Products > Test Equipment
Show us your square wave
Wuerstchenhund:
--- Quote from: joeqsmith on January 29, 2015, 05:57:56 pm ---Maybe the videos had nothing to do with sudden drop in responses. If I were in sales and made a bold statement how I lost count of the number of EE's who are noobs when it comes to PCs and how making such a change was going to cause all sorts of problems, and then have a customer call me out, I would not handle it by going silent.
Honestly, I never did figure out what they were talking about. I've had no problems with the 1Gb interface to date and never saw a down side to it.
--- End quote ---
Just because you were lucky doesn't mean that such mods are always troublefree. In fact, it might well be that your mod has other side effects you just didn't notice (yet). Just because something looks ok doesn't necessarily mean it is. Also, do you know how many different PCI 1Gbps network adapters exist? And just because you didn't see side effects with one makes you think it will always be allright? Hopefully not.
The simple fact is that these scopes are not designed as expandable systems, and just because you can plug in some PCI card doesn't mean it can be expanded like a standard PC. The scope as sold is the only supported (i.e. guranteed to work) configuration, aside from a few upgrades offered by LeCroy like CPU and RAM (which even if done with generic parts should be pretty painless). And really, it should be pretty obvious to an EE why on a single PCI bus with a theoretical max transfer rate of 133MB/s a 1Gbps network adapter (which in a good environment transfers between 90-100MB/s) doesn't leave much room for anything else. And something like 33MB/s isn't much for an acquisition system which captures over 20GB data per second, and while not everything in the sample memory goes to the CPU, everything that you want to see on the screen or that you want to process in any way does. Well, you do the math.
In addition, the acquisition system in these LeCroy scopes definitely *is* timing sensitive. I've been bitten by this myself when I upgraded my CPU (hint: never enable Hyperthreading on a WP7k(A) or WM8k(A), unless you want to reinstall your OS).
This aside, "just works" isn't really good enough if you want to use your test kit professionally, where people generally want to have something that is supported by the manufacturer and where problems are solved by their support. If you modded your scope most manufacturers simply tell you to piss off, and rightfully so.
Maybe these EE's you were talking about weren't such 'noobs' at all.
I'm not going to ask why you need a 1Gbps network adapter in your scope. The standard intel 100Mbps Ethernet port should be more than enough for transferring data or remote controlling it.
BTW, the Yahoo LeCroy forum is operated by a guy who has nothing to do with LeCroy other than using their scopes (and helping members). In fact, there are only two LeCroy affiliated member I know of, and they certainly don't use the forum as a marketing vehicle. But generally you can expect that the familiars there pretty well know know what they're talking about.
Wuerstchenhund:
--- Quote from: TunerSandwich on January 29, 2015, 06:18:14 pm ---Yes, but that is not a problem for the very specific things I use it for. I.E. checking control signal in SMPS and other (various) low frequency DC-DC applications. However, I would much rather see a true 12bit vertical reading, as I am not 100% sure on what levels of interpolation the ERES might be using....which obviously skews things to some degree or another.
--- End quote ---
There's no interpolation in ERES. You are getting the full 11bit resolution, at the cost of bandwidth. Here's a LeCroy document explaining ERES in more detail (it's from 1999 but still remains valid):
http://teledynelecroy.com/doc/digital-oscilloscopes-enhanced-resolution
--- Quote ---It has been an invaluable tool in catching over/under shoot, that normally would be missed. I would love to see a true 12bit capture, along with a higher sample rate and some reasonable mem depth, for longer power quality captures. That is probably my biggest complaint about the MXi I have. It starts to lose a lot of performance and resolution/fidelity 2 long capture windows. Obviously the PMA and other such utilities suffer because of that.
--- End quote ---
I know that they're working on expanding their High Definition 12bit technology into higher end scopes, I guess eventually all their mid-range and high-end scopes will be 12bit, aside from the LabMaster maybe (which is a different beast anyways). The HDOs are nice but they're essentially WaveSurfers on steroids only. There's also of course the WaveRunner HRO but again 2GSa/s only, and very likely one of the next models to go.
--- Quote ---If I expand the scope of my work (which is happening) the need for higher bandwidth, bit depth and sample-rate (plus mem) is there. I did notice there were some trade-offs in the HDO series. Would be nice to see LeCroy roll some technology into a single package.
I.E.
3GHz
12 bit
deep memory
industry leading sample rate
their excellent Ui/MAUI
bundle some spectral tools (with a dedicated FFT/spectrum button)
--- End quote ---
The button already exist on the WaveRunner 6zi/HDO. But I think that the SPECTRUM option should be standard for WaveRunner and higher models, really.
--- Quote ---all packaged in nice form factor (which I think LeCroy does quite well) for a market leading cost
--- End quote ---
Indeed, LeCroy does the packaging quite well, and often does have some things (i.e. an adjustable widescreen display with pivot mode on the WR6zi/HDO, or the detachable control panel and the dual BNC/SMA inputs on the WP7zi) you just can't find anywhere else.
Cost-wise I don't think they have a problem. LeCroy has been cheaper than Agilent/Keysight and Tek pretty much forever when comparing comparable scopes, and unlike Tek they are very flexible in their pricing.
--- Quote ---AND expand their current probe options.....
--- End quote ---
What do you miss?
--- Quote ---and update Wave studio (not a fan of it's interface, speed, etc...)
--- End quote ---
Well, it's ok for a free program, and while it's slow it still much better than the equivalents from Keysight and Tek. The update rate is difficult to increase as the program captures individual screenshots and not a video stream. If you want faster then just login via RDP. Works like a charm even on XP, and even better on Windows 7 scopes.
TunerSandwich:
What I would like to see them do, is sort of a "best of" from all of their current lines....
screen and interface options from the units you mentioned....12 bit, big mem, high sample rate....keep it in line with the general LeCroy "value model".
would like to see a current probe with more sensitivity and bandwidth at higher current (don't mind paying for that).....or at least update the AP015 to take just a bit more current for that 10 second window and give me 100MHz (and update the deskew process, to be a bit less "clunky"). They just seem to take a big jump from the CP031 to the CP150, with nothing really in between...
on the wave studio front...I would like to see them take a more direct approach, as opposed to screen capture (the current trace tools aren't at all good IMO)....maybe just use a template that looks like the scope Ui and stream data into the waveform and measurement sections (might not be possible, from a processing perspective).....also give us the ability to create new Ui building blocks in WS would be nice. Think of it as just a "customizable skin/bounding boxes" approach, with some blocks that contain a live update on statistics/waveforms.....and the ability to include markers/tags....that would be very useful for reporting.....also a direct "video capture" would be nice and maybe throw in some simple "one click" encoding and uploading buttons, for example a quick HD capture/encode/upload to a vimeo pro account, for sharing etc....obviously all of that can be done to some extent now, with discreet software packages and a lot of hassle....but a "one click" approach would be nice.....
maybe I am expecting/asking too much....
i would like to see all of those features, plus what we already discussed....in an 8 channel scope (modular front end would be awesome....like labmaster....especially external clock gen/sync)....for somewhere under $40k (with some options) maybe under $45k. In this day and age charging what they charge for PMA and spectrum, seems a bit out of line with others....
It would be very cool if someone came up with a more modular way of displaying data....tab view, and the ability to move statistics and waveform windows independently to various screens......AND allow users who have external touch screen monitors to retain the touch capability when splitting out to ext monitor.....and give me 2 ext monitor outs...
joeqsmith:
--- Quote ---Just because you were lucky doesn't mean that such mods are always troublefree. In fact, it might well be that your mod has other side effects you just didn't notice (yet). Just because something looks ok doesn't necessarily mean it is. Also, do you know how many different PCI 1Gbps network adapters exist? And just because you didn't see side effects with one makes you think it will always be allright? Hopefully not.
--- End quote ---
Data is data. Better than dealing with how someone feels it's going to work. I provided info on the board I am currently using. Also tested with a bottom end Star tech card. Saw no problems with it.
--- Quote ---The simple fact is that these scopes are not designed as expandable systems, and just because you can plug in some PCI card doesn't mean it can be expanded like a standard PC. The scope as sold is the only supported (i.e. guranteed to work) configuration, aside from a few upgrades offered by LeCroy like CPU and RAM (which even if done with generic parts should be pretty painless). And really, it should be pretty obvious to an EE why on a single PCI bus with a theoretical max transfer rate of 133MB/s a 1Gbps network adapter (which in a good environment transfers between 90-100MB/s) doesn't leave much room for anything else. And something like 33MB/s isn't much for an acquisition system which captures over 20GB data per second, and while not everything in the sample memory goes to the CPU, everything that you want to see on the screen or that you want to process in any way does. Well, you do the math.
In addition, the acquisition system in these LeCroy scopes definitely *is* timing sensitive. I've been bitten by this myself when I upgraded my CPU (hint: never enable Hyperthreading on a WP7k(A) or WM8k(A), unless you want to reinstall your OS).
This aside, "just works" isn't really good enough if you want to use your test kit professionally, where people generally want to have something that is supported by the manufacturer and where problems are solved by their support. If you modded your scope most manufacturers simply tell you to piss off, and rightfully so.
Maybe these EE's you were talking about weren't such 'noobs' at all.
I'm not going to ask why you need a 1Gbps network adapter in your scope. The standard intel 100Mbps Ethernet port should be more than enough for transferring data or remote controlling it.
--- End quote ---
Certainly if I worked for Teledyne, I would see making a general statement about EE's in this manner in a public forum as pissing my job down the toilet.
I data I presented in the video shows a point to point running 400Mb, no problem. Not sure why your thinking 100Mb on a Gig connection.
Looking at this particular DSO's dead time:
10GS/s, collecting 5Ms requires 640ms. If the PCI bus could handle 60MB sustained, it would require 83ms to move the data or about 13% of the bus BW. Say the Ethernet can move the data at 50Mb/s which is about what I was getting with the built in board. So about 6.25MB/second. Moving 5Ms will require about 800ms.
If we want to handle the data and not miss any of the little data the DSO does happen to collect, the 100Mb won't cut it. At 400Mb/s with the 1G Ethernet, this time drops to 100mS. Maybe enough time to move the data to the modern PC, post process and display it.
At 10GS/s and collecting 200Ks requires 35ms. Staying with 60MB on the PCI bus, it would require 3.33ms or about 9.5% of the bus. The Ethernet transfer would be about 32ms using 100Gb.
The one video I posted showed some of the longer collections. Dead times were several seconds. It's not a bad DSO but you can miss a lot of information with it. It's a pretty common complaint. I have no idea if their new products are better. Where I work we switched to Agilent.
I suspect there are other bottlenecks in this system causing the poor dead times beyond the PCI bus. May put a probe on it at some point to see what is going on.
I can't see calling Teledyne and ask for support on a 14 year old system. I bought this one for home use, not for anything "professional" but I appreciate your concerns.
--- Quote ---BTW, the Yahoo LeCroy forum is operated by a guy who has nothing to do with LeCroy other than using their scopes (and helping members). In fact, there are only two LeCroy affiliated member I know of, and they certainly don't use the forum as a marketing vehicle. But generally you can expect that the familiars there pretty well know know what they're talking about.
--- End quote ---
After posting about the VNA in that forum, I had Teledyne sales contact me using my work email wanting to know who he could contact. Don't kid yourself. They use it for marketing. No big deal. I would expect them to.
TunerSandwich:
--- Quote from: joeqsmith on January 30, 2015, 02:09:01 am ---
I data I presented in the video shows a point to point running 400Mb, no problem. Not sure why your thinking 100Mb on a Gig connection.
--- End quote ---
That is not possible. There is an error in the data/math there. 1Gb = 125MB, with NO protocol overhead....ethernet protocols are going to slash at least some margin off that....if you see 90-100MB full duplex you are lucky, and have a top NiC/cabling etc etc etc....
I have some fancy NAS/SAN devices here at work, running LACP (802.3ad) link aggregations, and top tier controllers, drives, cabling etc....and we are lucky to see a sustained 130-150 MB rate, on large blocks....forget small blocks of non contiguous file headers....that has generally mirrored my experiences in that realm for the last couple decades....
are you confusing MB and Mb? As you can see below Wuer is talking MB and above you are talking Mb....big difference there
Just to clarify are you saying 400Mb on 1Gb ethernet? If that is the case, sure....0.4Gb....but Wuer said 100MB, which is generally accurate on 1Gb ethernet, provided everything is going well and you have large contiguous blocks, with no dropped packets....
--- Quote from: Wuerstchenhund on January 29, 2015, 07:04:46 pm ---
And really, it should be pretty obvious to an EE why on a single PCI bus with a theoretical max transfer rate of 133MB/s a 1Gbps network adapter (which in a good environment transfers between 90-100MB/s) doesn't leave much room for anything else. And something like 33MB/s isn't much for an acquisition system which captures over 20GB data per second, and while not everything in the sample memory goes to the CPU, everything that you want to see on the screen or that you want to process in any way does. Well, you do the math.
--- End quote ---
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