Which (old) Logic Analyser?

[Sailor]

Now that (thanks to the good people of EEVblog  ) my Agilent MSO7054B is running with its proper memory size, my thoughts are turning to a reasonable logic analyser. But whereas it was fairly easy to make the scope choice, a quick look at all the LA models and their module options gives me brain-fade. Combine that with a quick skim on ebay where I see *wildly* varying prices for what appears to be somewhat similar items, and I realize that I don't even know enough about what is out there to even begin asking the right questions.

What I would like is somewhere in the region of 500MSa in timing mode, better than 200MHz in state mode, 70 channels at least, and lots of memory depth. I'm not fussed about portability, so a benchtop cage and a separate PC is ok. The only consideration there is that it costs a lot of money to air freight a boat anchor from the U.S. to Australia, so smaller is better in that regard.

And of course, it needs to be relatively ebay-cheap!

I've read some (but not all) of TiN's exploits with his 714 and its modules, but it would be good to get a range of opinions if people are willing to share their experiences with other makes/models.

I've got a TLA700 Series User Manual from the Tek site, there doesn't appear to be one for the 600 series. If anyone can point me to other good manuals I would appreciate it.

Regards,

[alexjordon27]

Hey there,
Thanks a lot for sharing this Logic Analyser post. I am really impressed with your post.

Thanks and please update some more relevant News on that.

Thanks & Regards
Alex

[Basstudio]

I have never used the portable USB types before but I have used the Agilent 16500/16600/16700/16800/16900 mainframes throughout my engineering career, personally I think these are the 'dogs bollocks'. However they are not cheap and not many appear on eBay these days because people don't get rid of them. I am not sure what you consider cheap but the common Agilent logic analysers like the 16500C usually sell between £200-400 here in the UK and a 16702B £600 and upwards BUT this will depend on what measurement modules are installed in the mainframe. The 16800 and 16900 are Agilent's current models and still remain expensive for one that works.

I am a bit of a sad logic analyser collector so if you are UK based and depending on your price point I do have a Agilent 16700A, 16700B and a 16702B for sale if you are interested  . Price always depends on what measurement modules are installed though.

[Sailor]

Thanks for the comments, I'll have a look at those models. I have a HP1630D, but with only a 1K sample depth and 10ns timing it's a bit limited. I don't think I've used it for 10 years or more! I'm in Australia, and from past experience getting gear from England is generally even more expensive than from the U.S., so I'll have to reserve judgement on your offer. However, I will definitely keep you in mind. Are any of your units in the ballpark of the performance that I mentioned I would be looking for?

Regards,

[esprits4s]

What's your budget?

16500C or 16700/16702 (a or b) are often available, with cards, for well less than $1K.  Prices go up quickly for 16800 or 16900 series.  16700 series are the current sweet spot for features and value in my opinion.

[Sailor]

I've just been looking at some documents on the 16702 and 16741 which seem to be a possibility for my specs. I see a 16702A plus 1 x 16741A on ebay now for $500 as a buy-it-now price, so maybe that's indicating a m/frame plus two modules for around the $1000 - $1200 landed here in Oz. But I see a dramatic difference in the front panel (at least) between a 16702A and B. It looks like they junked the keyboard from the /A (fair enough, I detest that sort of thing), but is there increased functionality in the /B, or is it simply nicer to use? I haven't yet got to reading about 16742s (I think that was a number I have seen somewhere, maybe has deeper memory???). Ignoring price for the moment, what are your thoughts on that sort of setup? Are there useful benefits in some of the variants ('A', 'B', etc) of the mainframe and the modules? Are probe sets readily available? And what is the software situation - are there any repair hassles if, for example, the disk/controller fail? I would obviously not be buying a new(ish) piece of equipment, but I also wouldn't want to discover that it was made of unobtainium, or that a crash might irrevocably destroy any licenses. As I said in my first post, I don't even know the right questions to ask about recent LA systems, so all input is greatly appreciated.

Regards,

[esprits4s]

The B version has a faster processor, more memory (128 to 256MB vs. 64 to 160MB), and larger screen (same resolution though).  The 16700B can often be found for much less than then 16702B and offers the same performance if you are okay with using a keyboard, mouse, and external monitor.  The B version also comes with a larger hard drive 18GB vs. 4.3GB.  Otherwise, they are pretty similar IIRC.  I haven't compared them in quite a few years, but I believe the GUI is the same and they can both use the same selection of line cards.

[esprits4s]

The nice thing about these Agilents is that a ton of them were sold and accessories are commonly available on Ebay for reasonable prices.  Here in the states, the Agilent series and accessories are a little more common on Ebay than the Tek equivalents.  They are huge though...  Shipping will cost a pretty penny.

[Shock]

Sailor check out the Pipistrello LX45 with OpenBench Logic Sniffer.
64MB, 200 MHz 8 and 16-bit, 100 MHz 32-bit capture. Approx 16 secs capture at 200MHz.

Pipistrello LX45
http://saanlima.com/store/index.php?route=product/product&product_id=51
5v tolerant IO board
http://saanlima.com/store/index.php?route=product/product&product_id=55

Port of OpenBench Logic Sniffer
http://saanlima.com/forum/viewtopic.php?f=9&t=8

I'm considering this setup myself but haven't got around to it yet.

[jpb]

Ignoring your statement that it should be "ebay cheap" and in case you've recently had a lottery win the Agilent e-bay store is doing a deal on their latest logic analysers:

http://www.ebay.co.uk/itm/Agilent-PREMIUM-USED-Logic-Analyzer-SPECIAL-/181342739240?pt=LH_DefaultDomain_0&hash=item2a38de9b28

They claim to give you $40K of memory for free not to mention a $76k main frame for just $9k!

They are premium used so you get the original warranty - so sell the car (and the house but not the shed where you have your lab) and get some good kit.

[PaulAm]

Going a bit older, you might also consider the 16500b, they can be found a little cheaper than the C and, if you get one with a LAN card, have about the same capability (less memory, and require an HP keyboard and mouse, but they can be run remote).  Not all of the cards are compatible though, so verify your chosen cards will work in the B if you go that route.  I would avoid the A series.  If I were looking for an LA now, I'd probably try to find a 16700 as the best compromise on age/price

If you go for any of the ebay deals, make sure they come with cables, they're expensive and difficult to find separately, but do not add that much to the purchase price when bundled.  I picked up a 16500b with the LAN option, 3 100MHz state cards, cables and a DSO card for $350  US + shipping.

[nctnico]

IMHO a TLA700 series mainframe is a better buy. It runs plain Windows and the software can be downloaded from Tektronix. Besides that the acquisition modules and probes can be found cheap on Ebay every now and then. I do advice to buy a complete set (mainframe, modules and probes) to get started.

[Sailor]

Thanks everyone for your inputs. I've been digging up all the datasheets, manuals etc for the Agilent and Tektronix systems, and then trying to rationalize one against the other. There seem to be roughly similar prices for similar systems on ebay, if you ignore the **absolutely ridiculous** prices that some sellers put on their goods! While the Agilent systems seem to have a lot more documentation available, I have to say that the Windows 2000 base of the Tektronix sits a lot more happily with me. I still run W2k on a couple of my older systems, and I have a pretty good handle on getting into the guts of things if I have to. Plus TiN's hack of the TLA7AAx module looks useful..., so I'm leaning the Tek way right now. Of course, when you see a nice unit for $300, then read on to discover that shipping is $1700, well, 

If anyone has reasonably extensive experience with comparable Agilent and Tektronix systems, it would be good hear their opinions.

Regards,

[TerraHertz]

If anyone has reasonably extensive experience with comparable Agilent and Tektronix systems, it would be good hear their opinions.

It seems to me that your primary problem is the shipping cost, US to Australia. Which I can make a useful suggestion about.
I bought a Tektronix TLA 721 mainframe, with control module, no other modules.
It was listed US $629.95, seller kindly dropped to US $375 when I asked nicely. ALWAYS ask, even if there is no 'make an offer' on the listing. Especially with high volume sellers. They often just want to move it.

Then I had it shipped to Oz via a reshipper in the US. http://www.shipito.com Who I can't recommend enough!
I'd been using them for a while by then, so knew the drill. They're very good, and obtain a huge discount from the international freight companies due to the large volume they ship. But I'd suggest you try a few lower value items via them before you do a big expensive item.
Anyway, the shipping costs were:
  About US $90 to ship UPS ground from the seller (I forget the state) to the reshipper in CA.
  Box was 71 lbs, 67 x 67 x 67 cm
  Freight quotes were:
       $470 via TNT
       $341 via fedex economy.
I chose Fedex, but that was a BIG mistake, that I won't make again. I'd rather have paid the extra $130, to not get screwed around by Fedex. It was the first time I'd seen them quote less than TNT, who are invariably excellent.
Anyway, it did get here undamaged. Best of all, one reason the seller dropped the price was he didn't know the Win2000 logon password. It turned out to be nothing, just press enter! (It took me a while before I thought of trying that, ha ha.)

Modules, probes and original manuals are easy. There are always lots of choices, and sometimes some very cheap ones.

Shipito have a freight cost estimator on their home page, so you can work out roughly what things will cost to bring to Oz, before you buy. Which means you can put the extra cash into the quality of equipment. (Or in my case, just be able to afford something at all.)


 

[Sailor]

Hey, that's good info TerraHertz. I have been kicking myself because I remembered reading a post in the last few days in which someone (probably you!) had talked of using a reshipper, but I didn't make a note of who it was.

Interesting words of yours 'I bought a Tektronix TLA 721 mainframe, with control module'. Does that mean that something advertised as a 721 mainframe might not have a controller in it? I've been trying to figure out exactly what is in things like the 711 and 721, and what the real difference is between them, etc, etc. And from that, to exactly how the windows system communicates with the sampling modules. And so on...

Regards,

[woodchips]

Silly question, but why do you need something so large and fast?

Worth considering something very much older? I find the most valuable thing in a LA for me is the range of disassemblers, 8085, 6801, 68000 etc etc but I am messing around with that era hardware. My most used LA is a Tek 318, all 16 channels and 10MHz! But it works straight away, no remembering all the menus, attaching 50 probes etc.

Define the problems the LA has to solve. I still prefer a scope, before prodding a signal you think, what am I expecting to see? With just one to three signals you can do that, not possible with 50 channels, the problem is buried in all the signal traces.

Just my thoughts.

[nctnico]

I agree that having a lot of channels isn't so important nowadays. I use 16 channels at most. A professional logic analyser has deep memory and software tools to deal with large amounts of data. The Tektronix software for example allows to search through the data looking for specific patterns.

[Sailor]

I guess it's a case of 'horses for courses', woodchips. I have done a lot of work over the years with my HP1630D, but as I noted earlier, it hasn't been in use for a long time, mainly because it's just not fast enough. It has 100MHz timing, but only 25MHz state, and most of the ARM chips these these days are capable  of running 'way faster than that. Although I agree that I can't see me ever needing a system with more than 68 channels, and rarely even that.

With just one to three signals you can do that,...

Yes, and I too have spent a lot of my life working just like that. It works if you're chasing a solid or frequent fault, but when the fault is very intermittent I find that method can get frustrating fast (slowly!). In those cases it's nice to be able catch a broad range of signals. Plus the deep memory of modern modules, and the complex triggering possibilities, all help to make life easier. My 1630D has got just 1024 points of data!

Regards,

[TerraHertz]

Hey, that's good info TerraHertz. I have been kicking myself because I remembered reading a post in the last few days in which someone (probably you!) had talked of using a reshipper, but I didn't make a note of who it was.

When embarking on a project, creating a folder for it and keeping notes in a text file of things like reference URLs, can't be beat.

Interesting words of yours 'I bought a Tektronix TLA 721 mainframe, with control module'. Does that mean that something advertised as a 721 mainframe might not have a controller in it?

Yes it does. Try doing searches for the model number, and note what you see in pics. The TLA 721 is just an empty frame. It needs a control module, that occupies 3 slots at the left. This is a custom PC, that runs the system.
Other things to be aware of:
 * The controller module has no ethernet port built in. You'll need a plugin 'type 2/type 3 PC Card' to provide network connectivity. Mine came with an Intel 10/100 adapter card and the cable.
* The power cord is special. Uses a 'high temp' IEC connector. You can buy them, but best if included in purchase.
* Make sure you see the thing booted and working. The module's hard disk is in a removable cartridge.
* Best to get a mainframe that includes some slot blanking panels. No one seems to ever list the blanking panels alone on ebay, and I don't like your chances of getting them from Tektronix for any reasonable price. It was just pure luck that the one I bought had 3, since at the time I didn't realize that was an issue.

I've been trying to figure out exactly what is in things like the 711 and 721, and what the real difference is between them, etc, etc. And from that, to exactly how the windows system communicates with the sampling modules. And so on...

Since Tektronix has become one of those bastard companies that removes online information about their older products, the best way to find details on their equipment is to obtain old Tektronix catalogs. Ebay has many, but mostly older ones. For the TLA series you want Tek test, measurement and monitoring product catalog, for years 2001 through 2004 or later. They do turn up. To really see how the TLA system evolved, best to get a series of the catalogs. Because don't expect Tektronix to ever publish a neat table of model numbers, module compatibilities and software versions.

Also the TLA series software manuals contain chapters detailing the hardware and module compatibilities for that particular software version. So once again, it helps to have several.

[esprits4s]

Since Tektronix has become one of those bastard companies that removes online information about their older products, the best way to find details on their equipment is to obtain old Tektronix catalogs.

I've never looked, but this is surprising since Tek is pretty good about having info on their older oscilloscopes available at tek.com.  Another plus for HP/Agilent then because they have tons of documentation on their out of production logic analyzers available for download.

[Sailor]

All good words. I've probably spent 20 hours or more this weekend scouring the net for TLA docs. Once you get past the first half-a-dozen or so easy ones, it's like pulling teeth. As esprits4s says, it's a vastly different proposition to the Agilent situation.

Because don't expect Tektronix to ever publish a neat table of model numbers, module compatibilities and software versions.

Certainly not like the attached Agilent file.

[nctnico]

The only problem is that the search engine on Tektronix' website isn't very good. However all the information and software is there! It just takes more effort to find it.

[TiN]

Also there is option to get TLA7016 if one really want to deal with bulky monitor-less frame.
TLA7016 is just a network module, which can be installed into almost any standalone frame, like TLA720, TLA721, TLA7XM (extension unit).
I saw before network unit for TLA7016 on bay sold for 300$USD, while TLA7XM or 720 can be bought for 300-400USD. With shipping it may get around 1K total,
but as a pros you will have latest generation frame as of today, which supports all new modules. And I saw TLA7XM with network module sold as TLA7016, with all app's running.
But anyway usually anything better than 7AA4 costs a fortune, and not much people here need that fast or serdes-capable LA From what I saw on spec-wise Agilent units are not as fast as Tek's.

I was able to use my 7AA4 to capture 400-533MHz DDR bus (was using mainly to mux it out to TDS7704B, but still was able to get meaningful data on TLA App), which is
kind'a over guaranteed spec for 7AA4. And it can go faster if use state mode. But big cons is the software, it's bulky and buggy, so be patient, when you use it, sometimes it's tricky
Don't know about Agilent's, never saw their LA's in person.

[Sailor]

That's not a bad idea, TiN. Is there a particular number for that network module? Or is it simply called a 7016 network module?

I've been looking at heaps of TLA720/721 and a couple of tla714 on the web. It seems that many of them are missing their hard drive. Old IDE drives and standard Windows OS are easy enough, but are there special drivers required? Then what about the Tek application s/w? And are there license numbers, IDs, etc required. Is all of that do-able, or is it *essential* to get a unit with a working drive and the Tek s/w?

Along the same lines, if I was to follow TiN's idea and get a mainframe and network card (whatever it may be), the same question arises about the application s/w, lic, ID, etc. How does one handle that?

[Sailor]

@TerraHertz
I've had a good read of the Shipito.com site, and it certainly sounds good. I threw some numbers into their calculator and the figures they came up with are quite attractive, especially when the dimensions/weight get beyond the normal postal limits. I'll give them a try when I finally settle on a LA.

Thank you.