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Doug_S
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RF Record and Playback Reference Application

Post your questions or feedback on the RF Record and Playback Reference Application here.
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TimS.
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Re: RF Record and Playback Reference Application

I receive Error -1074118655 at "niRFSA Initialize.vi" when trying to set the Range on the front panel of the "Set RFSA Record Settings.vi". The error was "Requested vertical range is invalid". I traced it back to the "Map Slide to RFSA Setings.vi" (Yes settings is actually spelled incorrectly in the VI name). I'm not sure what the invalid value is but for some reason it isn't outputting a valid "Scope Range (Vpp)". I've used the RF Record and Playback Reference application on the PXI-5661 hardware before and it has worked fine. The error that I'm receiving now is happening while running on the 5663 hardware. I thought that the reference application was able to run on that hardware as well, is this incorrect? Please advise.


Thanks,

 

Tim S.



Tim Sileo
RF Field Account Specialist
National Instruments



You don’t stop running because you get old. You get old because you stop running. -Jack Kirk, From "Born to Run" by Christopher McDougall.
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TimS.
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Re: RF Record and Playback Reference Application

I finally had some time to dive into the code a bit and I found a partial answer to my 5663/5661 question. The "Map Slide to RFSA Setings.vi" tries to set the "Scope Range (Vpp)" to either 0.2, 0.4, 1, or 2 depending on the range value selected on the "Set RFSA Record Settings.vi". This works for the 5661’s digitizer which has a max input vertical range of +10 Vpp but for the 5663’s digitizer the max vertical range setting is 1.4 Vpp. I modified the "Map Slide to RFSA Setings.vi" to not contain any values larger than 1.4 Vpp which gets rid of the error that I was having. However, I think this now reduces the functionality of the "Set RFSA Record Settings.vi" which had specific reference levels, scope vertical ranges, and instrument peak powers that were tied together. Also, the problem of the Saturation bar not working still isn’t fixed and that was a useful tool to help select the best recording quality.

 

-Tim S.



Tim Sileo
RF Field Account Specialist
National Instruments



You don’t stop running because you get old. You get old because you stop running. -Jack Kirk, From "Born to Run" by Christopher McDougall.
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Yardov
Posts: 331

Re: RF Record and Playback Reference Application

Hello Tim,

 

Sorry for the late response. You are absolutly right and thank you for sharing that with this group.

The examples you have support only the PXI-5661 and PXI-5672. I have attached a version that supports the PXI-5673 and PXI-5663 which has the change you mention.

The reason PXI-5661 requires to change the scope range is to have finer attenuation step level (since PXI-5600 has 10 dB steps).

The PXI-5663 has 1 dB steps and therefore, there is no need to change the scope range.

 

Let us know if you have any questions,

 

Gerardo O.
RF Systems Engineering
National Instruments
Member
TimS.
Posts: 141
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Re: RF Record and Playback Reference Application

The attached application works well. Thank you. I also received this attached version from Joe Svoboda at NI. Only some minor differences as far as I can see.

 

Thanks for the help,

 

Tim S.



Tim Sileo
RF Field Account Specialist
National Instruments



You don’t stop running because you get old. You get old because you stop running. -Jack Kirk, From "Born to Run" by Christopher McDougall.
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Yardov
Posts: 331
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Re: RF Record and Playback Reference Application

Hi Tim,

 

Yes, should be very minor changes and no functional changes.

And, by the way, the misspelling was a good catch on my code. Totally missed that.

 

Regards, 

Gerardo O.
RF Systems Engineering
National Instruments
Member
Arpine_Soghoyan
Posts: 30
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Re: RF Record and Playback Reference Application

Hi,

I used Record and Playback Reference Application v02 (lv85).zip 1091 KB application to run on the NI PXI 5663/5673 but was not able to do that.

There are missing vis when i try to run record and playback ui.vi such as;

TFA STFT spectrogram(complex).vi, TFA get time and freq scale info.vi, TFA set time and freq scale info.vi, TFA STFT spectrogram.vi

 

Is there a full record and playback application that will run on PXIe 1075 chassis with NI PXI 5663 and NI PXI 5673 on it.

 

Thanks,

Member
TimS.
Posts: 141

Re: RF Record and Playback Reference Application

Hi wrang,

 

The application should work for the 5663/5673. The VI's that are missing are because you don't have the Advanced Signal Processing toolkit. Those VI's are for the analysis section of the RF Record and Playback app and don't directly pertain to the 5663/5673 hardware. If you open up the example and remove the Analysis subVI that's in the event structure you should be able to run it (unless there are other toolkit VI's being used in the actual record/playback steps that you don't have). Also, I can't fully recall...but I think there is a property node or two that you may get an error with the 5663 since I think the app was originally written for the 5661 hardware. It's a quick fix if you do see it though.

 

Let us know how it goes.

 

Regards,

 

Tim



Tim Sileo
RF Field Account Specialist
National Instruments



You don’t stop running because you get old. You get old because you stop running. -Jack Kirk, From "Born to Run" by Christopher McDougall.
Member
Arpine_Soghoyan
Posts: 30
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Re: RF Record and Playback Reference Application

Hi Tim,

 

thanks for your reply. I have some other concerns.

 

1. Is it possible to generate GPS signal without external amplifiers ? What are the parameters I should give to Configure and Record data.vi in order to generate a GPS signal ?

 

2. If I want to add more functionality to the Record and Playback project let's say once the signal in generated using RFSG I want to do some additional calucation on it where can i put my code ? Attached is the block diagram of the vi and it shows my guessed location. Please correct me if I amd wrong.

 

Thanks

Member
TimS.
Posts: 141

Re: RF Record and Playback Reference Application

Hi wrang,

 

I'm not really an expert on the R&P app, I've just modified it heavily for use in other area's but I'll try to answer your questions.

 

1. I'm confused about your question for generating a GPS signal. You mention "Configure and Record" which is only used on the NI-RFSA recording part of the main app. If you want to record a GPS signal I know that other folks at my company have done that using the PXIe-5663 and this application. I'm not sure how there RF front end was set up though so idk if they needed external amplifiers to record it appropriately.

 

2. Depending on the sample rate which you're trying to playback it may or may not be a good idea to add anything into the playback loops. The spot in the code that you pointed out is directly after data is read from file and before it writes it to the queue to be written to RFSG memory. If you add code into the file reading loop that slows down the read process too much then you run the risk of not writing to the RFSG memory fast enough and you will receive underflow errors. If you want to modify the file data I would recommend doing it offline before trying to play it back using this application. If you just want to add in some code that does calculations for display purposes then you could create another Queue which would be used to pipe the file data to a third parallel while loop which can run asynchronously from the file read or RFSG write loops. This way, your calculations won't slow down the file read loop (as long as there is a very short timeout on the Enqueue to calculation queue block or if you use the lossy enqueue block). If your calculations need to capture all samples and stay in real-time then I don't think you'll be able to achieve this. The sample rate at which your system would fall behind is dependent on the particular PC hardware and how many calculations you want to perform so I can't give actual sample rates but it wouldn't be anywhere near the full bandwidth/sample rate that the PXIe-5673 or PXIe-5672 can achieve.

 

Regards,

 

Tim S.



Tim Sileo
RF Field Account Specialist
National Instruments



You don’t stop running because you get old. You get old because you stop running. -Jack Kirk, From "Born to Run" by Christopher McDougall.