实现modbus协议规范帧间隔必须在1.5~3.5字符之间判断功能

app/inc/hardware.h

@@ -6,15 +6,26 @@
 #if (MODBUS_USART_BAUDRATE > 19200U)
 
 /*固定等待1750us，再减去IDLE中断等待的1个字符时间*/
+/*1.5个字符=750us-1个字符时间*/
+#define MODBUS_IDLE_TO_T15_US \
+            ((750UL * MODBUS_USART_BAUDRATE - 10000000UL + MODBUS_USART_BAUDRATE - 1UL) / MODBUS_USART_BAUDRATE)
+/*2个字符=1000us*/
+#define MODBUS_T15_TO_T35_US    1000UL
+/*3.5个字符=1750us-1个字符时间*/
 #define MODBUS_IDLE_TO_T35_US \
-            ((1750UL * MODBUS_USART_BAUDRATE - 10000000UL + MODBUS_USART_BAUDRATE - 1UL) / MODBUS_USART_BAUDRATE)
-
+            ((1750UL * MODBUS_USART_BAUDRATE - 10000000UL + MODBUS_USART_BAUDRATE - 1UL) / MODBUS_USART_BAUDRATE)      
 #else
 
 /*IDLE中断已经过了1个字符的时间，还需等待2.5个字符*/
+/*1.5个字符-1个字符时间=0.5个字符时间*/
+#define MODBUS_IDLE_TO_T15_US \
+            ((5000000UL + MODBUS_USART_BAUDRATE - 1UL) / MODBUS_USART_BAUDRATE)
+/*2个字符时间*/
+#define MODBUS_T15_TO_T35_US \
+            ((20000000UL + MODBUS_USART_BAUDRATE - 1UL) / MODBUS_USART_BAUDRATE)            
+/*3.5个字符-1个字符时间=2.5个字符时间*/
 #define MODBUS_IDLE_TO_T35_US \
             ((25000000UL + MODBUS_USART_BAUDRATE - 1UL) / MODBUS_USART_BAUDRATE)
-
 #endif
 
 

app/src/hardware.c

@@ -110,7 +110,7 @@ void ModbusTimInit(void)
 
     TIM_DeInit(TIM5);
     TIM_TimeBaseStructure.TIM_Prescaler = 84U - 1U;                 /*84Mhz/84=1Mhz,1us计时*/
-    TIM_TimeBaseStructure.TIM_Period = MODBUS_IDLE_TO_T35_US - 1U;  /*计时周期1664us*/
+    TIM_TimeBaseStructure.TIM_Period = MODBUS_IDLE_TO_T15_US - 1U;  /*计时周期1664us*/
     TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;     /*向上计数*/
     TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
     TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
@@ -136,7 +136,7 @@ void ModbusNvicInit(void)
 
     /*定时器中断*/
     NVIC_InitStructure.NVIC_IRQChannel = TIM5_IRQn;
-    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 5;
+    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 4;
     NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
     NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
     NVIC_Init(&NVIC_InitStructure);

iar/settings/uCOS_Modbus.dnx

@@ -16,15 +16,15 @@
         <ShowSource>1</ShowSource>
     </Trace1>
     <StLinkDriver>
-        <stlinkResetStyle>0</stlinkResetStyle>
-        <stlinkResetStrategy>0</stlinkResetStrategy>
+        <stlinkserialNo>30303031</stlinkserialNo>
+        <stlinkfoundProbes />
         <CStepIntDis>_ 0</CStepIntDis>
         <LeaveTargetRunning>_ 0</LeaveTargetRunning>
-        <stlinkserialNo>24230357</stlinkserialNo>
-        <stlinkfoundProbes />
+        <stlinkResetStyle>0</stlinkResetStyle>
+        <stlinkResetStrategy>0</stlinkResetStrategy>
     </StLinkDriver>
     <DebugChecksum>
-        <Checksum>2912698606</Checksum>
+        <Checksum>3570680553</Checksum>
     </DebugChecksum>
     <Exceptions>
         <StopOnUncaught>_ 0</StopOnUncaught>
@@ -120,11 +120,26 @@
         <ShowTimeSum>1</ShowTimeSum>
         <SumSortOrder>0</SumSortOrder>
     </EventLog>
+    <DisassembleMode>
+        <mode>0</mode>
+    </DisassembleMode>
+    <Breakpoints2>
+        <Bp0>_ 1 "EMUL_CODE" "{d:\IAR_Project\TrainCamp_fubowen_Modbus\modbus\modbus_parse.c}.67.13" 0 0 1 "" 0 "" 0</Bp0>
+        <Count>1</Count>
+    </Breakpoints2>
+    <TermIOLog>
+        <LoggingEnabled>_ 0</LoggingEnabled>
+        <LogFile>_ ""</LogFile>
+    </TermIOLog>
     <LogFile>
         <LoggingEnabled>_ 0</LoggingEnabled>
         <LogFile>_ ""</LogFile>
         <Category>_ 0</Category>
     </LogFile>
+    <Aliases>
+        <Count>0</Count>
+        <SuppressDialog>0</SuppressDialog>
+    </Aliases>
     <DriverProfiling>
         <Enabled>0</Enabled>
         <Mode>3</Mode>
@@ -138,19 +153,4 @@
     <CallStackStripe>
         <ShowTiming>1</ShowTiming>
     </CallStackStripe>
-    <DisassembleMode>
-        <mode>0</mode>
-    </DisassembleMode>
-    <Breakpoints2>
-        <Bp0>_ 1 "EMUL_CODE" "{$PROJ_DIR$\..\modbus\modbus_parse.c}.67.13" 0 0 1 "" 0 "" 0</Bp0>
-        <Count>1</Count>
-    </Breakpoints2>
-    <Aliases>
-        <Count>0</Count>
-        <SuppressDialog>0</SuppressDialog>
-    </Aliases>
-    <TermIOLog>
-        <LoggingEnabled>_ 0</LoggingEnabled>
-        <LogFile>_ ""</LogFile>
-    </TermIOLog>
 </settings>

modbus/modbus_rec_send.c

@@ -1,4 +1,7 @@
 #include "modbus_rec_send.h"
+#include "hardware.h"
+
+MODBUS_RX_STATE ModbusRxState = MODBUS_RX_RECEIVING;
 
 
 /*USART接收空闲中断*/
@@ -17,13 +20,36 @@ void USART1_IRQHandler(void)
 
         /*判断是否接收到帧，触发TIM计时*/
         rxLenRemain = DMA_GetCurrDataCounter(DMA2_Stream2);
-        if(rxLenRemain != MODBUS_RX_BUF_SIZE)
+        ModbusRxLen = MODBUS_RX_BUF_SIZE - rxLenRemain;
+
+        if(ModbusRxLen != 0)
         {
-            /*启动TIM计时*/
-            TIM_Cmd(TIM5, DISABLE);
-            TIM_SetCounter(TIM5, 0);        /*清除计数值*/
-            //TIM_ClearITPendingBit(TIM5, TIM_IT_Update);     /*清除中断标志位*/
-            TIM_Cmd(TIM5, ENABLE);
+            switch (ModbusRxState)
+            {
+                /*正常接收数据*/
+                case MODBUS_RX_RECEIVING:
+                    ModbusRxState = MODBUS_RX_CHECK_T15;
+                    TimRestart(MODBUS_IDLE_TO_T15_US);
+                    break;
+
+                /*在判断t1.5～t3.5是否出现字符时，t3.5定时中断还未触发，又接收到了数据*/
+                case MODBUS_RX_CHECK_T35:
+                    ModbusRxState = MODBUS_RX_DISCARD_CHECK_T35;    /*判断为错误帧*/
+                    TimRestart(MODBUS_IDLE_TO_T35_US);              /*等待3.5字符该帧结束之后丢失该帧*/
+                    break;
+                
+                /*在t1.5～t3.5中出现字符，随后又接收到数据*/
+                case MODBUS_RX_DISCARD:
+                    ModbusRxState = MODBUS_RX_DISCARD_CHECK_T35;    /*判断为错误帧*/
+                    TimRestart(MODBUS_IDLE_TO_T35_US);              /*等待3.5字符该帧结束之后丢失该帧*/
+                    break;  
+                
+                /*在等待3.5字符该帧结束期间又接收到数据*/
+                case MODBUS_RX_DISCARD_CHECK_T35:
+                    ModbusRxState = MODBUS_RX_DISCARD_CHECK_T35;
+                    TimRestart(MODBUS_IDLE_TO_T35_US);              /*再等待3.5字符该帧结束之后丢失该帧*/
+                    break;
+            }
         }
     }
     OSIntExit();    /*退出中断*/
@@ -35,33 +61,123 @@ void TIM5_IRQHandler(void)
     uint16_t rxLenRemain;
 
     OSIntEnter();
+
+    rxLenRemain = DMA_GetCurrDataCounter(DMA2_Stream2);
+
     if (TIM_GetITStatus(TIM5, TIM_IT_Update) != RESET)
     {
-        /*清除TIM5更新中断标志*/
-        TIM_ClearITPendingBit(TIM5, TIM_IT_Update);
+        switch (ModbusRxState)
+        {
+            /*检查在t1-t1.5期间是否接收到数据*/
+            case MODBUS_RX_CHECK_T15:
+                /*在t1-t1.5期间接收到了数据，正常继续接收*/
+                if (MODBUS_RX_BUF_SIZE - rxLenRemain != ModbusRxLen)
+                {
+                    ModbusRxState = MODBUS_RX_RECEIVING;
+                    TimOff();
+                }
+                /*在t1-t1.5期间没收到，开始检查t1.5-t3.5期间是否接收到数据*/
+                else
+                {
+                    ModbusRxState = MODBUS_RX_CHECK_T35;
+                    TimRestart(MODBUS_T15_TO_T35_US);
+                }
+                break;
 
-        /*关闭DMA*/
-        DMA_Cmd(DMA2_Stream2, DISABLE);
-        /*清除传输已经完成TCIF2、传输已经完成一半HTIF2标志位*/
-        DMA_ClearFlag(DMA2_Stream2, DMA_FLAG_TCIF2 | DMA_FLAG_HTIF2);
+            /*检查在t1.5-t3.5期间是否接收到数据*/
+            case MODBUS_RX_CHECK_T35:
+                /*在t1.5-t3.5期间接收到了数据，判断为错误帧，等待串口空闲中断开启3.5字符等待定时器计时*/
+                if (MODBUS_RX_BUF_SIZE - rxLenRemain != ModbusRxLen)
+                {
+                    ModbusRxState = MODBUS_RX_DISCARD;
+                    TimOff();
+                }
+                /*在t1.5-t3.5之间都没接收到数据，该帧结束，开始帧解析*/
+                else
+                {
+                    ModbusRxState = MODBUS_RX_RECEIVING;
+                    ModbusParseWakeUp();
+                }
+                break;
+            
+            /*接收到错误帧，等待3.5字符之后丢弃该帧*/    
+            case MODBUS_RX_DISCARD_CHECK_T35:
+                /*在等待3.5字符期间又接收到了数据，等待串口空闲中断重新开启3.5字符等待定时器计时*/
+                if (MODBUS_RX_BUF_SIZE - rxLenRemain != ModbusRxLen)
+                {
+                    ModbusRxState = MODBUS_RX_DISCARD_CHECK_T35;
+                    TimOff();
+                }
+                /*在等待3.5字符期间没接收到数据，该错误帧结束，丢弃该帧，准备开始下一帧的接收*/
+                else
+                {
+                    ModbusRxState = MODBUS_RX_RECEIVING;
+                    ModbusDmaRestart();
+                }
+                break;
+        }
+    }
+    OSIntExit();
+}
 
-        /*计算数据长度*/
-        rxLenRemain = DMA_GetCurrDataCounter(DMA2_Stream2);
-        ModbusRxLen = MODBUS_RX_BUF_SIZE - rxLenRemain;
+void TimRestart(uint32_t timArr)
+{
+    /*启动TIM计时*/
+    TIM_Cmd(TIM5, DISABLE);
+    TIM_SetCounter(TIM5, 0);        /*清除计数值*/
+    TIM_SetAutoreload(TIM5, timArr);
+    TIM_ClearITPendingBit(TIM5, TIM_IT_Update);     /*清除中断标志位*/
+    TIM_Cmd(TIM5, ENABLE);
+}
 
-        /*释放接收到数据帧信号量，唤醒帧解析任务*/
-        if(ModbusRxLen >= 4)    /*4字节（1字节地址、1字节功能、2字节CRC）*/
-        {
-            OSSemPost(ModbusReceived);
-        }
+void TimOff(void)
+{
+    TIM_Cmd(TIM5, DISABLE);
+    TIM_SetCounter(TIM5, 0);        /*清除计数值*/
+    TIM_ClearITPendingBit(TIM5, TIM_IT_Update);     /*清除中断标志位*/
+}
+
+void ModbusParseWakeUp(void)
+{
+    uint16_t rxLenRemain;
+
+    TimOff();
+
+    /*关闭DMA*/
+    DMA_Cmd(DMA2_Stream2, DISABLE);
+    /*清除传输已经完成TCIF2、传输已经完成一半HTIF2标志位*/
+    DMA_ClearFlag(DMA2_Stream2, DMA_FLAG_TCIF2 | DMA_FLAG_HTIF2);
 
-        /*重新指定接收地址*/
-        DMA_MemoryTargetConfig(DMA2_Stream2, (uint32_t)ModbusRxBuf, DMA_Memory_0);
-        /*重启DMA*/
-        DMA_SetCurrDataCounter(DMA2_Stream2, MODBUS_RX_BUF_SIZE);
-        DMA_Cmd(DMA2_Stream2, ENABLE);
+    /*计算数据长度*/
+    rxLenRemain = DMA_GetCurrDataCounter(DMA2_Stream2);
+    ModbusRxLen = MODBUS_RX_BUF_SIZE - rxLenRemain;
+
+    /*释放接收到数据帧信号量，唤醒帧解析任务*/
+    if(ModbusRxLen >= 4)    /*4字节（1字节地址、1字节功能、2字节CRC）*/
+    {
+        OSSemPost(ModbusReceived);
     }
-    OSIntExit();
+
+    /*重新指定接收地址*/
+    DMA_MemoryTargetConfig(DMA2_Stream2, (uint32_t)ModbusRxBuf, DMA_Memory_0);
+    /*重启DMA*/
+    DMA_SetCurrDataCounter(DMA2_Stream2, MODBUS_RX_BUF_SIZE);
+    DMA_Cmd(DMA2_Stream2, ENABLE);
+}
+
+void ModbusDmaRestart(void)
+{
+    TimOff();
+
+    /*关闭DMA*/
+    DMA_Cmd(DMA2_Stream2, DISABLE);
+    /*清除传输已经完成TCIF2、传输已经完成一半HTIF2标志位*/
+    DMA_ClearFlag(DMA2_Stream2, DMA_FLAG_TCIF2 | DMA_FLAG_HTIF2);
+    /*重新指定接收地址*/
+    DMA_MemoryTargetConfig(DMA2_Stream2, (uint32_t)ModbusRxBuf, DMA_Memory_0);
+    /*重启DMA*/
+    DMA_SetCurrDataCounter(DMA2_Stream2, MODBUS_RX_BUF_SIZE);
+    DMA_Cmd(DMA2_Stream2, ENABLE);
 }
 
 /*modbus响应帧发送*/

modbus/modbus_rec_send.h

@@ -4,10 +4,23 @@
 #include "stm32f4xx.h"
 #include "modbus_parse.h"
 
+typedef enum ModbusRxStateType
+{
+    MODBUS_RX_RECEIVING = 0,        /*正在正常接收*/
+    MODBUS_RX_CHECK_T15,            /*等待第一次DMA检查，判断新字符是否在t1.5前开始*/
+    MODBUS_RX_CHECK_T35,            /*等待第二次DMA检查，判断t1.5～t3.5是否出现字符*/
+    MODBUS_RX_DISCARD,              /*当前帧已经确认错误，继续丢弃后续数据*/
+    MODBUS_RX_DISCARD_CHECK_T35     /*已收到错误帧的IDLE，等待连续t3.5静默*/
+}MODBUS_RX_STATE;
+
 
 
 int8_t ChcekCrc16(uint16_t recCrc16, uint8_t *data, uint16_t length);
 void AddCrc16(uint8_t *data, uint16_t length);
 void ModbusSend(uint8_t *txBuf, uint16_t len);
+void TimOff(void);
+void TimRestart(uint32_t timArr);
+void ModbusParseWakeUp(void);
+void ModbusDmaRestart(void);
 
 #endif