NI PCI-6542: Creating Dynamic Waveforms Using the HSDIO Library

Hello!

I am having problems understanding how to create waveforms using the HSDIO library to run on my PCI-6542 board. I need to create a program that turns one channel on for 12.5 microseconds, waits a set amount of time(i.e. 100 samples),  and turns another channel on for 12.5 microseconds.

This program is to be used in a phased array ultrasonic system.

Below is the Dynamic Generation example program that turns channels 0 - 2 on for 1024 samples.

/************************************************************************
*
*  Example Program:
*    DynamicGeneration.c
*
*  Description:
*    Generates a simple pattern on specified channels.
*
*  Pin Connection Information:
*    None.
*
************************************************************************/


/* Includes */
#include <stdio.h>
#include <limits.h>
#include "niHSDIO.h"

/* Defines */
#define WAVEFORM_SIZE 1024

int main(void)
{
   ViRsrc deviceID = "Dev1";
   ViConstString channelList = "0-2";
   ViReal64 sampleClockRate = 50.0e6;
   ViInt32 dataWidth = 4;
  
   ViUInt32 waveformDataU32[WAVEFORM_SIZE];
   ViConstString waveformName = "myWfm";
   ViInt32 timeout = 10000; /* milliseconds */
   
   ViSession vi = VI_NULL;
   ViStatus error = VI_SUCCESS;
   ViChar errDesc[1024];
   ViInt32 i;
   
   
   /* Initialize generation session */
   checkErr(niHSDIO_InitGenerationSession(
            deviceID, VI_FALSE, VI_FALSE, VI_NULL, &vi));
   /* Assign channels for dynamic generation */
   checkErr(niHSDIO_AssignDynamicChannels (vi, channelList));
   /* Configure sample clock parameters */
   checkErr(niHSDIO_ConfigureSampleClock(
            vi, NIHSDIO_VAL_ON_BOARD_CLOCK_STR, sampleClockRate));
   /* Query the Data Width Attribute */
   checkErr(niHSDIO_GetAttributeViInt32(
            vi, VI_NULL, NIHSDIO_ATTR_DATA_WIDTH, &dataWidth));

   /* Populate waveform with ramp data */
   for (i = 0; i < WAVEFORM_SIZE; i++)
   {
	   waveformDataU32[i] = i;
   }

   checkErr(niHSDIO_WriteNamedWaveformU32(
            vi, waveformName, WAVEFORM_SIZE, waveformDataU32));
   
   /* Initiate generation */
   checkErr(niHSDIO_Initiate(vi));
   
   /* Wait for generation to complete */
   checkErr(niHSDIO_WaitUntilDone(vi, timeout));
   
Error:
   
   if (error == VI_SUCCESS)
   {
      /* print result */
      printf("Done without error.\n");
   }
   else
   {
      /* Get error description and print */
      niHSDIO_GetError(vi, &error, sizeof(errDesc)/sizeof(ViChar), errDesc);
      printf("\nError encountered\n===================\n%s\n", errDesc);
   }
   /* close the session */
   niHSDIO_close(vi);
   /* prompt to exit (for pop-up console windows) */
   printf("\nHit <Enter> to continue...\n");
   getchar();
   return error;
}

Questions:

How can I change the values in waveformDataU32 to create off and on states(instead of just always on)?

How do I select the channel that waveformDataU32 is applied to?

Thanks!

Zachary Geier