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THarrington,
I’m assuming by top of the carrier you are looking at the signal shape in the frequency domain? If yes, then what you are seeing is likely just the fact that the VSG25 has a small pattern memory buffer and cannot transmit long sequences of unique symbols. The most symbols we can fit in a output buffer is 512. Ensure your “Data” setting in the VSG25 contains a large enough sequence of bits to ensure randomness. You can do this by inserting several PN9 sequences, one for each bit per symbol. This will ensure you have the maximum number of random symbols that will “fill out” the top of the carrier.
In general, this shouldn’t affect the measurement. If you need a more random looking signal, the VSG60 has the ability to transmit extremely long PRBS sequences (PN23).
If you would like to share a screenshot of the behavior, I can verify that my response is correct.
Andrew
In the Edit->Preferences menu, under the SCPI tab, you can disable the SCPI lockout dialog.
Andrew
Cyprien,
We appreciate some of your ideas and suggestions.
Regarding the power measurement. It is a channel power measurement using the user defined settings in the sweep settings control panel. The channel power result is what is plotted on the map. The channel power measurement is made in the frequency domain, not the time domain, so it may not be accurate for very short duration pulsed signals.
The GPS min delta and meas speed control how often the GPS is sampled. It can prevent you from taking measurements too often or too close together. If the meas speed interval has passed and the GPS reports a distance at least minimum distance from the last point, then a new point is plotted on the map using the most recent channel power reading.
I hope this helps. Let us know if you have follow up questions. There is some short descriptions of the controls in the Spike user manual as well.
Andrew
Some general questions, suggestions, and ideas,
– Ensure you are transmitting at the same sample rate as the recording occurred.
– Depending on the settings used when the recording was made, it’s possible the noise floor of the BB60 is contributing to the transmission. Is the SNR good enough on the re-transmission?
– Did any compression occur during recording? aka IF overloads?
– Are you transmitting at the right power?
– Are you running both devices simultaneously? If yes, that could cause signal drop outs, or if both devices were active during the recording, the recording could be compromised (dropped samples). In general, not every PC is capable of running multiple of our high speed USB devices.
– Do you have anyway to verify the recording is good by inspection? (aka software inspection?)
– Do you have any known good recordings you can try to transmit with the VSG60?
– What is the make/model of your PC? Are you using any USB hubs?
– Is your recording on an SSD with necessary read/write speeds? I’m assuming you are using the streaming output mode in the VSG60 software which is going to read from disk in real-time.Feel free to contact us at support@signalhound.com if you prefer direct email support.
Thank you for the feedback. This is also interesting to us and something that has been on our wish list for a while. I will see what we can do.
Regards
RVanDyke,
Thanks for the feature request. I think this is something we can easily add.
Regards
Jacks,
Please reach out to support@signalhound.com. We will be able to better assist this issue via email.
Andrew
Cyprien,
I just activated it by
– Launching Spike
– Changing the start freq to 201M
– Clicking ‘up’ on the RBW control from 100k -> 250k -> 6MHz.When the 6M RBW is active, the whole sweep updates at once (no partial updates). It takes ~5s for a full 12GHz sweep.
Let me know if this doesn’t work for you.
Hi Ed,
Currently, you can only export the demodulated bits manually. Other than streaming the data to disk, does the rest of the digital demodulation capabilities meet your requirements? Is there a specific file format you are used to using for this type of data? Any other products you use now to solve this issue?
Andrew
Thanks for the report Andy. I will look into this and let you know if I have follow up questions.
You probably just need to update Spike, you should see the picture below.
In the Network Settings utility, did you press the “List devices” button? That should list the network settings for all SM200Cs that are connected to the PC.
Do you happen to have a windows PC you could install Spike on and try the USB config?
I definitely trust that the Windows implementation of the USB network config to work 100%. When plugged in via USB to a Windows PC, it should also show up in the device manager as an SM200C in the Universal serial bus controllers tab in Windows (as long as you have installed Spike which installs the USB driver for the SM200C).
If on Windows you also get the device not found message in the network config dialog, or it’s not showing up in the device manager, it could be hardware failure.
When connecting in Spike, it should be toggling red/green on a ~1 second cycle, so definitely something not right.
If none of the above helps, email aj@signalhound.com and we can determine the next step. We might have to dig deeper into the FW and what might be happening.
If you connect the SM to the PC via the USB 2.0 cable, you can go to the “SM Network Configuration” menu item in the Utilities drop down in Spike (the device must be “disconnected” in Spike for this menu item to appear). This will allow you to poll the device for what it thinks it’s current network settings are. I don’t know how the network settings would have changed but this would allow you to at least verify everything is as expected.
Have you ruled out the SFP+ transceivers or fiber cables? We’ve definitely seen these go bad before.
Do you have any other equipment that can be easily swapped or ruled out? Do you use one of the QNAP adapters? NICs?
Does the LED do anything when attempting to connect in Spike?
We are using the Cypress Fx3 chip, so showing up as a Cypress Fx3 device might be fine. We just use the default libusb library on Linux, so I’m not sure we’d show up as a BB60C anyways.
If you are blinking red when idling, then the firmware on the BB60 is power cycling the device because it wasn’t able to establish/enumerate as USB 3.0. We see this when customers connect the device to a USB 2.0 port, or use 2.0 cables, hubs, etc. Is there anything you can troubleshoot in this regard? It should be solid green when connected and idle.
We have had success with VMWare products, such as VMWorkstation. In the VMWare products you have to enable high speed USB in the settings to control our products (or at least is used to be that way).
We have not used Oracle VMs before, nor have I heard of customer using them. I would say most customers have issues when running our products in VMs, and it’s almost always USB related.
I would recommend running native if possible, or trying VMWare if possible.
You could adapt from 2.4 to 3.5/2.92 which would give you the option to connect 2.92, 3.5, and SMA and go > 20GHz when needed. Since that adapter will be expensive, you could buy a cheaper connector saver, like SMA-SMA or 3.5-SMA if you plan on doing a lot of SMA mating cycles.
2.4 to N exists and isn’t horribly expensive,
Here’s some ideas,
Andy,
The 3D waterfall was removed in 2017. We decided to add more features to the 2D waterfall instead of supporting both moving forward.
Regards
Andy,
Gary was referring to the waterfall view in zero-span mode. Once in zero-span mode use the “Add Measurement” button in the upper left of the application to add a water fall plot. It shows you a very dense spectrogram plot over the duration of the time domain capture, usually overlapping FFTs by 90% or more depending on settings.
In sweep mode, it’s just a matter of clicking the “spectrogram” checkbox in the upper left as well. Same general functionality, less overlap between lines in the plot as compared to zero-span.
Speaking of which, maybe we should be a bit more consistent in our naming.
All of our waterfall/spectrogram views are “flat” 2D plots, if that is what you were referring to.
Let me know if you have more questions.
Yes you can. In general only one application can have a SCPI connection to Spike at a time. Any application that can communicate SCPI commands via the VISA SOCKET protocol can communicate with Spike.
We use IO libraries internally for testing, using the interactive IO panel. We have heard of customers using the SCPI capabilities in MATLAB and LabVIEW with Spike.
Eric,
Thank you for the report.
We have not done any testing with LTE-M signals, or any of the LPWA variants. Given this, I do not believe we can adequately support these measurements. I have added these comments to our development logs. In the future we might be able to introduce this capability.
Out of curiosity, what sort of equipment are you testing?