NI Vector Signal Transceiver

[Marsupilami]

UPDATE:
TLDR, it's kinda done.
https://hackaday.io/project/192236-industrial-6ghz-rf-analyzergenerator-in-a-desktop


------

Original post:


Hi Folks,

Pinky promise I'm not in any way affiliated, I'm just running a search once in a while on ebay for PXIe instruments for my collection, and I noticed that the running price for used PXIe-5644R VSTs dropped to around $350, which is insane. I'm guessing these are being phased out from certain manufacturing lines and hitting the used market in mass.
I was contemplating a while ago to make an adapter board and 3d print a bracket to be able to put this in a double 5.25" disk bay in a PC and wire it to a PCIe slot on the motherboard. Otherwise a used PXIe chassis / controller now costs more than the instrument itself.
Software out of the box is quite simplified, but if one doesn't mind a bit of coding this is a very capable piece of RF hardware for the price.

[rfclown]

Thanks for sharing this. I'll have to look into this unit when I have time. I'm always interested in SDR transceiver hardware. Crazy what you can get for the money once something starts getting dumped on the used market. My first was the original Agilent VXI VSA hardware. Then it was the e4406A. Those are Rx only. Lately I've been using ADALM Plutos since they are Tx and Rx, and are wider bandwidth. The limitations of Pluto are frustrating, but it's hard to complain for the price.

[Marsupilami]

That's some good stuff. I use a e4440a at work now. I like that series.

Meanwhile I got very excited about putting a PXI VST into a regular PC and started a challenge project on it.



I might say not bad since Monday. I'm only 72% that it will work and even if it does there are a bunch of mechanical integration issues, but I'll deal with that if I get there.

[RoGeorge]

Might be cheaper in both time and money to look for a second hand PXI chassis, either NI or Agilent.  If you do so, make sure the chassis comes with a CPU and a power supply modules, or else you'll need to buy them later.  AFAIK you'll still need proprietary software to fully control the hardware (unless the chassis+control unit you bought came with software, too), but I've heard NI has now a free to use license for their LabVIEW.

Either DIY or ebay buy, I'm curious how the project will go, good luck with it. 

[switchabl]

It is relatively easy to find a used PXI chassis and controller (or MXI interface). But PXIe stuff was still quite expensive last time I looked.

[Marsupilami]

I have all that stuff, this is not a practical matter.

It is possible to find chassis on ebay for around $500, like a PXIE-1062Q or 1071, but it's hit or miss, offered as parts since, I'm guessing, these sellers don't have reliable ways to test functionality. Tested, known good units are still above a thousand.
Controllers (CPU) are an even bigger problem. The cheapest solution is the PXIe-8379 thunderbolt remote controller. You can find these around $300. As far as I know these were never released fully to the public and they use Thunderbolt 2, which needs an adapter (Apple ~$50) to modern USB Type-C Thunderbolt 3 hosts and actually not many PCs work with them due to some legacy security feature. I bought an Intel NUC just for this purpose, and it sort of sees the device but not doing anything else. Out of 4 my old work Lenovo laptop was the only one that run just fine with it connected.
Embedded controllers are again go for above $1000 usually.

So if you add that together it's closer to 2 grand which is cost of doing business if the instrument itself is also 2 grand, but now you can buy those for 300 freaking dollars! And there are a bunch from multiple sellers.

The software is easy. The driver includes what NI calls "Soft Front Panels". These provide basic SA / SG functionality. The screenshot in my original post is from that.
Programming libraries are available freely for LabVIEW, CVI, Visual C\C++ and .NET.
The two things that are not possible without expensive, paid software is to have wireless standard measurements (e.g. LTE etc.) and to program the FPGA, because that needs a LabVIEW FPGA license. Latter one is a cool feature, but for general analyzer / generator use the default FPGA image has everything included.

What I'm trying to get to here is to have the board made cheap. Connectors are ~$20 apiece, so let's say total BOM cost is $100. Another $50-$100 is the PCIe extension cable, then the only other thing needed is a crappy old-ish PC to put this whole thing into. I'm planning on buying a refurbished Dell Optiplex for about $100, that has a full size 5.25" drive bay.

FYI: https://www.ni.com/en-us/support/documentation/supplemental/12/the-ni-vector-signal-transceiver-hardware-architecture.html

[zrq]

This looks very cool. I didn't know it's possible to build a PXIe to PCIe bridge without a serious amount of hacking.

I'm very tempted to grab one and pray/prey for PXIe chassis later. Even plus the price of a new PXIe-1090 controller it makes a competitive offer as a modern RTSA.

[samofab]

Meanwhile I got very excited about putting a PXI VST into a regular PC and started a challenge project on it.

@Marsupilami please do share the design, even if not finished. It sounds like a great idea.

[KE5FX]

Would be super interested in hearing how this goes as well.  Modular T&M gear is underrated.

[Marsupilami]

Thanks guys, interest keeps me going.

I started a thread in the projects section, I think it belongs there more.
https://www.eevblog.com/forum/projects/pxie-instrument-in-a-regular-pc/

[jhenderson0107]

I assembled a NI PXIe-5663E VSA and PXIe-5673E VSG piecemeal from eBay a few years ago.  They are installed in a PXIe-1078 chassis which includes a PXIe-8370 MXI adapter to allow a 15' cabled PCI Express connection to a desktop PC with a PCIe-8371 MXI adapter.  NI labels cabled PCI Express 'MXI'.  I almost exclusively use the soft front panel (SFP) turnkey software. 

Some positives:
  Full-featured and instantaneous remote control via mouse and keyboard
  SFP user interface very similar to stand-alone instruments
  GUI much more responsive than my vintage spectrum analyzer (E4440A)
  Very compact compared to stand-alone devices. 

Some negatives:
  Low frequency range restrictions
  SFP instruments can't be controlled using VISA.
  Performance is good, but not exceptional.

I am planning to sell it.  I prefer stand-alone instruments with Visa control. 
 
 

 

[Marsupilami]

Gathering that piece by piece sounds tedious.

I never really looked at these as proper replacement for boxed instruments. When doing measurements manually a physical UI will always beat the remote software imho. Also performance wise it's important to realize these devices are targeted for high-volume production test first and everything else second so their performance is tuned to that. The whole architecture excels at tasks where there's significant data to be moved and processed on the host PC.

All that being said 6GHz SA/SG combo for $350 makes it worth.

[jhenderson0107]

I agree and wouldn't hesitate for $350.  I also have two PXIe-1073 chassis (see attachment) which are even smaller and would be well-suited to hosting this VST.  They connect via single-lane MXI adapters to a PC also.  For a virtual instrument, single-lane is fine. 

[Marsupilami]

I agree and wouldn't hesitate for $350.  I also have two PXIe-1073 chassis (see attachment) which are even smaller and would be well-suited to hosting this VST.  They connect via single-lane MXI adapters to a PC also.  For a virtual instrument, single-lane is fine.

Yep, that'd be a good setup. What's that module in your chassis? I can't see the model number.

I did a quick search to see how much the 1073s are going used, and ohh eBay... I don't think this was ever released publicly either:


How cool is that 2 in 1!

[jhenderson0107]

...What's that module in your chassis? I can't see the model number...

That module is the PXI-4461 which is a 24-bit audio interface.  It's useful for accelerometer and audio testing. 

Regarding that 1078D chassis:  I have seen that before, but never in the wild.  Given its cost premium, I'd prefer to inject a decent 10 MHz reference clock onto the backplane via a PXI timing card. 

One cool thing about these NI chassis is that some slots support both PXI and PXIe connections ('H' -designated hybrid slots), so either type of 3U card can be used.  For example, the PXI-4461 is a legacy PXI card (not PCI Express).  It was cheaper and more than sufficient for audio transfer speeds. 

[jhenderson0107]

...I agree and wouldn't hesitate for $350. 

I didn't hesitate and purchased one.  It runs the standard RF spectrum analyzer and RF signal generator virtual instruments.  Works well and is very space-efficient. 

[Marsupilami]

I didn't hesitate and purchased one.  It runs the standard RF spectrum analyzer and RF signal generator virtual instruments.  Works well and is very space-efficient.

Nice!

[Marsupilami]

I've been posting about my trepidations in the Projects forum, but now that it's working I'll throw it in here too:

[Marsupilami]

For anyone that might care this is as done as probably it ever will be.
PCB files and info on hackaday.

I also started writing GNU Radio blocks for it and got the analyzer part working, but I kinda gave up when I realized that a no double copy custom buffer implementation is beyond my time budget. It was still fun. 

[KE5FX]

Does this look like the same Mini-SAS adapter you used? 

Edit: also, just to confirm, is the "VST PCIe MiniSAS 20230831A for hackaday.io.zip" file still the best version to send to JLCPCB?

I wrote a pretty handy console app to drive the bladeRF and VSG60A (which I keep meaning to release one of these days), and was thinking it might be nice to use it with these NI modules as well.

[Minki]

Try to start first step.....
Marsupilami would you like to share the housing step file...?I want  to 3D print a housing for it

Thank You

I wrote a pretty handy console app to drive the bladeRF and VSG60A (which I keep meaning to release one of these days), and was thinking it might be nice to use it with these NI modules as well.

Sorry a off topic question that do you know how to turn bladeRF to a wide band spectrum...?Very little information in combine the many time FFT result to pot out full spectrum.

[KE5FX]

(Attachment Link)
Try to start first step.....
Marsupilami would you like to share the housing step file...?I want  to 3D print a housing for it

Thank You

I wrote a pretty handy console app to drive the bladeRF and VSG60A (which I keep meaning to release one of these days), and was thinking it might be nice to use it with these NI modules as well.

Sorry a off topic question that do you know how to turn bladeRF to a wide band spectrum...?Very little information in combine the many time FFT result to pot out full spectrum.

With receivers that rely on host-based signal processing, you're always going to be limited by how quickly the device can stream data to the PC over USB or Ethernet.  It really just comes down to setting the frequency at either a high level (using existing control software) or low level (writing your own programs), taking a snapshot, and stitching the transformed 'periodograms' together.  That can be done by concatenating FFT bins logically before plotting them, or by plotting them and combining the images.

[Marsupilami]

Does this look like the same Mini-SAS adapter you used? 

Edit: also, just to confirm, is the "VST PCIe MiniSAS 20230831A for hackaday.io.zip" file still the best version to send to JLCPCB?

I wrote a pretty handy console app to drive the bladeRF and VSG60A (which I keep meaning to release one of these days), and was thinking it might be nice to use it with these NI modules as well.

I got this one, but it seems similar enough. (I had to patch a resistor on mine though, I don't know how others are configured but it all seems to be the same basic design.)
https://a.co/d/8VI1OF7

File sounds correct. I asked JLCPCB if they have a better format to share, but apparently they don't. I think PCBWAY let's you share a design on their website, JLC should have that function too.

Make sure you post if you get it to work!

[Marsupilami]

(Attachment Link)
Try to start first step.....
Marsupilami would you like to share the housing step file...?I want  to 3D print a housing for it

Oh wow, look at those boards! 

I decided not to upload the mechanical design to hackaday, as I used manufacturer models in there and I didn't want to figure out the licensing implications.
Also my design it not very useful if you're not using this PC case I believe, but I can send the files to you nevertheless.

The most important part I used is this: https://www.digikey.com/short/d5m828vt
(Please not that this cage doesn't have the front lip needed for the card ejector to work.)
You can also go to the Schroff website and download the solid model for it.
Unfortunately the card guides are a bigger problem. This would be the proper part: https://schroff.nvent.com/en-gb/products/enc64568-089
There are a few iterations of this from Schroff, but none of them are recently stocked at DigiKey or similar distributors.
I found a bag of these https://schroff.nvent.com/en-gb/products/enc64560-005 on ebay.
Simplifying and 3D printing these parts could be an option, but consider the heat generated by the device.

[Minki]

(Attachment Link)
Try to start first step.....
Marsupilami would you like to share the housing step file...?I want  to 3D print a housing for it

Oh wow, look at those boards! 

I decided not to upload the mechanical design to hackaday, as I used manufacturer models in there and I didn't want to figure out the licensing implications.
Also my design it not very useful if you're not using this PC case I believe, but I can send the files to you nevertheless.

The most important part I used is this: https://www.digikey.com/short/d5m828vt
(Please not that this cage doesn't have the front lip needed for the card ejector to work.)
You can also go to the Schroff website and download the solid model for it.
Unfortunately the card guides are a bigger problem. This would be the proper part: https://schroff.nvent.com/en-gb/products/enc64568-089
There are a few iterations of this from Schroff, but none of them are recently stocked at DigiKey or similar distributors.
I found a bag of these https://schroff.nvent.com/en-gb/products/enc64560-005 on ebay.
Simplifying and 3D printing these parts could be an option, but consider the heat generated by the device.

Thank for your share i will try to using PC to print the card guides.
Current the tricky part is this bar(?)

Since the plane will done by laser cut acrylic board

So no plane to buy the SUBRACK(For save some cost)
And how do i test the PCI-E to SFF-8643 card had the reset signal?Just probe the RST# pin when powwer on the PC?
And ...does those connector no need to solder?I see you didn't solder it in your photo.


Many Thank

[Marsupilami]

So no plane to buy the SUBRACK(For save some cost)
And how do i test the PCI-E to SFF-8643 card had the reset signal?Just probe the RST# pin when powwer on the PC?
And ...does those connector no need to solder?I see you didn't solder it in your photo.
Many Thank

The horizontal rails can be made from other stuff too. I made some card cages for storage some time ago. This used 10mm makerbeam extrusions.


Don't worry too much about the RST#. Plug it in and see if it works. If it doesn't that's something to look at.

The connectors not soldered are press fitted into the board. It is intentional. Mind you, it is not easy to do. My solution was something like this:

[KE5FX]

I noticed in the other thread that your original board had two backplane data connectors:



... as well as two trigger/clock/power connectors, which match the connectors on the back of the PXIe-5644R. 

However, your current board revision has two power connectors but only one data connector.  Is the other one not needed by the 5644R, or optional?

[Marsupilami]

On the 5644r nothing is connected on that block. Other than maybe ground. I don’t know why does it still have to be populated, maybe there’s a signal there that gets pulled down so that the backplane detects there’s something in that slot and enables power. Power is taken from the upper connector on both slots.

[KE5FX]

Got it... I see what you mean now, looks like there are only a few power pins connecting the slot-2 daughterboard to whatever is inside the adjacent shield. 

[zrq]

May you bother to discuss a bit more on the software side? (question posted on the other thread but it seems this one is more active).

If I understand right, if the description ini files in C:\ProgramData\PXISA\Chassis are created correctly (and the pxiesys.ini and possibly also the ChassisDescriptionFilePath registry), the adapter board can get recognized as a chassis and the VST board get enumerated (if it's already enumerated at UEFI booting and seen by Windows).
Or is it compulsory to write a stub DLL like NIPXIeSMu.dll to help enumeration and implement the SMBus operations?

[Marsupilami]

May you bother to discuss a bit more on the software side? (question posted on the other thread but it seems this one is more active).

If I understand right, if the description ini files in C:\ProgramData\PXISA\Chassis are created correctly (and the pxiesys.ini and possibly also the ChassisDescriptionFilePath registry), the adapter board can get recognized as a chassis and the VST board get enumerated (if it's already enumerated at UEFI booting and seen by Windows).
Or is it compulsory to write a stub DLL like NIPXIeSMu.dll to help enumeration and implement the SMBus operations?

I didn't do any of that. You plug in the board and it works. In MAX it looks a bit wonky since it won't sit under a chassis, as there isn't one, but it is working nevertheless just fine.
I tried an SMU some time ago that didn't do anything at all and I'm wondering what you just wrote might help in that case, but again for the VST I had to do zero extra software work other than installing drivers.

[KE5FX]

Make sure you post if you get it to work!

Some excellent results with your board:



Everything was pretty much plug and play, except for how difficult the 'plug' part is.  I was afraid I was going to break something by forcing or hammering the connector into place, and I don't have any mating hardware available to create a makeshift press-fit jig as you did.  So I ended just soldering the connector pins after poking them through the board as far as they would go:



Not ideal for a standard backplane installation since the connectors sit about 2mm above the board, but good enough for proof-of-concept.

For the PCIe interface, I decided to try this adapter for use with an M.2 slot on a LattePanda:



They are sold by a couple of different vendors under the same part number (S-M28643H-1-1).  It worked nicely with no additional resistors or other modifications.  I powered up the PXIe-5644R with a mini-ATX supply prior to booting the PC, and it showed up right away in NIMax:



Thanks again for doing all the homework on this!

[Marsupilami]

Some excellent results with your board:

Yaaay!
That’s a sick setup. Are you planning to package it in a small box or something?

The press-fit is pain, yes, but I’m glad you found a solution.

The datasheet of the VST has the max current draw, make sure your psu is fine with it.

Have fun and keep posting if you tweak it!

[KE5FX]

Yaaay!
That’s a sick setup. Are you planning to package it in a small box or something?

The press-fit is pain, yes, but I’m glad you found a solution.

The datasheet of the VST has the max current draw, make sure your psu is fine with it.

Have fun and keep posting if you tweak it!

I'm not concerned about the power supply but cooling is definitely a consideration.  Just sitting on the bench in the open air, the 5644R gets too hot to hold after a few minutes.  Forced air will be mandatory in any enclosed chassis, no question there.

It's tempting to mount a touchscreen display to a PXIe-1085 or similar crate, but there goes the "bargain" part of the project...   

[Marsupilami]

I’m cooling mine with a 140mm Noctua 12V PC fan. I bought the beefy industrial version but I keep it waaaay down with the controller. Probably one of the “silent” kinds would take care of it easily too.

[Kahooli]

I ordered one of these to join the gang. Seems like a great piece for relatively cheap.

[Marsupilami]

I ordered one of these to join the gang. Seems like a great piece for relatively cheap.

Ah, the infamous VST gang, yes. Welcome... I guess?

[zrq]

May I ask what version of the LabVIEW and NI-RF stack is used. Does them have to be an older version?

[Marsupilami]

May I ask what version of the LabVIEW and NI-RF stack is used. Does them have to be an older version?

I haven't tried the current RFSA/RFSG drivers, but whatever was latest a few months ago works well. LabVIEW is not required, but the latest should work fine.

I found one issue with RFSG, going back to 15.0 or something like that.
The soft front panel hangs when starting. The workaround I found was to create a simulated RFSG device in MAX. This way the SFP will show a selection dialog and will start up fine using the simulated device. After it's already running, it is safe to switch to the VST device from the menu.
No such problem with RFSA.

[KE5FX]

May I ask what version of the LabVIEW and NI-RF stack is used. Does them have to be an older version?

I downloaded these from NI for offline installation:

   5,046,984,704 ni-rfsg_23.8.0_offline.iso
   4,653,273,088 ni-rfsg_20.5.4_offline.iso
   4,751,687,680 ni-rfsa_20.5.4_offline.iso
   4,483,399,680 ni-rfsa_23.8.0_offline.iso

As I understand it, the 20.5.4 versions are the last ones that supported Windows 7.  Those are the ones I tested with, although I didn't try the signal generator app, only the spectrum analyzer. 

[zrq]

Thanks to Marsupilami and KE5FX, I got my setup up and running (after arguing for refund from ebay for one with PXIe connectors smashed and getting the second working one). The press fit connector is really a PITA, but it seems simply soldering them from the backside of the board works fine. One have to be careful not to accidentally fill the holes for not yet populated connectors with solder, otherwise cleaning the hole to let the other connector fit is another PITA without appropriate desoldering tooling.
I think I can win a prize if there were a competition for the sickest setup for the VST. Somehow the temperature raise is moderate despite there is only two low speed fans blowing towards the card.

[Marsupilami]

I think I can win a prize if there were a competition for the sickest setup for the VST.

Dude, what is this?
But, I'm happy you made it work. 

[zrq]

There is a toolkit by NI called RFmx, which can help taking advanced measurements from IQ waveforms to phase noise with these VSTs. It's not cheap at all though, but  .

[zrq]

I got a very simple GNURadio source working to some extent, there is no fancy zero-copy design but simply niRFSA_FetchIQSingleRecordComplexI16 and memcpy to GNURadio buffers. On my old i7-3770 test bed with an equally ancient display card, gr-fosphor runs perfectly stable up to 40 Msps and 45 Msps with seldom underflows. I'm using the newest NI suite under Windows 10, which modern GNURadio requires.



What's a bit curious is the NI's TDMS streaming example (https://www.vipm.io/package/national_instruments_lib_ni_streaming_host_example_for_the_ni_pxie_5644r/ , it works on LV2023 after installing LV2015 and the instrument design library) also caps at roughly 40MSps even to a RAM disk. It's supposed to work at full ADC speed of 120Msps per NI's description and the i7-3770 was a decent CPU in 2012 when the example code comes out. Is it possible that the DIY backplane is limiting the speed in some way? Did anyone manage to run the acquisition at a faster sampling rate?

I'd like to publish a write up on this and put the code somewhere once I get more time, feel free to ask me if there is anything I may be able to help before that. Also I still have a few backplane PCBs left. If someone in Europe want one at cost price, please let me know.

[Marsupilami]

I got a very simple GNURadio source working to some extent, there is no fancy zero-copy design but simply niRFSA_FetchIQSingleRecordComplexI16 and memcpy to GNURadio buffers.

This is pretty much where I got stuck too. I started looking at the custom buffer implementations, do do a proper no-double-copy version, but I didn't feel the documentation was solid enough for me to safely understand and be able to implement so I gave up.
I would be nice to have an efficient record and playback app though.

[zrq]

I got a very simple GNURadio source working to some extent, there is no fancy zero-copy design but simply niRFSA_FetchIQSingleRecordComplexI16 and memcpy to GNURadio buffers.

This is pretty much where I got stuck too. I started looking at the custom buffer implementations, do do a proper no-double-copy version, but I didn't feel the documentation was solid enough for me to safely understand and be able to implement so I gave up.
I would be nice to have an efficient record and playback app though.

I think I found the performance bottleneck, apparently the VST is only using 1x 2.5 GT/s PCIe lane, which in principle should run up to 4x. It probably the signal integrity problem with the homemade adapter board, maybe the soldered pressfit connector? and the longer than necessary (0.8m) SFF-8643 cable make it worse?

[KE5FX]

The link training happens at power-up time, IIRC.  Maybe it's not getting initialized properly.  Try powering up the VST before the PC is turned on, if you're not already doing that. 

The signal integrity of the connector should be fine.  You have to really screw something up badly to make a differential pair perform poorly at these rates.

[Marsupilami]

Mine is good.
PCI current link width = 4 in device manager

It is possible however if any of the TX or RX of the 3 other lanes fails the enumeration the link reverts to 1x.

[zrq]

Thanks for the help, I wonder if is there is anything can help troubleshooting this, a bit more information on where the link training failed would be nice. Well, a PCIe analyzer is certainly beyond my budget. Tried with another VST device and solder the R4 on the 10Gtek board (didn't do that as it appeared to work without it), but still only learned x1.

-> So I figured it out myself, it's simply because the SFF-8643 connector didn't mate properly with the board, so simply all differential pairs except one are not fully connected. 

[Marsupilami]

the SFF-8643 connector didn't mate properly

It's always something like that