Sonsivri

I've been thinking about the Saleae Logic Analyzer. The Logic 8 is quite cheap at $219 and I don't need one very often. But the Saleae site doesn't have much information and their response to questions has been diabolical!

Does anyone here use the Saleae Logic 8? I want to know if it can capture the full 8 signals at 10MHz or preferably 20MHz.
Anyone?
TIA.

http://www.sonsivri.to/forum/index.php?topic=49584.0

I did read that thread, Pickit2, but it's quite out of date now and the Saleae range has changed quite a bit. It's specifically the Logic 8 that I'm interested in.

(I'm sure the 'pro' models would suit me but unfortunately they don't suit my pocket!  :()

I use the Logic 8 at my work. Although I haven't used it on a 10 MHz or 20 MHz signal - my signals have been only a few MHz. I really like the thing - it's easy to use and the software is great. It claims to sample at 100 MHz for digital signals, so I'd think it would have no problems with your 10 MHz signals.

Hi Bigtoy, that's interesting.

The main thing that I'm concerned about is that earlier models used to be able to keep up the maximum sampling rate on only 1 or 2 channels but had to drop the rate as the number of channels being sampled increased. (The software automatically removed the higher rates from the options as the number of channels selected increased).

Could you possibly try a little experiment for me if you've the chance? Select all 8 channels and then try to select the 100MHz rate. If it lets you then I guess it's good to go. The only other limitation is the USB2 rate on the PC which I think would be OK.

You can actually test this yourself by downloading the Saleae software and running it without a Logic attached.  It will allow you to "simulate" different models and settings.  When the Logic 8 is selected, the maximum selectable samplerate is 25MS/s.

I have been using the cheap $8 ebay shit for debugging communications, not high speed tho.
Works pretty good I guess.

You can get a China clone of the Logic16 100MHz for about $30.
If software and hardware meet your requirements, sell the clone and buy the Logic8 to support Saleae.

Good tip.
Done that now - max sampling rate varies with number of channels from 100MHz down to 25MHz so OK for me!

I have two saleae, one Logic 8 and one Logic 16 (old versions).

Logic 8 is slow, I think it can't achieve required speeds by the OP but Logic 16 i think it can do. Of course, this is for old versions.

For me, the Logic 8 has a great advantage due to the slower speed, I can put a USB isolator between PC and Logic, whereas with Logic 16 it is not possible due to the maximum velocity of isolator (maybe there are fast isolators, but I don't have).  In fact, when using a isolator, Logic 16 is not detected by the PC. Obviously, the signals I measure are slow.

There are some alternatives in the same price range. 

The Rigol USB scope/logic analyzers can sometimes be found inexpensively on ebay:

http://www.batronix.com/shop/oscilloscopes/Rigol-VS5062D.html

I have one of these and it works well except Rigol has stopped updating the software.  

Older HP/Agilent logic analyzers are available for $200 (including cables/probes) on ebay too:

http://www.ebay.com/itm/HEWLETT-PACKARD-1650A-LOGIC-ANALYZER-WITH-CABLES-/251782414283?pt=LH_DefaultDomain_0&hash=item3a9f66bfcb

These only have 1K memory depth, but that's 1K transitions which is a lot more than 1K samples.  

Have you check the Intronix  Logicport device ?.
This is a very good logic analyser. I am using these for several years and really
recommended. Of course, it is  not too cheaper, but not expensive for the
tool. You can check the software (free) at company http://www.pctestinstruments.com/

Cheer's

I took the plunge and invested in a Logic Pro 16 late last year.

It has to be said that whilst I only use 7-8 channels max at the moment, the quality of the construction of the tool itself and of the software with all of its protocol analyzers are simply superb. It's the best investment I've ever made in a piece of test-kit.

I also tried one of the cheapie 8 channel clone devices and whilst it still works with the latest software the lack of shielding makes it flakey at the top end sampling rates.

I can wholeheartedly recommend the Saleae, and if 25MHz sampling is enough for your needs then I'm sure you won't be disappointed with the Logic 8.

I agree completely.  I own the original Logic 8, Logic 16, and new Logic 16 Pro and all of these devices are some of the best quality that I've sen.  I wholeheartedly recommend the extra cash for the Saleae product if it falls within someone's budget.

I've also owned (and built) several clones and while they are functional, I always find myself defaulting to the official hardware.  Even if someone offered me full retail value for the Saleae hardware I would decline.

a chinese version for Logic 16, is done a review in the link below,
http://www.cnx-software.com/2014/12/30/la1016-la2016-and-la5016-logic-analyzers-cost-as-low-as-44/

I use the Chinese clone 8-bit version. It works very reliably up to 8Mhz and sometimes up to 16MHz. I can't identify the reason that only sometimes can I get the higher speeds - it could be something as simple as PC bloatware operating in the background. A clean minimal W7 install would probably give consistent results.

However, there is normally a simple way round this - temporarily reduce the clock speed of the circuit being analysed. Typically the logic analyser is being used to understand some sort of protocol exchange (e.g. SPI). This will work the same at a slower speed. If then, when proved correct, it fails when  the clocks are increased the likelihood is that the issue is electrical rather than signalling. A logic analyser won't help you diagnose this - you need a scope to see the quality of the signal pulses.

Also use a 5$ clone, did to it a hot-air gun rework (a bit of reflow) just to resolder any solderings needed.
https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20170922021320&SearchText=USB+Logic+Analyze+24M+8CH
Still have it working ok some years now.