Siglent SDG5000 versus Rigols DS4000 function generator - Page 1
Forum section: electronics / testgear

author: rbola35618
author_rank: Frequent Contributor
timestamp: December 06, 2013, 02:24:15 am
content: Found a video showing the difference between the function generators when using the pulse function. The slow rise and fall time is one of the complaints I have on the Rigol function generator.

author: rockandroll
author_rank: Newbie
timestamp: December 06, 2013, 08:48:20 am
content: it seems that Siglent sdg800 series also have a fast rise and fall time as their SDG5000 ,and lower price than sdg1000https://www.eevblog.com/forum/testgear/sdg800simply-but-different/msg334841/#msg334841Quote from: rbola35618 on December 06, 2013, 02:24:15 am

author: Electro Fan
author_rank: Super Contributor
timestamp: June 24, 2014, 02:35:31 am
content: In the video Siglent says the Rigol generator has rise and fall times of 200 micro seconds but in the Rigol spec sheet Rigol claims less than 12 nano seconds? Any idea whether Siglent is a bit hard on Rigol or if Rigol isn't really meeting their spec?http://www.tequipment.net/assets/1/26/Documents/Rigol/DG4062/dg4062_doc_1.pdf

author: tautech
author_rank: Super Contributor
timestamp: June 24, 2014, 05:51:05 am
content: Quote from: Electro Fan on June 24, 2014, 02:35:31 amI suspect it is a case of normal Test Equipment manufacturers "one-upmanship".The Siglent SDG1000 series is rated rise time in pulse mode of >7ns @1KHz 1V p-pSorry I don't have the SDG5000 series specs.Nothing flash from Rigol or Siglent as an 30 Yr old Phillips pulse generator is 3ns and is mostly discrete construction.

author: hans
author_rank: Super Contributor
timestamp: June 24, 2014, 07:36:08 am
content: Quote from: Electro Fan on June 24, 2014, 02:35:31 amBecause of course you're going to try and put your competitors products in a bad shade.Not very impressed by that though. Engineers are the kind of people that look at datasheets and specification tables, compare and make their own decision. That kind of "marketing" is probably better suited for the average Joe buying a new toilet cleaner.AFAIK my Rigol DS1000 function generator has a ~10ns rise time or so.

author: rf-loop
author_rank: Super Contributor
timestamp: June 24, 2014, 08:24:25 am
content: Quote from: tautech on June 24, 2014, 05:51:05 amOf course Philips can have 3ns risetime. Making fast risetime pulses is very easy.My very old HP do specifications 1.3ns and measured around 1ns - 1.1ns. My very very old Tektronix do 70ps risetimes.But in this Philips I do not think you can free adjust rise and fall times in pulse mode and what is resolution for adjust pulse width and period.But then, of coure Rigol or Siglent can do if they want fast risetimes... but these kind of equipments - Arbitrary Function generators need lot of filtering. These are not at all made for fastest possible risetimes. There is lot of much more important things.Also it is good to keep risetimes slow. If do fast risetimes for noobs then internet is full of stories and bullshitvideos how strange things and bugs my oscilloscope have (not so seriously...)..In this particular case Rigol loose with Siglent just as 0-1.Note that this example in video is pulse mode!Of course Rigol (example square wave) risetime is as Rigol specification.Also in pulse mode it have much faster risetimes BUT this risetime in pulse mode have relationship with pulse frequency (pulse period) in Rigol afaik. But no one force you to use pulse function in Rigol if want fast risetime but low period pulses.In Siglent you can produce narrow pulses in pulse mode. You can also free adjust rise and fall times from around 6ns.Here Siglent .Mode Pulse in both images and this is what Rigol can not doin pulse modeafaik.But I do not have Rigol for real compare tests. Of course also Rigols have its strong points. There is not perfect universal machine what all things are best possible. One is strong with some things and one with some other things.What is best for some purpose or for some user it depends needs. If people do not know what he need then situation go very easy to point where try find universal machine what is good in all things and have lot of and some amount more functions so that becouse do not know what need then want all so that "if some day need". This is typical hobbyist problem with very limited budget and lack of knowledge what really need and what really do not need.Some people may also select so that how equipment looks "professional" on his table and he can tell to friends that I have this name and model of equipment and then friends look that oh you are clever. This effect can see also in other area than electronics.Good example is photographing. Peoples who have never take any single good photographs are talking about is Canon better than Nikon etc... and this Nikon have this some deep parameter or feature and function and this and that and canon is bullshit because it do not have this kind of dingledongle.But when they walk on the street, and other photographer see that he have this name and this model he "know" this guy is sure "professional"......and then some long time photographing "enthusiast" (with low budget) take very good picture with cheapest chinese pocket camera and win some photo competition... just because he know how to take good photograph.picture 1.Pulse frequency 100mHz (pulse period 10 seconds )Pulse width set 20.0ns Pulse risetime set 6nsPulse fall time set 12nsPulse rise and fall time can free set from 6ns to veeery slow. Example if pulse width is 1ms then rise or fall time can set to example 900us(this is not limit) and 6ns as shortest possible setting.There is small inaccuracy in shortest 6ns. In model 5082 (80MHz model)Picture 2Pulse width 1msRise 6nsFall 1msPeriod 1s (freq 1Hz)Both images are normal acq mode, Sin(x)/x off and just single shots and display mode dots.For image 2. SDS2304 run in Zoomed and in image just realtime one shot.Do these with Rigol using Pulse mode.

author: rf-loop
author_rank: Super Contributor
timestamp: June 24, 2014, 08:27:26 am
content: Quote from: hans on June 24, 2014, 07:36:08 amYes, Agilent and Tektronix are manufacturers who make toilet cleaners...heheHave you read many Agilent/HP and Tektronix papers where they always do this. And these papers are made for T&M professionals.Of course also chinese in mainland China and on the Taiwan island and have learned this lesson. And more is coming.In some Hewlett-Packard and later Agilent papers there is lot of "dirty things" but... if read carefully they do not exactly lie.It is a little questionable when done well hidden, aggressive advertising, hiding it, "applicaton Note" papers. They are readed by many engineers as the fact as of learning materials and used also as references. Actually they are least partially clever (and dirty) advertising..

author: KedasProbe
author_rank: Frequent Contributor
timestamp: June 24, 2014, 09:09:53 am
content: If I remember correct is that the Rigols rise/fall time in pulse mode is limited to a certain minimum percentage of the total period (meaning frequency dependent), while the Siglent is not or not that much limited.

author: rf-loop
author_rank: Super Contributor
timestamp: June 24, 2014, 09:20:35 am
content: Quote from: KedasProbe on June 24, 2014, 09:09:53 amSiglent is not limited.In pulse mode down to 1uHz (period 1000000s) and up to 20MHz (period 50ns)Risetime and fall time setting bottom limit is same 6ns.

author: tautech
author_rank: Super Contributor
timestamp: June 24, 2014, 09:28:15 am
content: Quote from: rf-loop onTodayat 06:24:25 PMPhillips PM5771 with adjustable rise and fall range from 2.4 ns to 100 us in 4 fine adjustable ranges.It is a dedicated 1 Hz to 100 MHz pulse gen.

author: jpb
author_rank: Super Contributor
timestamp: June 24, 2014, 09:49:06 am
content: Quote from: KedasProbe on June 24, 2014, 09:09:53 amThis is the key thing that Siglent are pushing in their video. They resample/re-interpolate pulse data in a much simplified version of what Agilent do for general waveforms with their TruForm resampling.The resampling alows fast rising edges on long pulses. The Rigol system just sets the pulse up in memory (if my understanding is correct) so the shape of the pulse is scaled by the overall pulse length which means long pulses have slow rise times. The problem is exacerbated with Rigol as it has a relatively short memory of just 16k.For short pulses Rigol has very fast rise times

author: rf-loop
author_rank: Super Contributor
timestamp: June 24, 2014, 09:54:56 am
content: Quote from: tautech on June 24, 2014, 09:28:15 amo-ou... oh THIS Philips. This model I have never meet.My HP 8161A (with some options (100MHz, double channel etc)) is also programmable pulse generator. It can not do sine etc. It is also just pulse generator. Specified for <=1.3ns risetimes and of course also with adjustable rise and fall times. This my unit is made 1989 and works as new.

author: rf-loop
author_rank: Super Contributor
timestamp: June 24, 2014, 10:09:48 am
content: Quote from: jpb on June 24, 2014, 09:49:06 amBtw, why need arb memory for doing slow period pulses?But what they do is some trics with used DAC's.Note that it is 500MSa/s system. Pulse risetime/fall time setting resolution is 0.1ns and width setting resolution 0.1ns but not all widths. In some wide pulses it is 1ns and example then 100s period and 10s width this width can set with 1us resolution. <1us width resolution is 0.1ns

author: jpb
author_rank: Super Contributor
timestamp: June 24, 2014, 10:52:00 am
content: Quote from: rf-loop on June 24, 2014, 10:09:48 amI think the Rigol at least is a straight forward DDS system without any means of sequencing or adding any extra delay.This means that it uses the fixed memory and just selects the memory location to next feed to the DAC using a phase accumulator which is incremented at a rate dependent on the frequency being generated.For slow period pulses each memory location will represent multiple actual samples at the 500MS/s fixed output rate but the time resolution will be determined by the number of memory locations. So given 16k of memory and say a 10 mS pulse period the size of each memory location will be 1E-2/16,384 seconds = 610 nsecs approx and if you need say 1 point on the slope itself the length of the slope will be of the order of 1200 nsecs even though the output samples are being sent with a gap of only 2 nsecs between them.What I presume Siglent does is to split the memory in some way so that the edges are treated differently to the flat parts of the pulse. Doing this means you can use different time scales for each part and have much more flexibility.

author: tautech
author_rank: Super Contributor
timestamp: June 24, 2014, 11:23:20 am
content: While I can't answer you question in depth I can supply some specs.Siglent SDG5000 series 500MSa/s and "Up to 512k sample points of internal waveform depth"

author: Electro Fan
author_rank: Super Contributor
timestamp: June 24, 2014, 02:41:05 pm
content: The Rigol spec sheet says for a pulse period of 66.7ns and a pulse width of 18ns the leading and trailing edge times will be 11ns. Now to be specific the specs are shown as equal to or greater than rather than less than; also they are distinguishing between "rising and falling" (which they provide elsewhere in the spec) and "leading and trailing". Maybe someone with a DG4000 could do some tests to see if it really lags so far behind the Siglent performance?

author: jpb
author_rank: Super Contributor
timestamp: June 24, 2014, 02:49:59 pm
content: Quote from: Electro Fan on June 24, 2014, 02:41:05 pmThis has been discussed in this thread :https://www.eevblog.com/forum/testgear/rigol-dg4000-arb-gen-as-pulse-generator/msg416483/#msg416483Quote from: kg4arn on August 25, 2012, 05:05:20 pm

author: Electro Fan
author_rank: Super Contributor
timestamp: June 24, 2014, 03:01:51 pm
content: Quote from: jpb on June 24, 2014, 02:49:59 pmJust checking to see if I understand; the answers seem to be:1. On the Rigol DG4000 as the period becomes relatively longer the pulse rise and fall times become less impressive using the pulse feature, but if you create a pulse using the arb capability you can work around the limitations of the pulse feature?2. For the pulse feature the Siglent outperforms the Rigol DG4000 on relatively long pulses when it comes to rise and fall times.Please feel free to correct me on this. Thx, EF

author: jpb
author_rank: Super Contributor
timestamp: June 24, 2014, 03:24:59 pm
content: Quote from: Electro Fan on June 24, 2014, 03:01:51 pmFirst, I should point out that I don't have a DG4000 but I have studied them a lot whilst trying to make up my mind as to what signal source to buy.Using arb you can create long pulses with a fast edge BUT you have to make the edge abrupt so you only have "fast" as an option not some prescribed slope. You can of course make your own slope using the data points but this runs into the issue of each data point being a relatively large time step equal to at least period/16,384. So you can have a rise time of around 5 nsecs (depending on the amplitude as the Rigol has different bandwidths for Vpp < 4V or > 4V) but you can't have a rise time of say 10 nsecs on a 100 msec pulse.The other drawback of arb is you'll probably have a bit more ringing.Siglent's scheme appears to be much more flexible - RF-loop did some measurements in his review:https://www.eevblog.com/forum/testgear/tests-siglent-sdg5082-waveform-generator/30/

author: Electro Fan
author_rank: Super Contributor
timestamp: June 25, 2014, 04:02:00 am
content: Anyone know how the arb waveform-creation PC software compares on the Siglent vs. the Rigol DG4000 in terms of flexibility and ease of use?