USB-Based Logic (and Protocol) Analyzers [Archive]

Mark_O

Mar 27, 2009, 03:34 AM

BTW, one really nice thing about Joe's Logic unit from Saleae that I should have mentioned...

even though the unit is limited to 24 MHz sample rates (this is a USB constraint), this also makes something very unusual possible. I.e., extremely large capture depths are possible, limited only by the RAM on your PC. This differs from almost all the other USB-LA units, which have their own internal cache of RAM for capturing (sometimes at much higher speeds), but once they're full, they're full. That is, you can only capture bursts as large as their internal RAM. The Logic doesn't have any internal capture RAM (other than the small streaming buffer via USB to the PC).

In the case of the ZeroPlus, that's 32k (they have more expensive units at 64k and much more expensive at 128k), though they do have compression available that can extend that quite a bit. The Intronix also has a memory limitation. But with Logic and a PC, you can capture such a huge chunk of data it can be difficult to find what you might want to see. ;) That's one reason I suggested to Joe last year that he add some post-capture search capability, similar to a virtual trigger, that would allow you to step from one relevant data cluster to another.

So the unit that Alison likes does have one extra unique thing going for it. Plus the PC software is so fast that you can scroll through millions of samples almost instantaneously (dragging the mouse moves it in real-time). That could be a bit mind-boggling, if you're used to the glacial speeds of the Thurlby. :)

- Mark

Mark_O

Mar 27, 2009, 03:41 AM

Thanks, tito.

Yes, I've heard good things about the USBee product line. They have a full range of options, at all price points (affordable to astronomical). Their GUI is also very attractive, similar to the Logic (USBee came first), and I especially like their sidebar display, with a vertical time-stamped list of commands and data (on some models, like the DX).

Also, similar to the Logic, their cheapest USBee SX (http://www.usbee.com/sx.html) (at $139) has 8-data lines, the same 24 MHz max-rate (same reason), samples directly to PC RAM (huge space), and adds a clock input (for State-mode capture up to 16 MHz... there you go, Alison), AND a signal generator output.

It has several protocol decoders as well, but they're nowhere near as well integrated, or as attractive as what Joe has done with Logic. Big win there.

- Mark

10Thumbs

Mar 27, 2009, 04:08 AM

I use the USBee logic analyzer at work. I like the fact that you have voltmeter and DSO features in addition to the logic analyzer. I believe it streams the captured data over the USB so there is no fixed limit on the buffer size.

You can also save traces to files and load them back in later to look at the waveforms.

Mark_O

Mar 27, 2009, 04:16 AM

I'm a little confused about the USBee SX model. On the product page for this unit (their only really affordable model), they show rather bland text windows with the protocol decoder output. All out of context, and separate from the timing displays. They also list a very limited range of available protocols, and their product comparison chart leaves many protocols out for the SX as well.

And yet on the page for their free USBSuite software (http://www.usbee.com/suite.html), they indicate it does work with their SX model, AND supports the full set of protocols, WITH a very fancy integrated protocol analysis display. :confused:

So either I'm missing something, or they're doing themselves a real disservice with their current web-page description of the SX unit.

- Mark

Mark_O

Mar 27, 2009, 04:20 AM

Good points, 10 thumbs. But before anyone gets confused, it should be mentioned that these features are only available on the AX model and up (at $545+).

USBee has models ranging up to $1495, with a wide-range of features.

- Mark

tune by tito

Mar 27, 2009, 06:02 AM

Mark O you are correct with the USBEE SX only few options work with this unit and the suite software, ZeroPlus LAP-16032 logic analyzer is better when it comes to protocols, USBEE when Data buffers storage is very important. LA1034 LOGICPORT LOGIC ANALYZER also have a limited memory, however for the price ZeroPlus LAP-16032 logic analyzer can't be beat!!!!!!!
we need to find some thing in between!!!!!
best regards tito

Alison F

Mar 27, 2009, 07:45 AM

Hi Mark (and all)

Well. I have Zeroplus LAP-16128U on the way. Just won it in an auction for £120.

So...

Mark_O

Mar 27, 2009, 06:12 PM

That's great news, Alison! Now you'll be able to tell all of us what's good and bad about it, without our risking any coin. :)

I'll be especially interested to hear how well it's acquisition front-end works, in terms of getting logic levels right in the presence of noise and ringing. It does have adjustable thresholds as well (+6V to -6V), so it's similar to the Rigol in that regard. Hopefully it's not similar in other ways. ;)

- Mark

Alison F

Mar 27, 2009, 07:18 PM

Well we'll see what it's like in the next few days. You can download the software to try in the meantime. It has a demo trace in it.

http://www.zeroplus.com.tw/logic-analyzer_en/products.php?product_id=19&pdn=3&pdnex=4

When installing do a custom install as it installs some annoying news-ticker which stays on top.

davidgrm

Mar 29, 2009, 05:07 PM

Yes Alison, I am also keen to hear how well it works, seeing that was my other choice. Interesting thing is on the Zero Plus site they dont say anything about Byte Master which has replaced the Zero Plus according to this page "http://www.saelig.com/miva/merchant.mvc?Screen=PROD&Product_Code=LA004&Category_Code=

I have spent the last few days testing the Intronix Logicport an as of yet I have not come across any glitches or similar problems. So far my only 2 complaints are the small capture memory and not being able to trigger on a sequence of bytes.
I have emailed Harrison Young at Intronix and he says that they will most likely not be able to add any new features due to the fact that the FPGA is 90% full.
One feature that the PC app could really do with is the ability to search within the data for a value. Apart from these minor issues I am really happy with this LA and have already used it to solve a few problems in my project that were just impossible to do with the Rigol. The PC software is fast and very easy to use. I would recommend this product although if you dont require as many channels or 500Mhz the Zero Plus / Byte Master might be the better option? Guess we will find out when Alison gets to play with it :) I just downloaded the Zero Byte software and spent a few minutes playing with it. I think I prefer the Intronix Interface. It is a lot more intuitive.

Alison F

Mar 29, 2009, 07:43 PM

Yep. The ZeroPlus interface is a bit complicated to say the least. All sorts going on all over the place. But I guess that's just the learning curve.

Hopefully it'll be tomorrow. :)

Mark_O

Mar 30, 2009, 02:11 AM

David remarked:
> Interesting thing is on the Zero Plus site they dont say anything about Byte Master which has replaced the Zero Plus... <

That's because the ByteMaster is an OEM product, manufactured by ZeroPlus specifically for Saelig. It's the same unit that Alison has on the way, but in a polished metal case, with the indicator LEDs harder to see. No one will have the ByteMaster other than Saelig. Saelig also hasn't indicated whether they'll offer any model other than the more expensive 128k unit ($299). I'd probably opt for the 32k unit, assuming their data compression works well. Vastly more affordable (e.g. $120 at NKC).

BTW, the reason that the ZeroPlus is out of stock everywhere at the moment is that they're getting ready to release a new version, called the Logic Cube, hopefully sometime mid-April, though it could always be delayed. It's in a new, white case, with similar capabilities, from what I've been able to determine. They won a "design award" for it, though I'm not sure why. I'll attach a pic. I liked the look of the old one better, personally. The pricing is expected to be the same. The only new thing I've found so far is that it's possible to stack several modules to get greater sampling width (# of channels).

> I have emailed Harrison Young at Intronix and he says that they will most likely not be able to add any new features due to the fact that the FPGA is 90% full. <

So, what are they saving that last 10% for then? ;)

> I am really happy with this LA and have already used it to solve a few problems in my project that were just impossible to do with the Rigol. <

That's good to hear.

Alison opined:
> The ZeroPlus interface is a bit complicated to say the least. All sorts going on all over the place. But I guess that's just the learning curve. <

I agree. However, that's primarily a result of them wanting to put as many of the settings/controls out on the form, for easy access and adjustment. There's always a tradeoff, though I think they went a bit too far. In actual operation, most of that menagerie of mini icons and readouts can just be ignored.

OTOH, GUIs that bury everything in menu trees, to avoid any appearance of complexity, are a real PITA to use (IMO). I have my own approach to UI design, and I tend to avoid both extremes.

- Mark

davidgrm

Mar 30, 2009, 04:24 PM

So, what are they saving that last 10% for then?

The reason is that if you use 100% then the FPGA software is unable to move stuff around in order to meet the speed requirement. So it appears that they have no plans to fill that space. :(
He did mention that he is working on a new model but it will be more expensive and will not be sold in the near future

Mark_O

Apr 01, 2009, 09:19 PM

Aly,

I'm looking forward to your comments on the ZeroPlus. I've been looking closely at it myself recently, but want to defer my detailed comments until you've had a chance to share yours. My summary though would be: very good hardware capabilities, software has both strong and weak points, and the documentation is its Achilles heel.

- Mark

Alison F

Apr 01, 2009, 10:42 PM

Hi Mark,

It's on it's way. I'm getting the learning curve out of the way first before I post.

You're quite right about the documentation, it's particularly bad. For example, the UART bus plugin. When viewing the documentation you expect to be told what the individual parameters actually do. Instead you are given a layman's explanation of what RS232 is, and it's not that detailed either. The information provided would be all of the pre-requisite outlines prior to even embarking on the project.

The software does in itself seem pretty stable though. Although aspects of it aren't really clear, hence my 'learning curve' comment earlier.

Regarding the UART and for reference. To decode regular RS232 data, I needed to change from MSB>LSB to LSB>MSB, and set the sampling rate to 50%. As to what that 'sampling rate' parameter actually does I have absolutely no idea, only that at the default of 70% I get junk. Also, if I allow the plug-in to auto lock to the baud rate, then the software gets stuck in a continuous loop. It doesn't crash per-se, but you can't stop it, and all you can do is to exit the program. Loading the saved file again locks it into that continuous loop. (yes, I save files and backup..)

The hardware device itself works although is a bit cheap and nasty, although on the better side of cheap, it's not that bad (nothing like the quality of the Rigol though). But on the whole it does seem stable. I've not had any USB device problems as of yet. I'll know more when the host computer goes into suspend and comes back up. That's usually a good way to upset everything.

I'm using a ribbon cable which I made up myself as I didn't want to open up the supplied cables incase I sell it on. At the moment I think I'm going to be keeping it.

But in summary, the documentation is practically useless.

There is ONE nice feature on it though, and that's after you've initially triggered, for it to only record data when a line meets a requirement, ie. high or low. 'enable' is what is called. Routinely when I deveop projects I use a dedicated line to trigger my LA at a specific point, I'll have a line of code which brings the line either high or low, and then trigger on that itself. I'm now able to capture a whole host of very specific data, making best use of the available LA capture depth. My R&S LA has this feature but you practically have to program the thing in a scripting language to get it to do it. With the ZeroPlus it's just a few mouse clicks.

Anything else while I think about it? Oh the assigned colours. They follow standard coloured ribbon cable ordering. I had read on a thread somewhere about someone saying that it followed resistor band ordering and complaining that it was inaccurate. So for the record, the default colours assigned by the software follow standardised colour ribbon cable ordering.

That's about it for the moment I think...

Ahh. The compression feature makes quite a bit of difference. I think it's said somewhere that it's hardware based compression. The 32K model should be more than sufficient. I'm using the 2K mode at the moment, with compression, and the 'enable' trigger feature mentioned earlier. I'm easily able to capture what I need to. One point, it would be nice if the sampling depth went in the order of 2, 4, 8, 16, 32 etc. But it doesn't. I think it jumps straight from 2 to 16, and it's at the lower capture depths where you only want to capture just a little bit more that this becomes an annoyance. Enabling or disabling compression can help somewhat, although 2, 4, 8... would be nice.

Like alot of these 'things' the main core function is there, but it's just the little things and polishing off which is forgotton.

And finally... The 'Intronix' I read about the other night, that looks GOOD. Another USA product. Somewhat the software is always polished off around the edges. The same can be said of Joe's Saleae Logic LA. I'd still be pretty tempted by the Saleae just for the quality of the software.

And in very very very final summary : The documentation is junior school grade. The software is stable and predictable, but not polished off. Apart from those comments the device is fine. It's totally usable. I think I would buy.

Give me a few days to play about some more, but I think for the money it's essentially worth it. Coupled with the Rigol (cue comments in the Rigol thread) they compliment each other nicely.

Phew. :)

Alison F

Apr 03, 2009, 11:15 PM

As a follow up...

I'm getting on quite well with this ZeroPlus it must be said. Contrary to what I said earlier about the software, it is actually very stable. It hasn't crashed once, aside from the continuous loop it gets stuck in when trying to analyse the UART baud rate on occasion.

What I do wish it could do though, would be to dump a huge long .BMP image. But that's just an observation.

It's doing everything that I'm wanting it to do, and hasn't been picking up the spikes seen on the Rigol MSO. I'm currently analysing a Hitachi 44780 4-bit LCD interface. 10Mhz seems to be about right to capture the signals like ENABLE which only last a microsecond. 1Mhz sometimes misses them, which is predictable, since 1Mhz = 1,000,000 so effectively one sample per microsecond.

On first glance the user interface does look daunting and all over the place, but that's just the learning curve. It's ability to display pulse durations in nS, uS, mS is proving useful for meeting manufacturer datasheet diagrams.

I'm rarely going above 16K in terms of capture depth. Compression also makes a big difference. For the most part 2K with compression is fine. 128K with compression and depth at 100Mhz still takes a second or so.

One place where the Rigol does shine is it's ability to trigger on a specific pulse width. The ZeroPlus doesn't do that. Neither does the Thurlby LA4800.

Quite pleased with this it must be said. For $120 it's a bargain.

Mark_O

Apr 04, 2009, 10:10 AM

Thanks for the followup comments, Alison.

I'm glad to hear that it's working out well for you. In particular, I'm pleased that the hardware threshold settings aren't causing any glitching anomalies. Thresholds on the ZeroPlus can be set from -6.0 to +6.0V, in 0.1V increments.

I'm very interested in your comments about compression and memory depth required. That was something I wasn't sure about. I.e., if the lower-capacity models (32k) would be useful, or if the more expensive 64k or 128k versions would be required. I'm happy to hear that's not the case.

> On first glance the user interface does look daunting and all over the place, but that's just the learning curve. <

Yes, there's plenty there to learn. Sadly, that process would be made much easier by a readable User's Manual, which this product lacks. I had to LOL when I noticed sections where an on-screen labeled button or setting was circled in red, and "explained" by repeating the exact same text again verbatim. :( Unbelievably poor.

> 10Mhz seems to be about right to capture the signals like ENABLE which only last a microsecond. 1Mhz sometimes misses them, which is predictable, <

10 MHz sampling is great, if you want to have good resolution on the timing characteristics and phase relationships. However, you could still pick up the presence of the pulses (through not accurate position or duration) as low as 2 MHz. If you supplied the system clock, and ran in synchronous mode, 1 MHz would then be adequate.

> For $120 it's a bargain. <

Agreed! I find it interesting that such a product, at that price, can outperform (in terms of reliability of readings) the similar 16-channel, 200 MSa/s LA side of the Rigol scopes, which adds as much as $800 to some models. The acquisition hardware is apparently of a much better design.

Especially when you consider that at that price it also provides half a dozen serial protocol analyzers, which the Rigol can't do even one. Though if you happen to be Werner, that's not quite true. ;) Since it doesn't have compression, or synchronous clocks (State-mode capture) it's good that the Rigol has 32x as much memory.

- Mark

davidgrm

Apr 04, 2009, 05:10 PM

I emailed Harrison @ Intronix about how many samples need to be the same before the compression kicks in. I pasted his reply below, this is might be the same as how it is done in the Zeroplus. It is interesting reading Alisons feedback regarding the Zeroplus and comparing them to the Intronix. They both seem to have their strengths and weaknesses. The Intronix can trigger on a pulse of a specific width or which lasts a certain number of samples.
Harrison Young from Intronix said:
The benefit begins with the third consecutive unchanged data sample. Any
number up to 17179869184 consecutive equal-valued samples consumes just
two memory locations (one for the value, one for a time stamp). However
any two sequential samples which are not equal will also consume just
two memory locations since no time stamp is needed

Alison F

Apr 04, 2009, 05:36 PM

Wow. A company which actually understood the question, and gave a meaningful answer. :)

Alison F

Apr 04, 2009, 09:19 PM

Here's an Export dump from the ZeroPlus software. The only graphical dump outputs the current display area.

What you see below is the initialisation sequence for a Hitachi 44780 LCD display module. The actual export data is cut down to only show actual data changes, ..failing to do this results in a 15MByte text file. This is achieved by an option when dumping.

I suggest that you cut and paste this data, ...actually... Here I'll attach it too.

TRIGGER is a line that I set aside, specifically to monitor an event via firmware.

// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

// Thanks for using ZEROPLUS Logic Analyzer

// Version:V3.03.04

// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

//Filename: a.txt

//File size:8 KB

----------------------------------------------------------------------------------------------------------------------------------

// File created on: 2009/04/05

// Logic Analyzer setup information

// Sampling mode:Compression

// Internal sampling frequency = 1000000 Hz

// RAM size = 2KB

// Use Data Compression.

// The number of Bus = 2

// The number of channel = 8

// Trigger Properties: Trigger position = 10%

// Trigger level: ||A Port = 1.50 V ||B Port = 1.50 V ||C Port = 1.50 V ||D Port = 1.50 V

// Trigger count = 1

// Trigger page= 1

// Enable setup : Enable Qualifier lengthens or shortens: no

// Delay time: Disable

// \"H\" stands for the signal of high pattern, \"L\" presents the signal of low pattern and \"X\" means don't care.

// Signal Trigger setup : \"D\" stands for don't care, \"H\" presents high pattern and \"L\" means low pattern.

// \"R\" means Rising Edge, \"F\" presents Falling Edge, \"E\" stands for Either.

// The display and trigger setup of Bus: According the character of the original file to present.

// The display of message: Total: 480.457ms Scale:4.096ms Compression rate: 234.598

Keeping the settings is essential to reproduce channels and Buses.

--------------------------------------------------------------

// Channel name:| LCD *DATA4 *DATA5 *DATA6 *DATA7 ENABLE R/S TRIGGER | Bus1 *TX

// Enable: | X X X X X X X X | X X

// Trigger: | X D D D D D D R | X D

//Sieve out the display of the data.------------------------------------------------------------------------------------------------

The style of the Data's display of Bus is Binary.

A Bar position: -014.362ms T Bar position: 0ns B Bar position: 64.742ms

//Channel name: | LCD *DATA4 *DATA5 *DATA6 *DATA7 ENABLE R/S TRIGGER

-014.362ms~-015us(14348) | 1111 1 1 1 1 0 1 0

-014us~-014us(1) | 1111 1 1 1 1 0 0 0

-013us~-001us(13) | 0000 0 0 0 0 0 0 0

0ns~60.63ms(60631) | 0000 0 0 0 0 0 0 1

60.631ms~60.631ms(1) | 0000 0 0 0 0 1 0 1

60.632ms~60.633ms(2) | 0000 0 0 0 0 0 0 1

60.634ms~60.634ms(1) | 0011 1 1 0 0 0 0 1

60.635ms~60.635ms(1) | 0011 1 1 0 0 1 0 1

60.636ms~60.636ms(1) | 0011 1 1 0 0 0 0 1

60.637ms~60.769ms(133) | 0011 1 1 0 0 0 1 1

60.77ms~60.77ms(1) | 0011 1 1 0 0 0 0 1

60.771ms~60.771ms(1) | 0000 0 0 0 0 0 0 1

60.772ms~60.772ms(1) | 0000 0 0 0 0 1 0 1

60.773ms~60.774ms(2) | 0000 0 0 0 0 0 0 1

60.775ms~60.775ms(1) | 0011 1 1 0 0 0 0 1

60.776ms~60.776ms(1) | 0011 1 1 0 0 1 0 1

60.777ms~60.777ms(1) | 0011 1 1 0 0 0 0 1

60.778ms~60.909ms(132) | 0011 1 1 0 0 0 1 1

60.91ms~60.91ms(1) | 0011 1 1 0 0 0 0 1

60.911ms~60.911ms(1) | 0000 0 0 0 0 0 0 1

60.912ms~60.912ms(1) | 0000 0 0 0 0 1 0 1

60.913ms~60.914ms(2) | 0000 0 0 0 0 0 0 1

60.915ms~60.915ms(1) | 0010 0 1 0 0 0 0 1

60.916ms~60.916ms(1) | 0010 0 1 0 0 1 0 1

60.917ms~60.917ms(1) | 0010 0 1 0 0 0 0 1

60.918ms~61.05ms(133) | 0010 0 1 0 0 0 1 1

61.051ms~61.052ms(2) | 0010 0 1 0 0 0 0 1

61.053ms~61.053ms(1) | 0010 0 1 0 0 1 0 1

61.054ms~61.055ms(2) | 0010 0 1 0 0 0 0 1

61.056ms~61.056ms(1) | 1111 1 1 1 1 0 0 1

61.057ms~61.057ms(1) | 1111 1 1 1 1 1 0 1

61.058ms~61.058ms(1) | 1111 1 1 1 1 0 0 1

61.059ms~61.19ms(132) | 1111 1 1 1 1 0 1 1

61.191ms~61.191ms(1) | 1111 1 1 1 1 0 0 1

61.192ms~61.192ms(1) | 0000 0 0 0 0 0 0 1

61.193ms~61.193ms(1) | 0000 0 0 0 0 1 0 1

61.194ms~61.196ms(3) | 0000 0 0 0 0 0 0 1

61.197ms~61.197ms(1) | 0000 0 0 0 0 1 0 1

61.198ms~61.198ms(1) | 0000 0 0 0 0 0 0 1

61.199ms~61.33ms(132) | 0000 0 0 0 0 0 1 1

61.331ms~61.332ms(2) | 0000 0 0 0 0 0 0 1

61.333ms~61.333ms(1) | 0000 0 0 0 0 1 0 1

61.334ms~61.335ms(2) | 0000 0 0 0 0 0 0 1

61.336ms~61.336ms(1) | 0100 0 0 1 0 0 0 1

61.337ms~61.337ms(1) | 0100 0 0 1 0 1 0 1

61.338ms~61.338ms(1) | 0100 0 0 1 0 0 0 1

61.339ms~61.471ms(133) | 0100 0 0 1 0 0 1 1

61.472ms~61.472ms(1) | 0100 0 0 1 0 0 0 1

61.473ms~61.473ms(1) | 0000 0 0 0 0 0 0 1

61.474ms~61.474ms(1) | 0000 0 0 0 0 1 0 1

61.475ms~61.477ms(3) | 0000 0 0 0 0 0 0 1

61.478ms~61.478ms(1) | 0000 0 0 0 0 1 0 1

61.479ms~61.479ms(1) | 0000 0 0 0 0 0 0 1

61.48ms~61.611ms(132) | 0000 0 0 0 0 0 1 1

61.612ms~61.613ms(2) | 0000 0 0 0 0 0 0 1

61.614ms~61.614ms(1) | 0000 0 0 0 0 1 0 1

61.615ms~61.616ms(2) | 0000 0 0 0 0 0 0 1

61.617ms~61.617ms(1) | 1111 1 1 1 1 0 0 1

61.618ms~61.618ms(1) | 1111 1 1 1 1 1 0 1

61.619ms~61.619ms(1) | 1111 1 1 1 1 0 0 1

61.62ms~61.752ms(133) | 1111 1 1 1 1 0 1 1

61.753ms~61.753ms(1) | 1111 1 1 1 1 0 0 1

61.754ms~61.754ms(1) | 0000 0 0 0 0 0 0 1

61.755ms~61.755ms(1) | 0000 0 0 0 0 1 0 1

61.756ms~61.758ms(3) | 0000 0 0 0 0 0 0 1

61.759ms~61.759ms(1) | 0000 0 0 0 0 1 0 1

61.76ms~61.76ms(1) | 0000 0 0 0 0 0 0 1

61.761ms~61.892ms(132) | 0000 0 0 0 0 0 1 1

61.893ms~61.894ms(2) | 0000 0 0 0 0 0 0 1

61.895ms~61.895ms(1) | 0000 0 0 0 0 1 0 1

61.896ms~61.897ms(2) | 0000 0 0 0 0 0 0 1

61.898ms~61.898ms(1) | 1010 0 1 0 1 0 0 1

61.899ms~61.899ms(1) | 1010 0 1 0 1 1 0 1

61.9ms~61.9ms(1) | 1010 0 1 0 1 0 0 1

61.901ms~62.033ms(133) | 1010 0 1 0 1 0 1 1

62.034ms~62.034ms(1) | 1010 0 1 0 1 0 0 1

62.035ms~62.035ms(1) | 0000 0 0 0 0 0 0 1

62.036ms~62.036ms(1) | 0000 0 0 0 0 1 0 1

62.037ms~62.038ms(2) | 0000 0 0 0 0 0 0 1

62.039ms~62.039ms(1) | 0001 1 0 0 0 0 0 1

62.04ms~62.04ms(1) | 0001 1 0 0 0 1 0 1

62.041ms~62.041ms(1) | 0001 1 0 0 0 0 0 1

62.042ms~64.604ms(2563) | 0001 1 0 0 0 0 1 1

64.605ms~64.742ms(138) | 0001 1 0 0 0 0 1 0

Mark_O

Apr 05, 2009, 09:17 AM

David,

thanks for the info on the Intronix compression. They must have one extra bit of memory per sample slot, to flag whether the 34-bit contents are a sample or a timestamp for repeated values. Good way to go.

Aly remarked:
> A company which actually understood the question, and gave a meaningful answer. <

True, but his info contradicts the Specs on their website, which indicates maximum compression is 2^33, not 2^34. I'd tend to believe him though, since a meta-bit is required, leaving all 34 channel bits to be used for the counter. That's asuming the counter is unsigned (and I can't think why it wouldn't be). Otherwise, the 2^33 limit would kick in.

David theorized:
> this is might be the same as how it is done in the Zeroplus. <

Similar, possibly, but the ZeroPlus only compresses runs of up to 255 duplicates. So the Intronix is more powerful. Of course, they also handle 34 parallel channels of data, vs. just 16 for the ZeroPlus.

OTOH, Intronix has a fairly shallow buffer, and handles a max of 2k samples (+possible compression), vs 32k (or 64k, or 128k) for the ZeroPlus. So ZeroPlus is more generous with buffer memory. Part of the reason being that their max sampling rate is 200 MSa/s, while Intronix does go to 500 MSa/s, so their memory chips would be more expensive. Lastly, the Intronix only allows compression up to 200 MSa/s. Beyond that, they do no compression (so that 2k will go _really_ fast at 500 MSa/s! :) (full in 4.0 uS flat!)

- Mark

Mark_O

Apr 05, 2009, 09:38 AM

I wrote:
> the ZeroPlus only compresses runs of up to 255 duplicates. <

Maybe, and maybe not. Based on the sample output that Alison posted, I see repeated runs up to 14348 samples. That still may be limited to 255 per run, with the 14348 continguous samples reported actually using 57 sample slots.

I just felt I should point out that I don't know for sure precisely how ZeroPlus does their compression. But the reported "Compression rate: 234.598" is consistent with using 57 sample slots for the huge run.

- Mark

davidgrm

Apr 05, 2009, 11:13 AM

Mark wrote
Intronix does go to 500 MSa/s, so their memory chips would be more expensive.
I read somewhere that the memory they use is all internal to the FPGA which according to Harrison is an Altera Cyclone1
Also regarding the 500Mhz. According to what he has told me in emails and the fact that it is a Cyclone1 I reckon that they are sampling on both the negative and positive edge of a 250Mhz clock. This also explains why certain operations such as the hardware duration measurement only work to an even number of samples.
Of course where this device has a big edge over the Rigol is that it allows you to sample in state mode using an external clock. So on my circuit running @ 27Mhz it requires much less memory than the Rigol sampling @ 200Mhz. Also with more trigger options you can narrow down the amount of data required. I assume that these last two points apply equally to the Zero Plus LA

Mark_O

Apr 11, 2009, 08:34 AM

After looking closely at the information available on the new "Logic Cube" (which is not a cube in any way, shape, or form :confused: ), it looks to me like its capabilities and features have not changed in any way. I guess we'll have to wait until later this month, or next, or the one after that, when they are finally shipping, to be able to tell for certain.

But other than putting it in a plain white plastic box with square edges, and making both the visibility of the indicator lights and the actuating controls less usable, I can see no other changes. For this, they won a "Design Award". :eek:

The older model, which Alison has, locates its indicator lights on the edge, which are easily visible whether the unit is standing up or laying flat. Unfortunately, the older units aren't available anywhere at this point (all sold out), except a few premium-priced 16128 models.

- Mark

Mark_O

Apr 11, 2009, 08:44 AM

The main disappointments for me w.r.t. the ZeroPlus are in the software. Beyond the learning curve and the poor quality of the User Manual, apparently it's not possible for an owner to either create their own protocol decoders, OR modify the existing ones.

While you can change some of the superficial visual characteristics (size, colors, etc.), it doesn't appear to be possible to change either the packet splitting or the labeling of the data. For example, with the CAN decoder, it displays the ID field as either an 11-bit or a 29-bit number... which is basically useless. 11-bit (Standard ID) CAN protocols like CANOpen and ISO-15765 break that field down into meaningful components, and 29-bit protocols like J1939 split it into Priority, PF, PS, DestinationAddress, etc. sub-fields.

This type of thing shouldn't be all that difficult, but it's not available on the ZeroPlus, which makes it a lot less useful in my book. Also, some of the information fields that ARE displayed (like IDE, SRR, etc.) don't actually show the data value for that field! If you look at the list view with the packet breakdowns, they just list the value of SRR as "SRR", which does nothing besides waste space, and make the line longer so it wraps. Also, for data fields with a limited number of possible values, it would be extremely helpful to be able to supply a list of labels, with mnemonic names for the values (commands, etc.). Which is also not possible. :(

So, some definite room for improvement on the protocol decoders. And disappointing to me personally, because I was hopeful they did a better job in that area. These deficiencies don't make it unusable, but it's a lot less comfortable when you have to manually do decoding and analysis by hand that would be trivial for the computer to handle.

- Mark

Mark_O

Apr 11, 2009, 08:53 AM

P.S. My comments and evaluations are based on my reading of the documentation for the product. I.e., I don't actually have one here to test. So if someone who does (Alison?) can correct me on any of the above comments, I'd be delighted to hear it.

- Mark

Alison F

Apr 12, 2009, 08:30 AM

You can change the field (channel) name.

You're totally right in terms of the BUS analysis being restricted. You get what you're given and that's about as far as it goes. I don't have the ability to analyse CAN here. Only the basic four which come with it. RS232, 7 Segment, SPI, IIC.

Which brings us back to Joe's offering, given that it's practically open source.

The ZeroPlus I would go for IF you can get it for the $120. That I think is a worthwhile price. But anything above that is just a rip off. It's good, but it's not that good.

http://microcontrollershop.com/product_info.php?products_id=1322 . They want $399. It's no way worth that.

If you can get the 32K version for $120 or thereabouts then get it. In that case I'd spend the money.

davidgrm

Apr 12, 2009, 10:08 AM

Just buy the Intronix - does CAN in all standard formats lol
The buffer is not too restrictive due to the compression. I have managed to capture a few hundred K of data into the buffer ... all depends on the speed at which the data changes.

Mark_O

Apr 12, 2009, 01:44 PM

Alison wrote:
> You're totally right in terms of the BUS analysis being restricted. You get what you're given and that's about as far as it goes. <

Thanks for the confirmation. That's a shame.

> I don't have the ability to analyse CAN here. Only the basic four which come with it. RS232, 7 Segment, SPI, IIC. <

Well, even in the case of RS232 or SPI, user customization would be valuable. Let's say you were looking at SPI bus communications with an Atmel Flash memory chip, or a hard-disk controller. Wouldn't it be quite helpful to be able to assign a list of mappings from a numeric constant to a mnemonic label, for say a command field?

> Which brings us back to Joe's offering, given that it's practically open source. <

I'll likely re-evaluate that, based solely on that capability. However, while it should work well for CAN, I don't think it's going to handle SPI data at 10 MBit/s very well, since it can neiher sample fast enough to provide a good capture, nor have a clock input to allow for synchonous (State-mode) captures. I'd want anything I bought to be able to handle the full range of serial busses I use. The ZeroPlus should handle SPI up to ~50 MBit/sec. in Timing-mode (asynch) or 100 MBit/sec in State-mode (synch), vs. about 6 MBit/sec for Joe's Logic unit. 6 MBit is too slow for my needs, which I believe is one of the reasons I dropped it initially.

- Mark

Mark_O

Apr 12, 2009, 01:51 PM

David suggested:
> Just buy the Intronix - does CAN in all standard formats lol <

That's not a bad idea. The Intronix unit appears very capable, though still providing no SDK for user customization, nor ability to define new protocols. :(

> The buffer is not too restrictive due to the compression. <

That was something I had been concerned about, and I appreciate your confirmation that the compression makes it very viable. That's good to know.

But to be honest, almost $400 is more than I'm willing to spend. I'd definitely never spend that much on a device without extensibility to define my own protocol decoders, and tweak the existing ones. I'm really looking for solutions in the $200 and under range.

Which brings us to the USBee products, specifically the SX model. I'll follow up on that later.

- Mark

davidgrm

Apr 12, 2009, 04:08 PM

I agree that it would be great if you could define your own protocol. I am not sure why Intronix don't give the capability to write your own data processing DLL. They dont seem too fussed about people using multiple copies of their software, in fact they suggest it. They are after all into selling the hardware. If only they realized that they would sell more hardware if they allowed users to customise the software.
The Intronix is quite flexible with regards to the protocol interpreters. This for example is their UART interpreter set-up:

Mark_O

Apr 12, 2009, 09:01 PM

David,

yes, good stuff. Thanks for the rs232 Settings example. I've played with their LogicPort demo software and I like it a lot. I liked their time-stamped State List as well. Though the CAN examples I saw were rather simplistic, and I saw no way to display the ID field as anything other than a raw 29-bit value. That's not going to work for J1939, amongst others.

- Mark

Mark_O

Apr 13, 2009, 12:11 AM

The USBee SX unit is an 8-channel USB/computer-based LA module, similar to Joe's Logic unit, which uses the memory of your PC to capture and store up to hundred's of millions of samples. It also shares the 24 MSa/sec capture ceiling, and is priced at $139, direct from the manufacturer.

It goes beyond in that it adds an external clock signal input, so it can operate in synchronous (State-mode), as well as asynch Timing-mode. It can be clocked up to 16 MHz in this configuration. It also adds an extra output channel, which can be used to trigger a DSO, to observe analog signals in parallel with the digital. In fact, ALL of the channels can be reversed from inputs to outputs, making it a high-speed pattern-generator, enabling things like playing back a captured sequence!

The company recently expanded support in their USBee Suite software package to incorporate all their modules, including the SX unit. This has a very classy looking UI (shown below), and already supports at least a dozen protocols for serial data analysis (SPI, I2C, I2S, Serial, CAN, USB, Async, 1-wire, PS/2, and a few more). Lastly, it also adds an side-bar time-stamped Event list, with vertical scrolling and matching color-coding for quick visual correlation.

The software is under active development, and will soon incorporate their Packet Presenter module, which allows complete user tailoring of the protocol decoders, as well as creation of new decoders for other protocols. That's the only fly in the ointment, since they don't plan on making the PP module available for the SX hardware. :( To get that capability requires stepping up to their AX module, at a hefty $545. That unit does add an extra analog input, for 1-channel DSO functionality, which an end-user may not need or want. But it does allow fully integrated MSO capability (both in a stand-alone App, and the USBee Suite), and a DVM.

Their website (http://usbee.com/sx.html) has lots of additional information. They also offer a Buy it and Try It, with a money-back guarantee. It's a pretty impressive unit, and if they were going to include the PacketPresenter capabilities I'd grab one immediately. I may still give one a try, in spite of the limitation of not being able to customize it, which none of the competition even offer as an option at any price.

- Mark

Mark_O

Apr 13, 2009, 12:51 AM

I should probably also mention that you can download and try out the USBee Software here (http://usbee.com/suite.html) in Demo mode, without even having any of the hardware modules. That way you can avoid paying non-refundable shipping fees if you don't need to see it in operation with your actual data.

- Mark

Mark_O

Apr 13, 2009, 11:32 AM

Also, it bears mentioning that unlike having an SDK or a DLL, where you have to write code to create a new protocol handler or tweak an existing one, the USBee Packet Presenter provides a simple descriptor-based definition "language".

So there's no code to write or compile. Just modify a simple text-file containing the description and reload it. Very easy, very powerful, and very fast.

- Mark

Mark_O

Apr 23, 2009, 02:58 AM

I just learned from CWAV that the USBee Suite will be adding a new capability usable on the SX module that will increase its flexibility substantially...

> For the SX (as well as all the USBees), we are adding an API that will allow you to create your own protocols and draw on the USBee Suite screen. This will fit what you need, and it should be out soon. <

This is exciting and impressive news, since having that ability will open the doors to being able to customize the displays and protocol decoders to handle just about anything. I've got an SX module on order, and will report back once I see what the new API is capable of.

I don't know what "soon" means, but the above posting was made 7 weeks ago, so hopefully it won't be much longer.

- Mark

Mark_O

Apr 23, 2009, 03:01 AM

BTW, the little $139 SX module can handle asynch protocols up to 6 mHz, synchronous protocols (like SPI) to 12 MHz, and externally-clocked protocols at 16 MHz. It can also capture hundreds of megabytes of samples, PC memory permitting.

- Mark

Mark_O

Apr 23, 2009, 03:25 AM

Alison summarized the ZeroPlus with:
> Quite pleased with this it must be said. For $120 it's a bargain. <

While it does have some significant limitations (that I enumerated a page or so back), I think for that price it is a good deal. Even better when it includes 6 free protocols (4 standard, plus 2 of your choice) for $108. That's the promo-price over at NKC Electronics (http://www.nkcelectronics.com/zeroplus-lap16032u-logic-ana16032.html), "Available Last Week of April 2009. Pre-order promotion will be over once we start shipping the product."

I think with 16-channels, 100 MHz asynch capture (75 MHz synchronous with external clock), and 32k +compression, that's a great deal. This is for their new white-box Logic Cube version. With US shipping at $13, I figured I could afford both, so I've placed an order for this unit as well.

- Mark

gfiber

May 16, 2009, 11:37 AM

I figured I could afford both, so I've placed an order for this unit as well.

- Mark[/QUOTE]

Did you ever order both the USBee and the Zeroplus LA?
If so and you received them how do you like them? One stand out over the other?

Gary K8IZ

Mark_O

May 17, 2009, 03:32 PM

Hi, Gary.

Yes, I did order both, and received them reasonably quickly. Good marks on delivery for both companies (USBee direct, and NKC Electronics). I've only spent a limited amount of time with each unit, but I'll share a couple comments...

> One stand out over the other? <

So far, I like the USBee SX better. What I've been using it for (serial comms analysis for SPI and CAN, and GPIO control signal monitoring) fit within its range of capabilities (8 channels, 24 MHz sampling). It's very easy to use, though there are improvements I'd like to see in the software.

The triggering is very primitive (a rising or falling edge on a single channel), but it can capture a huge amount of data. The problem then becomes finding the needle(s) in that haystack. I've requested a Search/Find capability, that would allow specifying a set of conditions, then letting you jump Fwd/Back to each match. That would be a huge win.

Unfortunately, the company has failed to respond, which I found somewhat surprising. I've posted requests and suggestions on their on-line Forum, and received no acknowledgment at all. I'm also very interested in getting my hands on their upcoming API (available "soon"... two and a half months ago) which will allow customizing the protocol handlers and displays, and have likewise received no reply to my inquiries there either. So that's been disappointing. Perhaps they're swamped or on vacation or something, because that's not what I've observed from them in the past (they've seemed "customer-friendly").

My disappointment on the Zeroplus LA was a lot more immediate. As soon as I opened it, I discovered they had turned this into their "economy model", with all "frills" stripped out. I.e., no padded carrying case, no printed manual, etc, etc, and no grabber clips. I.e., just the bare leads. Since I didn't happen to have a spare set of 20 micro-grabbers lying about, I had to place another order with NKC to get a set, and spend another $25.

I don't want to knock the retailer on this, especially since that's the best price I've ever found on a set of micro-grabbers like this. Basically a buck a piece, when usually I have to scrounge them up on eBay for $2-3 each. And the bonus is that they're 2 sets of 10-color-coded grabbers, which match the channels on the LA. But the fact is that I wasn't expecting this, which delayed my being able to use the Logic Cube by 10 days, and cost me more than I was expecting to spend. If I'd known in advance, I could have saved the extra shipping charge $$$ and time.

The software, as Alison already commented on, is fairly complex to use, and the documentation is atrocious. But it does work, and if you need more than 8 channels, the 16 on the Logic Cube are a win (I've used up to 12, so far). Also, the higher sampling rate is a big plus when looking at MCU signals, especially on a 66 MHz ColdFire 32-bit processor ($8) I started working with recently. I haven't decided yet which 2 "free" bonus protocols I want to enable. It will likely be CAN and something. They really should rewrite their docs in English though, because the current Chinglish set will drive potential customers away.

Physically, the Logic Cube, IMO, is worse than the older LAP model in every way (buttons, readouts, form-factor, no vertical-stand, etc.), but that doesn't affect its actual operation. For those applications where I need more than 8 channels or am working with signals requiring higher than 24 MHz sampling rates, the Logic Cube will clearly be the superior tool. Also, when I need to deal with anything other than strict 0-5V signals (which the USBee SX is limited to), the variable thresholds (+/-6V; +/-30V tolerant) on the LogicCube stand out. [The hysteresis levels on the SX are locked at +1.4V/+0.8V. And I don't see that it has ANY tolerance for voltages outside 0-5.5V... so it may be possible to accidentally destroy with excess voltages.]

Even with the extra cost for the grabbers factored in, the ZeroPlus price is still pretty amazing. Twice the channels, 4-5x the bandwidth, and 64 kB of high-speed sample RAM, vs. none. All for the same price as the SX. Each has its strong points, is a powerful and economical instrument, and I'm glad to have both in my tool kit.

- Mark

P.S. The SX comes with 12 standard protocols, and will (someday) allow the user to define as many additional protocols as they need (plus modify existing ones?). Their USBee Suite software is being actively improved, with several updates a month.

The ZeroPlus comes with 4 standard protocols, plus 2 more free ("for a limited time"). After that, they're $70 for one, or $100 for 3, with no user-defined protocols possible, nor ability to customize existing protocols.

darkith

Jun 24, 2009, 09:10 PM

Man, I'm on the fence on this one. I'm looking for a low-cost LA for SPI, Async, maybe a little I2C...but room to grow would be nice.

I like the Zeroplus for it's high speed capabilities (don't need it now, but may in the future), 16 channels, higher voltage tolerance (keeps the smoke in place). The cost of adding protocols kinda sucks though.

I like the USBEE-SX for the wide protocol support, signal gen, and the "big vendor, will have support for a while" feel. But I worry that the 24Msps will be too limiting.

I like the Saleae Logic for the openness, and (hopefully soon) Mac/Linux support. But I worry that Saleae might be facing stiff competition from the USBEE-SX (which was ~$250 until the Logic came out) and that they might not be there to support it. :(

A L.A. with decent high speed capabilities (higher than 24Msps), 16 inputs with voltage tolerance, and a decent quantity of protocols (or an interface for self-defined) would be awesome, but I haven't seen one. (And a Mac/Linux client seems pretty remote)

Anybody see any flaws in my conundrum?
D.

Mark_O

Jun 25, 2009, 07:47 AM

darkith,

every available option will have it's own strengths and weaknesses. Asking for one device that has them all is just dreaming, because some characteristics will be diametrically opposed. Low cost, for example, vs. a boatload of fancy features.

However, based on your requirements (needs/desires) for a) high speed, b) more than 8 inputs, and c) variable thresholds, I'd say the ZeroPlus would make the most sense for you. All that, plus a full set of leads, bundled with 6 protocols, for $150, and 3 more protocols down the road for $100, when you're ready for them.

Due to the nature of the beast, any unbuffered USB device is going to be limited to ~24 MSa/sec rates. And unbuffered is the only way to achieve 'cheap'. As much as you might like either of those options, for the reasons stated, it sounds like they won't meet your longer-term needs.

If cost isn't so much of an option, the LogicPort by Intronix is an excellent unit, as David has commented. 500 MHz sample rates, 34 channels, state-mode option, variable thresholds, compression, and a good selection of protocols. For $389.

- Mark

darkith

Jun 25, 2009, 12:23 PM

Yeah, the Zeroplus looks like a really good option. It hits the cheap price point initially (especially surprising given it is a buffered high-speed device), and then the expandability is there, though the protocols do up the cost.

How does the Zeroplus handle signals it doesn't recognize/have the decoder for? I assume it just doesn't do the nice on screen decoding into recognizable commands/values?

D.

Mark_O

Jun 25, 2009, 08:28 PM

darkith asked:
> How does the Zeroplus handle signals it doesn't recognize/have the decoder for? <

Well, you can still display them as normal logic traces, and likely see the packet structure, even though there's no decoding/interpretation. If you use a wrong decoder (one you have), it will attempt to interpret it, with obviously bogus results.

> ...surprising given it is a buffered high-speed device), <

Yes, and coupling that 16k buffer with compression means it's highly unlikely you'll ever have any trouble finding what you're looking for. The $400 LogicPort's buffer is only 2k deep, but with its compression I've never heard any complaints.

- Mark

Jan Rune

Jul 01, 2009, 05:22 PM

Interesting thread.

I decided upon the Zeroplus Logic Cube LAP-C 16128 after a few good reviews around and especially this one.

Will let you know what i think when i do get it...

shoutchen

Jul 08, 2009, 09:22 PM

FYI,

I have a barely used intronix logicport for sale if anyone is interested.

SteveH

Mark_O

Jul 08, 2009, 10:22 PM

Steve,

you'd probably generate more interest if you listed an asking price.

- Mark

shoutchen

Jul 08, 2009, 10:44 PM

All,

Last September,
I spent about 510.00 for the 1034 analyzer with input connector probe, a set of 38 ez hooks.
and a extra input connector probe and usb cable.
and shipping.

Best offer over 400.00 USD ships it to lower 48, paypal only

SteveH

Mark_O

Jul 21, 2009, 09:08 AM

USBee finally did come through with their API, which allows users to create their own analyzers for custom protocols on the inexpensive SX module. It's fairly straightforward, and does work, though I was a bit surprised they left a lot of the parsing burden on the end-user (actually, all of it). I.e., you'll have to write your own bit-scanning code to extract bits, bytes, fields, and frames from the raw data stream.

But it does allow full access to the captured data (all 8 channels), so you can see everything there is to see. And on the output side, pass interpreted text strings back that get fully integrated into the on-screen display, synchronized at the proper time points, just like the dozen standard protocols they include.

The most primitive aspect is the UI that allows the User protocol handler to be configured... just a text string that gets passed to your handler. But that is flexible enough to let you define just about anything you might want, including multiple protocols if you need them.

Their updated User Manual contains good information on writing your own analyzer, along with some sample code examples in Visual Basic. I'd say it's a very good first version, and if it gets supplemented with a small library of bit-scanning/packet parsing routines, it could be easy to use, as well as very powerful.

So kudos to the guys at USBee for making good on their promise to make a user-accessible API available, even on their low-end $139 SX acquisition module. Combined with the excellent UI on their USBee Suite software, which makes for easy navigation and display, it's a powerful tool.

- Mark

Mark_O

Jul 23, 2009, 09:01 AM

bigandy recently started looking at serial protocol analyzers, and the Saleae unit in particular (http://www.rcgroups.com/forums/showthread.php?t=1082893). He's looking at it in contrast to the USBee SX unit. So I thought I'd post a bit of direct comparison here, based on the latest versions of both products. As an experiment, I've gone back through and put the strong points for the USBee Suite in red, and those for Saleae Logic in blue.

Both are solid hardware/software solutions, with very similar architectures, PC interface (USB), and limitations (8 data channels, 24 MSa/s). The SX is a bit cheaper, while providing mostly a superset of what the Logic can do. Hardware-wise, it adds both an external-clock input, which makes synchronous state-mode capture possible, as well as providing both a trigger output (say, for syncing a scope), and making all 8 signal lines bi-directional, so they can optionally generate outputs as well as sense inputs (or be used to play back previously recorded signals). This capability is fully supported in their older legacy software (still downloadable), but is not yet available in their fancier USBee Suite.

On the software side, the Suite for the SX has several advantages: color-coded signal traces make it easier to differentiate signals, vs. the all black & white of the Logic. Plus the window is vertically resizable, as well as horizontal, so the traces can be made quite large and visible from a distance, vs. the fixed (small) height on the Logic. And an overview bar at the top of the panel both shows which subset of the captured data is currently being displayed in the main window (where am I?), and allows the viewport to be moved quickly to any position therein.

It also moves the meta-data panel out of the way (timing measurements, etc.) to an area at the bottom of the screen, while Logic has this data right on top of the traces, obscuring the rightmost part of the bottom 4 channels. The Suite for the SX also has a color-coded vertical event-list panel, which shows time-stamped protocol messages (sync'ed with the data traces to the left), that Logic lacks. And the pre-trigger point is set much more naturally by setting a relative point at any percentage of the capture buffer, while Logic has a menu allowing a fixed set of points to be specified (e.g. 10k, 100k, etc.) Lastly, the SX Suite supports 12 protocols internally, vs. 4 for the Logic.

OTOH, Logic provides a Session Save and Restore capability that is very useful, while the SX Suite can only export data in a variety of formats. Session capabilities allow for a complete reconstruction of all capture settings and display options. Good stuff. Logic is also much, much smoother in display updating and manipulation. Both products allow you to just grab the data area and drag it left/right to scroll, but Logic is a joy to use... super smooth and instantly responsive, while the SX Suite takes some time to "catch" and its updates are slow and clunky by comparison, even on a fast CPU.

Lastly, the triggering capabilities on Logic are vastly superior. While the SX Suite is limited to selecting either a rising or falling edge on a single channel, Logic allows up to all 8 channels to participate in the trigger-matching process, and for a full 4 sequential bit-states. I.e., you could specify a trigger as the sequence 1,0,-,1 on channel 1 ("-" being Don't Care), while channel 2 was 0,1,-,-. Along with any other combination of the remaining channels. Powerful stuff.

The only thing that really saves the SX Suite here is that both units can capture so much data that catching a specific trigger point is usually not that critical. However, that's also an Achille's heel, since both can capture millions of samples, but neither has any Search capabilities to allow locating desired or interesting sequences post-acquisition. So you're left to manually scroll through and visually search for relevant patterns in the data stream. :eek: Hopefully both will eventually incorporate this much-needed capability.

Lastly, both products now have an API that allows end-users to create custom decoders for their own protocols, when required. While both are usable, the USBee Suite is much simpler overall, and easier to use, without sacrificing any flexibility. The Logic API is more complex and harder to use, and provides virtually no documentation or discussion (USBee does a great job there). But as one strong point, Logic provides much better examples, with source code for a real-world serial protocol included. This is much more useful than the toy example that USBee includes, leaving all of the parsing and analysis work up to the end-user, with no significant example to start from.

Both products seem well-supported by their respective companies, with fairly regular updates (the USBee Suite just had 3 updates in the last week!, after several months of external inactivity while the user protocol capability was being implemented), and online Forums for discussion and questions.

I hope this helps you out, Andy, as well as anyone else looking for a similar solution. Let me know if the color-tagging makes it less readable, and I can nuke it.

- Mark

bigandy

Jul 23, 2009, 09:47 AM

HI Mark,

That is just fantastic, cheers! I don't think I have ever received such a comprehensive reply to a "what would you buy" type question!

It all makes sense to me, and your post sort of aligns with what I have started to identify as the pros and cons (from just looking at the software demos). One thing that I think has sold the USBee Sx for me, is the ability to turn it into an output generator :)

One thing regarding the triggering of the USBee Sx. I noticed when having a mooch around the old logic analyser software (not the newer suite) was that there are four boxes for selecting the bit states for a sequential trigger. I was assuming that this would work with the USBee SX hardware? Your comments suggest otherwise? I can see that facility being rather useful for me, so to not have it available is a bit of pain really. I know in the USBee suite software, the triggers are only available for single bit sequences at present.

Cheers
Andy

PS. The colours are really useful :)

Mark_O

Jul 23, 2009, 12:14 PM

bigandy commented:
> I noticed when having a mooch around the old logic analyser software (not the newer suite) was that there are four boxes for selecting the bit states for a sequential trigger. I was assuming that this would work with the USBee SX hardware? Your comments suggest otherwise? <

You know, you're absolutely correct, Andy! I had looked at the info page for the SX several times before I bought my unit, and did notice the capabilities of the separate Logic Analyser and Generator tools, but I've never actually used them. The older software for the SX does indeed support the more extensive triggering capabilities (4 states on 8 channels). Which is just as powerful as the Saleae Logic unit. In addition to that, it also supports a post-acquisition Search capability (Next and Previous), based on those same Trigger settings, that is extremely useful (that Logic does not have).

My apologies for not pointing that out, when my comparison efforts focused on the new Suite software (where all the new development is). Obviously, not all of the legacy capabilities have migrated yet into the Suite, but I see no reason why we shouldn't see them there at some point. I'm happy to see them employing a phased implementation approach, where we get the basic capabilities sooner, and the rest in stages. Much better than waiting a year or more with nothing, then getting it all at once. For now though, the two older Tools (last updated in 2000) will still be required to take advantage of some of the functionality that the SX hardware offers.

There were a couple other reasons why I tended to overlook the 2 separate Tools, beyond simply their age. No software is provided with the SX package, and it all needs to be located on the website and downloaded. This wouldn't be so bad, if things were better organized there. The actual software Tools you'll need for this are located in a download called "sxdemo.exe". Sorry, but it's not obvious to me from that, that this is the actual (and only) release tool file for use with the SX.

Then, after downloading and installing that package, when you go to the Help screen... none of the buttons work. That's because no Help files were downloaded. After scratching your head for a while, visiting the online Forum will reveal that "oh, the SX help is the same as the ZX help, so just download the ZX_Helpfiles.zip", or words to that effect. How obvious!

Unfortunately, after having done so, and unpacking the 170 MB! of help, contained in a set of AVI files, it's still not clear where you have to put these files so that the SX Tools will see them. The only guidance provided was a vague reference to the Program Files folder, which of course is where the program apps are located (a couple more subfolders deeper). To be honest, I've tried half a dozen logical places and still haven't located the magical spot, and thus I can't see any help in the SX Tools. Attempts to play these files outside the Tools simply crash Windows MediaPlayer, and the VLC player shows no video at all, just the audio soundtrack. So I have no clue what they look like.

Frankly, all this confusion is completely unforgivable (IMO) for a mature product that hasn't been updated in 9 years. And another reason I was focusing on the Suite. While the older LA tool does have the capability to analyze a few (3? 4?) protocols, it isn't very impressive, or very useful. The output streams appear in separate windows, with no connection or relation to the logic trace window, in any way whatsoever, AND with no time-stamping information. It's basically a batch processor that dumps its text output into a window. So I'd consider the value of the serial protocol decoders to be quite limited in the 2000 software, though the LA part itself looks quite decent.

Thanks very much for calling this omission to my attention. Mea culpa.

- Mark

bigandy

Jul 24, 2009, 08:57 AM

Ah, that's good then, I was wondering if the older two software tools were not compatible with the USBee SX, but if it works, brilliant!

I wondered about the help files too. I clicked the buttons, and nothing happened. I assumed the software was missing something. It seems pretty straightforward to my eyes though, I guess actually using it will reveal where the help files are needed though!

Just waiting for a price back from the UK distributor, but I'm going with the USBee SX for now. At least until the Saleae Logic unit has output capability anyway.

Cheers
Andy

Mark_O

Jul 24, 2009, 02:08 PM

> I wondered about the help files too. I clicked the buttons, and nothing happened. <

If I stumble across where they belong, I'll post here. I agree that the Help is not critical, but it would be nice to have at the beginning. However, most everything can be deduced by simple trial and error. Now that I've gone to the trouble to install the older software, I'd like to give the more powerful triggering, and the Search capabilities a try.

- Mark

bigandy

Jul 30, 2009, 06:11 AM

USBee SX ordered :)

Hopefully this will fill in all teh gaps that my Rigol MSO leaves :)

Andy

Mark_O

Jul 31, 2009, 04:23 AM

Hi, Andy.

One thing to be careful about is not to over-volt the inputs. It's designed for 5V logic (high will trigger at >=1.4V, and has 0.6V hysteresis, so goes low again at <=0.8V... very effective at minimizing spurious transients due to noise). But the inputs can't handle much over +5.5V, unlike the Rigol MSO pod, which can handle +/-40V.

One other handy thing about the SX that's frequently overlooked is if you need a bit of juice for a sub-circuit, you can tap off 5V from the SX, as well as a regulated +3.3V (though it doesn't specify how many mA each can source). Should be fine as long as you don't get greedy.

- Mark

bigandy

Jul 31, 2009, 09:16 AM

I had read that in the spec about the 5.5v max input voltage, but cheers for reminding me! I remember wondering if it would be easy to make a small add on interface for providing a bit of protection against over voltage on the input pins. For most of the time, I'll be dealing with 3.3 and 5v parts, but there may be occasions in the future where I look at something different :)

Cheers
Andy

Mark_O

Sep 27, 2009, 06:18 PM

Back in July, I wrote in my mini review...

> OTOH, Logic provides a Session Save and Restore capability that is very useful, while the SX Suite can only export data in a variety of formats. Session capabilities allow for a complete reconstruction of all capture settings and display options. Good stuff. <

> Lastly, the triggering capabilities on Logic are vastly superior. While the SX Suite is limited to selecting either a rising or falling edge on a single channel, Logic allows up to all 8 channels to participate in the trigger-matching process, and for a full 4 sequential bit-states. I.e., you could specify a trigger as the sequence 1,0,-,1 on channel 1 ("-" being Don't Care), while channel 2 was 0,1,-,-. Along with any other combination of the remaining channels. Powerful stuff. <

Neither of these was completely accurate. While it is true that the USBee Suite for the SX can export data in a variety of formats, the standard "Save Capture"/"Open" menu items provide a full StateSave and Restore capability... just like the Logic product.

And while the triggering capabilities are much weaker (at this point in time) in the SX's USBee Suite software (as I described previously), these are NOT a limitation of the hardware itself. The SX module has just as powerful triggering capabilities as the Logic... but they are only accessible in the older (legacy) Logic Analyzer software. There's no ETA on when (or if) they'll be added to the Suite, but I'd expect they would be eventually.

The USBee Suite is undergoing continual development, and they recently released a new Pro version, that adds Markers and Notes capabilities, amongst others (including the full Packet Presenter), for a cool $300. Which seems like a lot when compared to the $139 price tag on their SX product, but not so bad when viewed against the $500-1500 price tags on their more powerful hardware products. The Suite supports their full product line.

Considering that their initial plan was not to make the powerful (and expensive) Packet Presenter available on the SX module at any price, I actually consider them making the Pro available even at $300 a good thing.

I had already discussed some of the triggering issues here with Andy, but I just wanted to point these out, to clear up any potential misunderstanding, and set the record straight.

- Mark

Mark_O

Nov 21, 2009, 08:32 PM

Back in September, I had written about the USBee Suite Pro:
> The USBee Suite is undergoing continual development, and they recently released a new Pro version, that adds Markers and Notes capabilities, amongst others (including the full Packet Presenter), for a cool $300. Which seems like a lot when compared to the $139 price tag on their SX product, but not so bad when viewed against the $500-1500 price tags on their more powerful hardware products. The Suite (and Suite Pro) supports their full product line. <

My apologies for not getting back here before now, but it's been a hectic week.

CWAV, the USBee folks, have had a sale going on for several weeks now, with the $300 USBee Suite Pro marked down to $95! In my opinion, that's a real bargain. If you have any of the USBee capture devices, from the SX on up, I'd recommend grabbing it at that price while you can. It says it's going back up to full price again on Monday, so you've only got until midnight (timezone unknown) on Sunday to order. Here's a link to their order page (http://usbee.com/cwavproducts.aspx) which shows the active sale prices. They have other items on sale as well, so you might want to check it out. E.g., the EX2 Experimenters Board (basically an SX module, without the case or cables) for only $99.

Beyond the Markers and Notes capabilities, and the very powerful PacketPresenter (http://usbee.com/dxpp.html) (which once was only available with their $1500 DX module) for anyone who has any need to customize their protocol handlers (or even write new ones), which I mentioned earlier, they've recently added SmartSearch to the Pro, which is really excellent.

http://www.usbee.com/prosearch.jpg

Having the ability to capture huge amounts of data in the standard Suite is a double-edged sword, in the sense that it may be difficult to locate what you're looking for in the massive stream, if it only occurs infrequently. The idea of "needle in a haystack" comes to mind. But with the ProSearch, you can quickly and easily locate not only every such matching occurance, but get a count, and step back and forward through them with a single click. Really awesome stuff, and definitely the missing piece of the puzzle in terms of providing powerful LA and protocol analyzer capabilities.

For low-speed comms, this will even give the multithousand dollar Tek and Agilent protocol analyzers a run for their money. You can read about the standard and extended Pro features (http://www.usbee.com/suite.html#features) at their website. The Pro is the only version supporting delta time-stamping, and also has an auto-trigger capability, so with smaller capture buffer settings, you can continuously re-trigger, to monitor changing signal streams. Very cool.

Once again, sorry I couldn't get in here with the info sooner, to give you guys more time to evaluate and take advantage of this.

- Mark

P.S. The analog channel capabilities pictured aren't available on the SX (which has no analog acquistion hardware), but are on the AX models and up that do have analog sections.