LabVIEW
How come I do not get the same signal in LabView??
When you use the XY-Graph, you bundle the x-value array together with the y-value array. This creates a a list of x,y pairs according to the index in the arrays.
In your case, you're using the "Extract Waveform Graph" as the x-array, and the "Extract Waveform Graph 2" as the y-array. If the x-array was a ideal triangle curve, the XY-Graph would plot the y-values from the lowest x-value to the highest and back again.
In your case the y-values would all be in the range -0.025 - 0.1. The signal that you expect to get would only be achieved with y-values that have two significant peaks (sawtooth style).
Best regards,
Philip C.
National Instruments
In your case, you're using the "Extract Waveform Graph" as the x-array, and the "Extract Waveform Graph 2" as the y-array. If the x-array was a ideal triangle curve, the XY-Graph would plot the y-values from the lowest x-value to the highest and back again.
In your case the y-values would all be in the range -0.025 - 0.1. The signal that you expect to get would only be achieved with y-values that have two significant peaks (sawtooth style).
Best regards,
Philip C.
National Instruments
Your XY graph pretty much shows what you would expect if you plot the data seen in "Extract waveform Graph" as X and "Extract waveform Graph 2" as Y. It seems to me that your raw data is incorrect. Especially the Y data looks suspect, because it is basically constant within noise. It almost looks like your X data contains the sum of the desired x and y data (ramp-up, ramp down, resp, PLUS the peak, while the current y data contains only noise. Is it possible you have some wires crossed?
Could you show us the code? How is the data acquired?
Could you show us the code? How is the data acquired?
The question is how you are acquiring the data. LabVIEW will handle any level of data since it's using floating point datatypes.
How do you acquire the signal? What hardware do you use? To me, the y-signal looks like pure noise. The XY-Graph will not give you the expected signal until you are able to acquire a cleaner y-signal (sawtooth peaks).
Best regards,
Philip C.
National Instruments
How do you acquire the signal? What hardware do you use? To me, the y-signal looks like pure noise. The XY-Graph will not give you the expected signal until you are able to acquire a cleaner y-signal (sawtooth peaks).
Best regards,
Philip C.
National Instruments
Hi Mike,
It's up to the data acquisition to get the right signal - LabVIEW can handle any signal.
If you are using Virtual Channels, make sure that you specify the correct range - not the default "-10 to 10 volts". When your signal is small, the resolution will get higher with decreasing range (the same number of bits to cover a smaller range).
If you are not using Virtual Channels you can use the "high limit" and "low limit" inputs on the "AI Acquire Waveform.vi" to define the range.
Depending on your signal level, you might consider using signal conditioning. It would be able to boost the signal strength and filter out the noise.
Read more about Signal Conditioning her
e and here.
Best regards,
Philip C.
National Instruments
It's up to the data acquisition to get the right signal - LabVIEW can handle any signal.
If you are using Virtual Channels, make sure that you specify the correct range - not the default "-10 to 10 volts". When your signal is small, the resolution will get higher with decreasing range (the same number of bits to cover a smaller range).
If you are not using Virtual Channels you can use the "high limit" and "low limit" inputs on the "AI Acquire Waveform.vi" to define the range.
Depending on your signal level, you might consider using signal conditioning. It would be able to boost the signal strength and filter out the noise.
Read more about Signal Conditioning her
e and here.
Best regards,
Philip C.
National Instruments
