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GSingh,
You could use PyVISA to control the VSG60 software using SCPI commands. You can read about our SCPI commands and see some examples in the SDK.
If you are using the API directly to control the instrument, you will need to generate your own complex I/Q waveform to output to the device. For a multi-tone signal, you could sum your complex sines/tones into an I/Q buffer to transmit. Just ensure that you scale the final result so that the peak magnitude of any given sample doesn’t exceed 1.0, and ideally, select a final buffer size that allows all of your complex sines to phase wrap nicely.
Unfortunately we don’t have any Python sample code for doing this. There are probably RF/DSP libraries that make it easy to generate complex sine waves with a given frequency.
Let us know if you have follow up questions.
Andrew
Miran,
Yes, you are correct in your understanding about the limitations of the Spike software.
Until we are able to add something to address this in the software, I would take a combined approach, setting the ref level offset to 40dB and then adjusting your path loss table by 40dB. Together you will get the same result with the ability to set the ref level to +60dBm. You should be able to save the path loss table with a preset for quick loading of this setup.
I will add this to our request log and determine the best approach to this.
Andrew
Hugh,
Did you change the monitor configuration recently? If you went from 2 monitors to 1 for instance, it might put the application where the second screen used to be (off screen)
Let’s try this. Close Spike and delete the file at this location.
C:\Users\YourUserName\AppData\Roaming\SignalHound\Layout.ini
Once deleted, restart Spike.
If you don’t see the AppData folder at first, it is a hidden folder, you will have to “Show hidden folders” in the file explorer settings menu.
Let me know if this resolves the problem.
Andrew
We do not have a block diagram that covers sweep/real-time mode signal processing. If you have a specific question about it, I can try to answer it for you.
Andrew
Michael,
Copied from the VSG60 users manual. This should clear things up. In this description, average power = average power of the I/Q samples, power = (i^2 + q^2)
Output Signal Average – When enabled, the signal generator output level will be adjusted to ensure the average signal power transmitted is equal to the output level selected. The average signal power is calculated after any I/Q scaling is applied. For example, if the waveform has an average power of -6dBFS (after scaling), and the output level is set to -20dBm, the output level is adjusted to -14dBm to ensure the average signal power output is -20dBm. The output level cannot be adjusted beyond +10dBm. For signals with long off durations, this should be disabled, as the average power of the signal will be significantly lowered with long off periods.
Andrew
GRedpath,
The RMS detector is the same as using “Power” Video Units and “Average” detector in our software. This should be the default setup in SEM mode.
Let me know if you have follow up questions.
Andrew
Hello GRedpath,
Unfortunately this is not possible right now. We have received this request before, and last time we investigated it, we determined it will take additional (non-trivial) development to add this. I don’t have a timeframe for when we would have this feature, but now that multiple people are asking for it, I can bump it up in priority. I appreciated you reaching out to us and also providing the standard you are testing. I will add that to our notes.
Let me know if you have follow up questions.
Andrew
lsullivan,
The FIR filter uses the standard overlap save algorithm. We do not use a library except for the FFT portion of overlap-save. Everything else is custom implemented. The maximum filter order is 1024 taps.
Regards
lsullivan,
What is the nature of your question? Do you have a specific application in mind, or is there an issue you are having with the I/Q data?
Our API accounts for all filter delays and scaling factors. The size of the filter will primarily only affect the filter transition bandwidth.
Andrew
Hello,
The OpenGL failure suggests a graphics issue. We are likely using some rendering feature that is not supported by your GPU. Do you know what CPU/GPU are in your system? We can try to find a driver for your GPU, which can often resolve the issue.
Andrew
lsullivan,
The filters used when I/Q streaming are FIR filters. We use 1 or more filters depending on decimation selected. The design method used is the standard windowed sinc method. The bandwidth and filter order is determined by both the decimation and bandwidth chosen by the user during configuration. Additionally, the frequency/magnitude response of the filters are modified by the IF flatness corrections, which are device specific, providing calibrated I/Q output.
Andrew
ASmilie,
You will need to call smConfigure again for any new parameter changes to take effect. You can only have 1 sweep configuration active at a time. After each smConfigure, you should re-acquire the sweep parameters as well.
Andrew
Michael,
We recommend this USB card to our customers. We know it works with our products.
It’s important to know that the number of USB host controllers can affect performance. Each host controller is a 5Gbps link that is shared between 1 or more ports. Most PCs have 1 controller for all available ports. The card I linked above has 2 controllers, where the 2 ports on the left are shared between 1 controller and the two ports on the right the other.
In general if you are running our devices at full data rates (I/Q streaming), you can run 1 or 2 simultaneously on one controller without data loss. It depends on the USB hardware. That means you will need 2-4 controllers for your setup. If you aren’t running them all simultaneously, then this won’t affect you as much.
You might also find a 4 physical core CPU to be insufficient if running 4 simultaneously. I personally haven’t done this before, but I know some customers how have (with high core count Xeon processors).
If you find a configuration that works, let us know, we would love to be able to share with other customers.
Andrew
Hi Miran,
We don’t have any plans to add this currently, but I will certainly add this to our feature request log. I believe this to be an easy addition. I appreciate your feedback and request.
Andrew
Hi lsullivan,
The filter used for I/Q streaming and downsampling is a FIR filter.
The VBW filter used in sweeps is an IIR filter.Regards
DSelvam,
Power consumption is ~6W over USB 3.0.
We have not tested Win10 IOT. Can you install traditional x86 applications and drivers on Win10 IOT?
If you decided to try it, the platform must be an Intel x86/x64 architecture, with minimum processing requirements of a dual core i5/i7 processor. We do not support ARM architectures.
Andrew
Hi DSelvam,
Sorry for the inconvenience.
Can you please follow the instructions in the link below and let us know if it resolves your problem?
https://signalhound.com/sigdownloads/Other/TG%20VCP%20Instructions.pdf
Andrew
We use the FFT provided through the Intel IPPs libraries.
July 28, 2021 at 7:54 am in reply to: [Spike feature request]: new marker checkbox (in Scalar Network Analysis-mode) Thank you for the feature request qswitch. I can definitely see how that would be helpful.
Andrew
Version 3.0.5 was released in 2015, and unfortunately we don’t maintain releases from that far back. Additionally, if you have newer BB60C hardware, version 3.0.5 may not support it. The API interface has not changed much since then. If you have the header file from the old project built against 3.0.5, compare it to the newer version found in the SDK.
Regards