Siglent Bench DMMs SDM3065X, SDM3055 and SDM3045X

[Martin72]

Pics I´ve made from the reference.

[KungFuJosh]

Don't waste time trying to reverse engineer this upgrade, it can't be done. The standard SDM3065X doesn't have the interface components installed which is what makes it a factory only option selected when you purchase it.

It probably can be done. Not having a few minor parts and a mount isn't an issue if you have an SC model to reference what parts are needed. I think that would be the easy part of making the upgrade. The card itself, the limitations of the firmware/interface, and the switching scheme might be slightly trickier than my skills, but I'm sure somebody could figure that out.

I won't likely spend any time on it now that I have a Keithley on the way with the specs I need.

Thanks,
Josh

[KungFuJosh]

Here's a 3-hour test comparing the DAQ6510 (same analog board as DMM6500) and my SDM3065X. Both had hours of warmup time. Both were set to 10PLC. Everything I could set the same, I did.

The Siglent appeared more stable*, but also more susceptible to environmental change. By the end of the test, my office wasn't just colder, the humidity dropped to 26%. Gross.

The DAQ was less susceptible to environmental change, but was slightly further off from the expected ref value.

Last cal for the DAQ6510 was in April 2024. SDM3065X was September 2023.

Overall, neither of them suck. 😉

Thanks,
Josh

*I found the setting, the DAQ was sampling too fast. I'll eventually do another test with the slower sample rate.

ETA: The SDM3065X is my loudest DMM. The DAQ is much quieter.

[KungFuJosh]

Here's a weird bug on the SDM3065X:

Condition: Continuity mode with screensaver active for extended period.
Action: Press key to wake screen (not sure if specific key matters).
Result: Beeper stops working, but still display correct value on screen.
Fix: Adjust Threshold value (up or down and back to same value will work), or power cycle. Nothing else works to remedy it (including deactivating/reactivating beeper or changing volume level).

Firmware V3.01.01.12R1.

Thanks,
Josh

[msemhs]

I just got the SDM3065X-SC, and the FW loaded on it is 3.02.01.13. I can't find any info on their site.  Has anyone seen any release notes for this?  The latest one Siglent has on their site is V3.01.01.12R1

[t1d]

Re: Siglent SDM3065X - Firmware is current @ V3.01.01.12R1

Original Post
https://www.eevblog.com/forum/testgear/siglent-new-bench-dmm-sdm3055/msg4144669/#msg4144669
Beginning at Page 46 @ Post #1134
Ending at Page 47 @ Post #1152


I would like to (finally) address my units low buzzer volume. I have found a convenient mounting location, on the faceplate. I want to discuss 1) any consequences of using that location and, 2) if there are no problems with using the location, how best to wire the buzzer.

Location
I have discovered that there is a sixth meter probe hole, in the front, metal, face bracket. It is below the black, LoSense Probe Hole and to the left of the Red, 10A RMS Probe Hole. See picture. This hole is perfectly sized to accommodate the buzzer. I have not removed the face bracket, yet, but it appears that there may be space to tuck the buzzer in between the front of the metal, face bracket and the back of the plastic front panel.


Note: The hole in the metal, face bracket is covered by a very thin shim of black plastic. I confirmed the hole's location, by shining a flashlight through the plastic faceplate.

Accommodations
A hole would need to be opened in the plastic faceplate. For appearance sake, I recommend only making the opening the size of the small hole that is on the top of the buzzer. I don't think a larger hole in the faceplate will make the buzzer louder, because the hole in the top of the buzzer is the limiting factor.

Wiring
I am concerned with this hack introducing noise into the case. So, I am considering the following method of wiring...

Common copper solder wire wick is woven in the shape of a tube. I would use it to create a shielded wire loom in which to run a twisted pair of wire, for the buzzer. The wire loom would be grounded to the case/Earth GND. Care would be taken to not ground it to Circuit GND. I will cover the loom with heat shrink, as well.

There appears to be room to attach the loom to the side of the case. However, it will have to be routed under the fan housing. There is space to do this, as the PCB is cut out, under the fan.

Attachment
I would simply glue the buzzer to the metal, face bracket. I prefer a product called Shoe Goo.

I apologize for the lack of case pictures. Health problems prevent that effort, presently.

I look forward to your thoughts and suggestions. Thank you for your help.

EDIT:
I am moving this topic out of the Siglent Bench DMMs SDM3065X, SDM3055 and SDM3045X thread, in the hopes that it will make the information easier to be found and to be followed.
Please join us, at the new thread!
https://www.eevblog.com/forum/testgear/siglent-sdm3065x-low-buzzer-volume-repairhack-attempt/new/#new

[t1d]

tautech shared these thoughts:
"Use a audio twin coax for the buzzer cable.
Maybe just gluing the buzzer to the front panel and nothing else will increase its volume."

@ tautech
I found a nice space, between the plastic faceplate and the metal, face bracket. I put these details in the post, above, so you will need to read that post, again.
Great ideas! Thank you!
t1d

The coax shield would be tied to Earth Ground, not Circuit Ground; correct?

[tautech]

You might also consider a replacement/new buzzer, maybe one with a louder output.
Dunno anything about these things but other members will have some ideas.

[KungFuJosh]

At 10PLC measuring VDC the SDM3065X does 6 readings per second here in the US. Is there also some sort of filtering/averaging besides that? Or is it just a delay between readings?

Thanks,
Josh

[2N3055]

At 10PLC measuring VDC the SDM3065X does 6 readings per second here in the US. Is there also some sort of filtering/averaging besides that? Or is it just a delay between readings?

Thanks,
Josh

ADC is averaging for 10NPLC, pushes result out, rinse and repeat.
It is not quick measure, pause, measure, pause...

[KungFuJosh]

At 10PLC measuring VDC the SDM3065X does 6 readings per second here in the US. Is there also some sort of filtering/averaging besides that? Or is it just a delay between readings?

Thanks,
Josh

ADC is averaging for 10NPLC, pushes result out, rinse and repeat.
It is not quick measure, pause, measure, pause...

Interesting. Keithley and Keysight both offer additional averaging on top of the PLC, so I was curious if there's something else going on there.

I have the extra averaging off for the attached test. It was interesting watching the Keysight/Siglent compete for biggest PP. 😉

[mawyatt]

With KS34465A you can get an additional digit with Math Function MX + B in the display.

Best

[skander36]

With KS34465A you can get an additional digit with Math Function MX + B in the display.

Best

Keithley also do this.
Also Keysight can be "determined" to display 7,5 digit.
But as a professional said here on the forum, we can trust only the numbers that manufacturer warrant for them in the specifications. The rest is "uncertainty fog".

[mawyatt]

With KS34465A you can get an additional digit with Math Function MX + B in the display.

Best

Keithley also do this.
Also Keysight can be "determined" to display 7,5 digit.
But as a professional said here on the forum, we can trust only the numbers that manufacturer warrant for them in the specifications. The rest is "uncertainty fog".

Yes, the DMM6500 has the MX + B Math feature.

Did not know that the KS34465A Digit Mask had 7 1/2 digit selection. Ours don't show this. Is this a select option or something with the newer firmware?

Agree, these "Extra Digits" don't convey much is absolute terms, and are often just a "Random Number" but can help with direct comparisons or relative measurements.

Best

[skander36]

...
Ours don't show this. Is this a select option or something with the newer firmware?
...

I didn't done myself this mod, someone did this for me. The firmware must be unpacked enable the option (the fw. is common for 6.5 and 7.5 models), and repacked.

[KungFuJosh]

While fun, and I would certainly do it for that purpose, there isn't a lot of value in those extra digits...except maybe the Keithley. It's interesting to me how similar the Siglent and Keysight behave. I'll post a few more screenshots in the other thread.

[Kleinstein]

If comparing different meters, one should have the same scale. It is confusing with different scales.
This thread is already long and about the Sigilent meters - so better keep the compare part out of this thread. Much is about different meters and the reference used.

[skander36]

... yeah, is somewhat confusing.
I think they want to signal that the result is math processed, I don't have an explanation about why they choose to display with X.

[hfleming]

I just got the SDM3065X-SC, and the FW loaded on it is 3.02.01.13. I can't find any info on their site.  Has anyone seen any release notes for this?  The latest one Siglent has on their site is V3.01.01.12R1

Can confirm. Just received my new SDM3065X with firmware version 3.02.01.13. Weird that it is not on Siglent’s website.

[valcher]

I bought mine in April last year and the firmware was already 3.02.01.13. It will soon be a year.

[Martin72]

It may well be that a change in the hardware, due to obsolescence or similar, triggered a change in the firmware.
However, this is only necessary for new production and was therefore not launched as an official update.
So my thoughts on this, I would leave it at that for now.

[Mahagam]

SDM3055. hw/sw on the first picture
Img 2 and 3 - temperature measurement with the only difference: REL button was pressed, but no reaction!
Img 3 and 4 - same type K thermocouple connected, and REL button works perfect

Also, I`ve got some strange readings (text and excel chart below) which looks a little bit strange, but I cannot reproduce this behavior now.

*idn?
Siglent Technologies,SDM3055,SDM35HBD7R1727,1.02.01.28
fetch?
+2.25929622E+01,+2.26003335E+01,+2.25975692E+01,+2.25929622E+01,+2.25948050E+01,+2.25938836E+01,+2.30929622E+01,+2.30929622E+01,+2.30948050E+01,+2.25957264E+01,+2.25920408E+01,+2.26012549E+01,+2.26067833E+01,+2.25994120E+01,+2.25994120E+01,+2.30975692E+01,+2.25938836E+01,+2.25948050E+01,+2.25975692E+01,+2.25994120E+01,+2.26030977E+01,+2.26058619E+01,+2.31040191E+01,+2.26030977E+01,+2.26030977E+01,+2.26067833E+01,+2.26021763E+01,+2.25957264E+01,+2.26003335E+01,+2.26067833E+01,+2.26049405E+01,+2.26113903E+01,+2.31123117E+01,+2.31169188E+01,+2.26178402E+01,+2.26104689E+01,+2.26049405E+01,+2.31067833E+01,+2.26067833E+01,+2.26049405E+01,+2.31067833E+01,+2.26104689E+01,+2.26169188E+01,+2.31187616E+01,+2.26169188E+01,+2.26132331E+01,+2.31104689E+01,+2.31113903E+01,+2.31104689E+01,+2.26095475E+01,+2.26104689E+01,+2.26132331E+01,+2.26113903E+01,+2.26077047E+01,+2.26030977E+01,+2.31021763E+01,+2.26030977E+01,+2.26067833E+01,+2.26067833E+01,+2.26058619E+01,+2.26058619E+01,+2.26049405E+01,+2.26113903E+01,+2.26086261E+01,+2.26067833E+01,+2.26095475E+01,+2.26077047E+01,+2.31086261E+01,+2.26141546E+01,+2.26159974E+01,+2.26123117E+01,+2.26077047E+01,+2.26095475E+01,+2.26132331E+01,+2.31150760E+01,+2.31141546E+01,+2.26058619E+01,+2.31123117E+01,+2.31169188E+01,+2.26159974E+01,+2.26150760E+01,+2.26058619E+01,+2.26003335E+01,+2.26086261E+01,+2.26077047E+01,+2.26040191E+01,+2.26058619E+01,+2.26086261E+01,+2.26086261E+01,+2.26086261E+01,+2.26040191E+01,+2.26058619E+01,+2.26021763E+01,+2.25994120E+01,+2.26040191E+01,+2.26021763E+01,+2.26030977E+01,+2.26030977E+01,+2.31049405E+01,+2.26012549E+01,+2.26049405E+01,+2.26049405E+01,+2.30984906E+01,+2.30984906E+01,+2.25984906E+01,+2.26012549E+01,+2.25984906E+01,+2.30938836E+01,+2.31003335E+01,+2.26040191E+01,+2.31021763E+01,+2.31012549E+01,+2.26049405E+01,+2.26021763E+01,+2.25975692E+01,+2.25948050E+01,+2.30966478E+01,+2.25984906E+01,+2.25994120E+01,+2.31049405E+01,+2.31077047E+01,+2.31058619E+01,+2.31040191E+01,+2.26040191E+01,+2.26030977E+01,+2.26021763E+01,+2.26021763E+01,+2.26058619E+01,+2.26058619E+01,+2.26058619E+01,+2.31104689E+01,+2.26123117E+01,+2.26095475E+01,+2.31095475E+01,+2.31077047E+01,+2.26086261E+01,+2.26104689E+01,+2.31058619E+01,+2.26049405E+01,+2.26049405E+01,+2.26021763E+01,+2.31049405E+01,+2.31077047E+01,+2.26049405E+01,+2.26095475E+01,+2.26077047E+01,+2.26003335E+01,+2.30994120E+01,+2.30994120E+01,+2.31003335E+01,+2.26086261E+01,+2.26095475E+01,+2.26030977E+01,+2.25948050E+01,+2.25957264E+01,+2.30938836E+01,+2.30938836E+01,+2.30948050E+01,+2.30948050E+01,+2.30975692E+01,+2.30966478E+01,+2.31003335E+01,+2.25975692E+01,+2.26003335E+01,+2.26003335E+01,+2.30957264E+01,+2.30892766E+01,+2.25920408E+01,+2.30957264E+01,+2.30938836E+01,+2.25938836E+01,+2.25892766E+01,+2.25938836E+01,+2.30883552E+01,+2.25865124E+01,+2.25837481E+01,+2.30911194E+01,+2.30901980E+01,+2.30883552E+01,+2.30920408E+01,+2.30948050E+01,+2.30994120E+01,+2.30929622E+01,+2.25920408E+01,+2.25883552E+01,+2.30920408E+01,+2.25966478E+01,+2.25957264E+01,+2.26012549E+01,+2.31030977E+01,+2.31003335E+01,+2.31040191E+01,+2.31021763E+01,+2.31049405E+01,+2.31003335E+01,+2.26021763E+01,+2.26012549E+01,+2.25984906E+01,+2.25984906E+01,+2.26030977E+01,+2.25984906E+01,+2.30975692E+01,+2.31030977E+01,+2.25938836E+01,+2.30883552E+01,+2.30948050E+01,+2.31003335E+01,+2.26003335E+01,+2.25975692E+01,+2.25994120E+01,+2.26003335E+01,+2.25994120E+01,+2.25966478E+01,+2.25920408E+01,+2.25948050E+01,+2.31012549E+01,+2.30984906E+01,+2.30938836E+01,+2.26012549E+01,+2.26021763E+01,+2.26012549E+01,+2.25957264E+01,+2.30948050E+01,+2.31040191E+01,+2.26095475E+01,+2.31067833E+01,+2.30994120E+01,+2.26040191E+01,+2.31077047E+01,+2.31067833E+01,+2.26104689E+01,+2.26132331E+01,+2.26113903E+01,+2.26095475E+01,+2.26086261E+01,+2.31150760E+01,+2.31113903E+01,+2.31030977E+01,+2.26040191E+01,+2.31030977E+01