NI-SCOPE--how to plot channel 0 voltage vs. channel 1 voltage?

[jrs100]

I am using LabView 6.1, NI-SCOPE software, and an NI 5102 digitizer.

I am using both channels 0 and 1 in the digitizer to receive voltage-time data and need to plot the voltage from channel 0 versus the voltage from channel 1 in a continuous fashion. Can somebody help me with this?

Thanks,
-Robby

[Jeremy R.]

jrs100,

Asuming you will be using an example program that ships with the NI-SCOPE driver, all you really need to do in order to graph chan 0 vs. chan 1 is to replace the waveform graph or chart (which will graph both channels with respect to time) with the XY graph that will graph X vs. Y. (the example pogram also needs to be using a multi read function to acquire from multiple channels)

As far as continuously acquiring goes, you are going to be limited with the 5102. There are a few example programs such as the Fetch Forever.vi, but the 5102 is not compatible with these VIs because it does not support multi-record acquisitions. The best solution for continuous with the 5102 is to acquire 1 large record for each channel, graph the data, and then initialize the board to acquire a new record. Of course, with this method you will be missing data from one acquisition to the other, but there is no way around that given the functionality of the 5102. Hope this helps.

Best Regards,
Jeremy R.
NI - Applications Engineer

[jrs100]

Thanks for the help!

I've downloaded a vi from NI web site that performs a multi-channel acquisition (vi attached). When I try to change the waveform graph to an XY plot, I am unable to connect the multi-read icon to the XY plot input. It seems to be that the two are not compatible as the colors for the input/outputs are not the same. Is this correct?

Thanks again,
-Robby

[Jeremy R.]

Looking at the example, you cannot wire the data directly to the XY graph. If you use context help (CTRL-H) and hover over the XY Graph, LabVIEW will show you what data type you will need. Basically, you will need a cluster of two array elements (the X array and Y array) for the graph. So it's just a matter of data manipulation. I have newer versions of LabVIEW so I cannot send you the code, but I did attach a screen shot that shows how you can extract the data from your Multi Read.vi and send to an XY graph. Good luck.

Best Regards,
Jeremy Ross
NI - Applications Engineer