Siglent SGD2042X rotary encoder poor performance

[szszoke]

I have a Siglent SDG2042X and I'm really disappointed in the rotary encoder's performance.

Unless I turn it really slowly, it either skips steps or even counts backwards.

I have an SPD3033X-E and while the rotary encoder performance is not perfect there either, it is a lot better.

I tried contacting product support from Germany and I got a reply that the SDG2042X should not have worse rotary encoder performance than the SPD3033X-E.

Well. It is a lot worse for me.

The person asked for a video where the issue is visible.

After I sending that video I feel like I was ghosted so I'm posting here in the hopes of learning more about this issue.

My observation is that if I turn the knob on the SPD3033 at a rate of about 5 detents/seconds, the unit registers at least 4 steps.

If I do the same on the SGD2042, the unit registers 1 or maybe 2 steps but very often it counts 1-2 steps in the wrong direction.

Can someone try their own unit and tell me if the rotary knob behaves the same way?

Here is the link to the video:
https://youtu.be/R8IEwfWY9nI

[electr_peter]

I can confirm slow rotary encoder on Siglent SDG2042X with latest FW 2.01.01.35R3B2. I would prefer for it to respond faster, it is pretty slow. Rotary encoder misses some faster steps, but do not change direction or do something random. It is not a bug IMHO

SDG2000X FW revision 2.01.01.35R3B1 has a note on rotary encoder:

Fixed several bugs
a) [2017/04/07-92573] Digit changes when setting delay of Pulse by the knob

t seems there were some problems with rotary encoder and button debouncing (Dave noted that on SDG2000X review video, EEVblog #806​ - Siglent SDG2000X, 17:20) so Siglent made very conservative button debouncing algorithm. As a side effect, this slows down rotary encoder response rate.

[szszoke]

I can confirm slow rotary encoder on Siglent SDG2042X with latest FW 2.01.01.35R3B2. I would prefer for it to respond faster, it is pretty slow. Rotary encoder misses some faster steps, but do not change direction or do something random. It is not a bug IMHO

SDG2000X FW revision 2.01.01.35R3B1 has a note on rotary encoder:

Fixed several bugs
a) [2017/04/07-92573] Digit changes when setting delay of Pulse by the knob

t seems there were some problems with rotary encoder and button debouncing (Dave noted that on SDG2000X review video, EEVblog #806​ - Siglent SDG2000X, 17:20) so Siglent made very conservative button debouncing algorithm. As a side effect, this slows down rotary encoder response rate.

I don't think that the issue Dave found at 17:20 is related to debouncing. I would expect missed steps/double steps but nothing like that seems to happen. The fact that the selected digits jumps back one position when crossing zero seems to be more of a software thing.

The rotary encoder seems to be a lot faster on the video. That tells me it was working fast at some point but somehow a firmware update managed to break it.

[szszoke]

I just received a reply to the email that I sent to Siglent and they were able to confirm the issue on at least one unit.

I will send them a link to this post.

If you have this issue and want it addressed, please write in this thread.

It would be helpful to know if this is a widespread issue or just limited to a few users.

Please also write if your rotary encoder works better than what you can see on my video.

[electr_peter]

I tested it more carefully. Rotary encoder responds to slow pulses fine, a bit faster pulses are still recognized and from a bit faster speed almost all pulses are lost. Slow - fine, medium - fine, fast - misses almost all steps.
To achieve actual changes, user must not overspeed on the knob. That is annoying.

I compared with other test gear, almost all looked better in this regard. Most encoders respond correctly to fast input, some respond slow, but at least respond somewhat. Siglent is worse because it stops counting pulses on fast rotation.

In video encoder is turned a bit faster than break-over point, thus most pulses are not recognized. It has same behavior to my eye as unit at hand.

This all points to mechanical encoder and limited processing speed on FW side. Currently maximum "allowable" turning speed is too slow.

[exe]

I haven't powered my sdg2042 since a while, but as far as I remember, the encoder performance was always disappointing for me, I complained about it here a few years ago (strangely nobody else reported that). Worse yet, my encoder has one dead spot.

[joeqsmith]

I have a Siglent SDG2042X and I'm really disappointed in the rotary encoder's performance.

Unless I turn it really slowly, it either skips steps or even counts backwards.
....

Old post but we recently purchased one of these brand new.  A toe dip into the world of Siglent.   I would expect it to be a later model than the one you have.  I see the same symptom.   I can't believe they would release it like this but I suspect it's a good indication of their general quality. 

[pope]

Same with the SDG1032X. Pretty disappointing.

[joeqsmith]

Clip of the new Arb.   My camera had a problem with that light blue on light blue lettering.  Not the best contrast.   

[slavoy]

Try to update the firmware.

2/16/2020 1.01.01.33R1B6 1. Optimized debounce of the front panel buttons

https://www.siglenteu.com/service-and-support/firmware-software/waveform-generators/#sdg1000x-series

[joeqsmith]

Looking at the system info, it was shipped with the latest firmware installed.   

[slavoy]

I also bought mine a few days ago. I repeated what you did in your video and my generator doesn't act that way. The only similarity is that it counts encoder pulses up to a certain speed. It should be more responsive. But it rarely goes back one digit. I have to turn the knob very quickly. Mine is also updated to 1062X from the tutorial on this forum and does not have the latest firmware. Perhaps that also matters or simply the encoder is broken.. I did the update practically right after the purchase.

[brainwash]

Maybe only tangentially related: I looked inside a higher-end OEM car stereo unit and they had a separate 8051 handling the volume encoder. This was >10 years ago. At that time I thought that was needlessly complicated, but have been bitten a lot by shoddy encoder implementations.
I suspect that the software polls (instead of using interrupts) the state and this tested fine while there were no features in the device. Once you start adding features, the encoder check loop doesn't run as often and you get missed pulses or reversal. Or maybe they are using interrupts which are being preempted by other ones.

[joeqsmith]

I also bought mine a few days ago. I repeated what you did in your video and my generator doesn't act that way. The only similarity is that it counts encoder pulses up to a certain speed. It should be more responsive. But it rarely goes back one digit. I have to turn the knob very quickly. Mine is also updated to 1062X from the tutorial on this forum and does not have the latest firmware. Perhaps that also matters or simply the encoder is broken.. I did the update practically right after the purchase.

When you have no quality control, I expect the products will not behave the same.  I'm surprised that they wouldn't have caught it during the final functional test.  Maybe they skip that step.  Also possible, that what I show is considered acceptable to them.   

From my own perspective, I expect test equipment to work out of the box.  There may be some bugs but I expect the basics to all be solid.  This encoder is pretty much the cornerstone of the UI if I were to use the unit standalone.   I didn't spend any more time looking at the unit because of this one problem.  The thought that they couldn't even get this right doesn't give me a lot of confidence in the rest of the design.   

[TurboTom]

SDG6000X shows the same crappy encoder behaviour. Even at fairly moderate speed (i.e. thumb and index finger controlled rotation), it shows occasional "hickups". Fast turning results in unpredictable counting results, even reversal can be observed, just as Joe pointed out.  Since my "instument under test" has about three years under the belt, I cannot tell for sure if its performace was as poor as that right from the start but I remember I've never been to amazed by the U/I's look and feel, partly related to the encoder...

[joeqsmith]

Viewer posted a comment suggesting that the Siglent doesn't maintain the correct version numbers in their released firmware.  The suggestion is to program the Arb with the latest firmware even though it appears to already have the current release.   Its the pinned comment if interested.

Is there a way to save the firmware from the Arb to the USB stick before loading the new?  If indeed they are correct, the last thing I want to do is destroy the evidence.

[Fungus]

Wonder where the Siglent reps are...?

[joeqsmith]

Wonder where the Siglent reps are...?

In the OP, seems they tried to contact them a year ago. 


***
SP

[joeqsmith]

It looks like the video satisfied the group suggesting to reprogram the same firmware into the arb.   

Interesting how many suggest not using the encoder or turning it slower.   Looking at my home TE, much of it that has a dial offers a recess to insert your finger (see attached), or they have a suicide knob on them.   The Siglent doesn't have this feature so my finger tends to slip. 

When I run a signal generator standalone, it's not uncommon that I will use them dynamically.  I may sweep the frequency, duty cycle, voltage by hand for a quick test.  That encoder needs to be smooth and I don't want to think about it skipping and flipping directions.   It's difficult to create a linear ramp when the variable you are adjusting is changing directions.   

I've shown where even at home I will use LabView to automate my equipment.  That's great for some experiments but there are cases I just want a quick and dirty source.  The encoder really shines as a UI for these applications (there's a reason for them).   Siglent just doesn't seem to understand how they are used.     

For those suggesting to just buy better equipment,  we do.    It's not mine and I will not be pulling it apart to show the internals or attempting to hack it.   
**
poor wording.

[joeqsmith]

Talking with a friend of mine, they also have the same arb and it too has the same encoder problem.

SDG6000X shows the same crappy encoder behaviour.

Plenty of people commented how they do not have a problem with the encoder.   I was thinking to get a higher end Siglent for my home use but from the photos, I assumed it was the same encoder and your comment gave me no confidence that a new one would be any better.   I could get one and then modify it but one person wrote me about all the firmware problems they had ran into with theirs.     

[joeqsmith]

tautech  3 weeks ago
This ^ yet Joe does have a quite reasonable expectation for the encoder to perform better than it does however one doesn't normally use the encoder for large adjustments when keypad use is faster and more precise. Despite this, the issue of encoder performance is in front of high ranking personnel at Siglent for them to review and review they should as their products are making headway onto the benches of experienced engineers many of which have only previously used A brand equipment. Poor performance will only have them resist obtaining further Siglent products. Nevertheless here in NZ SDG1032X remains our most popular AWG.

Makes you wonder why they include an encoder if their customers use the keypad.  Personally I am a fan of having the encoder for reasons I previously mentioned. 

As I mentioned, I am thinking to get one for my own private use.  Does the encoder work any better on Siglent's higher end units?   
https://siglentna.com/waveform-generators/sdg2000x-series-functionarbitrary-waveform-generators/

[tautech]

tautech  3 weeks ago
This ^ yet Joe does have a quite reasonable expectation for the encoder to perform better than it does however one doesn't normally use the encoder for large adjustments when keypad use is faster and more precise. Despite this, the issue of encoder performance is in front of high ranking personnel at Siglent for them to review and review they should as their products are making headway onto the benches of experienced engineers many of which have only previously used A brand equipment. Poor performance will only have them resist obtaining further Siglent products. Nevertheless here in NZ SDG1032X remains our most popular AWG.

Makes you wonder why they include an encoder if their customers use the keypad.  Personally I am a fan of having the encoder for reasons I previously mentioned. 

As I mentioned, I am thinking to get one for my own private use.  Does the encoder work any better on Siglent's higher end units?   
https://siglentna.com/waveform-generators/sdg2000x-series-functionarbitrary-waveform-generators/

Had a SDG2042X out for PD checks today and I can make the encoder skip if I twist it fast enough as will a SDG6022X also however in the way I normally use these and don't forget I have used these for many years a skipping encoder has never been an issue and really only noticed it when you did a video about it but not as a result of a YT follower but it came up randomly on my YT page refresh.
Nearly a decade back SDG1000 (before 1kX) their encoders and/or keypads did play up until a firmware update was released that specifically targeted debounce issues which fixed those units until szszoke and you raise this issue again.

FYI Siglent arbs have always sported both keypads and encoders and we each have a preferred way of using them which for me is small increments usually always with the encoder and large ones with the keypad as I often find my time precious so need to use any instrument in the most efficient way.
YYMV.

I can't comment on encoders in SDG7000A arbs until one crosses my desk however at the price they are that might be quite a while.

Has your SDG1032X encoder settled with some use ?

[hpw]

I have a Siglent SDG2042X and I'm really disappointed in the rotary encoder's performance.

If I do the same on the SGD2042, the unit registers 1 or maybe 2 steps but very often it counts 1-2 steps in the wrong direction.

Can someone try their own unit and tell me if the rotary knob behaves the same way?

The point is that is a mechanical piece and has it's MTBF. So cheap as it gets to survive the warranty period. 


The question will be:

- how to replace or damage the sandwiched gear, or requires a full/complete front to replace

- where and which part to order, length, solder figures to PCB, steps incremental,  knob to fit over


my LeCroy WM8000A (2003 manufactured) did the same on horizontal stepping, RS-Component as original as about 3$/piece and gear at may at xx..xxxk US as new 

 

[joeqsmith]

my LeCroy WM8000A (2003 manufactured) did the same on horizontal stepping, RS-Component as original as about 3$/piece and gear at may at xx..xxxk US as new 

Most of my equipment is in that 20+ year old range as well.   So far, I have not had any problems with encoders outside of some that had been damaged during shipping  (broken shafts).   

The Siglent was new in the box from the factory and it seems a common problem with the brand.  I can't imagine having a scope of other equipment from them with problematic encoders.   

[electr_peter]

Siglent released new firmware 2.01.01.37R3 for SDG2000X, it is discussed on the forum. FW upgrade seems to improve rotary encoder operation IMO.