串行通信问题

只看该作者 · 2012-4-20 19:12

我使用PC104总线的主板，挂一个数据采集卡，作为下位机采集模块，采集到结果通过RS485送给上位机，采用的是中断方式的串行通讯。一开始通讯正常，但是一端时间，大概发送1000次左右，下位机就会死机，反复调试都是这样，不是很明白。现在把代码贴出来，就高手指教！
void interrupt(*oldport1isr)();
void interrupt ComInt()/*中断服务程序*/
{
unsigned char ReceiveFlag;

unsigned int cnt;

unsigned char panelid = 0;

OverTimeFlag = 0;

CheckSumReceive = 0;

CountByte = 0;

awresult = 0;
tempresult = 0;
ppmresult = 0;

closeint();

for(cnt = 0; cnt < 8; cnt++)
{
CommandReceive[cnt] = 0;
}

overtimejudge();

panelid = (unsigned char)(para[0]);

if(OverTimeFlag == 0)
{
CommandReceive[0] = inport(PORT); /*First byte receive,if don 't match panelid,return interrupt funtion*/

if(panelid == CommandReceive[0])
{
panelright();
}
else
{
;
}

}
delay(DELAYTIME);
outportb(PORT + 2, 0x07);

outport(0x20, 0x20);
outport(0x20, 0x20);

}

void readparameter()
{
FILE *fp;

int i;

fp = fopen( "config.ini ", "r ");

if(fp == NULL)
{
printf( "Can not open file\n ");
}

for(i = 0; i < 3; i++)
{
fscanf(fp, "%f ", para + i);
}

fclose(fp);
}

void senddata(char data)
{
unsigned int i;
for(i = 0; i <    SendDelayTime; i++)
{
;
}

outportb(PORT + 1,0x00); /*Turn Off Interrupt */
outportb(PORT + 4, 0x0B); /*Turn on DTR,RTS,OUT2,send mode*/
outportb(PORT, data);
}

void initcom()/*串口初始化*/
{
outportb(PORT + 1, 0); /*Turn off interrupt*/

oldport1isr = getvect(INTVECT); /*Save old interrupt vector for recovery*/

setvect(INTVECT, ComInt);

outportb(PORT + 3, 0x80); /*Set DLAB on*/
outportb(PORT,0x0C); /*Set 9600 baud rate*/
outportb(PORT + 1, 0x00);
outportb(PORT + 3, 0x3B); /*8 bits,1 parity,1 stop bit */
outportb(PORT + 2, 0x07);
outportb(PORT + 4,0x0A); /*Turn off DTR,Turn on RTS,OUT2,receive mode*/

}

void openint()/*开中断*/
{

outportb(PORT + 4,0x0A); /*Turn off DTR,Turn on RTS,OUT2,receive mode*/

outportb(0x21, (inportb(0x21) & 0xF7)); /*Set programmable interrupt controller*/

outportb(PORT + 1, 0x01); /*Interrupt when data received*/
}

void closeint()/*关中断*/
{
oldport1isr = getvect(INTVECT);

outportb(PORT + 1,0);                                                    /*Turn off Com2 interrupt*/

outport(0x21, (inportb(0x21) | 0x08));

}

void panelright()/*下位机判断是否命令是自己的板号*/
{
unsigned char i;

for(i = 1; i < 7; i++)
{
receive6commandbyte(i);

if(OverTimeFlag != 0)
{
break;
}
}

if(CountByte == 6)
{
receive6bytecomplete();
}
}

void receive6commandbyte(unsigned char order)
{
overtimejudge();

if(OverTimeFlag == 0)
{
CommandReceive[order] = inport(PORT);

CheckSumReceive += CommandReceive[order];

CountByte++;
}
}

void receive6bytecomplete()
{
overtimejudge();

if(OverTimeFlag == 0)
{
CommandReceive[7] = inport(PORT);

if(CommandReceive[7] == CheckSumReceive)
{
if(BeginJudge == 0)
{
beginmeasure();
}
else
{
sendresult();
}

}
else
{
checksumwrong();
}

}

}

void sendresult()
{
   /*发送测量结果*/
}
void beginmeasure()
{
/*开始测量*/

}

void beginsucess()
{
      /*返回启动测试成功的信息*/
}

void checksumwrong()
{
/*上位机命令校验和出错后下位机返回出错信息*/
}

void overtimejudge()/*上位机命令是8个字节，判断有没有接收超时*/
{
unsigned char ReceiveFlag;
unsigned long cnt = 0;

do
{
ReceiveFlag = inport(PORT + 5);

cnt++;
if(cnt > TimeExceed) /*Overtime judge,wait for 300ms*/
{
OverTimeFlag = 1;
break;
}
}
while(!(ReceiveFlag&1));
}

unsigned int sample(int chx)
{
/*开始采样*/
}

void main()
{
clrscr();

arrayinit();

readparameter();

enable_gpio();

initcom();

openint();

while(1)       /*一直等待上位机命令*/
{
initcom();
openint();

delay(DELAYTIME);

feedDog();

setvect(INTVECT, oldport1isr);

}

}