T640_DTU/USER0813/Modbus.c

#include "includes.h"
unsigned char g_ucModbusRefreshEN = 1;//更新寄存器列表中的数据的使能标志位，1使能，和ModbusRecvProcess配合使用，用于控制收发
unsigned char g_ucModbusRefreshSHUTDOWN = 0;//控制maintask中的更新寄存器列表中的数据的总开关,1关闭，0开启
unsigned short g_ucModbusRefreshTimeOut = 5;//自动读取从机VALUE的等待超时时间，用于收发控制
unsigned short g_ucRegNumCount = 0;//当前正在处理的寄存器地址在列表中的序号。用于控制收发逻辑
SUT_MODBUS_REGPACK sutModbusRegPack = {0};
/**********************************************************************************************************
ModbusRecvProcess()
处理接收到的MODBUS数据 ：slave(u8)|function(u8)|bytecount(u8)|value1H(u8)|value1L(u8)|value2H(u8)|value2L(u8)|......|valueNL(u8)|CRC(u16)
成功返回1
失败返回0
num:代表寄存器列表里第几个元素
************************************************************************************************************/
unsigned char ModbusRecvProcess(unsigned char *pMsg,int len,unsigned short num)
{
	unsigned short crc,CRC16;
	unsigned char i;
	unsigned short value[MODBUS_REG_NUM_MAX];
	
	if(len < 5) return 0;//长度小于5的不是MODBUS数据，就不处理
	CRC16=crc16_calc(0xffff,pMsg,len-2); 
	crc=((unsigned short)pMsg[len-1]&0xff)<<8;
	crc+=(unsigned short)pMsg[len-2]&0xff;
	if(crc != CRC16) return 0;//CRC校验不对，不处理

	if(pMsg[1] == HOLDINGREG){//功能码=0x03,保存进寄存器列表
		for(i = 0;i < pMsg[2]/2;i++){
			value[i]=((unsigned short)pMsg[i*2+3]&0xff)<<8;
			value[i]+=(unsigned short)pMsg[i*2+4]&0xff;
		}
		sutModbusRegPack.RegList[num].value = value[i-1];
	}else if(pMsg[1] == WRITESINGLEREG){//功能码=0x06,说明配置寄存器参数成功
		g_ucSetControlAckResult &= 1;
	}else{
		g_ucSetControlAckResult &= 0;
	}
	
	
	return 1;
}

/**********************************************************************************************************
ModbusCmdReadOneValue()
发送请求，读MODBUS设备指定一个寄存器地址的参数
num:代表寄存器列表里第几个元素
************************************************************************************************************/
void ModbusCmdReadOneValue(SUT_MODBUS_REGLIST *pMsg,unsigned short num)
{
	unsigned short crc,CRC16;
	unsigned char Pack[8],i;
	Pack[0] = (pMsg+num)->slave;
	Pack[1] = HOLDINGREG;
	Pack[2] = (unsigned char)((pMsg+num)->addr >> 8);
	Pack[3] = (unsigned char)((pMsg+num)->addr & 0xff);
	Pack[4] = 0;
	Pack[5] = 1;
	CRC16=crc16_calc(0xffff,Pack,6); 
	Pack[6] = (unsigned char)(CRC16 & 0xff);
	Pack[7] = (unsigned char)(CRC16 >> 8);
	RS485_DIR_HIGH;
	for(i=0;i<8;i++)
	{
		USART_SendData(USART1,Pack[i]);
		while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET);
	}
	RS485_DIR_LOW;
}

/**********************************************************************************************************
*更新寄存器列表参数
************************************************************************************************************/
void ModbusRefreshValue(void)
{
	if(g_ucModbusRefreshEN == 1)
	{
		g_ucModbusRefreshEN = 0;
		g_ucModbusRefreshTimeOut = 0;
		g_ucRegNumCount++;
		if((sutModbusRegPack.RegNum - 1) < g_ucRegNumCount) g_ucRegNumCount = 0;			
		ModbusCmdReadOneValue(sutModbusRegPack.RegList,g_ucRegNumCount);
	}
	else
	{		
		if(g_ucModbusRefreshTimeOut > 5)//返回超时,重置g_ucModbusRecv=1
		{
			g_ucModbusRefreshEN = 1;
			g_ucModbusRefreshTimeOut = 0;
		}
		g_ucModbusRefreshTimeOut++;
	}
}


/**********************************************************************************************************
*向MODBUS设备发送配置参数命令
数据格式 ：slave(u8)|function(u8)|AddrH(u8)|AddrL(u8)|valueH(u8)|valueL(u8)|CRC(u16)
************************************************************************************************************/
void ModbusCmdSetValue(SUT_MODBUS_REGLIST *pMsg)
{
	unsigned short crc,CRC16;
	unsigned char Pack[8],i;
	Pack[0] = pMsg->slave;
	Pack[1] = WRITESINGLEREG;
	Pack[2] = (unsigned char)(pMsg->addr >> 8);
	Pack[3] = (unsigned char)(pMsg->addr & 0xff);
	Pack[4] = (unsigned char)(pMsg->value >> 8);
	Pack[5] = (unsigned char)(pMsg->value & 0xff);
	CRC16=crc16_calc(0xffff,Pack,6); 
	Pack[6] = (unsigned char)(CRC16 & 0xff);
	Pack[7] = (unsigned char)(CRC16 >> 8);
	RS485_DIR_HIGH;
	for(i=0;i<8;i++)
	{
		USART_SendData(USART1,Pack[i]);
		while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET);
	}
	RS485_DIR_LOW;
}