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Re: Advice on Logic Analyzer
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Does the LogicPort use transitional sampling?
It appears to with a spec that that includes "compression":
"Maximum sample compression: 2^33 to 1 (sample rates to 200MHz)"

If that is the case then the 2048 sample memory isn't as limiting as a
normal time sampling 2048 sample logic analyser. But I'd go for the
bigger memory unit myself.

Dave.

Re: Advice on Logic Analyzer
On Mon, 14 Apr 2008 17:39:26 -0700 (PDT), "David L. Jones"

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Yes.


It's not a universal tool, as evidenced by the "entire screenful"
example above, but I've been really happy with mine. I've also used
deep-memory realtime, non-transition analyzers and prefer the
LogicPort. A 1 Mbit/channel buffer at even a relatively slow 10 Msps
fills up in only 100 msec.

I am surprised, though, that Intronix hasn't come out with a follow-on
product with more sample memory. The LogicPort has been out for quite
a while (as these things go).

--
Rich Webb     Norfolk, VA

Re: Advice on Logic Analyzer
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Interesting to had seen what jumped out in this conversation, all the
finer nuances :) Bob was right, times are changing

It seems that Janatek, the company that manufactures the Annie-USB and
Logic-16 has been around for some time. What I also like about the
Annie-USB is that it is also a pattern generator. These things cost
some money if you buy it separate. Anyway I came across an article on
their website that eloborate on which aspects you should consider when
comparing pc based logic analyzers.  http://www.janatek.com/faq_buying_logic =
_analyzer.html

The rocky's also seems to me worth considering

Re: Advice on Logic Analyzer
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http://www.janatek.com/faq_buying_logic_analyzer.html
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Well to be fair, nobody's usually dumb enough to want to sample an
entire screen full of RGBI data, usually you just use a RGBI monitor
for that!
Looking at one line is usually enough. Except when you interlace the
display, and the physically "next" line on the screen is an entire
vsync time away. Of course you could program the triggers to ignore
the rest of the field but now I don't remember if you could do that
with the Logicport.

You know, it is spring cleaning time here in the northern hemisphere.
Maybe I'll put my logicport up for sale, since I haven't used it in a
year and that's an important criteria in the cleaning.

Re: Advice on Logic Analyzer

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http://www.janatek.com/faq_buying_logic_analyzer.html
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That depends on what you want to do with your data. I don't know about
the Janatek LA, but my own LA (a tektronix DAS9200) allows to read the
acquisition memory into the PC for automated analysis or drawing
pretty pictures on the screen based on the data.

--
Programmeren in Almere?
E-mail naar nico@nctdevpuntnl (punt=.)

Re: Advice on Logic Analyzer

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Isn't that what any PC-based logic analyzer do in principle? Capture
the data and then relay it to its software on your pc for 'pretty
pictures' :) What I like about that compared to standalone LA's is the
inherent mobility it creates. You can move about with your analyzer
and keep the captured data on your flash. Most of these programs can
export the captured waveforms to a CSV, text or bitmap file that you
can e-mail or compare. If you have some time, go download their
demostration software or another manufacturers.

I'm pretty convinced to go for a pc based rather than standalone,
maybe jump with me?


Re: Advice on Logic Analyzer
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Data storage is standard, usually on disk, most have printer outputs
as well.

 Most of these programs can
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Are you likely to want to email your data?

 If you have some time, go download their
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Maybe you report back how you get on with it.


Re: Advice on Logic Analyzer

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No, it is very nice to be able to have an LA with an API or protocol
with which you can read the data into your own application.

--
Programmeren in Almere?
E-mail naar nico@nctdevpuntnl (punt=.)

Re: Advice on Logic Analyzer
On Wed, 16 Apr 2008 02:21:48 -0700 (PDT), logicgeek

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Naw.  I want split.  Capture in stand alone, USB or Firewire to PC, or
dump to memory card.  Do all the heavy lift analysis on PC.

Re: Advice on Logic Analyzer

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 The reason that Logicport will not soon be coming out with a follow-
on product with more sample memory is stated in an article published
recently on Evaluation Engineering: Quote
                  The LA1034's logic and memory are entirely contained
within a single FPGA," commented Harrison Young III, company CEO.
"This keeps the speed up
                   and the cost down compared with products having
external memory interfaces. The LA1034's efficient lossless
compression algorithm allows its buffer
                   depth to be greatly extended with no loss in signal
integrity."
The small sample buffer available in the Logicport is that which is
available within the mentioned single FPGA, if they should bring out
anything with a slightly larger internal memory, they would have to
redesign the whole instrument. Also data compression works in certain
cases, but certainly is no magic. Otherwise every company would have
offered it, since it saves a lot of development and manufacturing
costs.


Re: Advice on Logic Analyzer
On Wed, 16 Apr 2008 02:14:35 -0700 (PDT), logicgeek

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Yup. And FPGAs keep getting wider, deeper, and faster, so I'd expect a
follow-on.

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Well, yeah, but that's the beauty of HDLs innit?. It's not like they'd
have to respin from, say, a discrete transistor layout to logic gates.

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Once again, there is no universal, single best solution. For my part,
I've used PC-based analyzers with each approach and find that the
transitional sampling technique in the LogicPort is the better fit.

--
Rich Webb     Norfolk, VA

Re: Advice on Logic Analyzer
On Wed, 16 Apr 2008 02:14:35 -0700 (PDT), logicgeek

[snip...snip...]
 
One notes that the entire posting history, via Google Groups, for
snipped-for-privacy@yahoo.co.uk consists of six messages subtly promoting
the Janatek product.

One notes that Janatek's mailing address is Stellenbosch,
Western-Cape, South-Africa.

One notes that, in contrast to the "yahoo.co.UK" e-mail address, the
actual posting IP is 198.54.202.254, which is a .za (South Africa)
domain with a Western Cape contact address.

Gentlemen, I think we have a sock puppet.

--
Rich Webb     Norfolk, VA

Re: Advice on Logic Analyzer
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Most of these PC based instruments are very poor to start with, after
a few years they become unsupported and if you break them in the bin
they go. You would do much better looking on ebay for an Agilent or
Tek instrument for less money.

Re: Advice on Logic Analyzer

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It's faster and cheaper to analyze your logic before you build it.

John


Re: Advice on Logic Analyzer
On Apr 15, 9:52 am, John Larkin
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But what if you're analyzing someone else's design from twenty years
ago and there's no documentation?
Sometimes a new design has to work with old stuff.
I wonder if there's a logic analyzer with enough input range to handle
the logic levels inside a 6R1A?

Re: Advice on Logic Analyzer
On Apr 15, 9:52A0%am, John Larkin
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That's small company talk for sure!

A large company has vastly different day to day problems that what you
normally experience.

Re: Advice on Logic Analyzer
On Tue, 15 Apr 2008 12:23:28 -0700 (PDT), stevepierson

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Yup. The more people you put on a project, the less they understand.

John



Re: Advice on Logic Analyzer
On Tue, 15 Apr 2008 13:10:03 -0700, John Larkin

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Yup.  Design-by-committee never works.

The Girl Scouts are heading that way... combining neighborhoods so
we're looking at managing 1000's of girls rather than 100's... with
all functions "by committee".

My wife just outfoxed them and designated herself as Registrar and me
as the Committee ;-)

                                        ...Jim Thompson
--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
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Re: Advice on Logic Analyzer
On Apr 15, 5:37A0%pm, Jim Thompson <To-Email-Use-The-Envelope-I...@My-
Web-Site.com> wrote:
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I disagree, design-by-committee works more often then not. A guy in
his garage will product a vastly superior product if he doesn't give
up, run out of money, run into health problems etc etc.  A large
company is mostly immune to those issues, it may produce crap, but at
least it's making and selling something!

Re: Advice on Logic Analyzer
On Tue, 15 Apr 2008 12:23:28 -0700 (PDT), stevepierson

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Simply not true.  Been both ways, and guess what the generally support
for analyzing your logic before you build it is much better in large
companies.  That generally is the gotcha.

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