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How to synchronize an input signal with the "Check Reference Signal" module

Using DASYLab 9.0.2, I created a reference signal using the "Reference Signal" module (5khz sine wave).  I'm trying to monitor an input, using the "Check Reference Signal" module to trigger data acquisition whenever the input deviates from the reference signal by more than 2-3%.  In theory, this works great.  However, when I set everything up in DASYLab, I found that the input sine wave and the reference signal were not on phase, and I haven't been able to come up with any way to shift, delay, or otherwise sync the two signals.

Any tips or ideas?  I was hoping to use DASYLab because it has a purpose-built module for this function.  I do have Labview to work with as well, but am not sure how to set up a VI to monitor the signal in a similar fashion.

Thanks for any help!
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Hi dnlwthrn,

I'm not sure exactly how to shift or delay a reference signal phase to be in synch with an analog input phase in DASYLab.   It sounds like your expecting them to be off phase at some point after you start your program.  Theoretically, I believe your going to have to find a way to start generating the sinewave when the analog input crosses like 0V on a rising edge (assuming your sine wave generation starts at the same 0V).  This will start the two in phase so that when they start to vary in phase you can throw your trigger to begin taking samples.  Are you trying to trigger when the reference signal deviates by 2-3% in phase, amplitude, frequency, or all?  In addition, could you tell me what DAQ card are you using with what drivers? 

Thanks,
Paul C.
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Paul,
Thanks for the input.  I'm actually trying to use the "Reference signal" module to record a sample of the actual data stream, and then check the data input against that reference.  The way I understand the modules in question, that should be possible.  However, I can't seem to get it to work.  First off, the comparator side of things (the Check Reference Signal module) doesn't have the ability to play back the reference signal, so I have no way of seeing how much out of phase the signals are.  Second, and a bigger problem at this point, DASYLab doesn't like me sampling at 500khz and trying to do any sort of analysis or triggering.  I run into errors and eventually it locks up with a FIFO error.

I'm using IOTech's Wavebook 516E for data acquisition.  I'm currently trying to build a Labview program to accomplish the same thing, but its going slowly (I don't have a lot of experience with Labview, just started using it this year).


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Hi dnlwthrn,

I'm afraid you might need to contact IOTech if you're having FIFO errors with your Wavebook.  If the Wavebook 516E comes with some type of test panels, you might be able to test those rates to see if it is a hardware issue.  I would recommend trying to establish what exact rates your having the FIFO error.  I also noticed that on IOTech's site they have some LabVIEW examples that you might want to take a look at.  The website to download this can be found here.  In regards to your questions about the "reference signal" module, I did find a "check reference curve" module.  However, it didn't seem to checks for any other variations other than amplitude.  You might try contacting the Dasylab support found here for additional help getting the module to work.  .  If you want to compare to signals in LabVIEW, there are many vi's that can compare two signals.  You can compare the correlation, phase, amplitude, FFT's, etc.  It looks like your getting good help in your other thread, found here, on getting this to work in LabVIEW.

I hope this helps,
Paul C.
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