I am using Visual Studio 2005 (in C#). I'm trying to use the SampleCompleteEventHandler as my callback function when acquiring data. Here's basically what I have coded.private void startButton_Click(object sender, System.EventArgs e){ try { //Create a new task myTask = new Task(); //Create a virtual channel myTask.AIChannels.CreateVoltageChannel(physicalChannelComboBox.Text, "", (AITerminalConfiguration)(-1), Convert.ToDouble(minimumValueNumeric.Value), Convert.ToDouble(maximumValueNumeric.Value), AIVoltageUnits.Volts); //Configure the timing parameters myTask.Timing.ConfigureSampleClock("", Convert.ToDouble(rateNumeric.Value), SampleClockActiveEdge.Rising, SampleQuantityMode.ContinuousSamples, 1000); //Verify the Task myTask.Control(TaskAction.Verify); //Prepare the table for Data InitializeDataTable(myTask.AIChannels,ref dataTable); acquisitionDataGrid.DataSource=dataTable; // Create the event myTask.SampleComplete += new SampleCompleteEventHandler(myTask_SampleComplete); // Start the acquisition myTask.Start(); } catch (DaqException exception) { //Display Errors MessageBox.Show(exception.Message); myTask.Dispose(); } }void myTask_SampleComplete(object sender, SampleCompleteEventArgs e){ // Read Data}I never get into the myTask_SampleComplete function. I know it's acquiring data, because if I change it to finite sampling instead of continuous and wait for it to be done, it finishes. It still never fires the event to call the callback function though.Is there something I'm doing wrong?

Ah yes! Simulated devices are very similar to real hardware, but do have some considerations when it comes to timing and synchronization. There’s a Developer Zone article entitled “NI-DAQmx Simulated Devices” that describes these considerations in section 4. One of the points is that “An NI-DAQmx simulated device never issues a software event or causes a timed loop to execute.” I hope that clarifies the behavior you are experiencing. With your actual hardware, everything should work fine with firing the event.

Measurement Studio for .NET Languages

DAQmx Task Sample Complete Event not received

Solved!

Please keep the post to one thread. This question was addressed here.

Regards,

h_baker
National Instruments
Applications Engineer

Message 11 of 11

(1,261 Views)

Measurement Studio for .NET Languages

DAQmx Task Sample Complete Event not received

Re: DAQmx Task Sample Complete Event not received