LeCroy 3034 - how to set up ARINC429 data display?

[peter-h]

I have the option unlocked, selected in the channel, but no way to get any analysis (1s and 0s ) showing up.

Nothing in the manual, either. Some stuff online, but only advertising material. Not showing how to set it up.



ARINC429 has no separate clock or CS. It has two signals which are complementary, so only one of them should be needed, for a scope display.

How is one supposed to set this up?

I know that a couple of years ago this scope was used for SPI decoding, by somebody else. IIRC this required one to set up a zoom region and it would decode data within that region. This doesn't seem to do anything either.

[Martin72]

Hi,

I have the option unlocked

Interesting, it must be a hidden feature on this scope series - The Arinc429 decode option normally starts with waverunner 9000....

[peter-h]

So, how do you set it up on a 9000? Do you need two probes, what do you do about the clock and the CS, etc?

There is stuff like this online
http://cdn.teledynelecroy.com/files/appnotes/testing_debugging_avionics_arinc_429_milstd1553.pdf
but I can't find anything on how to actually set it up.

[2N3055]

What Martin says is that that scope shouldn't have ARINC429 as an decode option at all.
Avionics family of protocols start at HDO4000A series (and only basic ones for that one).

If that option was enabled by "user generated code" it might be that scope accepted it in license validation part, but since it doesn't have actual decode code for it, it called SPI decoder by mistake. Something is wrong.

For ARINC you need only one signal (A, B, or differential and setup for that choice), and you need to chose word format (data encoding). Threshold, maybe parity and baud rate. That's all.

Your scope is in a weird state.

[peter-h]

Do you mean it is not showing required config options?

[2N3055]

Do you mean it is not showing required config options?

Exactly, those are SPI decode setup options...

I would reset scope to factory defaults, try some other protocol (like UART or I2C) and see if they show proper setup dialog.
Then, again, try ARINC, and if it again shows SPI settings dialog, something is wrong.

I already said what I suspect is happening.

Officially there are no avionics protocols available for old WS3000 nor new WS3000Z. Basic (TD) avionics protocols decode start with HDO4000A, and advanced trigger/decode/graph/measure/eye (TDME) start with HDO6000B  and up.

[Martin72]

If that option was enabled by "user generated code" it might be that scope accepted it in license validation part, but since it doesn't have actual decode code for it, it called SPI decoder by mistake. Something is wrong.

Exactly this is what I think about - It´s like having 1Ghz option on the sds2K+...

[tv84]

If that option was enabled by "user generated code" it might be that scope accepted it in license validation part, but since it doesn't have actual decode code for it, it called SPI decoder by mistake. Something is wrong.

That's a good idea: try decoding a SPI signal with those settings. If it works then your "ARINC selection" is the same as SPI.

[peter-h]

I can't get any decoding to work on ARINC429.

Where is the config option for factory defaults?

I went to the update firmware option and it said it needs a BIOS update, so I selected that. The firmware was from March 2021 anyway, which is much later than the date after which this scope was "discontinued"

It then showed a very bright colour screen (four rectangles) with a counter which ran for a few mins. It ended with SYS UPDATE DONE. No idea what that was about!

Then it rebooted. Old config preserved.

It is doing "something" because if I tick the Decode On checkbox, the scope really slows down - as if looking for data. I think one of the screens has changed a bit

[nctnico]

If it isn't officially supported then likely the libraries to do the actual decoding are missing. Remember your scope is running a cut-down version of the Windows OS and likely a special version of the software. A long time ago Microsoft sold Windows-CE (AFAIK obsolete nowadays) as being an OS that could run your existing code written for Windows but in reality that was only true for applications which aren't more complex than 'hello world'. In any other case getting existing code to run meant doing major rewrites.

If you want to do Arinc decoding then you'll need a different oscilloscope.

[peter-h]

I have two ARINC429 analysers - old ex Ebay stuff from MAXT. One is PCMCIA in a winXP laptop, and the other is a PCI card in my PC (which is much more solid). These have loads of features; I can load e.g. an AHRS decode package and have the the labels all decoded. And generate all kinds of simulation data. I wasn't expecting that level of support on a scope. Just a display of the 1s and 0s in the 32-bit packet. I've written a load of ARINC429 code, using a HI3593.

I was keen to see if this scope can be made to do decoding. It may just be handy one day, but probably not since the UI on these scopes is only just usable on "normal" signals (the touch screen is completely useless, so I use a trackball) and IME the main benefit of a DSO is the storage aspect of it. It can of course display the data (see screenshot below) but that is as far as I can get - no analysis.

ARINC429 doesn't appear under the trigger options, which include all sorts like CAN STD etc. But that would be complicated; you really need the huge library of label formats to trigger on values, because the values vary per label. And there are many cases of the same label having different meanings.

I also wondered if the Decode 2 option (my last post above) might work, since it has no clock/cs options, just data. But no luck with that.

Probably the problem is that I have no info on how to use any of these features. For example what does Configure Table do?

[tautech]

What are ch3 and 4 ? Doesn't look like they're related to a data bus.  Turn them OFF.
You have Stop'ed the scope which is symptom you don't have stable triggering.
The packet is 5 div long so set trigger Timeout for slightly longer than the packet to get stable triggering.

Then I'm lost as never seen a packet with positive and negative pulses. 
Ch2 looks like a CS or is it just a fluke it aligns with a series of negative pulses ?

[peter-h]

I did that but it makes no difference.

The reason I stopped the scope is because the transmitting device is sending out about 20 different packets, so triggering, while possible, is pretty difficult, and data analysis must be possible on captured data (I've seen it done with SPI).

Checking and unchecking the View Decode very much changes the display; it makes it update much slower, as if the scope was looking for something.

The data is what ARINC429 looks like. -5V to +5V swing.

[tautech]

I did that but it makes no difference.

The reason I stopped the scope is because the transmitting device is sending out about 20 different packets, so triggering, while possible, is pretty difficult, and data analysis must be possible on captured data (I've seen it done with SPI).

Checking and unchecking the View Decode very much changes the display; it makes it update much slower, as if the scope was looking for something.

The data is what ARINC429 looks like. -5V to +5V swing.

OK thanks, never seen it before. Is Ch2 related, see edit to previous post.

Decode ON can slow system performance in some scopes so it's important to get all the little things right and ensure you have other unused features OFF.

My first rule when trying to do any decoding is to get stable triggering which might be with the trigger set to another bus related channel which is why you don't want any other signals present to confuse the issue. 

After some quick Googling it seems like using Zoom mode to better see the packet timing structure looks like a good place to start.
https://teledynelecroy.com/serialdata/serialdatastandard.aspx?standardid=319&capid=105&mid=520

[Martin72]

I´m curious about the Arinc source..

[peter-h]

I also feel fairly sure that zoom is needed to get any data analysis to work.

The source is a Sandel SG102 AHRS. Why do you think this is relevant? It is just a standard low speed ARINC source. I have a few of them kicking around. But I also have the two analysers (PCMCIA & PCI) which can generate any packet, with a specified rate. So, yeah, I can set up one of these to generate just one packet, repetitively.

It still doesn't do anything.

[tautech]

Peter, in a packet what is the normal first edge ? Positive or Negative ?
From what I see in your screenshot the scope is triggering on the 4th first positive edge within the packet.

Not that should be a concern if it repeatedly triggers and as long as it's stable and other settings correct you should get a decode.
Do you have a 'display decode' setting ?

[Martin72]

Hi,

Why do you think this is relevant?

No, not relevant - Just for me, haven´t heard from this before.

It still doesn't do anything.

If the scope doesn´t got the decode protocol in "real", and it seems so, it won´t do anything.

[peter-h]

Triggering is basically easy if there is a gap between packets. Same with any scope. This is not an issue.

And usually there is a substantial gap.

To do it really properly, i.e. assuming no inter-packet gap, you have to decode the data. The encoding can be found online; I have never bit-banged it; I've always used a chip to do that. It may be somewhat similar to Manchester, which I have done in hardware many times since the 1980s. If you are doing ARINC429 on the cheap (not common because the other end usually costs 4 digits, but if you need say 10-20 channels then it will get very expensive very fast unless you DIY, and an FPGA is a popular solution) then you can bit-bang the TX easily enough (the specific slew rate is the only slight challenge), and you can bit-bang the RX with a comparator feeding a GPIO pin.

I think there is something "big" missing here. Either the scope doesn't support it despite having the software key in there, or there is some config item missing. Look at that thread about the 3034 FFT being completely useless unless a key item of knowledge is implemented

There is a display decode option - see earlier screenshots. It is "trying" to do something.

[nctnico]

Why not first try to decode something the oscilloscope is supposed to support like (I guess) UART, I2C or SPI? Now you are tracking 2 problems at once. You can split that into 2 seperate problems by first getting something to work that should work for sure.

[2N3055]

Like I said already, my theory is that someone  used "homemade" key to enable ARINC on a scope that doesn't support that.
Scope is now behaving weirdly..

All LeCroy MAUI scopes use same windows software for PC based platforms.

For embedded platforms like WS3000 some porting was done to WinCE (ARM) and it is possible that license manager was ported in full. And it is known thing that license manager doesn't really check options much for validity for specific platforms.
There are many occasions where users of x86 based scopes had problems after enabling options their particular model didn't support. License manager happily let you do so, and later you had problems with scope.

Normally you don't have that problem because LeCroy wouldn't sell you option that is invalid for your scope.

Your scope never had and never will support ARINC. Even if LeCroy decides to add ARINC (and/or other avionics protocols) to WS3000 class device they will do it for new, current model 3000Z.

[peter-h]

Is there some way to reset the scope, but without losing the installed options?

I will try it on SPI at some stage but it takes a lot of setting up (access to signals etc). RS232 would be a lot easier; I have a signal handy so will try that sooner.

What were the "later problems with a scope"? Did new software keys stop existing options working?

[Azusa]

Hi peter:
How you generated the key for ws3000？
I tried the script on forum but it doesn't work at this model.