Author Topic: EEVblog #790 - Lecroy Wavejet 354 Touch Oscilloscope Teardown  (Read 22273 times)

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Offline Laertes

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Re: EEVblog #790 - Lecroy Wavejet 354 Touch Oscilloscope Teardown
« Reply #50 on: September 07, 2015, 06:37:41 pm »
How do you know it's a firmware bug? The WaveJet problem sounds like a hardware defect (if it's the non-A version in the white case then it may well be that the decoder is worn out and needs replacing, which isn't difficult to do), as does the HDO4000 problem as this definitely isn't normal. The HDO Series had some minor issues when they came out but that has long been fixed with a firmware update.
The WaveJet issue only happens when the scope is in lowest voltage range, not in the others. As far as I can tell, it also only happens when both channels are on. It is not a hardware issue.

As for the HDO4000... I'm honestly not sure, can you update the firmware via USB Stick? I know for sure the FW has never been updated since it was bought, so it might still have bugs from early releases. I can't hook the scope up to the internet, thanks to our IT department(though I honestly have strong scruples hooking a >$10k machine with completely unprotected Windows on it to the internet, but for just a quick update I probably wouldn't mind).

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And the main reason to run Windows on a scope is that you can run other applications (i.e. Mathlab) on it
Do people use this feature? I can't imagine a reason to, not when I have a dozen computers right next to it, with much more power and much more convenient UIs...
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especially with the XDEV options available for many LeCroy scopes is great as you can write your own software that has full access to the raw data stream of the DSO.
THAT I can get behind, especially for more specific applications(maybe stuff like using your scope for a quick Test Jig that is more complicated than simple masking or something).
But you could just as well do that with VxWorks or even Linux or anything that is more reputable than Windows. Then again, scopes don't need to be able to run 24/7 for five years straight or anything like that, so the serious stability issues that you might experience on Windows will probably not have any effect at all. Wonder if it is easier to port Windows to the scope rather than Linux or VxWorks. Also, I wonder how the choice of operating several platforms(someone stated the WaveJet ran VxWorks, right?) came about...

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In addition, there's a huge difference between a bug that causes the device to crash/freeze/whatever and a bug that produces untrustworthy data, the latter of which Rigol and Siglent have seen quite a bit with their firmware problems.
I agree. Rigol's firmware is much worse than that of LeCroy or Keysight, there's no doubting that. I merely wanted to state that I feel that sometimes, people are a little bit harsh on the issues Rigol has/blow them out of proportion. The problems that cause wrong waveforms are of course absolutely not acceptable, but so far the only one I have seen is the one Dave showed in one of his videos with the AC trigger issue. I don't know if that exists on the somewhat advanced expensive Rigol 4000...

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Why remove a product that still sells well enough and has earned itself a great reputation amongst its customers?
Why spend money "improving" a scope that still sells well with something that hardly adds any value(or is that another misconception of mine? does the touchscreen add significant value in your eyes?)
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Yes, if you pay list price or buy from resellers. However, LeCroy is pretty keen to get a bigger foothold in the low end scope market, and therefore wants to get the WaveSurfer 3000 out there. There often are very good deals available with the WS3k (while there isn't much for the WaveJet!), and if you talk directly with LeCroy there's a good chance you can get a WS3054 for the same price as a WaveJet 354T.
I did not know that. Will remember it, though, for the next investment - go talk to LeCroy...

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It doesn't. I work in a similar field (although I mostly need MIL-1553 while I rarely touch ARINC429), and when I still worked in Germany (which admittedly has now been a little while ago) the majority of scopes in that field where Agilent and Tek, with LeCroy mostly limited to the high end (i.e. WaveRunner and up). They seem to be even less common here in the UK (probably because Agilent had manufacturing over here), and only when I work in the States I'll see them in larger numbers.
Interesting how our experiences differ in that respect. I worked optical semiconductor testing before getting into avionics and they had some really high end LeCroy gear. But in the Avionics market I have seen the low-end stuff quite often. Maybe their campaing to get into the lower end market is already paying off?

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Also, both standards (ARINC429 and MIL-1553) are pretty common amongst the options found on Agilent/Keysight and Tek scopes, aside from the very bottom end models. Even the low-end DSOX3k(T) can optionally decode ARINC429 and MIL-1553 (the Tek MDO3k seems to only do MIL-1553, as did older Agilent DSO7k Series). Most of the larger models can decode ARINC429 as well. Plus, the DSOX3k(T) is probably the cheapest scope that can decode ARINC429 (LeCroy's cheapest scope to do that is the WaveSurfer 10 which is $10k and only cheaper when compared with the larger DSOX3kT models; however, for ARINC429 even the 100MHz 2Ch variant of the DSOX3(T) would suffice).
A half-well trained HAM radio operator with a little morse knowledge and a speaker would suffice to decode A429 ;)
Forcing those who need it to buy bigger scopes earns you more money, though...

[qoute]
So how does buying another Rigol scope fix the inherent firmware issue you just lost several hours on? Exactly, it doesn't. Plus even that single incident meant you lost valuable time that could have earned you much more than the price difference between a B-brand like Rigol and a big brand like LeCroy, Keysight or even R&S (which is pretty expensive, even for a big brand).

I appreciate that for a hobbyist the purchase price of a scope is often a big investment, however in a commercial environment $5k are often pocket change compared with the money that is involved. The $5k WaveJet might very well be used by an engineer with a charge out rate of $300 or more who could easily work on stuff which earns the company in excess of $1k (as it's the case in some industries). The price difference between a WaveJet and a Rigol isn't even worth considering, especially when that means moving from a manufacturer with a rock-solid, proven product to a cheap B-brand with a bag of firmware problems, a gamble which easily could result in the business losing money, losing customers and get you fired.
[/quote]
I still don't quite agree. I own Rigol in private and I have not ever spent even just an hour working around an issue on the scope to get my actual work done, and I have done a few projects similar in complexity to the ones I would at work. Of course, the question remains whether the benefits of switching toward cheaper stuff outweigh the risks and clearly, that is not the case for the engineers out there. So, my initial question is thoroughly answered.

Thank You!
 

Offline Wuerstchenhund

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Re: EEVblog #790 - Lecroy Wavejet 354 Touch Oscilloscope Teardown
« Reply #51 on: September 08, 2015, 05:44:10 am »
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How do you know it's a firmware bug? The WaveJet problem sounds like a hardware defect (if it's the non-A version in the white case then it may well be that the decoder is worn out and needs replacing, which isn't difficult to do), as does the HDO4000 problem as this definitely isn't normal. The HDO Series had some minor issues when they came out but that has long been fixed with a firmware update.
The WaveJet issue only happens when the scope is in lowest voltage range, not in the others. As far as I can tell, it also only happens when both channels are on. It is not a hardware issue.

Have you tried updating the firmware? Although it still could be a hardware defect.

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As for the HDO4000... I'm honestly not sure, can you update the firmware via USB Stick? I know for sure the FW has never been updated since it was bought, so it might still have bugs from early releases. I can't hook the scope up to the internet, thanks to our IT department(though I honestly have strong scruples hooking a >$10k machine with completely unprotected Windows on it to the internet, but for just a quick update I probably wouldn't mind).

You don't connect a scope to the open internet, Windows or not.

As for updating the HDO (or the WaveJet), just go to the LeCroy website, download the firmware update, put in on a USB stick and run the file on the scope. It's really worth updating at least somewhat regularly because aside from bug fixes these updates also often include various improvements or new functions. For example, the WS3k comes with a buil-in signal generator which can be enabled through a software option, and when it came out it could only generate standard waveforms (i.e. sine, square, triangle etc). A later firmware update turned it into a full arbitary waveform generator, plus all WS3k's got the DVM readout for free.

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And the main reason to run Windows on a scope is that you can run other applications (i.e. Mathlab) on it
Do people use this feature? I can't imagine a reason to, not when I have a dozen computers right next to it, with much more power and much more convenient UIs...

Yes, people use this - a lot, especially on high end scopes. A separate PC is worthless when you want to access raw sampling data in real-time, which you need to do on the scope itself.

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especially with the XDEV options available for many LeCroy scopes is great as you can write your own software that has full access to the raw data stream of the DSO.
THAT I can get behind, especially for more specific applications(maybe stuff like using your scope for a quick Test Jig that is more complicated than simple masking or something).
But you could just as well do that with VxWorks or even Linux or anything that is more reputable than Windows.

No, not really, at least not unless you reinvent the wheels. Like it or not, Windows is the platform with the by far largest amount of available software.

Also, it's no longer 1999 and we no longer run Windows 98 which admittedly wasn't the most reliable OS, and at least the Windows NT descendants (W2k, WinXP, Vista, W7, Win8/8.1, lets just leave Win10 out of it for now) are rock-solid unless the hardware they run on is shit or the user does something stupid.

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Then again, scopes don't need to be able to run 24/7 for five years straight or anything like that, so the serious stability issues that you might experience on Windows will probably not have any effect at all.

Again, there are no stability issues, unless you introduce some. But then the OS doesn't matter, as you can easily drive Linux or VxWorks against the wall as well.

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Wonder if it is easier to port Windows to the scope rather than Linux or VxWorks.


These days it is, especially when modern high end scopes contain a normal x86/x64 PC.

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Also, I wonder how the choice of operating several platforms(someone stated the WaveJet ran VxWorks, right?) came about...

Older scopes used embedded platforms (i.e. PowerPC for LeCroy scopes), and for those running WindowsNT didn't bring any benefits. Plus VxWorks required a lot less ressources, which in those days were much more limited.

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I agree. Rigol's firmware is much worse than that of LeCroy or Keysight, there's no doubting that. I merely wanted to state that I feel that sometimes, people are a little bit harsh on the issues Rigol has/blow them out of proportion. The problems that cause wrong waveforms are of course absolutely not acceptable, but so far the only one I have seen is the one Dave showed in one of his videos with the AC trigger issue. I don't know if that exists on the somewhat advanced expensive Rigol 4000...

At the end it up to you to say how much these issue matter, but for me they matter - a lot. I don't want that for my small home lab, and in the professional environment I work that simply is unacceptable. Plus the savings aren't worth it.

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Why remove a product that still sells well enough and has earned itself a great reputation amongst its customers?
Why spend money "improving" a scope that still sells well with something that hardly adds any value(or is that another misconception of mine? does the touchscreen add significant value in your eyes?)

For the same reason that Keysight gave the aging DSOX3k a similar facelift - to make a product more attractive and looking a bit more 'fresh' by adding stuff that at the end of the day doesn't cost them much money. And although the real-world value is certainly limited (especially of touch on these scopes) it also (and more importantly) conveys the message that the manufacturer does care about this product and its customers.


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Yes, if you pay list price or buy from resellers. However, LeCroy is pretty keen to get a bigger foothold in the low end scope market, and therefore wants to get the WaveSurfer 3000 out there. There often are very good deals available with the WS3k (while there isn't much for the WaveJet!), and if you talk directly with LeCroy there's a good chance you can get a WS3054 for the same price as a WaveJet 354T.
I did not know that. Will remember it, though, for the next investment - go talk to LeCroy...

However, don't forget that in general stuff in Germany is pretty expensive compared to many other countries, and while I found the US headquarters very helpful and prices (even for spare parts) pretty good, this wasn't necessarily equally true of European pricing. But at the end of the day if you're willing to haggle then it's very likely that you'll be offered a good deal, especially when you accidentally drop the name 'Keysight' in there

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It doesn't. I work in a similar field (although I mostly need MIL-1553 while I rarely touch ARINC429), and when I still worked in Germany (which admittedly has now been a little while ago) the majority of scopes in that field where Agilent and Tek, with LeCroy mostly limited to the high end (i.e. WaveRunner and up). They seem to be even less common here in the UK (probably because Agilent had manufacturing over here), and only when I work in the States I'll see them in larger numbers.
Interesting how our experiences differ in that respect. I worked optical semiconductor testing before getting into avionics and they had some really high end LeCroy gear.[/quote]

Ok, that's a bit different then (I thought you were talking about system design and integration, i.e. building Avionics kit and integrating it into aircraft). And yes, it's true, LeCroy is pretty common in the semiconductor industry in general. I've seen a lot of WavePros and WaveMaster there.

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But in the Avionics market I have seen the low-end stuff quite often. Maybe their campaing to get into the lower end market is already paying off?

Quite possible, although no low-end LeCroy supports either ARINC nor MIL-1553 (the smallest model scope that does is the WaveSurfer 10, which is a mid-range scope).

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A half-well trained HAM radio operator with a little morse knowledge and a speaker would suffice to decode A429 ;)
Forcing those who need it to buy bigger scopes earns you more money, though...

That's not the reason why LeCroy's low end scopes don't do ARINC/MIL-1553. Other than Agilent/Keysight who produce their own entry level scopes (DSOX2k/3k), LeCroy has no interest designing low end stuff, and therefore just buys their entire entry-level portfolio in. The WaveAce (Siglent SDS1000 rebadges) are primitive scopes that don't do any decoding. The WaveJet is bought-in, too, and Iwatsu doesn't see any benefit in adding ARINC/MIL-1553 decode. The WaveSurfer 3000 (which sits between entry level and lower mid-range) only came out a year ago, and while LeCroy produces the firmware for it (hardware is Siglent) and already has added more decoding capabilities (i.e. CAN) there doesn't seem to be enough demand for ARINC/MIL-1553 on the WS3k to justify the costs of adding it (although personally I'd really like to see MIL-1553 on that scope).
« Last Edit: September 08, 2015, 07:14:55 am by Wuerstchenhund »
 

Offline John Coloccia

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Re: EEVblog #790 - Lecroy Wavejet 354 Touch Oscilloscope Teardown
« Reply #52 on: September 10, 2015, 03:51:21 pm »
Actually, a lot of people don't. Why? Because they have been using X brand for decades and their gear has earned their trust for various reasons, so they just buy X brand again. It's a safe bet thing.

Spot on. When selecting lab gear, the most important things to me are confidence and familiarity. I may even have lots and lots of code written to interact with a particular brand of equipment. The edges of the specs don't mean much to me.  If something is really on the edge, I just go one step up and I'm in my comfort zone again. It's different as a small business, as I am now, or as a hobbyist.  Then I'm very keen on things like optimizing cost and performance. At a larger company? If I spend a day exploring different scopes and trade offs, and honestly it would probably take more than one day to really figure it all out, how much does that cost? Engineers are expensive...$150 to $200 an hour billable is pretty common. Who's paying for that? It would be silly to spend $1500+ on overhead when I can just overspend a bit on a scope that will get amortized over 10 years or more of use.
 

Offline LabSpokane

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Re: EEVblog #790 - Lecroy Wavejet 354 Touch Oscilloscope Teardown
« Reply #53 on: September 10, 2015, 04:50:59 pm »
Actually, a lot of people don't. Why? Because they have been using X brand for decades and their gear has earned their trust for various reasons, so they just buy X brand again. It's a safe bet thing.

Spot on. When selecting lab gear, the most important things to me are confidence and familiarity. I may even have lots and lots of code written to interact with a particular brand of equipment. The edges of the specs don't mean much to me.  If something is really on the edge, I just go one step up and I'm in my comfort zone again. It's different as a small business, as I am now, or as a hobbyist.  Then I'm very keen on things like optimizing cost and performance. At a larger company? If I spend a day exploring different scopes and trade offs, and honestly it would probably take more than one day to really figure it all out, how much does that cost? Engineers are expensive...$150 to $200 an hour billable is pretty common. Who's paying for that? It would be silly to spend $1500+ on overhead when I can just overspend a bit on a scope that will get amortized over 10 years or more of use.

Exactly.  The above, plus when you do encounter a problem, the company you "overspent" on answers the phone.  Or even better, as has happened multiple times now to me, this "overpriced" company surfs EEVBlog forums and proactively contacts you when they spot a question.  Those people cost money, and I knowingly chose to pay for their services with my equipment purchase.  They're worth it, and I thank them.   :-+   
 

Offline f4eru

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Re: EEVblog #790 - Lecroy Wavejet 354 Touch Oscilloscope Teardown
« Reply #54 on: November 25, 2015, 12:17:00 pm »
You saw the teardown, now look at the manufacturing :


WARNING : Windows Inside !!
Never Ever design a series product with windows! You've been warned. See the trouble they have to keep it virus free until they ship the unit :)
« Last Edit: November 25, 2015, 12:25:02 pm by f4eru »
 


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