StartTrigger called on both Rising Edge and Falling Edge?

[DRT]

I am attempting to perform a finite sample analog input, triggered by an external digital signal.

I modified one of the NI sample programs as a test.

The problem I am getting is that my analog in callback is being called on both the rising edge and the falling edge of the digital signal, so I am collecting 2 samples at each step.

Here is the code that sets up the task:

myTask = new Task();

myTask.AIChannels.CreateVoltageChannel(physicalChannelComboBox.Text, "",

   AITerminalConfiguration.Rse, 0, 10, AIVoltageUnits.Volts);

//Configure Timing Specs

myTask.Timing.ConfigureSampleClock("", 30000, SampleClockActiveEdge.Rising, SampleQuantityMode.FiniteSamples, 1000);

//Configure Start Trigger

myTask.Triggers.StartTrigger.ConfigureDigitalEdgeTrigger("/Dev1/PFI0", DigitalEdgeStartTriggerEdge.Rising);

//Verify the Task

myTask.Control(TaskAction.Verify)

// Create the analog reader

myTask.Stream.Timeout = -1;

analogInReader = new AnalogMultiChannelReader(myTask.Stream);

analogInReader.SynchroniseCallbacks = true;

analogReader,BeginReadMultiSample(1000, myAsyncCallback, null);

// My Callback

private void AnalogInCallback(IAsyncResult ar)

{

    data = analogInReader.EndMultiSample(ar);

    analogInReader.BeginMultiSample(1000, myAsyncCallback, null);

}

Any suggestions on how to prevent the start trigger from triggering on both rising and falling edge?

[DRT]

OK, while waiting I did some further tests, and it appears that I have noise on the line, causing the problem.