Siglent Bench DMMs SDM3065X, SDM3055 and SDM3045X

[inzekt]

Yeah, that's why I'm a bit upset. And it is a regular thing with Chinese manufacturers, that there are a lot of inconsistency and trial/error in their product range. I'm glad that we have opportunity to own such capable devices such a low price point, but have to be realistic about what to expect in terms of regulations, conformity and consistency when it comes to documentation and specifications. Even with a product that is more than 8 years old in the lineup. After 8 years, one of the main specification aspect is overlooked in the documentation is worrying

Nevertheless, I'm all-in-all happy with it, it's a good instrument and only managed to freeze it two times via the dual display feature

[tautech]

Nevertheless, I'm all-in-all happy with it, it's a good instrument and only managed to freeze it two times via the dual display feature

Please state FW version installed.

[inzekt]

It's the latest firmware.

[PushUp]

Sorry, for disturbing this "Siglent" topic, but I was curious about the behaviour of my 5¾-digit with 480.000 counts...


Unfortunately, my cheap power supplies are not good enough, to come any closer, but I am quite happy with the result, as this DMM is also quite old and has never seen a newer FW for years... - still hoping to get a successor with a bigger display:





Cheers!

[jysd]

Anyone had issues with their SDM3065X resistance measurement being off, like completely off? Measuring a 4.3kOhm resistor and it reads 3.88843kOhm while my Brymen BM869s reads 4.2960kOhm (which is correct).

I was reading a KTY-sensor with the meter and got confused as the KTY seemed to be off by like 6 degrees C (in a range where it's supposed to be +-1.5C accurate). Tried the Brymen and got correct readings.

I've not used the benchDMM much at all (it states 24 starts since I bought it a couple of years ago), so I can't say if this is something that has happened now or been there from the beginning.
From what I can tell the voltage measurements are just fine, or Brymen and the Siglent seem to agree on numbers at least

Anyone experienced something like this before or got any input?

EDIT: Sorry, forgot to say that I have tried 4 wire measurement, exact same error(s).

[inzekt]

Anyone had issues with their SDM3065X resistance measurement being off, like completely off? Measuring a 4.3kOhm resistor and it reads 3.88843kOhm while my Brymen BM869s reads 4.2960kOhm (which is correct).

I was reading a KTY-sensor with the meter and got confused as the KTY seemed to be off by like 6 degrees C (in a range where it's supposed to be +-1.5C accurate). Tried the Brymen and got correct readings.

I've not used the benchDMM much at all (it states 24 starts since I bought it a couple of years ago), so I can't say if this is something that has happened now or been there from the beginning.
From what I can tell the voltage measurements are just fine, or Brymen and the Siglent seem to agree on numbers at least

Anyone experienced something like this before or got any input?

If you zero the leads, what does it say? Also did you try to measure it with a 4wire method also? Is the resistor in-circuit?

[tautech]

Anyone had issues with their SDM3065X resistance measurement being off, like completely off? Measuring a 4.3kOhm resistor and it reads 3.88843kOhm while my Brymen BM869s reads 4.2960kOhm (which is correct).

I was reading a KTY-sensor with the meter and got confused as the KTY seemed to be off by like 6 degrees C (in a range where it's supposed to be +-1.5C accurate). Tried the Brymen and got correct readings.

I've not used the benchDMM much at all (it states 24 starts since I bought it a couple of years ago), so I can't say if this is something that has happened now or been there from the beginning.
From what I can tell the voltage measurements are just fine, or Brymen and the Siglent seem to agree on numbers at least

Anyone experienced something like this before or got any input?

Please confirm firmware version in use.
3.01.01.12R1 is the latest.

[jysd]

Sorry forgot to say that I have tried 4 wire measurement, same error.
One pair of leads (Sensepeek with pogo pins) reads 0.22 Ohm
Brymen leads read 0.12 Ohm (0.10 Ohm on BM869s)

It happens that they have been in curcuit measurements, even the KTY measurement that goes to a soldering pen/tweezer because it was connected to the board.
For the 4.3k at least one end of the path is or should be high impedance.

I can't really reproduce it now with external resistors, of course. I think I might have jumped to conclusions and should probably have done some more testing before writing out here

I just double checked with the BM869s, I get slightly different readings 4.283 vs 4.296 depending on which "direction" I'm measuring on the resistor, and yeah that should perhaps have been a giveaway.
Probably just a coincidence that BM869s gave accurate measurements "in circuit" while the Siglent didn't :S

I'll wear the dumb-hat and be happy that my meter seem to be OK. Sorry for the noise!

[PushUp]

SDM 3055 with 220.000 counts vs. 240.000 counts
SDM 3055X-E with 240.000 counts


Just in order to end this discussion for my brain and maybe some other users, I checked my PDF-Collection:

Considering the fact, that it is the old bumper design of the SDM 3055 - like the one mjlorton shows in my previous posted yt-video, the official "Siglent-Products-Selection-Guide-March2020" from 2020 clearly speaks from a 240.000 counts DMM. I may find a newer catalogue with the newer bumper design, but as I want to end this discussion in a calm way, I will not search any further...





From what I have read so far, any/some/most Siglent DMMs do not boot any more, as long as you don't update to the latest FW, which may withdraw you an ability you may had, once you bought it?! That is, at least for me, not the best behaviour to trust in a brand like Siglent...because not anyone having a Siglent DMM does know the EEVBlog-Forum with tautech and his indefatigable work for ages... 


I haven't seen the model SDM 3055X-E in Europe so far, but as mentioned before, it seems to be like the good old one being used by mjlorton in his yt-video:





...where it "also" speaks from a "real" 240.000 counts DMM:






Cheers! 

[KungFuJosh]

They're capable of 240,000 counts, but for whatever reason, Siglent decided to limit them to 220,000.

I have the 3055X-E latest firmware, and it is also limited to 220,000 counts. I don't know who cares enough about that difference to use outdated firmware.

[PushUp]

The only Siglent device I have, is a cheap scope SDS 1202X-E. I also had problems with a FW update in between, so that I went back to the oldest FW, as I couldn't save pictures... Luckily, I have never had a boot issue, like the users of a Siglent SDM DMM, despite the old FW on my 1202X-E.
The latest FW, however, solved this USB problem, so that I have nothing to complain any more, apart from the fact, that I haven't used the scope for 2-3 years... Ha ha ha... 


Unfortunately,  I don't know, whether this is a good idea, to try the same thing I did with my scope, going also back to an older FW, when it may does not boot any longer afterwards...thus you need a special medicine, which only tautech distributes via this EEVBlog-Forum via PM, which is also quite confusing... 

Considering the latest datasheet of the Siglent SDM 3055X-E, I posted above, you should have at least a claim to get your money back, to buy another brand, because this is definitely not a fine move by Siglent...or they should resolve this 240.000 counts thingie, when it is done by mistake.

Best wishes for your decision - or maybe tautech has a further solution for you?!


Cheers!

[tautech]

The only Siglent device I have, is a cheap scope SDS 1202X-E. I also had problems with a FW update in between, so that I went back to the oldest FW, as I couldn't save pictures...

Only a few were affected by this, AFAIK USB stick incompatibility.

Unfortunately,  I don't know,..............when it may does not boot any longer afterwards...thus you need a special medicine, which only tautech distributes via this EEVBlog-Forum via PM, which is also quite confusing... 

Every Siglent branch has the same tools we have and share most of them on request and every good supplier should be able to source them too to support their customers....if they could be bothered. 

[Mortymore]

...
Considering the latest datasheet of the Siglent SDM 3055X-E, I posted above, you should have at least a claim to get your money back, to buy another brand, because this is definitely not a fine move by Siglent...or they should resolve this 240.000 counts thingie, when it is done by mistake.
...

Josh has an "SDM 3055X-E" just because he upgraded his SDM3045X

And about the Siglent PDFs collection for the SDM3055, there's info wrong in them, some that were never right and after the latest update of the manual, are still wrong, and  some have been corrected, but there's also information missing of functions added through firmware updates previous to the latest manual release.
So, don't expect to get an intel of all the functionality of the meter, or assertiveness of what it's stated in the manual.

[PushUp]

Well, speaking for those having a real "Siglent SDM 3055/3055X-E" my sense of what is right or wrong is very simple: When a brand does promote its product with pictures as shown above, of being able to measure 240.000 counts, to get a selling advantage about rival companies, there is no denying the fact, that you take away an essential property, when you do it via a FW update within the same series.

The time dependent boot problem of Siglent SDM DMMs is a reason for me, not to buy this product; normally a FW update gives you more features and/or improves stability. This behaviour to withdraw a pre-assured property, proved by their own official pictures and own product descriptions, is a no go, as long as this is not done by mistake and will be resolved - this is just my simple sense of justice.


Cheers!   

[Martin72]

    

[KungFuJosh]

...
Considering the latest datasheet of the Siglent SDM 3055X-E, I posted above, you should have at least a claim to get your money back, to buy another brand, because this is definitely not a fine move by Siglent...or they should resolve this 240.000 counts thingie, when it is done by mistake.
...

Josh has an "SDM 3055X-E" just because he upgraded his SDM3045X

And about the Siglent PDFs collection for the SDM3055, there's info wrong in them, some that were never right and after the latest update of the manual, are still wrong, and  some have been corrected, but there's also information missing of functions added through firmware updates previous to the latest manual release.
So, don't expect to get an intel of all the functionality of the meter, or assertiveness of what it's stated in the manual.

More importantly, I love my Siglent DMMs. I don't care at all about the minor difference in counts, it makes no difference to me. Ohhhhh no! My meter changes range at 2.2V instead of 2.4V...what am I going to do?? 🤣

For the record tho, the 3045X and 3055X-E are identical hardware; they dumbed it down for the global market to make extra money on the older 3055 (non X-E).

[Kleinstein]

The change in the range at 22 V or 2.2 V (for the 3055) can be an issue, as the higher ranges are no longer high impedance. It's only a few applications, but it can be a deal breaker for a few.
Not sure why they reduced the range: could be a mistake, problems with some units to properly work all the way to the old full range, or for the 3065 maybe also a calibration issue as some calibrators get a lot worse above 22 V.

[KungFuJosh]

The change in the range at 22 V or 2.2 V (for the 3055) can be an issue, as the higher ranges are no longer high impedance. It's only a few applications, but it can be a deal breaker for a few.
Not sure why they reduced the range: could be a mistake, problems with some units to properly work all the way to the old full range, or for the 3065 maybe also a calibration issue as some calibrators get a lot worse above 22 V.

It makes no difference to the 3065X. The 3065 is 2,200,000 counts, and only ever stated an overage of 10% per range. 2.2V was always the changing point for that one.

[tautech]

The time dependent boot problem of Siglent SDM DMMs is a reason for me, not to buy this product; normally a FW update gives you more features and/or improves stability.

There is NO time dependency regarding boot freezes and FW releases have until recently helped remedy the NAND flash problem.
But, if you were to keep up with developments these last few weeks you will have noticed a completely new OS for SDM3055 is in the latest FW versions, which if we are to interpret this correctly, should bring an end to boot freeze issues.
And added support for 30A shunts.....which I am to compare with a 30A HPAK shunt when I visit Defpom today.

Even HPAK has their issues with boot freezes......

[TheDefpom]

I actually think that the count changed from 24 to 22 when they added the user calibration to the meters, so it might be my fault LOL. 

When I built the web page to generate calibration adjustment files for the Siglent meters all references and information (even from feedback I got) pointed to the 3045/3055 being 24 count, so I had to build that in.

When I did the SDM calibration adjustment demonstration video I pushed Siglent to improve the firmware on all meters to add user calibration, this, to their credit, they did do, however I think at that same stage they may have decided to make all the meters use the same count, maybe it was to make the firmwares more similar to make updates easier, or they are sharing a code base, who knows. 

[KungFuJosh]

I actually think that the count changed from 24 to 22 when they added the user calibration to the meters, so it might be my fault LOL. 

[tautech]

SCD30A 30A shunt for SDM3055/65X

In the recent EMEX 3 day exhibition we did a prolonged run with the new 30A shunt and compared accuracy reported on SDM3055 vs the SDL1030X Eload.
Eload was set in CC mode @5A with SPD3303X-E in Parallel mode supplying the current.

3-4mA variance was most seen which IMO is pretty decent calibration of a 30A capable shunt extending SDM 10A range to 30A capability.

When visiting Defpom today we tested a HPAK 30A shunt with almost identical specs to Siglents SCD30A 30A shunt.

SDM3055 I had was used.

The results were ..... interesting.
HPAK shunt was more accurate at low current settings where there was no requirement for it with 10A capability already. 
We tested to 15A where SCD30A gave better accuracy.