X-Plot Channel 1 vs. Channel 0 in Signal Express

[ElQuimico]

Hello All! This is probably obvious, but I have not been able to find it. I am trying to use signal express to record 2 differential analog imputs in a DAQ device (NIDaqMX). I have differential Channel 0 and differential Channel 1. I can record channel 0 vs. time and 1 vs. time, but I need to be able to generate a Channel 1 vs Channel 0 plot. Is there a way to do this in Signal Express?

Your help will be greatly appreciated.

Thanks in advance,
Diego J. Diaz

[Robert_F]

Hi Diego,

You can plot the data in a XY graph through the Data View tab.  Right-click on the graph, select View As then XY Graph.

[ElQuimico]

Rob,

   Thanks! I have found that option, but in the LabView Signal Express LE that I have installed, it still only plot Channel 1 or Channell0 vs time. I am trying to find a way to plot Channel 1 vs. Channel 0 not time. I am still looking for a way that it may allow me to do this. I am sort of starting to guess that it is beyong the capabilities of SIgnal Express. I can export Ch 1 and Ch 0 to excel and append them manually, then plot them, but that way I can't tell of something went wrong until after I am done and analyzing.

Thanks for all the help!
Diego J. Diaz

[Phil_J1]

Hi Diego, are you logging in single point mode or are you logging a waveform?

Phil

[ElQuimico]

Hello Phil, Rob, All;

    Thanks for your replies. I will give a bit of background of what I am trying to accomplish. We have an old piece of electrochemical instrumentation (potentiostat) that used to collect data to an X-Y recorder. It sends an analog (up to) -10 to 10 V signal on an X channel and another one on an Y channel. We can use knobs in the instrument to "scale" the signal (or in LabView or Excel). Now, the X-Y recorder is gone to the old instrumentation heaven and I am trying to use and USB-6008 or USB-6009 (I have both) to collect data. X-axis is the voltage to which I assign channel #0 and the current is assigned to channel 1. Now, I can collect different "waveforms". It is usually a linear ramp (low-high-low) in cycles or steps (low to high to low asd a staircase instead of a ramp). I can collect either channel separately, but can't plot current vs potential (1 vs 0). I can do current vs time or potential vs time.

Thanks for all the help. Hope this bit of background can help in finding a solution.

Diego J. Diaz

[Phil_J1]

Hi Diego,

So it sounds like you found the option to "View as XY Graph" on the Data Viewer. But you're saying that the X-Axis still says "Time", is that correct? There is actually a bug in SignalExpress 2.0 where the X-Axis label does not get updated correctly when switching to View As XY Graph eventhough the data being shown is actually correct. (this is being addressed in the next release). In this case, the 1st signal is the X-Axis and the 2nd signal is the Y-Axis. If you wish to switch them, you can right-click on the XY graph to show the menu and select "Plot Order...". In the dialog that appears, select the signal you want to have as the X-Axis and click "Move To Front" and select "ok". This will switch the 2 channels around. Note that the X-Axis will still say "Time" because of the bug I mentioned above.

If this doesn't help, feel free to include your SignalExpress project as that may show us more.

Phil

[ElQuimico]

Phil, Rob, All;

    Thank you so much for the help. I finally got it. Assuming the "bug" I was able to get it to work. Still sorting a few minor details on how it "refreshes" on the screen, but it is working now. I will "tweak" the last details now.

Thank you so much for the help.

Diego J. Diaz

[Hunter_E]

I am new to signal express and am having the same problem with SE 2013.  I can't seem to find a way to display a graph with anything other than time on the X-axis.  Can someone help outline it for me?  I add a display>> XY graph>> drag in data>>right-click and select properties and can't get anywhere from there.  I'll attach my project for reference.  I am trying to measure Load vs displacement on a 50K loadcell and a 6-inch linear pot excited at 5V.

[OKors]

You shouldn't even need to go into properties.
Drag and drop two or more signals into a graph (does not have to be xy graph at this point can be a chart). Right click on the graph and select View As... XY graph.

Alternatively you can add an Amplitudes and Levels step which will convert the waveform data into scalar data (under DC in the A&L step), then follow the above procedure only this time right click, View As, Scalar XY Data.

This will yield much cleaner (smoother) looking signals.