I am having difficulties coding a Butterworth filter. I need to acquire the data from an NI analog input, apply the filter and then continuous plot to the Waveform graph. I have looked at the white paper but am still struggling to get the coding correct. Can someone please help? Here is what I have so far. I need to apply the filter before I execute the append but I don't how to apply it. I'm getting errors. I can append the data continuously to the Waveformgraph fine so I know I'm good up to this point.
'Create aquiring task with channels. Channels configurued in another sub
Dim data() As AnalogWaveform(Of Double)
Dim i As Integer = 0
Dim myTask As New NationalInstruments.DAQmx.Task("myTask1")
reader = New AnalogMultiChannelReader(myTask.Stream)
'Create Filter and set filter parameters
Dim newFilter As New ButterworthLowpassFilter(filterOrder, samplingFrequency, cutoffFrequency)
Dim samplingFrequency As Integer = 1000
Dim filterOrder As Integer = 4
Dim cutoffFrequency As Double = 3.0
'This block of code appends raw data to the WFG, currently no filtering applied
Try
data = reader.ReadWaveform(samplingFrequency)
i = 0
For Each WaveformGraph In WFGS 'Collection of WaveformGraph objects
WaveformGraph.PlotWaveformAppend(data(i))
i = i + 1
Next
Catch
End Try
