Author Topic: Benefits of going with all Siglent setup  (Read 3940 times)

0 Members and 1 Guest are viewing this topic.

Online mawyatt

  • Frequent Contributor
  • **
  • Posts: 663
  • Country: us
Re: Benefits of going with all Siglent setup
« Reply #50 on: October 27, 2020, 02:27:34 am »
So if I'm not wrong my calc for MSOX3104T would go like this, for those conditions:

[attachimg=1]

and

[attachimg=2]

so that gives:

[attachimg=3]


Although ENOB is not single number, it is frequency/ENOB graph....

Shouldn't the ENOB be computed based upon a sine wave input of full scale peak to peak (8 divisions)? If so then the relative signal power would be (4*scalefacor/rt2)^2, or 8*(Scale Factor)^2.

Best,
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike
 

Offline 2N3055

  • Super Contributor
  • ***
  • Posts: 3338
  • Country: hr
Re: Benefits of going with all Siglent setup
« Reply #51 on: October 27, 2020, 08:32:43 am »
So if I'm not wrong my calc for MSOX3104T would go like this, for those conditions:

[attachimg=1]

and

[attachimg=2]

so that gives:

[attachimg=3]


Although ENOB is not single number, it is frequency/ENOB graph....

Shouldn't the ENOB be computed based upon a sine wave input of full scale peak to peak (8 divisions)? If so then the relative signal power would be (4*scalefacor/rt2)^2, or 8*(Scale Factor)^2.

Best,

To be honest ENOB is supposed to be measured specified with the actual signal at actual frequency, so it includes both noise and distortions in SINAD.

In this case we assume (for 2mv/div for instance) full scale P-P sine signal of 16 mV.  RMS of that (11,35mV) divided with RMS of noise (110 uV) gives 10641 ratio, convert that to dB (power ratio) gives 40,2dB,  and converted to ENOB :6,397 bit.

I did quick test with R&S method and got same results.

These tests will have major source of error in scopes built in RMS function and it's limits to deal with calculating RMS of noise and otherwise very complex signal.
 
Please correct me if I'm wrong..

Regards,
 

Offline Howardlong

  • Super Contributor
  • ***
  • Posts: 5034
  • Country: gb
Re: Benefits of going with all Siglent setup
« Reply #52 on: October 27, 2020, 08:59:37 am »
Please note that my table was effective resolution, not ENOB; there is a difference.

TurboTom: I do still have the scopes, but I'm very time poor at the moment.
 

Online mawyatt

  • Frequent Contributor
  • **
  • Posts: 663
  • Country: us
Re: Benefits of going with all Siglent setup
« Reply #53 on: October 27, 2020, 01:06:05 pm »
So if I'm not wrong my calc for MSOX3104T would go like this, for those conditions:

[attachimg=1]

and

[attachimg=2]

so that gives:

[attachimg=3]


Although ENOB is not single number, it is frequency/ENOB graph....

Shouldn't the ENOB be computed based upon a sine wave input of full scale peak to peak (8 divisions)? If so then the relative signal power would be (4*scalefacor/rt2)^2, or 8*(Scale Factor)^2.

Best,

To be honest ENOB is supposed to be measured specified with the actual signal at actual frequency, so it includes both noise and distortions in SINAD.

In this case we assume (for 2mv/div for instance) full scale P-P sine signal of 16 mV.  RMS of that (11,35mV) divided with RMS of noise (110 uV) gives 10641 ratio, convert that to dB (power ratio) gives 40,2dB,  and converted to ENOB :6,397 bit.

I did quick test with R&S method and got same results.

These tests will have major source of error in scopes built in RMS function and it's limits to deal with calculating RMS of noise and otherwise very complex signal.
 
Please correct me if I'm wrong..

Regards,

I had seen the IEEE definition on ENOB, and agree it's without signal distortion and not at a specified signal frequency since no signal is actually applied. So maybe a best case ENOB, or as Howard mentioned Effective Resolution.

From above "In this case we assume (for 2mv/div for instance) full scale P-P sine signal of 16 mV.  RMS of that (11,35mV) divided with RMS of noise (110 uV) gives 10641 ratio, convert that to dB (power ratio) gives 40,2dB,  and converted to ENOB :6,397 bit."
Since the peak to peak full scale signal would yield a sine wave of 4 divisions peak, the RMS would not be of the 8 division peak to peak value, but of the 4 division value. So this would yield 4*2mV/rt2 = 5.657mV RMS, not 8*2mV/rt2 = 11.35mV??

Just trying to follow the thinking behind these calculations, so I can supply a similar set of values that are consistent with what's been shown.

Best,
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike
 

Online mawyatt

  • Frequent Contributor
  • **
  • Posts: 663
  • Country: us
Re: Benefits of going with all Siglent setup
« Reply #54 on: October 27, 2020, 01:22:20 pm »
Please note that my table was effective resolution, not ENOB; there is a difference.

TurboTom: I do still have the scopes, but I'm very time poor at the moment.

Could you show how you calculated the Effective Resolution in your table so we can compare results on an "Apples to Apples" basis.

BTW thanks for showing the table and taking the time to post these results :-+

Best,
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike
 

Offline 2N3055

  • Super Contributor
  • ***
  • Posts: 3338
  • Country: hr
Re: Benefits of going with all Siglent setup
« Reply #55 on: October 27, 2020, 02:03:10 pm »
So if I'm not wrong my calc for MSOX3104T would go like this, for those conditions:

[attachimg=1]

and

[attachimg=2]

so that gives:

[attachimg=3]


Although ENOB is not single number, it is frequency/ENOB graph....

Shouldn't the ENOB be computed based upon a sine wave input of full scale peak to peak (8 divisions)? If so then the relative signal power would be (4*scalefacor/rt2)^2, or 8*(Scale Factor)^2.

Best,

To be honest ENOB is supposed to be measured specified with the actual signal at actual frequency, so it includes both noise and distortions in SINAD.

In this case we assume (for 2mv/div for instance) full scale P-P sine signal of 16 mV.  RMS of that (11,35mV) divided with RMS of noise (110 uV) gives 10641 ratio, convert that to dB (power ratio) gives 40,2dB,  and converted to ENOB :6,397 bit.

I did quick test with R&S method and got same results.

These tests will have major source of error in scopes built in RMS function and it's limits to deal with calculating RMS of noise and otherwise very complex signal.
 
Please correct me if I'm wrong..

Regards,

I had seen the IEEE definition on ENOB, and agree it's without signal distortion and not at a specified signal frequency since no signal is actually applied. So maybe a best case ENOB, or as Howard mentioned Effective Resolution.

From above "In this case we assume (for 2mv/div for instance) full scale P-P sine signal of 16 mV.  RMS of that (11,35mV) divided with RMS of noise (110 uV) gives 10641 ratio, convert that to dB (power ratio) gives 40,2dB,  and converted to ENOB :6,397 bit."
Since the peak to peak full scale signal would yield a sine wave of 4 divisions peak, the RMS would not be of the 8 division peak to peak value, but of the 4 division value. So this would yield 4*2mV/rt2 = 5.657mV RMS, not 8*2mV/rt2 = 11.35mV??

Just trying to follow the thinking behind these calculations, so I can supply a similar set of values that are consistent with what's been shown.

Best,

My logic is that full screen at 2 mV/div is 16 mV from top to bottom (8 mV above and 8mV below zero). If you inscribe sinewave inside, top to bottom, RMS of that sinewave would be 16 mV/1.41= 11,35 mV.
That is full scale RMS. That is also how I understood IEEE excerpt in R&S whitepaper.

But, I agree it is beside point to call upon some standard if all conditions are not observed. And I agree that we shouldn't call it ENOB but effective resolution.
 
We could simply define a figure of merit that would  compare full scale with residual RMS and P-P noise..  It would serve well as relative comparison and would be somewhat easier to reproduce.

There were previous comparisons made, including calculating noise PSD and such...
 

Online mawyatt

  • Frequent Contributor
  • **
  • Posts: 663
  • Country: us
Re: Benefits of going with all Siglent setup
« Reply #56 on: October 27, 2020, 02:25:33 pm »


My logic is that full screen at 2 mV/div is 16 mV from top to bottom (8 mV above and 8mV below zero). If you inscribe sinewave inside, top to bottom, RMS of that sinewave would be 16 mV/1.41= 11,35 mV.
That is full scale RMS. That is also how I understood IEEE excerpt in R&S whitepaper.

But, I agree it is beside point to call upon some standard if all conditions are not observed. And I agree that we shouldn't call it ENOB but effective resolution.
 
We could simply define a figure of merit that would  compare full scale with residual RMS and P-P noise..  It would serve well as relative comparison and would be somewhat easier to reproduce.

There were previous comparisons made, including calculating noise PSD and such...

The RMS of a sinusoid is (peak value)/rt2, not (peak to peak value)/rt2. In your example you have a full scale 8 division sine wave at 2mv/div, so 16mv peak to peak and thus 8mv/rt2 RMS value.

Agree a FOM should be utilized and I'm all ears for what should be utilized/created for such.

Best,
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike
 

Online mawyatt

  • Frequent Contributor
  • **
  • Posts: 663
  • Country: us
Re: Benefits of going with all Siglent setup
« Reply #57 on: October 27, 2020, 03:03:47 pm »
Just did a quick test of the SDS2102X Plus in 8 bit, 10 bit, and ERES (3) modes using this as a means to evaluate Effective Resolution in bits. I'm not saying this is right or wrong way, just the way I chose to measure and calculate. Used 20MHz BW with 50 ohm in-scope termination, 1us/div sweep. Noise was averaged Standard Deviation to remove DC offset effects as mentioned.

Effective Resolution Bits (ERB) = {10*log[(8*(SF/N)^2 +1)] -1.76}/6.02, where N is Standard Deviation noise, SF is Scale Factor in V/div

Scale    500uv   1mv    2mv    100mv    200mv     500mv     1v
8 bit N  23.4uv  24uv  38.6uv  1.47mv  2.95mv    7.55mv    14.56mv
ERB     5.63      6.59    6.90     7.30      7.29         7.26        7.31

10 bit N 16.9uv  17uv   20uv   316uv    432uv      1.83mv    2.32mv
ERB     6.10      7.09     7.85    9.50      10.06       9.72        9.96

ERES N 12uv     12uv   14uv     132uv    190uv      725uv     860uv
ERB     6.59      7.59    8.37     11.60     11.89      11.80      11.39

FFT NF -122      -120   -120     -118      -108        -100        -97
in dBm


Added FFT noise floor in 8 bit mode using 2.5MSPS, 2097512 pts, delta f 1.19Hz and 16 average.

I computed these on my HP32 calculator, so hopefully no mistakes ::)

Best,
« Last Edit: October 27, 2020, 04:59:12 pm by mawyatt »
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike
 

Offline 2N3055

  • Super Contributor
  • ***
  • Posts: 3338
  • Country: hr
Re: Benefits of going with all Siglent setup
« Reply #58 on: October 27, 2020, 07:21:01 pm »


My logic is that full screen at 2 mV/div is 16 mV from top to bottom (8 mV above and 8mV below zero). If you inscribe sinewave inside, top to bottom, RMS of that sinewave would be 16 mV/1.41= 11,35 mV.
That is full scale RMS. That is also how I understood IEEE excerpt in R&S whitepaper.

But, I agree it is beside point to call upon some standard if all conditions are not observed. And I agree that we shouldn't call it ENOB but effective resolution.
 
We could simply define a figure of merit that would  compare full scale with residual RMS and P-P noise..  It would serve well as relative comparison and would be somewhat easier to reproduce.

There were previous comparisons made, including calculating noise PSD and such...

The RMS of a sinusoid is (peak value)/rt2, not (peak to peak value)/rt2. In your example you have a full scale 8 division sine wave at 2mv/div, so 16mv peak to peak and thus 8mv/rt2 RMS value.

Agree a FOM should be utilized and I'm all ears for what should be utilized/created for such.

Best,

 :palm: |O
'nuf said.... I'm gonna go hide now...

corrected..
« Last Edit: October 27, 2020, 07:28:19 pm by 2N3055 »
 

Offline rf-loop

  • Super Contributor
  • ***
  • Posts: 3490
  • Country: cn
  • Born with DLL21 in hand
Re: Benefits of going with all Siglent setup
« Reply #59 on: October 28, 2020, 06:48:19 am »
So if I'm not wrong my calc for MSOX3104T would go like this, for those conditions:

[attachimg=1]

and

[attachimg=2]

so that gives:

[attachimg=3]


Although ENOB is not single number, it is frequency/ENOB graph....

Shouldn't the ENOB be computed based upon a sine wave input of full scale peak to peak (8 divisions)? If so then the relative signal power would be (4*scalefacor/rt2)^2, or 8*(Scale Factor)^2.

Best,

To be honest ENOB is supposed to be measured specified with the actual signal at actual frequency, so it includes both noise and distortions in SINAD.

In this case we assume (for 2mv/div for instance) full scale P-P sine signal of 16 mV.  RMS of that (11,35mV) divided with RMS of noise (110 uV) gives 10641 ratio, convert that to dB (power ratio) gives 40,2dB,  and converted to ENOB :6,397 bit.

I did quick test with R&S method and got same results.

These tests will have major source of error in scopes built in RMS function and it's limits to deal with calculating RMS of noise and otherwise very complex signal.
 
Please correct me if I'm wrong..

Regards,

I had seen the IEEE definition on ENOB, and agree it's without signal distortion and not at a specified signal frequency since no signal is actually applied. So maybe a best case ENOB, or as Howard mentioned Effective Resolution.

From above "In this case we assume (for 2mv/div for instance) full scale P-P sine signal of 16 mV.  RMS of that (11,35mV) divided with RMS of noise (110 uV) gives 10641 ratio, convert that to dB (power ratio) gives 40,2dB,  and converted to ENOB :6,397 bit."
Since the peak to peak full scale signal would yield a sine wave of 4 divisions peak, the RMS would not be of the 8 division peak to peak value, but of the 4 division value. So this would yield 4*2mV/rt2 = 5.657mV RMS, not 8*2mV/rt2 = 11.35mV??

Just trying to follow the thinking behind these calculations, so I can supply a similar set of values that are consistent with what's been shown.

Best,

My logic is that full screen at 2 mV/div is 16 mV from top to bottom (8 mV above and 8mV below zero). If you inscribe sinewave inside, top to bottom, RMS of that sinewave would be 16 mV/1.41= 11,35 mV.
That is full scale RMS. That is also how I understood IEEE excerpt in R&S whitepaper.

But, I agree it is beside point to call upon some standard if all conditions are not observed. And I agree that we shouldn't call it ENOB but effective resolution.
 
We could simply define a figure of merit that would  compare full scale with residual RMS and P-P noise..  It would serve well as relative comparison and would be somewhat easier to reproduce.

There were previous comparisons made, including calculating noise PSD and such...

This your RMS is corrected after this original msg, so I do not take this accidental human mistake on table.

But I want ask one think.

There are these..
"My logic is that full screen...blablabla.."
Then also
"That is full scale RMS."

Not all scopes have ADC full scale same is display full height. 
Of course it do not make big difference but... small error there and other error here and there... and we talk finally perhaps big error.

Many scopes (but not all) what I have handled have ADC full scale around or over 10 vertical div and displayed part of whole vertical is 8 div. But different scopes may be different in this. 

If 2mv/div and ADC FS is  example bit over 10 div. For simplify think 10div.
In this case FS  sinewave is 20mVp-p  so 7.071 mVrms. I think there need use this ADC full scale in calculations  what is used in individual scope instead of displayed part of signal if it is different.

If practice and theory is not equal it tells that used application of theory is wrong or the theory itself is wrong.
-
Harmony OS
 

Offline Fungus

  • Super Contributor
  • ***
  • Posts: 11893
  • Country: 00
Re: Benefits of going with all Siglent setup
« Reply #60 on: October 28, 2020, 08:40:22 am »
You're right to question them, as did I at the time.

The figures are from the scope's own measurements.

Did you do a self-cal immediately before making those measurements?
 

Offline 2N3055

  • Super Contributor
  • ***
  • Posts: 3338
  • Country: hr
Re: Benefits of going with all Siglent setup
« Reply #61 on: October 28, 2020, 08:45:25 am »

This your RMS is corrected after this original msg, so I do not take this accidental human mistake on table.

But I want ask one think.

There are these..
"My logic is that full screen...blablabla.."
Then also
"That is full scale RMS."

Not all scopes have ADC full scale same is display full height. 
Of course it do not make big difference but... small error there and other error here and there... and we talk finally perhaps big error.

Many scopes (but not all) what I have handled have ADC full scale around or over 10 vertical div and displayed part of whole vertical is 8 div. But different scopes may be different in this. 

If 2mv/div and ADC FS is  example bit over 10 div. For simplify think 10div.
In this case FS  sinewave is 20mVp-p  so 7.071 mVrms. I think there need use this ADC full scale in calculations  what is used in individual scope instead of displayed part of signal if it is different.

I agree with that and know that scopes usually have a bit of "reserve" so not all of the ADC range is "mapped" to the screen. But I was going with what is visible on screen, so if you compare two scopes side by side looking at same signal what you would get.  But as you say well, things are even more complicated. On my MSOX3000T i press vertical knob and put it in a fine mode.. I'm not going to do the detailed test  now, but you can look at the signal at 113 mV/div. or 271 mV/div.  or 7 mV/div. Is that 7mV/div really 10 mV /div software magnified or 4 mV/div scaled to 7 mV/div. It probably doesn't have real lineary variable gain amplifier (like analog ones did). Or maybe it does?

Those details would need to be available to be able to test all of it to into details.  But that even might be unnecessary to most people. They might want to know simply noise levels (or whatever specification that is important to them) in like to like scenarios for their intended purpose. Like, if I do lot of work on 3,3V logic signal, i would view it at 430 mv/div.... What is noise there, for instance ? Or I will simply use 500 mV/div to compare two scopes doing same job..

Thing is, people tend to want simple decisions. Like which scope has less noise.. and it gets complicated quick. Do they think visible noise on trace on screen? Or what AC RMS measurement is calculating..
Scopes with faster retrigger rate will visibly have it more, those with different display engine will have different, two same scope with different display intensity will have different, different  time bases etc etc...

There will be some fast truths: for instance, at 1 mV/div MSOX3104T you are looking at 4mV/div magnified in software.. And it's not as good as on a scope that has 1 mV/div real range.
BUT, you get that 4 mV/div (and its software maginification) with full 1 GHz bandwith.. So for something that is few mV and FAST, it's better than 1 mV/div with 200 MHz bandwidth limit on small ranges.
And if you're looking at lower frequencies, you enable Hires, and noise goes down, and it's nice and clean...

But all those technical details on the side, fact is that Rigol scopes with new chipset have fat traces (in X-Y mode trace is as fat as a finger), while new generation Siglents look nice and clean. It is obvious they have less visible noise on screen on lower ranges. And they also have real low ranges not software magnifications. And sometimes bandwidth limits at very sensitive ranges,or not, based on model.

So if you are doing some sensitive (low signal level) analog stuff at not very high frequencies (up to 100 ish MHz) new Siglents have better front end for that.
For looking at digital level signal, you probably won't care which one......

For my money, and for like prices, as my only scope, for instance I would go with Siglent SDS2000X+ any day instead of Rigol MSO5000 or Keysight DSOX1204. I would also buy GW Instek 2000E series before Rigol MSO5000 or Keysight DSOX1204. I tried it (GW INSTEK) and there many things on that scope I would have done differently, but I really liked what it can do. It simply works and does the job. It is more mature platform than SDS2000X+, which means more limited, and not expecting any further major development, but more stable.. Pretty much no bugs to be found.. Very much like Keysight.
ON the other hand SDS2000+ holds more promise.. It will develop further... How much, we will see..

I will draw a paralel, when in 80-ies a noname manufacturer Ibanez started making "some cheap Japanese guitars".. Or when Yamaha started selling their guitars to the west... There were also literally hundreds of other manufacturers, making very good stuff, but that got forgotten and disappeared... We are at that same era of T&M instruments. It is a bit of gamble... To those buying Yamaha and Ibanez, gamble worked well, for some others not so much..  And which one is which, only future will tell..

Regards,


 
The following users thanked this post: Performa01

Offline Performa01

  • Frequent Contributor
  • **
  • Posts: 940
  • Country: at
Re: Benefits of going with all Siglent setup
« Reply #62 on: October 28, 2020, 09:14:49 am »
Just for completeness:

The SDS2000X+ and also SDS5000X have 30 LSB/div, that is 240 steps for full screen. Very little overhead.
The SDS1000X-E (and most likely also SDS2000X-E) have 25 steps per division, hence only 200 counts full screen.

The SDS2000X+ can maintain the full extended bandwidth of 500 MHz down to 500 µV/div.

All contemporary Siglent DSOs prvide fine adjust of the vertical gain, and these are true hardware PGA steps.
 
The following users thanked this post: 2N3055

Offline Howardlong

  • Super Contributor
  • ***
  • Posts: 5034
  • Country: gb
Re: Benefits of going with all Siglent setup
« Reply #63 on: October 28, 2020, 01:58:22 pm »
You're right to question them, as did I at the time.

The figures are from the scope's own measurements.

Did you do a self-cal immediately before making those measurements?

Yes. One reason why I mentioned I am time poor at the moment, I don't have much time available to go and re-do all these tests again.
 

Offline Howardlong

  • Super Contributor
  • ***
  • Posts: 5034
  • Country: gb
Re: Benefits of going with all Siglent setup
« Reply #64 on: October 28, 2020, 02:59:33 pm »
Please note that my table was effective resolution, not ENOB; there is a difference.

TurboTom: I do still have the scopes, but I'm very time poor at the moment.

Could you show how you calculated the Effective Resolution in your table so we can compare results on an "Apples to Apples" basis.

BTW thanks for showing the table and taking the time to post these results :-+

Best,

Here's the spreadsheet I used.




 

Online mawyatt

  • Frequent Contributor
  • **
  • Posts: 663
  • Country: us
Re: Benefits of going with all Siglent setup
« Reply #65 on: October 28, 2020, 03:15:07 pm »
[attach=1]
Just for completeness:

The SDS2000X+ and also SDS5000X have 30 LSB/div, that is 240 steps for full screen. Very little overhead.
The SDS1000X-E (and most likely also SDS2000X-E) have 25 steps per division, hence only 200 counts full screen.

The SDS2000X+ can maintain the full extended bandwidth of 500 MHz down to 500 µV/div.

All contemporary Siglent DSOs prvide fine adjust of the vertical gain, and these are true hardware PGA steps.

I can confirm that the vertical scale fine adjustment appears to be from a PGA on SDS2102X Plus, and not in software.

Another important aspect of the vertical input is that the trace vertical position (offset) adjustment apparently is introduced near the front end which allows high levels of DC offset from the signal source to be nulled and not saturate the postamps or ADC.

Here's a quick test DC coupled at 5m/div with a 30mv peak to peak sine wave that has a 2 volt DC offset! This huge offset correction (>50X) works at the lower scales also (>100X), but I don't know what the offset range is (takes a long time to twiddle the offset knob), so gave up after 400mv offset on the 500uv scale with a 3mv peak to peak signal!!

This is an often overlooked important feature of a vertical channel front end, the old Tek scopes got this right, but wasn't sure if these new DSOs did. In many cases you can utilize this feature instead of employing a differential probe.

To get this right as evidently Siglent has, you must introduce the offset correction well up towards the channel input front, since any prior high gain amps will saturate with a large offset, and/or the ADC will saturate. To do this requires very low noise offset correction circuitry with high resolution, so a good hi-res DAC with a low noise reference is required.

Anyway another pleasant surprise feature/capability I didn't expect with these modest $ DSOs :)

Best,
[attach=1][attach=2]

Edit to add why this input channel offset correction range is important.

Here's an example of a 1Hz 10mv peak to peak triangle wave with a 100mv offset. Note scale factor to "see" the waveform without offset correction is 50mv/div DC coupled.
[attachimg=4]

Now introduce AC coupling and change scale to 2mv/div
[attachimg=5]
Yikes, that's not a triangle waveform :o
With AC coupling this become the derivative of the input, and the derivative is a squarewave ???

Now use DC coupling and the offset adjustment to null the 100mv input offset ;)
[attachimg=6]
That's certainly looking better :-+

Best,


Edit: Sorry I can't get the images into the text flow, they just all show up at the bottom no matter what I try :P
« Last Edit: October 28, 2020, 05:26:50 pm by mawyatt »
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike
 
The following users thanked this post: 2N3055

Online mawyatt

  • Frequent Contributor
  • **
  • Posts: 663
  • Country: us
Re: Benefits of going with all Siglent setup
« Reply #66 on: October 28, 2020, 05:23:16 pm »
Please note that my table was effective resolution, not ENOB; there is a difference.

TurboTom: I do still have the scopes, but I'm very time poor at the moment.

Could you show how you calculated the Effective Resolution in your table so we can compare results on an "Apples to Apples" basis.

BTW thanks for showing the table and taking the time to post these results :-+

Best,

Here's the spreadsheet I used.

Thanks. If I interpret the spreadsheet correctly you are using Effective Resolution Bit as Log(FS/N)/Log(2) and not the standard ENOB of (SINAD -1.76)/6.02, where in our case SINAD would be 10*Log(FS/N +1) using RMS values and no distortion term, since no input signal is actually applied.

Using what I did which includes the ADC quantizing error term but no distortion term I get similar but slightly 0.3 bit lower (not surprising since 1.76/6.02 ~0.3 bit) results, for example.

MSO8104A
2mv        5.26     vs.   5.55
100mv     6.71    vs.   7.01
200mv     6.71     vs.   7.01
500mv     6.74     vs.   7.03
5V           6.70     vs.   6.99



Best,

 
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike
 

Offline RBBVNL9

  • Regular Contributor
  • *
  • Posts: 70
  • Country: nl
Re: Benefits of going with all Siglent setup
« Reply #67 on: October 28, 2020, 05:29:22 pm »
Back to the original question...

Quote
Other than the brand look and feel and having similar interfaces (I would hope) are there other advantages of going with the same manufacturer?

I have several Siglent 'x' devices, but they do not really have the same look and feel, as you (rightfully) hope. Their user interfaces differs in many ways, and the 'deeper' you go (e.g. configuring the communication interfaces), the larger the differences. While the screens with their underlying 5 or 6 soft buttons suggests a consistent UI approach, this is not the case, and the overall button 'logic' varies. Physical button placement varies quite a bit. For instance, the SDG AWG and SDL electronic load both have 10 digit keypads, but they keys are just the other way around. Also the PC software for these devices seems to have nothing in common, entirely different programs. Some have 'real' on/of buttons, some soft buttons. The cases stack reasonably well, but as others have noted, their depth is sometimes different.

Having that said, I selected them for what I needed for specific use cases, and feel happy for what they do at their price point. They are quite nice devices and I would buy them again.
 

Offline Howardlong

  • Super Contributor
  • ***
  • Posts: 5034
  • Country: gb
Re: Benefits of going with all Siglent setup
« Reply #68 on: October 28, 2020, 06:33:49 pm »
Please note that my table was effective resolution, not ENOB; there is a difference.

TurboTom: I do still have the scopes, but I'm very time poor at the moment.

Could you show how you calculated the Effective Resolution in your table so we can compare results on an "Apples to Apples" basis.

BTW thanks for showing the table and taking the time to post these results :-+

Best,

Here's the spreadsheet I used.

Thanks. If I interpret the spreadsheet correctly you are using Effective Resolution Bit as Log(FS/N)/Log(2) and not the standard ENOB of (SINAD -1.76)/6.02, where in our case SINAD would be 10*Log(FS/N +1) using RMS values and no distortion term, since no input signal is actually applied.

Using what I did which includes the ADC quantizing error term but no distortion term I get similar but slightly 0.3 bit lower (not surprising since 1.76/6.02 ~0.3 bit) results, for example.

MSO8104A
2mv        5.26     vs.   5.55
100mv     6.71    vs.   7.01
200mv     6.71     vs.   7.01
500mv     6.74     vs.   7.03
5V           6.70     vs.   6.99



Best,

 

Yes, as I stated before, effective resolution isn’t the same as ENOB. As you say, effective resolution gives an apparently “better” result than ENOB.
« Last Edit: October 28, 2020, 06:39:37 pm by Howardlong »
 

Online mawyatt

  • Frequent Contributor
  • **
  • Posts: 663
  • Country: us
Re: Benefits of going with all Siglent setup
« Reply #69 on: October 28, 2020, 06:51:11 pm »
Back to the original question...

Quote
Other than the brand look and feel and having similar interfaces (I would hope) are there other advantages of going with the same manufacturer?

I have several Siglent 'x' devices, but they do not really have the same look and feel, as you (rightfully) hope. Their user interfaces differs in many ways, and the 'deeper' you go (e.g. configuring the communication interfaces), the larger the differences. While the screens with their underlying 5 or 6 soft buttons suggests a consistent UI approach, this is not the case, and the overall button 'logic' varies. Physical button placement varies quite a bit. For instance, the SDG AWG and SDL electronic load both have 10 digit keypads, but they keys are just the other way around. Also the PC software for these devices seems to have nothing in common, entirely different programs. Some have 'real' on/of buttons, some soft buttons. The cases stack reasonably well, but as others have noted, their depth is sometimes different.

Having that said, I selected them for what I needed for specific use cases, and feel happy for what they do at their price point. They are quite nice devices and I would buy them again.

This is an area where Siglent could make significant improvements. I can't say about Rigol and others since I don't have that equipment, but also have 3 different Siglent instruments and they are not generally consistent.

Likely why they will not make significant in-roads into major electronics companies because;

A) The equipment decision makers are older and tend to use tried and true instruments they know and have experience with.

B) The cost of learning a new interface can often exceed the instrument cost, so a more expensive user friendly known instrument may cost less in the long run.

C) Calibration (if required) is well known and established for "Brand Name" instruments, but may be spotty for unknowns.

I know these from prior experience, and made decisions on Tektronix & HP based upon such. Most new equipment could be quickly placed into service without lengthily manual studies or unproductive fiddling. When the engineering cost can range from 200~$500/hr in IC fabless design centers, and even more for IC fab facilities the actual cost of a new instrument can often be evaluated by it's learning curve and not it's direct initial cost.

Siglent should take note of this uniform UI experience if they expect to move up the instrument food chain.

BTW one clever way HP/A/KS ( and Tek, R&S) to get exposure to younger EEs was to supply the University labs with the latest equipment, this way grad students were exposed before they graduated. 

Best,
« Last Edit: October 28, 2020, 07:07:37 pm by mawyatt »
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike
 

Offline RBBVNL9

  • Regular Contributor
  • *
  • Posts: 70
  • Country: nl
Re: Benefits of going with all Siglent setup
« Reply #70 on: October 28, 2020, 07:20:54 pm »
Quote
Siglent should take note of this uniform UI experience if they expect to move up the instrument food chain.

Totally agree. Not only may that - slowly - position them more upwards, but also make them more appealing across a wider base of users from diverse profiles.

Addressing the learning curve is important in places where hourly wages are high, but also in teaching environments (e.g. universities) and other places where the users are diverse, frequently changing, etc. 

Quote
The equipment decision makers are older and tend to use tried and true instruments they know and have experience with.

Sure. But if the Siglents etc. are wise, they would realise that their current adopters might be the 'older' men in the future that specify instrument acquisition/procurements. The older brands already realise this, they offer educational discounts not because they are charities, but because they know it will lead to more sales on the longer term.

Finally, also having a well developed Microsoft Windows and MacOS software environment, supporting all instruments from within the same, easy to use software package, would make more people lend towards new purchases from the same brand. Some of the current software hardly seems to be beyond the Beta stage, if not before, with terrible installation procedures. And it seems that for every device, they are redeveloping new software from the ground up - an expensive development' I'd think.

Finally, a device we a well developed UI is also a pleasure to work with, something that invites you to take it up again and use it.

Much if this could even be done by firmware updates for existing devices, and PC/Mac software development.
 

Online mawyatt

  • Frequent Contributor
  • **
  • Posts: 663
  • Country: us
Re: Benefits of going with all Siglent setup
« Reply #71 on: October 28, 2020, 07:25:30 pm »
Please note that my table was effective resolution, not ENOB; there is a difference.

TurboTom: I do still have the scopes, but I'm very time poor at the moment.

Could you show how you calculated the Effective Resolution in your table so we can compare results on an "Apples to Apples" basis.

BTW thanks for showing the table and taking the time to post these results :-+

Best,

Here's the spreadsheet I used.

Thanks. If I interpret the spreadsheet correctly you are using Effective Resolution Bit as Log(FS/N)/Log(2) and not the standard ENOB of (SINAD -1.76)/6.02, where in our case SINAD would be 10*Log(FS/N +1) using RMS values and no distortion term, since no input signal is actually applied.

Using what I did which includes the ADC quantizing error term but no distortion term I get similar but slightly 0.3 bit lower (not surprising since 1.76/6.02 ~0.3 bit) results, for example.

MSO8104A
2mv        5.26     vs.   5.55
100mv     6.71    vs.   7.01
200mv     6.71     vs.   7.01
500mv     6.74     vs.   7.03
5V           6.70     vs.   6.99



Best,

 

Yes, as I stated before, effective resolution isn’t the same as ENOB. As you say, effective resolution gives an apparently “better” result than ENOB.

Don't think it really matters as long as all comparisons are done using the same methodology and calculations. ADCs and DACs have a long history of confusing and not directly applicable specs that caused all kinds of havoc for designers. I recall almost 40 years ago some Sony 10 bit DACs that were designed for high end TV RGB displays actually performed better than 12 bit and most higher order DACs when used at RF frequencies. When folks starting using ENOB with specified frequencies things got much better for the design engineer instead of the usual sample, try and test approach. I know we were asked many times about why we were using only 10bit Sony DACs, and not higher order types from well known sources, the simple answer was they are better and we measured them :o
« Last Edit: October 28, 2020, 07:28:36 pm by mawyatt »
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike
 

Offline tautech

  • Super Contributor
  • ***
  • Posts: 20557
  • Country: nz
  • Taupaki Technologies Ltd. NZ Siglent Distributor
    • Taupaki Technologies Ltd.
Re: Benefits of going with all Siglent setup
« Reply #72 on: October 28, 2020, 07:38:27 pm »
FYI a large # of the DSO range has the same 'look and feel' which started with a new UI in the now dated SDS2000 which was then adopted into X model DSO's, SDS1000X, SDS2000X and later into SDS1000X-E and SDS2000X-E.
All these scopes have a very very similar UI.

SDS2000X Plus and SDS5000X are newer and completely different UI ventures that the SDS6000 Pro also shares if we ever get to see them in the west in other than in LeCroy colors.
Some front panel layout consistency was maintained in SDS5000X to previous ranges however SDS2000X Plus has modifications to group lesser used buttons away from the everyday use ones. These small front panel changes have also been adopted in the SDS6000 Pro.

X models in all the product lines have different UI's from previous product incarnations where the earlier AWG for example all had the same basic UI. This is unchanged albeit with a later X UI version in the current X model AWG range.
Avid Rabid Hobbyist
 

Offline Fungus

  • Super Contributor
  • ***
  • Posts: 11893
  • Country: 00
Re: Benefits of going with all Siglent setup
« Reply #73 on: December 18, 2020, 09:00:55 pm »
It is however possible the Vrms calculation in the MSO5000 is wrong  >:D

It's also possible that the Siglent is wrong and that the real Vrms figure is higher.  :popcorn:
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf