCP协议，那么当准备处理一个新数据帧的时候，移植层就必须首先向协议栈发送一个事件标志。然后，协议栈调用一个返回值为接收到的Modbus TCP数据帧的函数，并且开始处理这个数据帧。如果数据有效，则相应的Modbus反馈帧将提供给移植层生成反馈帧。最后，该反馈被发送到客户端。
(原文来自
freemodbus
)
1.1 移植准备
FreeModbus协议对硬件的需求非常少——基本上任何具有串行接口，并且有一些能够容纳modbus数据帧的RAM的微控制器都足够了。
- 一个异步串行接口，能够支持接收缓冲区满和发送缓存区空中断。
- 一个能够产生RTU传输所需要的t3.5字符超时定时器的时钟
对于软件部分，仅仅需要一个简单的事件队列。
在使用操作系统的处理器上，可通过单独定义一个任务完成Modbus时间的查询
。小点的微控制器往往不允许使用操作系统，在那种情况下，可以使用一个全局变量来实现该事件队列。
2 下载demo
在freemodbus的GitHub上下载最新的代码
https://github.com/cwalter-at/freemodbus
2.1 拷贝基础代码
文件夹中demo是一些不同嵌入式平台的例子，将modbus 文件夹拷贝到自己的工程目录，并添加到工程。
进入demo 文件夹，将BARE文件夹中的port文件夹拷贝到自己的工程目录，并添加到工程。
3 增加硬件驱动层代码
3.1 修改串口驱动
3.1.1 修改portserial.c
打开port目录下的portserial.c,增加串口使能接口、串口初始化设置、发送数据，接收数据等接口。
/*
* FreeModbus Libary: BARE Port
* Copyright (C) 2006 Christian Walter <wolti@sil.at>
*
* 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: $Id$
*/
#include "port.h"
/* ----------------------- Modbus includes ----------------------------------*/
#include "mb.h"
#include "mbport.h"
/* ----------------------- static functions ---------------------------------*/
void prvvUARTTxReadyISR( void );
void prvvUARTRxISR( void );
/* ----------------------- Start implementation -----------------------------*/
void
vMBPortSerialEnable( BOOL xRxEnable, BOOL xTxEnable )
{
if(TRUE==xRxEnable)
{
USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
}
else
{
USART_ITConfig(USART1, USART_IT_RXNE, DISABLE);
}
if(TRUE==xTxEnable)
{
USART_ITConfig(USART1, USART_IT_TXE, ENABLE);
}
else
{
USART_ITConfig(USART1, USART_IT_TXE, DISABLE);
}
}
BOOL
xMBPortSerialInit( UCHAR ucPORT, ULONG ulBaudRate, UCHAR ucDataBits, eMBParity eParity )
{
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
USART_InitStructure.USART_BaudRate = ulBaudRate; // 设置了USART传输的波特率 ；
if(ucDataBits == 9)
USART_InitStructure.USART_WordLength = USART_WordLength_9b; // 9位数据 ；
else
USART_InitStructure.USART_WordLength = USART_WordLength_8b; // 8位数据 ；
if(eParity == MB_PAR_ODD)
USART_InitStructure.USART_Parity = USART_Parity_Odd; // 无校验位；
else if(eParity == MB_PAR_EVEN)
USART_InitStructure.USART_Parity = USART_Parity_Even; // 无校验位；
else
USART_InitStructure.USART_Parity = USART_Parity_No; // 无校验位；
USART_InitStructure.USART_StopBits = USART_StopBits_1; // 在帧结尾传输1个停止位 ；
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None; // 硬件流控制失能 ；
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; // 接收发送使能 ;
//USART1端口配置
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_10; //GPIOA9与GPIOA10
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//复用功能
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //速度50MHz
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; //上拉
GPIO_Init(GPIOA,&GPIO_InitStructure); //初始化PA9，PA10
GPIO_PinAFConfig(GPIOA, GPIO_PinSource9,GPIO_AF_USART1);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource10,GPIO_AF_USART1);
USART_Init(USART1, &USART_InitStructure);
USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
USART_Cmd(USART1, ENABLE); //
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(USART1, ucByte);
while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET);/*等待发送完成*/
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(USART1);
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.
*/
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.
*/
void prvvUARTRxISR( void )
{
pxMBFrameCBByteReceived( );
}
3.1.2 修改中断响应函数
void USART1_IRQHandler(void) //串口1中断服务程序
{
u8 Res;
OSIntEnter();
if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)
{
//Res =USART_ReceiveData(USART1);//(USART1->DR); //读取接收到的数据
prvvUARTRxISR();
USART_ClearITPendingBit(USART1, USART_IT_RXNE);
}
if(USART_GetITStatus(USART1, USART_IT_TXE) != RESET)
{
prvvUARTTxReadyISR();
}
OSIntExit(); //退出中断
}
3.2 修改时钟驱动
3.2.1 修改porttimer.c
设置一个能够产生RTU传输所需要的t3.5字符超时定时器的时钟。
根据官网的描述，
-
当波特率 > 19200bps时，采用定时器时钟固定为1750us ,
-
当波特率 < 19200bps时，定时器时钟为3.5个字符传输时间长
在文件中的 xMBPortTimersInit函数的参数usTim1Timerout50us为50us的倍数
/* ----------------------- Start implementation -----------------------------*/
BOOL
xMBPortTimersInit( USHORT usTim1Timerout50us )
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
TIM_TimeBaseInitStructure.TIM_Period = usTim1Timerout50us;
TIM_TimeBaseInitStructure.TIM_Prescaler=16800-1; //定时器分频 50us
TIM_TimeBaseInitStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式
TIM_TimeBaseInitStructure.TIM_ClockDivision=TIM_CKD_DIV1;
TIM_TimeBaseInit(TIM2,&TIM_TimeBaseInitStructure);//初始化TIM
TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE); //允许定时器更新中断
TIM_Cmd(TIM2,ENABLE); //使能定时器
return TRUE;
}
porttimer.c完整文件
/*
* FreeModbus Libary: BARE Port
* Copyright (C) 2006 Christian Walter <wolti@sil.at>
*
* 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: $Id$
*/
/* ----------------------- Platform includes --------------------------------*/
#include "port.h"
#include "config.h"
/* ----------------------- Modbus includes ----------------------------------*/
#include "mb.h"
#include "mbport.h"
/* ----------------------- static functions ---------------------------------*/
void prvvTIMERExpiredISR( void );
/* ----------------------- Start implementation -----------------------------*/
BOOL
xMBPortTimersInit( USHORT usTim1Timerout50us )
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
TIM_TimeBaseInitStructure.TIM_Period = usTim1Timerout50us;
TIM_TimeBaseInitStructure.TIM_Prescaler=2100-1; //定时器分频 50us
TIM_TimeBaseInitStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式
TIM_TimeBaseInitStructure.TIM_ClockDivision=TIM_CKD_DIV1;
TIM_TimeBaseInit(TIM2,&TIM_TimeBaseInitStructure);//初始化TIM
TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE); //允许定时器更新中断
TIM_Cmd(TIM2,ENABLE); //使能定时器
return TRUE;
}
inline void
vMBPortTimersEnable( )
{
/* Enable the timer with the timeout passed to xMBPortTimersInit( ) */
TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
TIM_SetCounter(TIM2, 0);
//TIM_Cmd(TIM2, ENABLE);
TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
}
inline void
vMBPortTimersDisable( )
{
/* Disable any pending timers. */
TIM_SetCounter(TIM2, 0);
//TIM_Cmd(TIM2, DISABLE);
TIM_ITConfig(TIM2, TIM_IT_Update, 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.
*/
void prvvTIMERExpiredISR( void )
{
( void )pxMBPortCBTimerExpired( );
}
3.2.2 修改中断响应函数
void TIM2_IRQHandler(void)
{
OSIntEnter(); //进入中断
if(TIM_GetITStatus(TIM2,TIM_IT_Update)==SET) //溢出中断
{
prvvTIMERExpiredISR();
}
TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
OSIntExit();
}
3.3 中断配置
在系统初始化中配置中断映射
void InterruptConfig(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
//NVIC_DeInit();
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
//USART1中断
NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
NVIC_InitStructure.NVIC_IRQChannel=TIM2_IRQn; //定时器3中断
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=1; //抢占优先级1
NVIC_InitStructure.NVIC_IRQChannelSubPriority=9; //子优先级8
NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
3.4修改mbconfig.h
在修改确认 使能打开MB_RTU_ENABLED
/*! \brief If Modbus ASCII support is enabled. */
#define MB_ASCII_ENABLED ( 0 )
/*! \brief If Modbus RTU support is enabled. */
#define MB_RTU_ENABLED ( 1 )
/*! \brief If Modbus TCP support is enabled. */
#define MB_TCP_ENABLED ( 0 )
4 数据处理
int main(void)
{
delay_init();
InterruptConfig();
eMBInit(MB_RTU, 0x01, 0, 115200, MB_PAR_NONE);//初始化freemodbus 设置RTU模式和ID等
eMBEnable();
OSInit(&err); //初始化UCOSIII
//创建开始任务
OSTaskCreate((OS_TCB * )&StartTaskTCB, //任务控制块
(CPU_CHAR * )"start task", //任务名字
(OS_TASK_PTR )start_task, //任 务函数
(void * )0, //传递给任务函数的参数
(OS_PRIO )START_TASK_PRIO, //任务优先级
(CPU_STK * )&START_TASK_STK[0], //任务堆栈基地址
(CPU_STK_SIZE)START_STK_SIZE/10, //任务堆栈深度限位
(CPU_STK_SIZE)START_STK_SIZE, //任务堆栈大小
(OS_MSG_QTY )0, //任务内部消息队列能够接收的最大消息数目,为0时禁止接收消息
(OS_TICK )0, //当使能时间片轮转时的时间片长度，为0时为默认长度，
(void * )0, //用户补充的存储区
(OS_OPT )OS_OPT_TASK_STK_CHK|OS_OPT_TASK_STK_CLR, //任务选项
(OS_ERR * )&err); //存放该函数错误时的返回值
OSStart(&err); //开启UCOSIII
}
//创建串口任务
void start_task(void *pdata)
{
OS_CPU_SR cpu_sr=0;
pdata = pdata;
OSStatInit(); //初始化统计任务.这里会延时1秒钟左右
OS_ENTER_CRITICAL();
// other task
//--------------------------------
//创建串口任务
//控制任务
OSTaskCreate((OS_TCB* )&DataTaskTCB,
(CPU_CHAR* )"Data Task",
(OS_TASK_PTR )DataTask,
(void* )0,
(OS_PRIO )DATA_TASK_PRIO,
(CPU_STK* )&DATA_TASK_STK[0],
(CPU_STK_SIZE)DATA_STK_SIZE/10,
(CPU_STK_SIZE)DATA_STK_SIZE,
(OS_MSG_QTY )0,
(OS_TICK )0,
(void* )0,
(OS_OPT )OS_OPT_TASK_STK_CHK|OS_OPT_TASK_STK_CLR,
(OS_ERR* )&err);
OSTaskSuspend(START_TASK_PRIO);
OS_EXIT_CRITICAL();
}
单独的任务处理数据收发
void DataTask (void *pdata)
{
OS_ERR err;
while(1)
{
eMBPoll();
OSTimeDlyHMSM(0,0,0,10,OS_OPT_TIME_PERIODIC,&err);//延时10ms
}
}
4.1 拷贝寄存器处理
拷贝
eMBRegHoldingCB//保持寄存器
eMBRegInputCB//输入寄存器
eMBRegCoilsCB//线圈状态寄存器
eMBRegDiscreteCB//离散输入状态寄存器
到main文件中
MBErrorCode
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 - usRegHoldingStart );
switch ( eMode )
{
/* Pass current register values to the protocol stack. */
case MB_REG_READ:
while( usNRegs > 0 )
{
*pucRegBuffer++ =
( unsigned char )( usRegHoldingBuf[iRegIndex] >> 8 );
*pucRegBuffer++ =
( unsigned char )( usRegHoldingBuf[iRegIndex] &
0xFF );
iRegIndex++;
usNRegs--;
}
break;
/* Update current register values with new values from the
* protocol stack. */
case MB_REG_WRITE:
while( usNRegs > 0 )
{
usRegHoldingBuf[iRegIndex] = *pucRegBuffer++ << 8;
usRegHoldingBuf[iRegIndex] |= *pucRegBuffer++;
iRegIndex++;
usNRegs--;
}
}
}
else
{
eStatus = MB_ENOREG;
}
return eStatus;
}
/**
* @功能
* @参数
* @返回值
*/
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 - usRegInputStart );
while( usNRegs > 0 )
{
*pucRegBuffer++ =
( unsigned char )( usRegInputBuf[iRegIndex] >> 8 );
*pucRegBuffer++ =
( unsigned char )( usRegInputBuf[iRegIndex] & 0xFF );
iRegIndex++;
usNRegs--;
}
}
else
{
eStatus = MB_ENOREG;
}
return eStatus;
}
/**
* @功能
* @参数
* @返回值
*/
eMBErrorCode
eMBRegCoilsCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNCoils,
eMBRegisterMode eMode )
{
eMBErrorCode eStatus = MB_ENOERR;
int iNCoils = ( int )usNCoils;
unsigned short usBitOffset;
/* Check if we have registers mapped at this block. */
if( ( usAddress >= REG_COILS_START ) &&
( usAddress + usNCoils <= REG_COILS_START + REG_COILS_SIZE ) )
{
usBitOffset = ( unsigned short )( usAddress - REG_COILS_START );
switch ( eMode )
{
/* Read current values and pass to protocol stack. */
case MB_REG_READ:
while( iNCoils > 0 )
{
*pucRegBuffer++ =
xMBUtilGetBits( ucRegCoilsBuf, usBitOffset,
( unsigned char )( iNCoils >
8 ? 8 :
iNCoils ) );
iNCoils -= 8;
usBitOffset += 8;
}
break;
/* Update current register values. */
case MB_REG_WRITE:
while( iNCoils > 0 )
{
xMBUtilSetBits( ucRegCoilsBuf, usBitOffset,
( unsigned char )( iNCoils > 8 ? 8 : iNCoils ),
*pucRegBuffer++ );
iNCoils -= 8;
usBitOffset += 8;
}
Led_Update();
break;
}
}
else
{
eStatus = MB_ENOREG;
}
return eStatus;
}
eMBErrorCode
eMBRegDiscreteCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNDiscrete )
{
eMBErrorCode eStatus = MB_ENOERR;
short iNDiscrete = ( short )usNDiscrete;
unsigned short usBitOffset;
/* Check if we have registers mapped at this block. */
if( ( usAddress >= REG_DISC_START ) &&
( usAddress + usNDiscrete <= REG_DISC_START + REG_DISC_SIZE ) )
{
usBitOffset = ( unsigned short )( usAddress - REG_DISC_START );
while( iNDiscrete > 0 )
{
*pucRegBuffer++ =
xMBUtilGetBits( ucRegDiscBuf, usBitOffset,
( unsigned char )( iNDiscrete >
8 ? 8 : iNDiscrete ) );
iNDiscrete -= 8;
usBitOffset += 8;
}
}
else
{
eStatus = MB_ENOREG;
}
return eStatus;
}
5 验证
代码验证通过，移植成功
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