前段时间用西门子提供的Prodave5.5开发了基于YFIOServer的驱动程序，很可惜以太网方式它不支持，所以只好用西门子的softnet来开发相应的驱动了。
SoftNet的服务程序
目前采用的是同步方式的读写，可支持自恢复功能。
（采用异步方式初次读写可以成功，下次在读写时却失败，不是很明白！）
读写核心代码：
int fix_field_read(int Addr,int intNum,BYTE *bDataValue,long lngMode,int blockno)
{
struct S7_READ_PARA read_para;
int32 iRet;
ord16 orderid=0;
long lngTimeNum=0;
long lngOK=1;
read_para.access=S7_ACCESS_SYMB_ADDRESS;
switch(lngMode)
{
case MODE_I:
sprintf(read_para.var_name,"IB%d,%d",Addr,intNum);
break;
case MODE_Q:
sprintf(read_para.var_name,"QB%d,%d",Addr,intNum);
break;
case MODE_M:
sprintf(read_para.var_name,"MB%d,%d",Addr,intNum);
break;
case MODE_DB:
sprintf(read_para.var_name,"DB%d,B%d,%d",blockno,Addr,intNum);
break;
}
//IOF->ShowMessage(1,1,read_para.var_name,"--");
iRet=s7_read_req(cp_descr,cp_cref,0,&read_para);
if(iRet!=S7_OK)
{
//IOF->ShowMessage(1,1,read_para.var_name,"s7_read_req");
return 1000;
}
do
{
iRet=s7_receive(cp_descr,&cp_cref,&orderid);
switch(iRet)
{
case S7_READ_CNF:
{
//--------------------------------
if(s7_get_read_cnf(( void *)0,(ord16 *)&intNum,(void *)bDataValue)!=S7_OK)
{
return 1001;
}
lngTimeNum=IOD->Overtime+1;
//----------------------------------
lngOK=0;
}
break;
default:
Sleep(1); //等待1ms
break;
}
} while(lngTimeNum++<IOD->Overtime && iRet!=S7_ABORT_IND);
return lngOK;
}
int fix_field_write(int Addr,int intNum,BYTE *bDataValue,long lngMode,int blockno)
{
struct S7_WRITE_PARA write_para;
int32 iRet;
ord16 orderid=0;
long lngTimeNum=0;
long lngOK=1,i;
write_para.access=S7_ACCESS_SYMB_ADDRESS;
switch(lngMode)
{
case MODE_I:
return 999;
break;
case MODE_Q:
sprintf(write_para.var_name,"QB%d,%d",Addr,intNum);
break;
case MODE_M:
sprintf(write_para.var_name,"MB%d,%d",Addr,intNum);
break;
case MODE_DB:
sprintf(write_para.var_name,"DB%d,B%d,%d",blockno,Addr,intNum);
//IOF->ShowMessage(1,1,write_para.var_name,"fix_field_write");
break;
}
write_para.var_length=intNum;
for(i=0;i<intNum;i++)
{
write_para.value[i]=bDataValue[i];
}
iRet=s7_write_req(cp_descr,cp_cref,0,&write_para,(void *)0);
if(iRet!=S7_OK)
{
//IOF->ShowMessage(1,1,"Error:s7_write_req","fix_field_write");
return 1000;
}
do
{
iRet=s7_receive(cp_descr,&cp_cref,&orderid);
switch(iRet)
{
case S7_WRITE_CNF:
{
//--------------------------------
if(s7_get_write_cnf()!=S7_OK)
{
return 1001;
}
lngTimeNum=IOD->Overtime+1;
//----------------------------------
lngOK=0;
}
break;
default:
Sleep(1); //等待1ms
break;
}
} while(lngTimeNum++<IOD->Overtime && iRet!=S7_ABORT_IND);
return lngOK;
}
注意：I和Q变量不知为什么，读写失败。