c51_modbus.c

可用于 51系列单片机与触摸屏之间的通讯 （一般用modbus实现通讯）

//在触摸屏上作个位开关，单片机系统用LED指示
//在单片机的硬件系统中用拨码开关来模拟数据输入，在eView上显示
//本程序实现位的读写和字的读写，为一对一通讯，eView为主机

#include<reg52.h>
#include<absacc.h>
#include<intrins.h>
#include<ctype.h>

/* These macro define simple data type */
#define uchar unsigned char
#define ulint unsigned long
#define uint  unsigned int

/* These macro for Mudbus function code */
#define ReadCoilSta 0x01       // 0X read coil function
#define ForceSingleCoil 0x05   // 0X force single coil function
#define ReadHoldReg 0x03       // 4X read input register
#define PresetMulReg 0x10      // 4X write multi register 

/* These macro describe index of communication message  from start to end */
#define CommIndexSlaveID 0     // macro for slave ID
#define CommIndexFunction 1    // macro for function code

#define CommIndexStartAdrHi 2  // macro for data hight adr    
#define CommIndexStartAdrLo 3  // macro for data low adr

#define CommIndexNoPointHi 4   // macro for hight quantity datas 
#define CommIndexNoPointLo 5   // macro for low quantity datas

/* These macro describe recieve message lenght of different function code */
/* But not include data lenght ,the data is master write to slave */
/* because we don't know the data lenght prior, it depend on ComBuf[ComIndexNoPoint] value */
#define ReadCoilStaIndexEnd 7     // 0~7,0x01,0X
#define ForceSingleCoilIndexEnd 7 // 0~7,0x05,0X

#define ReadHoldRegIndexEnd 7     // 0~7,0x03,4X
#define PresetMulRegIndexEnd 8    // 0~8,0x10,4X

/* these macro describe send or recieve allowed */
#define SEND 1       // send allowed
#define RECIEVE 0    // recieve allowed

#define SlaveID 0x01   // the slave's ID

#define SendRecieveDelay 50 // Send turn to Recieve or Recieve turn to Send delay time vlaue  

#define MaxDataLen 30  // preset CommBuf array Max lenght
#define MaxRegLen 20   // preset SlaveOutputBuf Max lenght


/* variable for modbus is following */
bit    data  RecFinishF;

uchar  data  CommIndex;
uchar  data  CommIndexEnd;
uchar  idata CommBuf[MaxDataLen];
uchar  idata SlaveOutputBuf[MaxRegLen]; // Hight 8 bit of word is front,Low 8 bit is back
uchar  idata SlaveInputBuf[MaxRegLen];
/* exp data define */
#define SlaveAdr XBYTE [0xD800]
sbit LED0=P1^0;
uchar idata ForceCoilBuf[10];
uchar count=0;
uchar forceval=0x00;
//bit forcesendF=0;


/* Table Of CRC Values for high-order byte */

uchar code  auchCRCHi[] = {
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81,
0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01,
0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81,
0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01,
0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81,
0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01,
0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81,
0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01,
0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81,
0x40
} ;

 /* Table of CRC values for low-order byte    */

uchar code auchCRCLo[] = {
0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06, 0x07, 0xC7, 0x05, 0xC5, 0xC4,
0x04, 0xCC, 0x0C, 0x0D, 0xCD, 0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09,
0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A, 0x1E, 0xDE, 0xDF, 0x1F, 0xDD,
0x1D, 0x1C, 0xDC, 0x14, 0xD4, 0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3,
0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3, 0xF2, 0x32, 0x36, 0xF6, 0xF7,
0x37, 0xF5, 0x35, 0x34, 0xF4, 0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A,
0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, 0x28, 0xE8, 0xE9, 0x29, 0xEB, 0x2B, 0x2A, 0xEA, 0xEE,
0x2E, 0x2F, 0xEF, 0x2D, 0xED, 0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26,
0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60, 0x61, 0xA1, 0x63, 0xA3, 0xA2,
0x62, 0x66, 0xA6, 0xA7, 0x67, 0xA5, 0x65, 0x64, 0xA4, 0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F,
0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8, 0x68, 0x78, 0xB8, 0xB9, 0x79, 0xBB,
0x7B, 0x7A, 0xBA, 0xBE, 0x7E, 0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5,
0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71, 0x70, 0xB0, 0x50, 0x90, 0x91,
0x51, 0x93, 0x53, 0x52, 0x92, 0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C,
0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B, 0x99, 0x59, 0x58, 0x98, 0x88,
0x48, 0x49, 0x89, 0x4B, 0x8B, 0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C,
0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42, 0x43, 0x83, 0x41, 0x81, 0x80,
0x40
} ;


uint crc16(uchar *puchMsg,uchar usDataLen) // puchMsg message to calculate CRC upon 
{		                                   // usDataLen quantity of bytes in message 
  uchar uchCRCHi = 0xFF ;  // high byte of CRC initialized      
  uchar uchCRCLo = 0xFF ;  // low byte of CRC initialized       
  uint  uIndex  ;          // will index into CRC lookup table  
   while (usDataLen--)             // Pass through message buffer       
	 {
	    uIndex = uchCRCHi ^ *puchMsg++ ; // calculate the CRC          
	    uchCRCHi = uchCRCLo ^ auchCRCHi[uIndex] ;
	    uchCRCLo = auchCRCLo[uIndex] ;
	 }
   return (((uint)(uchCRCLo) << 8) | uchCRCHi) ;
}

//crc校验
/*------------- init code is following ----------------*/
//初始化
void initSFR(void)
{
  TH1=0xfa;
  TL1=0xfa;         // botelv set 9600 bps/s 
  TMOD=0x21;        // T1 8bit timer for uart band rate, T0 16bit timer 
  PCON=PCON | 0x80; // band rate is 2 times 
  SCON=0x50;        // uart mode is 01,start bit + 8 bit data +stop bit : peer to peer communication 
  PS=1;             // uart intrrupt is hightest 串口中断
  TR1=1;            // start T1 
  ES=1;             // serially interrupt allow 
  EA=1;             // chief interrupt allow 
}

void initvar(void)
{
  uchar i;
   for (i=0;i<=250;i++)
     _nop_();
   T0=RECIEVE;
   RecFinishF=0;
   CommIndex=0;
   CommIndexEnd=0xff;  // First enlarge recieve lenght
   for (i=0;i<MaxRegLen;i++)
     SlaveOutputBuf[i]=SlaveAdr;
}
	
void init(void)
{
  initSFR();
  initvar();	
}	

void AnalyzeRecieve(void)
{
  uint crc16tem;
  uchar i,j;
   if (CommBuf[CommIndexSlaveID]==SlaveID)  // The slave ID is matched
     {        
        crc16tem=crc16(CommBuf,CommIndex-1); // calculate CRC check, erase two CRC byte ????
        if (crc16tem==(((uint)(CommBuf[CommIndexEnd]) << 8) | CommBuf[CommIndexEnd-1]))
          {                                  // crc16 check is OK
            switch (CommBuf[CommIndexFunction])
              {
                 case ReadCoilSta:
                    CommBuf[CommIndexSlaveID]=SlaveID;         // 0
                    CommBuf[CommIndexFunction]=ReadCoilSta;    // 1
                    CommBuf[2]=CommBuf[CommIndexNoPointLo] / 0x08;  // 0x16 bit
                    
                    for (i=0;i<MaxRegLen;i++)  // sim inputval for test
                      SlaveOutputBuf[i]=forceval;  // send data of master force coil val ????