Digital 'scope & spectrum analyzer Re: [Open-graphics] PCIe know-how?

James Richard Tyrer tyrerj at acm.org
Tue Mar 6 19:50:36 EST 2007


Dieter wrote:
>>> You need to be able to *capture* the data in real time, in order to
>>> do a single sweep mode, for non-periodic signals.  The processing and
>>> display of that data don't have to be real time.
>> Yes, that is true for some applications, but unless this is a real time 
>> spectrum analyzer ($$$$) -- which is useful for some applications such 
>> as looking for noise and intermittent distortion -- you are going to be 
>> working with a stable periodic wave form.
> 
> That was in reply to:
> 
>>>> To be more specific, 
>>>> a digital oscilloscope displays a periodic signal on the screen and the 
>>>> refresh scans rather slowly from left to right.
> 
> Single sweep mode is a very useful, often essential, feature for an
> oscilloscope.

Yes, a one shot scope is a useful device.  With analog this was a scope 
with a storage CRT.  With digital this requires a very fast flash ADC 
(perhaps more than one).  I think that this is going to be rather 
expensive compared to a scanning type D-scope for stable AC signals.

The nice feature of one shot D-scopes is that they can record a lot more 
data than an analog one -- you can record a lot more data than will fit 
on the screen at once.

-- 
JRT


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