Hi folks,
Is there a way to retrieve the data of a waveform/trace out of the M8190A? I am wondering in which way the Soft Front Panel synthesizes some multi-tone frequencies. I communicate with the M8190A over the PCI Express bus via MATLAB interface (VISA). I tried the use the
:TRAC2:DATA? 1,0,48
VISA command (which seemed for me the command I want to use), but it seems to only return an empty character array/string (namely: ''). Note that I am using port 2.
The problem I want to solve is actual deeper. I try to synthesis some obscure frequencies and it is not possible to synthesis these without having a little voltage jump/artifacts between the end and the begin of the sample vector (resulting in harmonic distortion products). However, the multi-tone setup of the Soft Front Panel is perfectly able to synthesyse those frequencies. Therefore I am wondering how the Soft Front Panel does this by hoping to extract the traces out of the M8190A.
Now I am already typing a story over here, another small question: How do the trace values (between 8192 and -8191 or alike) and the ":VOLT2:AMPL" command relate? It seems that when trace value is at it highest state (8192), the output voltage is equal to the amplitude given by the :VOLT2:AMPL command. Is this correct? And how do those bit values (-8191 to 8192) relate to voltage levels? Is the zero volt (0 V) defined? Or is the closest value +LSB/2 and -LSB/2?
Thanks a lot
Hi Wobbert,
Use this equation when creating your multitoned signals
Fresolution = FsampleRate * Cycles / Points
Where
Fresolution is the finest frequency you can generate and is equal to FsampleRate / Points.
FsampleRate is the Arb sample rate. Range: 100 MHz to 8 GHz.
Cycles is the number of cycles in the sine wave. Range: 1 to less than Points/2 and must be an integer value.
Points is the number of points in the waveform. Range: I don't remember but it must be an integer multiple of 48 points.
If your waveforms are not a multiple of 48 points The M8190A may be padding them with zeros or rounding their length down to be a multiple of 48 points. This is most likely causing the glitch that you see.
Hope this helps
Pete