Maker Pro
Maker Pro

PCI interface

V

vasile

Jan 1, 1970
0
No, thats not real time rendering(well, its becoming that way). That is ray
tracing but games now days use ray casting. You cannot ray trace in real
time yet to any significant degree.








I'm not going to argue about it any more. You don't have to understand or
believe what I'm saying. Your ringing example is no counter example though
because you still cannot see the higher frequency components. There is
always a band limiting aspect after the conversion and your not taking that
into account. That or you act like I'm going to only display the such a
small portion of the total spectrum of the signal to make it useless. That
is not the case. I will display what is only necessary for real time and
leave the rest for non-real time purposes.

I guess we have two different approaches. My goal is not to see the complete
signal in real time but have a history of the whole signal so I can go look
back at it. For example, I could use a scope like this as a logic analyzer.
A digital signal is simply a signal. I would digitize it, go look at it and
see what happened. With a analog scope this is impossible because you have
no way to see the history. If you try to view it in real time then chances
are you'll not catch anything because it went by too fast. If you have the
whole signal stored in memory then you can easily go back and do processing
on it and view it. You can even view it for ringing and such and get all the
details you need up to the bandwidth/sample rate of the conversion. Ofcourse
even if its not in real time you don't need to display unnecessary
information that the user cannot process.

About the haystack. No, thats not true. You don't understand very well. You
can have triggers, intelligent searches, etc... I'd take that ability to be
able to go back and look at some instant of the signal that was momentary
than loose it for ever. Ofcourse if your dealing with several seconds of a
signal samples at about 1GS/s then it would probably take you several days
to find some random event that happened. Having some intelligent way to go
through the signal would move that down to a few mins. Similary to how a
word processing application works. If your looking for every instance of
some word you do not have to manually search through the whole document.

You could have something like "bookmarks" that set a bookmark when a search
"trigger" occured. This way you can very easily navigate to specific events.

That's the equivalent feature of Wave inspector from Tektronix:
http://www.tek.com/site/ps/0,,3G-20156-INTRO_EN,00.html
 
J

Jon Slaughter

Jan 1, 1970
0
That's the equivalent feature of Wave inspector from Tektronix:
http://www.tek.com/site/ps/0,,3G-20156-INTRO_EN,00.html

Yeah, thats very similar to what I'm talking about except that it will, of
course, be done on the pc. The point is to shift as much of the hardware and
software as possible onto the pc because most people have pc's, pc's are
general,they tend to be more cost effective, and have better suite of
tools(both software and hardware).

My idea was essentially creating that type of scope but the only draw back I
see(as most) is that the amount of memory it has(looks like 10MB per
channel). I figure that using the pc for memory can increase that by a
factor of a 100. But if I were to use the memory of the pc I might as well
use the display, hard drive, user interface(mouse, keyboard), etc...

I just don't see any need for such a scope being 7k$+. (Atleast they could
add a gig of memory).

What I don't understand is how they achieve the 5GS/s rate. Do they
interleave ADC's or what? How else can they get that fast? Are there ADC's
ICs that do that now?

Thanks,
Jon
 
N

Nico Coesel

Jan 1, 1970
0
Jon Slaughter said:
Yeah, thats very similar to what I'm talking about except that it will, of
course, be done on the pc. The point is to shift as much of the hardware and
software as possible onto the pc because most people have pc's, pc's are
general,they tend to be more cost effective, and have better suite of
tools(both software and hardware).

My idea was essentially creating that type of scope but the only draw back I
see(as most) is that the amount of memory it has(looks like 10MB per
channel). I figure that using the pc for memory can increase that by a
factor of a 100. But if I were to use the memory of the pc I might as well
use the display, hard drive, user interface(mouse, keyboard), etc...

I just don't see any need for such a scope being 7k$+. (Atleast they could
add a gig of memory).

What I don't understand is how they achieve the 5GS/s rate. Do they
interleave ADC's or what? How else can they get that fast? Are there ADC's
ICs that do that now?

It is probably a matter of interleaving and/or using proprietary
chips. IIRC Maxim is boosting on their website that they can deliver
custom ADCs with a much higher bandwidth than available on their
website. Still, the ADC is only a very small part. You'll need to
tackle all kinds of other problems too like clock jitter and the
probing part.
 
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