Forum Replies Created
- Posts
Michael,
In general, single ended USB 3.0 cables off of Amazon or other supplier will work with the VSG60A and BB60C. You would usually only run into problems using a single ended cable on ultra low power laptops like the Surface Pro. You are free to try those, or if you want one of our double ended y-cables you can reach our to our sales department at sales at signalhound dot com. I believe we can sell and ship you new cables.
Regards
Jorge,
We don’t use Go here, but a quick search reveals tools like this that might be able to help.
https://golang.org/cmd/cgo/We don’t have any examples using Go in our SDK but it looks like it should be possible.
Regards
Michael,
This is usually indicative of general USB data loss or USB transfer issues. If you keep seeing this, email me at aj at signalhound dot com and we can try to troubleshoot this.
Regards
This is an area we will be improving soon. The next version of the VSG60 software will improve the usability of the external within the main application.
Right now though, there are 2 ways to take advantage of the external trigger.
1) Use the API. The API manual documents the trigger functionality and we provide an example of using the trigger in C++. This information can be found in the SDK download.
2) In the main application, certain modes, such as pulse, ramp sweep, all digital modulations, and ARB output will output an external trigger. When any of these modes are configured with “Single” triggering enabled, each press of the trigger button will output the RF waveform synchronized with an external trigger event.In the next release of the VSG60 software, the external trigger will also work when those output modes are configured in “Continuous” trigger mode, outputting a trigger on every loop of the configured RF waveform.
If you have follow up questions, let us know.
Andrew
CKWong,
I am able to reproduce this issue. The issue appears to affect the step sweep mode with certain configurations. I will need to fix this and issue a new release of the software.
I apologize for the inconvenience. I do not have a workaround at this time.
I will respond on this forum topic when I have released the new version.
Regards,
AndrewSerpi,
25C above external is a big delta. Is the unit in a drawer or positioned in a tight spot? A small amount of air flow could drastically change the internal temperature.
We calibrate the BB60C in an environmental chamber which has high air flow via several fans. The internal temperature is typically ~10C above external in the chamber. Meaning, the highest internal temperature we are calibrating at is ~75C.
Given your current setup, you could operate to 50C external and still be within calibration. The device will continue to operate above that, although potentially outside the specified performance.
Regards,
AndrewHello,
Is the crash specific to one certain VSG60 configuration? Can you operate the VSG60 in any transmit output? For example, does a simple CW output work? If the crash is associated with just the step sweep, it might simply be a bug with that specific configuration that we can investigate and fix. Let me know the full settings used when a crash occurs.
That being said, you might need to run the VSG60 on a separate PC to run them both simultaneously. Most PCs will have difficulty running two of our high speed USB 3.0 devices simultaneously due to the shared USB 3.0 bus. If you continue to see disconnections on the BB60C, you will need to either, use a different PC for each device, or you could try installing a USB 3.0 adapter card and plugging one of the devices into that card. The card will add another USB 3.0 bus, so putting one on the adapter card’s bus, and one on the PC’s bus can resolve this.
Here are two adapter cards customers have used in the past with success.
I look forward to your response.
AndrewThanks for the update! Glad that fixed it. Let us know if you run into any other issues.
Cheers
Michael,
Are you using the latest version of Spike? (3.5.16) The latest version included a bug fix that was supposed to address this.
http://www.signalhound.com/Spike
Regards
Hi John,
Broadcast masks were introduced into Spike under the Spectrum emission mask measurements awhile back (analysis mode drop down menu). For the SA44B, you may need to disable the outermost ranges (the ones that are > -80dB down) as the SA44B doesn’t have the dynamic range to measure these ranges. The noise floor will trip it. That being said you will still be able to visualize the ranges.
If you have any questions as you start working with this measurement, please let us know.
Regards,
AndrewThe VSG60 does have SCPI support. It is through the VSG60 application. You would launch the app on the remote PC, then you would be able to use SCPI to control the app (socket interface, default port 5024). The app does have a generic ARB mode, it will load several types of custom I/Q waveform files such as binary, CSV, wav, and some others. The ARB mode can be fully controlled via SCPI, including loading files. With this approach, your waveforms would have to be stored in a file.
The API will only communicate with a locally connected device. To use this in the same fashion, you would have to build some sort of local application that controls the unit and awaits commands from your remote script. This might ultimately provide more flexibility at the cost of more upfront work.
You can find the VSG60 SCPI manual in our SDK, linked below.
https://signalhound.com/software/signal-hound-software-development-kit-sdk/If you have additional questions let me know.
Andrew
It just looks like your scaling/conversion if off.
The Spike user manual documents the equations used to convert the file contents to scaled I/Q values, if you haven’t seen this already.
Have you stepped through your code and verified scale factor is correct?
Have you tried verifying your conversion works for fixed values? You could force 1+0i (SHRT_MAX,0) and fixed scalings to verify the conversion works properly.
That should fix the AMvTime plot. Our I/Q plot is in mV, so there would need to be another conversion if you wanted those units. Right now you are simply plotting I/Q straight from the device it appears.
I’m not sure whats happening with the FM. Maybe really small values create this? zero values? It doesn’t look like a phase discontinuity. Maybe phase wrapping like Justin said?
Regards
Cyprien,
If you use the time overview plot, you can drag the left/right vertical black bars to zoom in on a particular section of the plot. When you do this all other plots will update to only show this region of the capture. The AM vs time plot Avg power will update to reflect the avg power of just this region of the capture.
Regards,
AndrewHi Cyprien,
Thank you for your feedback.
I agree, more functionality could definitely be added to the I/Q playback. You are running into some of the limitations of the feature. I can acknowledge some of your points.
– There is no controls or keys for scrubbing through the file, such as step forward/back/etc, other than the single step button for advancing 1 step.
– There is not currently a way to go to an exact time.
– The rectangle viewport has a minimum size so it can always be grabbed easily. This might be deceiving for very large captures.
– The resolution on the rectangle position is 1 pixel. With your file at 8GB in size, 1 pixel might be a lot of samples. Finding a signal this way will be difficult.It was originally designed for shorter captures, and the controls reflect that. I have added some of your ideas to my notes. When we are able to revisit this portion of the software I think we should be able to add much of this.
One suggestion I might have, is to increase your sweep time to the maximum allowed, which will clamp at 4M points. This will effectively make your rectangular view into the file as large as it can be. Then you more easily use the per view zoom/scroll when you have found a signal of interest. This may not work for all use cases.
Additionally, signals can also be video triggered in the file. If your signals of interest have clear RF level rises, use the video trigger to find your signals. This might introduce some lag at large file sizes.
I should also mention, there exists third party software solutions that have extensive capabilities in this domain. See our third party vendors at this link. https://signalhound.com/support/third-party-software/ In particular, offerings from 3dB labs and Procitec have the types of features you are looking for.
I appreciate you taking the time to provide this feedback.
Regards,
AndrewVolker,
Thanks for the feedback!
This did come up in discussion when developing the feature. Those noise sources need a 28V supply which none of our devices can provide. We would have to rev the hardware for this.
An alternative is to use the trig port to drive something external that powered the noise source. Is this what you had in mind?
I look forward to your response.
Andrew
DDR,
In general, our VSG’s are not an alternative to an 80MHz ARB/function generator.
That being said, if you have specific signal generation requirements, we could help you determine if the VSG25/60 would be suited for any part of your application.
Regards
Hi Bill,
Very fascinating behavior. From the measurements point of view, nothing changes with the dialog active. Sweeps are still polled at the same speed, etc. The dialog being active could trigger other system behavior, maybe the system is giving increased CPU resources to our application with the dialog entry open, or something like that.
If you change the start freq from 10Hz to 100Hz or even 1kHz, does the USB error go away? The 10Hz start frequency requires a large continuous acquisition, and if your system was barely meeting USB throughput, that might push it over the edge.
Things that can affect USB throughput,
– Ensure your PC is set to “High Performance” power options. See the picture on my reply in this forum post. https://signalhound.com/support/forums/topic/vsg60a-stability-in-cw-mode-versus-multitone/
– Disable any anti-virus temporarily.
– If the BB60C is connected through a USB 3.0 hub, try removing the hub as a test.
– It sounds like your test setup is using another USB device. If that device is also a high USB usage device, that could be contributing to this.
– Keep your laptop on wall power.In general I would not expect the auxillary power cable not being plugged in to result in data loss, but its possible. Does plugging it in resolve the issue? There is a separate low voltage warning you would see, and you might see sagging measurement values if power was an issue.
I look forward to your response.
-AndrewBill,
Your first screen shot (630) shows an uncal USB warning, which would indicate data loss over USB during the measurement. This would generally affect the measurement negatively as there would be discontinuities in the acquisition, increasing the phase noise. The fact that you had a good measurement (no USB warning) with the dialog open is interesting, but might be a coincidence. USB data loss is generally random. In theory, nothing is different about the measurement when the dialog is open.
This USB warning will appear in most measurement modes. Can you confirm that you are seeing this reliably in either sweep or phase noise mode? If yes, we will want to troubleshoot this. If yes, can you provide the make/model/CPU of your PC?
You can reply here, or directly to me at aj@signalhound.com. I can send you some troubleshooting steps to try to help this.
I look forward to your response.
Regards,
Andrew April 6, 2021 at 12:53 pm in reply to: Spectrogram Frequency Limits Do Not Change on Recorded Spectra Thanks Gary. I appreciate the feedback as always. I agree this would be a useful feature. I’ll look into what improvements we can make on this for future releases.
Regards
Volker,
Thanks for your feedback. I have made a note of this for the next time we revisit the Noise figure measurement.
Regards,