simulated sinus != circle?!

[mael15]

hi,

i use a simulated signal for working on my application without a physical device. i am getting the attached picture as a signal and i wonder if this is correct? if the simulated signal is using a sinus algorithm, isn´t there supposed to be a circle on my screen?

thanx!

[mael15]

ok, i just figured the signal does not have to be a circle. question still is if the the attached image is correct?

[Dennis_Knutson]

Who knows. If you are simulating a sine wave, I would expect to see a sine wave.  Your image says nothing about how you are simulating a signal, how you are displaying it. Actually, it says nothing at all about what you are doing.

[mael15]

thanx,

well, you cannot really change a lot about the simulated signal, so it is not my choice to use a sinus signal. i do not produce it, the national instruments driver does.

so, what information can i give you?

this is the task:

DAQmxCreateAIVoltageChan(getHandle(), cstring, channelName[k], DAQmx_Val_RSE, -10, 10, DAQmx_Val_Volts, NULL)

[Dennis_Knutson]

I am perfectly aware of what the DAQmx driver does for a simulated signal. What you have not provided is what programming language you are using, what function in that language you are using to display the data, etc. If you are using LabVIEW, then you would typically view the data with a waveform graph.

[mael15]

ok, i understand. i do not use labview but c++ and the algorithm for displaying is rather complicated and distributed among many files. i know it would be best to show you my algorith, but this is very complicated in my case.

i interpret the first input channel as x and the second as y. if one would only scale down the samples from a x/y voltage input to fit them in a x-y-diagramme, would the signal look like my image? i am trying to figure out if i have some sort of distortion im my algorithm.

in the measurement and automation explorer i can only see one part, so i cannot see how an undistorted image would look like.

[Dennis_Knutson · Accepted solution]

That's a little bit more information. An xy plot will appear as a circle if the two signals are equal in frequency and phase. The two simulated channels are not equal in phase as explained in the help.

[mael15]

so i guess it should look like it does. thank you for you help!