Siglent Technologies SDS1202X-E  -  FREQ MEASUREMENT CAPABILITIES.... - Page 1
Forum section: electronics / testgear

author: Hank69
author_rank: Contributor
timestamp: February 16, 2023, 05:10:33 am
content: I am looking at the above scope for home hobby work and specifically in the lower frequency range. I understand that this unit "may" have issues measuring/displaying low frequencies, I.E. < 100, <10 HZ. From what I've read the unit has a hardware freq counter and not sure if also an actually measured value is process by the scope CPU itself. Any replies from users that may have used this model to measure/display the low frequency stuff will be appreciated.... Thanks, HankP.S. I have seen pictured units with a display of f=500.000 HZ - top right corner of scope and this would leave one to believe it may be capable, but, can't trust the advertising illustrators....

author: tautech
author_rank: Super Contributor
timestamp: February 16, 2023, 08:01:43 am
content: Typically 10 Hz is as low as you can go however for the 4ch version the recently added Counter allows for lower frequencies and the other rule of thumb is to have a full period displayed rather than just a part of one.Frequency measure and HW counter start displaying instability below 10 Hz.HW counter results are dependant on trigger levels and this can be used to advantage at times.Some SDS1104X-E screenshots attached FYI showing simple measure, Statistics, Counter and at top right the HW counter.Signal source SDG6022X

author: Hank69
author_rank: Contributor
timestamp: February 16, 2023, 03:52:11 pm
content: tautech, Thanks for the reply. I will just order this SDS1202X-E and run it through it's paces. I totally agree to have the scope give you the best information you have to "feed" it at least one or more waveforms to get the picture.... I was able to measure in the 5.xx Hz range, sub 10 Hz with my Hanktek DSO2C15 and thought a "better" scope - Siglent - would have equal to or better performance than a scope half the cost....

author: bdunham7
author_rank: Super Contributor
timestamp: February 16, 2023, 04:24:35 pm
content: Quote from: Hank69 on February 16, 2023, 03:52:11 pmI'd highly recommend you consider the SDS1104X-E instead. I know it is more money, but it is also much more than a 4-channel version of th SDS1202X-E. I wouldn't generally rate scopes based on one seldom-used (by most) feature, although of course you should consider what is important to you.The 1104X-E has 3 different frequency counters. The first trigger-based simple counter, the most basic, goes down to 10Hz. The hardware counter is reciprocal and goes down to 2.00000Hz, although it appears there can be issues with this at the very limits depending on your capture length and so forth. The measurements menu has a frequency counter that works explicitly with the screen capture so you have to set the scope up correctly to get this to work. However, it goes well below 2 Hz, although with not so many decimals. I'm conducting an experiment now to see how low I can get it to go--I'll post it in a while.Finally, you always can use the cursors and measure frequency manually. Since the slowest sweep speed is 100s/div, in theory you could get down below .001Hz. You would have to be very patient!

author: bdunham7
author_rank: Super Contributor
timestamp: February 16, 2023, 08:01:35 pm
content: So here are some very low frequency measurement examples. These captures take a long time (1400 seconds!) but in the first two you can see the result from the measurements menu, which requires at least two trigger events to be in the capture (on the screen). It accurately measures 10mHz and then 2mHz. When you try to do 1mHz, you run into the problem that even though an entire waveform fits, you might not have two trigger events dependign on random luck. In the third picture, the meeasurement has failed because there of where the waveform is. It might work on another capture. So the lowest guaranteed reading would be about the point where you have two full waveforms on the screen, or about 1.42mHz. If you use the manual method and cursors, in theory you could measure about half that, or about 714µHz.Obviously you probably won't need to go that ridiculously low, but that's how you go about it. AFAIK, the SDS1202X-E will do this last method and cursors, but doesn't have the hardware counter.

author: Hank69
author_rank: Contributor
timestamp: February 16, 2023, 11:47:56 pm
content: Thank to my repliers ;-)My projects are not complex circuits, just control and command of various "retirement projects" around the house and a few that are not in the "operate fast mode", but, with circuits operating in the sub 10 Hz range. ME/WE may think ME/WE may need more scope than ME/WE think ME/WE may need.... I'LL STOP NOW.... My Hantek DSO2D15 will, in reality, perform all I REALLY need to do.... (AND, it can measure 7.38 Hz very well)....

author: Roger Need
author_rank: Regular Contributor
timestamp: February 17, 2023, 12:22:14 am
content: Quote from: tautech on February 16, 2023, 08:01:43 amTautech,As a distributor you have contacts at the Siglent factory. Have you heard if they will be updating the 1202X-E to have the FFT marker plotting and counter features of the 1104x-E?Roger

author: tautech
author_rank: Super Contributor
timestamp: February 17, 2023, 12:37:51 am
content: Quote from: Roger Need on February 17, 2023, 12:22:14 amTBH I doubt they ever will.Plenty of time has gone by that several features from 4ch X-E may have been added but zip has been done.There are more features in the 2ch SDS2202X-E but it costs more than the 4ch SDS1104X-E and still lacks some features those good little scopes have.But later this year we will have further choices but sorry at this time can't disclose.

author: BillyO
author_rank: Super Contributor
timestamp: February 17, 2023, 01:52:59 am
content: I maybe seeing things but I think I see the writing on the wall for end to 2ch scopes.

author: Hank69
author_rank: Contributor
timestamp: February 19, 2023, 04:49:59 pm
content: During the process to choose a scope that WILL read/measure a sub 10 Hz signal, I did discover during my "Scope go round" testing that the SDS1202X-E DOES measure these signals. The attached pix shows that even though the top right "freq box" only displays an "f< 10Hz", in the measurement option screen there is a bevy of options of which to choose that will display the data at the bottom info bar and is also measured with a cursor measurement - see pix.... The Hantek DSO2D15 which I also tested, did a very good job with these low frequencies, but, for just a "few" dollars more, the features and quality of operation of this Siglent model will be my scope of choice....