Siglent Bench DMMs SDM3065X, SDM3055 and SDM3045X

[Kean]

Look closely at those listings.  A simple copy/paste error.

The one for the SDM3045X https://www.siglent.eu/product/1141054/siglent-sdm3045x-4-1-2-digits-dual-display-digital-multimeter

Accessoires Included: 1 x Siglent SDM3065X Multimeter

The one for the SDM3065X https://www.siglent.eu/product/1141078/siglent-sdm3065x-6-1-2-digits-dual-display-digital-multimeter

Accessoires Included: 1 x Siglent SDM3045X Multimeter

[vutt]

I guess my slightly sarcastic post wasn't clear enough.

It's not about price. Look at included accessories list. SDM3065X page says that you will get 3045x model and SDM3045X product page suggest that you will get 3065X model.
I left feedback message for them, hopefully they will fix it.

I'm actually about to buy SDM3055 model because with additional 4% EU bank transfer discount they have the best price atm
Edit: Nevermind it looks like Welectron has better price. Thanks 2N3055 for hint 

[smbaker]

I'm tossing around the possibility of buying an SDM3045X or SDM3055 in a few weeks. I've read a few threads around here, but I haven't really come across a good summary of the differences. As I understand, the basic difference is the extra digit, higher count, and better components (including precision divider) on the 3055. 3055 has a fan whereas 3045X does not. Are there other relevant differences?

How is the 3045X firmware compared to the 3055? Is it receiving the same level of updates and are bugs fixed in a timely manner?

I read about an "annoying relay click" problem on the 3045X. Has that been fixed? Does the same problem exist on the 3055?

I also read that the 3045X can be reflashed to a 3055X-E by patching the firmware. What are the advantages of this? I haven't found an English datasheet to compare the 3045X and the 3055X-E, but from the context it in the other threads, it sounds like it might update the ranges to more convenient/traditional levels (200mV, 2V, ...).

Thanks,
Scott

[tautech]

I'm tossing around the possibility of buying an SDM3045X or SDM3055 in a few weeks. I've read a few threads around here, but I haven't really come across a good summary of the differences. As I understand, the basic difference is the extra digit, higher count, and better components (including precision divider) on the 3055. 3055 has a fan whereas 3045X does not. Are there other relevant differences?

How is the 3045X firmware compared to the 3055? Is it receiving the same level of updates and are bugs fixed in a timely manner?

I read about an "annoying relay click" problem on the 3045X. Has that been fixed? Does the same problem exist on the 3055?

I also read that the 3045X can be reflashed to a 3055X-E by patching the firmware. What are the advantages of this? I haven't found an English datasheet to compare the 3045X and the 3055X-E, but from the context it in the other threads, it sounds like it might update the ranges to more convenient/traditional levels (200mV, 2V, ...).

Thanks,
Scott

Models in order of release, SDM3055, 3045X and last 3065X with 3055 release date preceding Siglents move to adding X to their later instrument ranges and therefore was never given an X but bumpers were updated to match the later X models.
SDM3055X-E has never been a western market model so English datasheets are nonexistent and the relay range move is in the same measurement range as 3055 and 3065X whereas for 3045X it's in the middle of a range that is common for a large # of measurements so yes the 3055X-E cross flash aligns 3045X ranges with the more traditional 200mV/2V/20V ranges.

FW versions are reasonably aligned and all models had an update August/Sept last year.
All 3 models use different Vref's and there are a few differences in their feature sets that you need hunt out in datasheets and manuals.

[smbaker]

SDM3055X-E has never been a western market model so English datasheets are nonexistent and the relay range move is in the same measurement range as 3055 and 3065X whereas for 3045X it's in the middle of a range that is common for a large # of measurements so yes the 3055X-E cross flash aligns 3045X ranges with the more traditional 200mV/2V/20V ranges.

Okay, I think I'm starting to understand what happened. Someone took a meter with 200mV/2V/20V/... ranges and for marketing purposes to set is aside from the 3055, tried to make it appear to have 600mV/6V/60V ranges. I can understand the marketing "why" behind this, but it seems like a very poor engineering decision.

The 3045X being "newer" than the 3055, are there any known hardware improvements between hardware revisions? Is there any reason, other than the cost savings and the lack of a fan, why someone would choose a 3045X over a 3055 ?

I don't mind the annoying relays on my 3045x, but I have a growing list of annoyances.
1) the meter will not remember ANY settings at all, so I have to leave it on 24/7 if I don't want it to be essentially factory defaulted.
2) the display doesn't retain settings between functions, so if you want a trend chart on DCV, but a numerical reading on 2wire ohm, you have to manually change it every single time you switch between these
3) after a month or so of use, this pile of junk is locking up now, so I have to reboot the ****ing thing. the UI itself locks up, but the meter still will actually function just in an extremely delayed manner.

Are other people experiencing these problems? or is this believed to be just one example of a faulty meter? These problems would be assumed to be common to the 3055 as well as the 3045X ?

I suppose I'm used to my Siglent function generator coming up in default mode every time I turn it on, though I use the function generator much less often that I would be using a DMM. I can see how this would be annoying.

If money was no object, I'd plan for a 34461A. But unfortunately money does matter.

[bdunham7]

I suppose I'm used to my Siglent function generator coming up in default mode every time I turn it on, though I use the function generator much less often that I would be using a DMM. I can see how this would be annoying.

These are often RTFM issues.  I don't know which AWG you have, but on mine I have power-up options in the utility menu for default, last and user.  DMMs may have similar features.  As far as the other issues stated , I don't want a 'self-driving' instrument that learns about me, I want an easy to drive instrument that I can learn how to use.  YMMV.

If money was no object, I'd plan for a 34461A. But unfortunately money does matter.

Unfortunately I don't think the value proposition for Siglent bench DMMs is as great as it is for some of their other products--unless you want a mediocre/OK meter with a scanner card option in which case they are a great deal.  Still, if you want 'bench', along with the logging, dual-display and all that sort of thing and you aren't obsessed with accuracy, there's nothing in an A-brand anywhere near the price point.  If it were me in your shoes, I'd probably just buy the SDM3045X and hack it.   The fake range thing would be quite annoying otherwise.

[eloso]

When choosing between 3045 and 3055 I suggest you make sure you understand the implications of the relay switching in/out half way through both the auto and the fixed range. This is not about a trivial noisy click. It is about a very noticeable delay between readings. It is about messing up your data logging. It is about the relay clicking in and the machine pausing every single time that you make a ny and all measurements above 2V.  i.e. take probe off the circuit, reading drops to zero, relay clicks off. Put probe back on circuit (5V point) slight ahem, pause, cough, relay click, numbers whizzing around then settles down.  Even in the fixed range.  This made it the most unpleasant meter I have ever had.


I traded it in for a 3055 (Siglent were helpful) after Siglent confirmed there was nothing that could be done.

Now I have a meter that hangs together properly, seems to have fewer bugs, and that apart from a bit of fan noise, I am now very, very  happy with. BTW mine does remember most settings when switched off - i.e. it comes up in current mode when I switch it off in current mode etc.  The 3045 didn't. I bought a voltage reference, and 30 seconds from pressing power I havev a rock steady reading. All digits. Every time.  Can't comment on absolute accuracy but it sure as heck looks bang on for repeatability.

Having used both, I also appreciate the extra digit and whilst I can't be sure, the thing seems faster.   I only went for the 3045 in the first place becasue I knew there was no fan.  Knowing what I know now, this is a no brainer. The 3045 is an awful machine.

But I'm not arguing - its a personal choice, and that is just my personal opinion.

Regards

Eloso

[smbaker]

But I'm not arguing - its a personal choice, and that is just my personal opinion.

Thanks. I think I'm convinced that a stock 3045 is not the way to go. A 3045 hacked/reflashed to 3055X-E, maybe.

For a hundred bucks more though, I can have a real 3055, with the only drawback as far as I'm aware at this time being that it has a fan.

[Peter_O]

You can change the fan easily.

Original is running on 12V full speed.
It tries to move more air than the punched outlet would allow for, which makes it very noisy.



I've swapped in a Sunon, which is more quiet at 12V already. With a 300 Ohm resisor it runs at 7V, which is well within specs 4.5V-12V. It shifts more than enough air and the noise is fine now.





Of course you loose the warranty. But it's eevblog here after all, isn't it? 

[t1d]

Tech support have informed me beeper volume is already set at max in FW. 

I have suggested a HW and FW change to increase overall volume and to also make it user adjustable.


In the meantime the VMC out BNC can be set to provide a positive or negative trigger out that may suffice for those wanting to trigger an external beeper circuit as a work-around.

If I get a chance I'll investigate a simple HW mod to increase beeper volume. With luck we only need to change some gain settings. 

@tautech Re: SDM3065X DMM   
I (continue) to have trouble hearing the continuity tone. The problem is both the frequency and the low volume. I am running the latest firmware = SDM3065X_3.01.01.10. The tone adjustment (only) changes the frequency. I have that set in the middle, which helps, a bit. As I understand from your prior post, the factor sets the tone's volume to its greatest amplitude and that there is no other firmware setting to increase the volume. Is that still true? If so, what do you suggest I do?
- Is there any firmware hack?
- Is there any known DIY internal hardware adaptation? (Yes, I read about using a separate mic/amp/speaker.) If not, has it been determined that a hardware solution is not possible, for some reason? My warranty runs through November/2022, but I would be most willing to build a solution, thereafter. EDIT: As I can not open mine, yet, does anyone know the general layout of the buzzer circuit? Method for creating the frequency, type of speaker, etc.

[tautech]

Tech support have informed me beeper volume is already set at max in FW. 

I have suggested a HW and FW change to increase overall volume and to also make it user adjustable.


In the meantime the VMC out BNC can be set to provide a positive or negative trigger out that may suffice for those wanting to trigger an external beeper circuit as a work-around.

If I get a chance I'll investigate a simple HW mod to increase beeper volume. With luck we only need to change some gain settings. 

@tautech Re: SDM3065X DMM   
I (continue) to have trouble hearing the continuity tone. The problem is both the frequency and the low volume. I am running the latest firmware = SDM3065X_3.01.01.10. The tone adjustment (only) changes the frequency. I have that set in the middle, which helps, a bit. As I understand from your prior post, the factor sets the tone's volume to its greatest amplitude and that there is no other firmware setting to increase the volume. Is that still true? If so, what do you suggest I do?

Consider constructing something using the VMC BNC output.
From the User manual:
The multimeter outputs a low-true pulse from the [VM Comp] connector after every measurement.

While the VMC output seems perfect quick tests with a DMM show ~0.1V between measurements (idle state) and ~0.050V when measurement is taken it might be better to check this with a scope to see what's really going on when it activates.

- Is there any firmware hack?
- Is there any known DIY internal hardware adaptation? (Yes, I read about using a separate mic/amp/speaker.) If not, has it been determined that a hardware solution is not possible, for some reason?

Have a hunt through this thread as Alex may have a solution:
https://www.eevblog.com/forum/testgear/hacking-the-siglent-sdm3055/

My warranty runs through November/2022, but I would be most willing to build a solution, thereafter. EDIT: As I can not open mine, yet, does anyone know the general layout of the buzzer circuit? Method for creating the frequency, type of speaker, etc.

Here a pic of the PCB's from a post earlier in this thread where the round black buzzer is bottom right by the red wire.

The buzzer is near the RHS ventilation grille and its volume is compromised as the fan is also fitted on this side and if the SDM is fitted within a stack of instruments then another instrument fitted close to it will further impact on buzzer volume. 

Just how buzzer volume can be best addressed is an interesting challenge however rather than it be top PCB mounted, under the PCB and with its own enclosure vent/grille should significantly improve buzzer volume.
That would be an interesting mod for SDM owners to experiment with. 

[2N3055]

To increase the volume maybe little 3d printed cap with horn for the buzzer? 

[Peter_O]

...

Why has what I thought was the thread title changed
from "Siglent Bench DMMs SDM3065X, SDM3055 and SDM3045X"
to "Siglent NEW Bench DMM SDM3055"?

It's before the first coffee today morning and I'm confused. 

[tautech]

...

Why has what I thought was the thread title changed
from "Siglent Bench DMMs SDM3065X, SDM3055 and SDM3045X"
to "Siglent NEW Bench DMM SDM3055"?

It's before the first coffee today morning and I'm confused. 

Siglent NEW Bench DMM SDM3055 was the original thread title way back in 2014 when I started this thread and the only model available at that time however when 3045X and 3065X came along it made sense to have them all together in the one thread.
The original topic URL never changes even after edits to the topic title.

t1d's post captured the original URL somehow and Quoting it only keeps that confusing change going although if we just Reply the topic name should return to the post title.
Nothing to worry about.   

[t1d]

Thanks, tautech, for your reply!

As I don't want to void my warranty, VCM looks like the way to go. However, VCM is outside of my knowledge base. Any tips, for the VCM learning curve? Maybe start with what "VCM" stands for; lol... I can DIY microcontroller circuits. Would that be a good approach? I will be researching VCM, while awaiting your reply... I am not afraid to do my homework.

Alex's thread did not contain anything on my topic.

I was aware of the buzzer (verses speaker.) Does anyone know how it is driven?

I apologize, if I posted on the wrong thread. Yes, I thought that I was on the 3065X et al thread. Is there a separate 3065X thread? Moderator, feel free to move my post.

[tautech]

Thanks, tautech, for your reply!

As I don't want to void my warranty, VCM looks like the way to go. However, VCM is outside of my knowledge base. Any tips, for the VCM learning curve? Maybe start with what "VCM" stands for; lol... I can DIY microcontroller circuits. Would that be a good approach? I will be researching VCM, while awaiting your reply... I am not afraid to do my homework.

Alex's thread did not contain anything on my topic.

I was aware of the buzzer (verses speaker.) Does anyone know how it is driven?

I apologize, if I posted on the wrong thread. Yes, I thought that I was on the 3065X et al thread. Is there a separate 3065X thread? Moderator, feel free to move my post.

Connect a scope to the VMC BNC and see what's going on when you do a measurement.
We haven't got much to go on about VMC other than what's mentioned in the Acquire section of the user manual.

By all means explore this here and write up your findings in such a way I can add it into the POI list in the OP.

[t1d]

You posted while I was writing... Here's what I wrote:
=============================================

For clarification, I am a hobbyist and I am still learning. As I am self-taught, there are gaps in my knowledge base.

Okay, VCM = Variable Coded Modulation, I think. Low = True condition. So, hold the MCU pin high, when it goes low, through the VCM connector, have the buzzer buzz? If so, what reverse polarity protection would be needed to protect the VCM.

You mention connecting it to a scope. There is a BCN output. Using a BNC to BNC cable, do I need any sort of termination? What kind of information am I going to see? The VCM voltage going low and any probe bounce? What voltage is the high state of the VCM. I do have an el-cheapo USB logic analyzer (that I have never used.) Should I use that and look for a true communication output? (Not worded well.)

Thanks for your continued help and support!

[tautech]

No time to investigate today t1d but maybe this evening.
Just a slow pulse from a AWG for a repeatable measurement and into 1 ch of a scope and another channel monitor the VMC output which should corelate with the slow pulse from the AWG.

Nothing hard....just take a step back and have a think about it. 

[Kean]

Okay, VCM = Variable Coded Modulation, I think. Low = True condition.

It is not VCM but VMC.

The BNC output signal is "VM Comp", short for "Volt Meter Complete".  It outputs a pulse (usually low) after each completed measurement, which is useful for synchronising measurements between equipment.

In the settings the VM Comp polarity can be inverted.  There are no other settings, so I don't see how this can be used to assist with an external continuity buzzer.

[t1d]

Okay, VCM = Variable Coded Modulation, I think. Low = True condition.

It is not VCM but VMC.

The BNC output signal is "VM Comp", short for "Volt Meter Complete".  It outputs a pulse (usually low) after each completed measurement, which is useful for synchronising measurements between equipment.

In the settings the VM Comp polarity can be inverted.  There are no other settings, so I don't see how this can be used to assist with an external continuity buzzer.

Thanks, Kean! Thanks for the correction of the term, too.

My investigations confirm your comments. I scoped the VMC output. Yes, it only appears to be a triggering mechanism, having no data.

Test Setup =
1104X-E Scope Probe (x10/DC Coupled/BWL20MHz) connected to VMC Output with a bare BNC Connector.
DMM Probes connected to 3065X DMM.
DMM set for Continuity.

What I found =
The VMC is referenced to ground and outputs a continuous +5V pulse at ~8.5KHz. When I touch the DMM probe tips together and create continuity, the VMC simply skips a pulse. This skipped pulse serves as the VMC's notification that a reading has been taken, via a low voltage state output. To be clear, while the probes have continuing continuity, the VMC continues to output a pulse, but at only one-half the frequency; ~4.7KHz. There was a lot of jitter present, so the frequencies may have been as low as 8KHz and 4KHz. No data is transmitted. Click on image below to enlarge.

Buzzer Application =
I think that the VMC output could easily be used to drive a MCU, to drive a buzzer. The MCU would simply listen for a significant reduction in frequency and then drive the buzzer circuit. However, the question is not if it can be done, but how well it would work in the real world. I agree with you that that seems rather iffy. But, given that the 3065X's continuity response is already known to be painfully slow, maybe a small additional delay would not be noticeable.

The Better Solution =
My personal preference is to wait for the seven months remaining on of my warranty period and then implement a hardware solution. Maybe place the buzzer on the bottom of the PCB, as tautech has suggested... Maybe move the buzzer closer to the front of the unit, via a long twisted-pair of wires. But, I have concern that doing so might spread noise within the case... Maybe change the buzzer type and add some type of amplification... Thoughts and suggestions for a hardware solution are welcome.

[Wrenches of Death]

>I have suggested a HW and FW change to increase overall volume and to also make it user adjustable.

Being able to change the frequency is more important than the volume. I have no idea if mine even works, I can't hear it even with my ear against the vent. If it's above about 3500hz, it doesn't exist in my world.

Being able to set it to a thousand or two hertz would be nice. Once you get up in age, high pitch hearing disappears.

WoD

[t1d]

>I have suggested a HW and FW change to increase overall volume and to also make it user adjustable.

Yes, this dead horse has been beaten by many, for a long time. Best I can tell, the short story is that, yes, Siglent did respond by adding a selection of three frequencies.  However, they were not able to increase the actual volume, because it was/is already set to its maximum. It is also well known that the problem is made worse by the location of the buzzer. It is deep within the cabinet and near the fan.

Being able to change the frequency is more important than the volume. I have no idea if mine even works, I can't hear it even with my ear against the vent. If it's above about 3500hz, it doesn't exist in my world.

Being able to set it to a thousand or two hertz would be nice. Once you get up in age, high pitch hearing disappears.

WoD

I am in a similar situation and that is why I was/am investigating solutions. As said, many others have beaten this horse for a long time. I am late to the game. Many others have also said it is a shame that Siglent has not offered a solution for current owners or corrected the flaw in their production of new units. I agree.

[bdunham7]

Thoughts and suggestions for a hardware solution are welcome.

Maybe just a 3.5mm 'audio out' jack?  And headphones for noisy environments?

[t1d]

How about this, for a 3065X low beeper volume solution... Setting up a full laptop, via USB, and running EasyDMM is a solution, yes? What about using a Raspberry Pi Pico to build a smaller USB dongle type of solution. I am not much of a coder, myself, but maybe someone could suss out how to just access the EasyDMM beeper signal. Since it is Siglent's problem, I think they should be willing to disclose how to code accessing that one function... The beeper signal in EasyDMM, that is...

Or, Siglent could add a select-able beeper function to the firmware that outputs a USB signal in a common code format. That seems like what Siglent would be more willing to do... And, we could easily DIY a solution with any USB capable MCU... The PIC18F4550 has on-chip USB. The Arduino Uno has on-PCB USB.

Hmm... We really don't need that coded in some USB language, I guess... Just make the USB Data out pin high when there is continuity and have any old MCU monitor Data out pin? As said, this is outside of my knowledge base.

If someone wants to look at the USB Rx/Tx for this application, I would be glad to send you one of my DIY USB2.0 Tappers. It allows you to easily access (tap) and/or break each of the four legs of USB2.0 = +5V, Data-, Data+, GND, free of charge. Requires your commitment and USA/48 address... Your choice of bare board, kit, or assembled.

If that person would also be willing to use a PIC18F4550 (which is the better choice than an Arduino, IMO, for this application) I would be glad to also send you one each of my Sandwich Bread and Lunch Break PIC18F4550 demo boards (Think Pinguino.) The Sandwich Bread plugs into a breadboard. The Lunch Break includes two breakout sockets, per pin. Both have 20MHz oscillators and USB2.0(B) connectors. Also free of charge. Requires your commitment and USA/48 address... Your choice of bare boards, kits, or assembled. The boards are PIC18F45K50 compatible, too. Includes one chip, 4550, or 45K50.

If MCU USB compatibility is not needed. I also have lots of other PIC demo boards.

[Wrenches of Death]

Or, Siglent could add a select-able beeper function to the firmware that outputs a USB signal in a common code format. That seems like what Siglent would be more willing to do... And, we could easily DIY a solution with any USB capable MCU... The PIC18F4550 has on-chip USB. The Arduino Uno has on-PCB USB.

That's a lot of work.   

It wouild be a lot easier if Siglent would just modify the firmware to allow the setting of the frequency of the beep. My Keysight U1252B handheld multimeter allows the beep frequency setting to be changed in setup. The choices are 300, 600, 1200, and 2400 hz.

If enough people complain, maybe it'll get done.   

WoD