Dustin-
I have read the Knowledge Base article:
" This error indicates that you are configuring your task incorrectly. As
you may know, there are two types of tasks: Dynamic Tasks and Static
Tasks. Dynamic Tasks are created manually in LabVIEW, Static Tasks are
generated from the NI-DAQmx Base Configuration Utility."
As I am working in a text-based environment, programming C-code, this does not shed any light. I am not using LabVIEW, and I am not using the NI-DAQmx Base Configuration Utility. So I am not sure what I am supposed to gain by reading that article. I am still clueless on what the difference is between a dynamic task and a static task, and what if anything that has to do with my problem.
I browsed the sample codes in the examples directory, and they do not shed any light on this issue.
To recap what may not have been clear in the original posting:I am trying to do multiple DO operations (as well as AI, but I haven't got that far yet). I created a test code to do this. I can do this with one instance of a CreateTask if I keep all the code in the main calling program. If I separate the guts of the DO from the main program and put it into a subroutine, I get the 200428 error, but only on the second execution of that subroutine- the first one works fine. Here is the version of the code with this problem, I have put a note where the subroutine is successfully called and where it fails. The subroutine in question is called "writeDigPort":
#define DAQmxErrChk(functionCall) { if(DAQmxFailed(error=(functionCall)) ) {goto Error; }}
int writeDigPort(TaskHandle taskhandle,uInt32,int);
int acquireNScans(char[],uInt64,float64,char[]);
int genDigPulseTrain(char[],int,int,uInt32,float32);
int main(void) {
TaskHandle taskHandleDO = 0;
int direction ;
// Set Channel Numbers, filenames
char chan[] = "Dev1/port1";
// Task parameters
int32 error=0;
char errBuff[2048];
// Begin Program
DAQmxErrChk (DAQmxBaseCreateTask ("",&taskHandleDO));
DAQmxErrChk (DAQmxBaseCreateDOChan(taskHandleDO,chan,"",DAQmx_Val_ChanForAllLines));
DAQmxErrChk (DAQmxBaseStartTask (taskHandleDO));
direction = 1;
/********** Subroutine Works Successfully! *****/
DAQmxErrChk (writeDigPort (taskHandleDO,1,direction)); //First execution of DO subroutine works successfully
usleep(1000000);
direction = 0;
/***********Subroutine Fails with 200428 ******/
DAQmxErrChk (writeDigPort (taskHandleDO,1,direction)); //Second execution of DO subroutine fails with 200428
Error:
if (DAQmxFailed (error))
DAQmxBaseGetExtendedErrorInfo (errBuff, 2048);
if (taskHandleDO != 0)
{
DAQmxBaseStopTask (taskHandleDO);
DAQmxBaseClearTask (taskHandleDO);
}
if (error)
printf ("DAQmxBase Error: %ld: %s\n", error, errBuff);
return 0;
}
int writeDigPort(TaskHandle taskHandleDO, uInt32 lineNum,int direction)
{
// Task parameters
int32 error = 0;
char errBuff[2048];
// Channel parameters
//char chan[] = "Dev1/port1";
// Write parameters
uInt32 w_data[1];
int32 written;
printf("Entering writeDigPortFunc.c\n");
// Create Digital Output (DO) Task and Channel
printf("direction = %d\n",direction);
if(direction == 0) {w_data[0]=0;} //set all channels to zero
else {w_data[0]=lineNum;} //turn on selected channel
printf("Data to write: %ld\n", w_data[0]);
printf("taskHandle: %d\n",taskHandleDO);
//DAQmxErrChk (DAQmxBaseCreateDOChan(taskHandleDO,chan,"",DAQmx_Val_ChanForAllLines));
//DAQmxErrChk (DAQmxBaseStartTask (taskHandleDO));
DAQmxErrChk (DAQmxBaseWriteDigitalU32(taskHandleDO,1,1,10.0,DAQmx_Val_GroupByChannel,w_data,&written,NULL));
printf("after\n");
Error:
if (DAQmxFailed (error))
DAQmxBaseGetExtendedErrorInfo (errBuff, 2048);
if (taskHandleDO != 0)
{
DAQmxBaseStopTask (taskHandleDO);
DAQmxBaseClearTask (taskHandleDO);
}
if (error)
printf ("DAQmxBase Error %ld: %s\n", error, errBuff);
return 0;
}
Any advice is appreciated.
thanks,
eric
