Hello,
I am trying to output three different continuous signals through a single task on a Digital output device NI 9403.
Essentially, one is pulsing high or low, while the others are constantly high. However, I cannot seem to get this to output correctly. From all the documentation I read and example code I look at, this appears to be right. Please let me know if anyone sees anything wrong. Thanks,
int32 error = 0;
TaskHandle taskHandle = 0;
uInt32 dataStep[30]; // Buffer of 30, 10 per line
char errBuff[2048] = { '\0' };
// Create the Digital output task for three lines
char const* PortName = "cDAQ2Mod4/port0/line8,cDAQ2Mod4/port0/line10,cDAQ2Mod4/port0/line13";
DAQmxErrChk(DAQmxCreateTask("", &taskHandle));
DAQmxErrChk(DAQmxCreateDOChan(taskHandle, PortName, "", DAQmx_Val_ChanForAllLines));
// Setting up the output data. Again, first 10 is a pulse wave, second two are consistently 1
int cc = 0;
for (int i = 0; i < 10; i++) // Pulse
{
if (cc == 0)
cc = 1;
else
cc = 0;
dataStep[i] = cc;
}
for (int i = 10; i < 20; i++) // High or Low for Direction
dataStep[i] = 1;
for (int i = 20; i < 30; i++) // Always 1 for power on
dataStep[i] = 1;
// Set timer to 100Hz
DAQmxErrChk(DAQmxCfgSampClkTiming(taskHandle, NULL, 100.0, DAQmx_Val_Rising, DAQmx_Val_ContSamps, 100));
// Write the buffered data. Group by channel, so first 10 to first line, second 10 to second line, third 10 to third line
DAQmxErrChk(DAQmxWriteDigitalU32(taskHandle, 10, 0, 0.0, DAQmx_Val_GroupByChannel, dataStep, NULL, NULL));
// Start Continuous Task until stopped
DAQmxErrChk(DAQmxStartTask(taskHandle));
