Data Collection Problem

[Vlngrl87]

We have a laboratory setup in which a voltage is collected by a photodetector.  The goal is to send this information to the computer via a PCI 6115 card, which will be replacing the oscilloscope used currently.  A program has been written for this data collection and manipulation, based off of data collection using the DAQ assistant.  We're having a problem in the data collection process, though.  The waveform of points (1000) collected needs to have a certain shape (ie length of tail), so we were going to use a sample waveform to adjust the rate of the sampling, so that the desired shape was obtained.  We keep having the problem that no matter what rate is selected, the program cuts off sampling at a certain point (like there is a certain default rate that overrides the one input) so that we end up with half waveforms or just stretched ones.  I've taken the DAQ assistant apart piece by piece and changed anything I can think of, but the problem still exists.    Do you have an idea why this might be happening?  I've attached an example of the file.

[Jordan F]

Try running one of the programs in the example finder on how to acquire and graph a voltage with an internal clock (finite).  See if you have the same behavior when you change the sample rate and number of samples acquired.  This program can be found under Help>>Find Examples>>Harware Input and Output>>DAQmx>>Analog Measurements>>Voltage>>Acq&Graph Voltage-Int Clk.vi.  I would recommend changing the chart on the front panel with a waveform graph.  If we can get the behavior desired with this example then we can later implement into your system.