Rigol DS1052E- How many FFT points - Page 1
Forum section: electronics / beginners

author: Flavour Flave
author_rank: Regular Contributor
timestamp: January 23, 2011, 05:36:29 pm
content: Actually it is the upgraded DS1102E thanks to you guysAnyway, does anyone know how many points the Rigol DS1102E FFT function uses? Because I want to work out the FFT noise floor. Couldn't find it in any of the documentation.ThanksJust needed to know because I was reading this Analog Devices tutorial herehttp://www.analog.com/static/imported-files/tutorials/MT-001.pdf

author: pfm
author_rank: Regular Contributor
timestamp: March 20, 2012, 08:09:39 pm
content: bump.seeking the same info (number of FFT points) for this Rigol series and can't seem to find it anywhere and found this thread while searching for it. Hoping someone knows and will post here.Thanks.

author: Bored@Work
author_rank: Super Contributor
timestamp: March 20, 2012, 10:37:46 pm
content: Typically, in such simple oscilloscopes the manufacturers just use enough data points to fill the screen. Because of the negative frequencies and the symmetry, this means using twice as many data points (ok, in theory (W - 1)/2) as input to the FFT as the screen is wide.

author: slateraptor
author_rank: Frequent Contributor
timestamp: March 21, 2012, 01:33:50 am
content: Quote from: BoredAtWork on March 20, 2012, 10:37:46 pmProbably less if their engineers optimized for bezel thickness, e.g. (<total horizontal pixels> - <horizontal bezel pixels>) buckets...viz. information limit is dictated by screen resolution, so it wouldn't make sense to have more buckets than horizontal pixels...unless the number of buckets is base-2 or coprime factorable.

author: pfm
author_rank: Regular Contributor
timestamp: March 21, 2012, 01:53:22 am
content: called Rigol, its 600 points. Its kind of eluded to in the "programming guide" as well.Hope this helps anyone looking for this info.

author: slateraptor
author_rank: Frequent Contributor
timestamp: March 21, 2012, 02:02:53 am
content: Quote from: pfm on March 21, 2012, 01:53:22 am600 buckets is a curious choice. *shrug*

author: IanB
author_rank: Super Contributor
timestamp: March 21, 2012, 06:06:35 am
content: Quote from: pfm on March 21, 2012, 01:53:22 amI guess the information had been alluding you, then?

author: pfm
author_rank: Regular Contributor
timestamp: March 21, 2012, 12:41:23 pm
content: correctbut I guess I can say I do pretty well for English being my 2nd, or rather make that 3rd language...

author: pfm
author_rank: Regular Contributor
timestamp: March 22, 2012, 07:20:19 pm
content: does 2) apply to the onboard fft as well ? I got the impression its 600 regardless.for external fft(using 3rd party programs) it would ofcourse be limited by the current memory depth.

author: kusanagi
author_rank: Newbie
timestamp: March 27, 2012, 04:36:36 am
content: '600 points' is curious for FFT process.If it is so, that is DFT, not FFT.I checked the manual of Agilent DS1k series, which are brother products of Rigol's.It clearly states 'Fixed at 1024 points'.But Rigol says nothing.If it is 1024-point process, how does it map points to output?FFT waveform actually occupies 10divs with DS1052E.Number of pixels for 10div is 250 points.This is another question.

author: slateraptor
author_rank: Frequent Contributor
timestamp: March 27, 2012, 04:55:56 am
content: Quote from: kusanagi on March 27, 2012, 04:36:36 amI'm more inclined to suspect that the supposed 600 buckets is a misinformed fib rather than a DFT implementation, even if this information is reported from Rigol. Unfortunately, I don't think there's really any way to validate the claim shy of direct firmware disassembly and inspection.

author: slateraptor
author_rank: Frequent Contributor
timestamp: March 27, 2012, 09:54:33 am
content: I'm not even going to try...