Version 6 AI in version 8

Question

I am trying to create modify a VI that was created using labview v6.0.  I am modifying it in 8.0.  The old program uses the Analogue input VI called 'AI Acquire Waveforms'  I just uses a device number with the appropriate count, rate and other settings.  Instead I want to use a VI in the Universal Library for LabView with version 8.0 program.  The VI I specifically want to use is called AI Sc Fgd i think.  Same sort of idea, uses a 'Board number' instead of device number.  The main difference is that on the 'AI Acquire Waveforms' VI, the output wire type is a 2D array, an Actual period time, and an error out.  On the other AI Sc Fgd it has a single array of ADData type, an Actual rate, and an error out.  The 2D array must be transformed in order to be graphed.  So to ge to the point here, the old version does the transform and uses two Array Index VIs for index 0,1.  How can I make the same output for the AI Sc Fgd?  Thanks,
-Tekky

Answer 1

Hello Tekky,
I can't find the 'AI Sc Fgd' VI you referenced.  Can you tell us where its located on the function palette?  The AI Acquire Waveform VI is a Traditional NI-DAQ VI that is available in LabVIEW 8.0.  It is found in the functions palette under Measurement I/O > Data Acquisition > Analog Input.  If you don't have this palette, you may need to reinstall Traditional NI-DAQ 7.4.1 and make sure support is enabled for LabVIEW 8.0.  The AI Acquire Waveform VI can either output a 1D array of DBLs or Waveform data, and you can select which format to output data by right-clicking on the function and choosing Select Type.  The AI Acquire Waveform VI is a top level VI that contains the AI Waveform Scan subVI, which outputs a 2D array of DBLs.  The Index Array function is used to extract the first column of data, since its assumed that your only acquiring from a single input channel.  If the data from your function is already a 1D array, you should just be able to pass that directly to a waveform graph or numerical array indicator.
Also, all these functions are Traditional NI-DAQ VIs.  Have you considered using the NI-DAQmx driver and function calls?  These functions are much easier to use and actually operate more efficiently.  More information about the NI-DAQmx functions can be found here:
Learn 10 Functions in NI-DAQmx and Solve 80% of Data Acquisition Applications
Also you can check to see if your DAQ device is supported under the DAQmx driver here:
NI-DAQmx Driver Support Versions
I hope this helps,
Travis G.
Applications Engineering
National Instruments
www.ni.com/support