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Products => Test Equipment => Topic started by: roli_bark on May 13, 2013, 04:49:48 am

Title: Decreasing the DSO sampling rate (intentionally) - is there a way ?
Post by: roli_bark on May 13, 2013, 04:49:48 am
Is there a method to decrease a DSO sampling rate intentionally so that longer capture window times can be achieved [at one-shot capture mode] ?

For example, given a 1Mb/s max digital data input, and a 1G Sa/s scope with a 100Mpts memory depth.
A one shot capture at full memory depth will span a 100ms time window.
Is there a way to intentionally decrease the sampling rate to, say, 10M Sa/s (which is enough for sampling a 1 Mb/s data), and with the same memory depth get a span x100 (1G Sa/s  /  10M Sa/s) folds more - e.g. 10 Seconds ?
 
Title: Re: Decreasing the DSO sampling rate (intentionally) - is there a way ?
Post by: amspire on May 13, 2013, 05:14:47 am
Is there a way to intentionally decrease the sampling rate to, say, 10M Sa/s (which is enough for sampling a 1 Mb/s data), and with the same memory depth get a span x100 (1G Sa/s  /  10M Sa/s) folds more - e.g. 10 Seconds ?
The scopes adjust the sampling rate to suit the timebase speed and the capture memory size.

For a particular scope, it depends on the scope firmware. Here is the way the firmware of a Rigol DS1052E is set for sample rate versus timebase settings + memory depth).

https://www.eevblog.com/forum/blog/rigol-ds1052e-sample-rate-vs-timebase-setting/msg115617/#msg115617 (https://www.eevblog.com/forum/blog/rigol-ds1052e-sample-rate-vs-timebase-setting/msg115617/#msg115617)

Other scopes have a different formula. Hate to say it, but it is a case of reading the manual for a particular scope.

In general, the answer to your question is "Yes".
Title: Re: Decreasing the DSO sampling rate (intentionally) - is there a way ?
Post by: roli_bark on May 13, 2013, 05:21:26 am
Thanks. I'm ashamed to say - yes, I did not  :).
I'm a newbie at this, and didn't get yet the chance into looking deeply at my scope user manual.

Thanks again,