Author Topic: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes  (Read 160395 times)

0 Members and 2 Guests are viewing this topic.

Online tautech

  • Super Contributor
  • ***
  • Posts: 15022
  • Country: nz
  • Taupaki Technologies Ltd. NZ Siglent Distributor
    • Taupaki Technologies Ltd.
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1375 on: May 29, 2019, 03:48:59 pm »
P4250 or CP-3308R  which would couple to the Siglent better.
They're fine for 100x passive probes and give additional protection at mains voltages but either cannot provide isolation if/when required.

Like a truck tractor unit, it's no good to anyone without a trailer to put on the back just as a scope is limited without the right probe to safely do a job.
There's a reasonable selection of differential probes available from several manufacturers, the Pintek DP-25, Daves HVP70 and another from Micsig depending on how deep you pockets are. For high BW and HV you can pay several x the value of an entry level DSO to properly equip them for 3ph mains work.
https://www.eevblog.com/product/hvp70/

And yes, an isolated channel DSO can sidestep the need for differential probes and you can rest assured I've long asked Siglent to develop one.  :horse:
« Last Edit: May 29, 2019, 03:53:04 pm by tautech »
Avid Rabid Hobbyist
 

Offline HendriXML

  • Frequent Contributor
  • **
  • Posts: 467
  • Country: nl
    • KiCad-BOM-reporter
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1376 on: May 29, 2019, 08:02:07 pm »
Suppose a stupid question. But is there any reason a siglent scope would not support an externally powered usb hub.
I don’t know how much power it draws, but if the scope is used as a power source, then the chances are quite high that the ground connection of the BNC is used to conduct most of the (negative side) current. Just like a SAG1021 does. One might think, that the connection is really short and almost no voltage will drop. But because those BNC are not made of copper (I assume), the drop might still be some mV’s. I don’t know what the output range is of the probe, but that might be significant.
Having an external power source will be better in that regard.
« Last Edit: May 29, 2019, 08:18:08 pm by HendriXML »
“I ‘d like to reincarnate as a dung beetle, ‘cause there’s nothing wrong with a shitty life, real misery comes from high expectations”
 

Online Rerouter

  • Super Contributor
  • ***
  • Posts: 4087
  • Country: au
  • Question Everything... Except This Statement
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1377 on: May 29, 2019, 08:02:30 pm »
New broken out protocol trigger commands, there where some with typo's in the string, I've just marked which they where

TRIIC      TRIG_IIC   TRIIC?   TRIG_IIC?
TRSPI      TRIG_SPI   TRSPI?   TRIG_SPI?
TRUART      TRIG_UART   TRUART?   TRIG_UART?
TRCAN      TRIG_CAN   TRCAN?   TRIG_CAN?               
TRLIN      TRIG_LIN   TRLIN?   TRIG_LIN?


TRIIC:SCL   TRIG_IIC:SCL      Command / Query
TRIIC:SDA   TRIG_IIC:SDA      Command / Query
TRIIC:CON   TRIG_IIC:CONDITION   Command / Query
TRIIC:QUAL   TRIG_IIC:QUALIFIER   Command / Query
TRIIC:ADDR   TRIG_IIC:ADDRESS   Command / Query
TRIIC:DATA   TRIG_IIC:DATA      Command / Query
TRIIC:DAT2   TRIG_IIC:DATA2      Command / Query
TRIIC:RW   TRIG_IIC:RW      Command / Query
TRIIC:ALEN   TRIG_IIC:ADDR_LEN   Command / Query
TRIIC:DLEN   TRIG_IIC:DATA_LEN   Command / Query


TRSPI:CLK   TRIG_SPI:CLK      Command / Query
TRSPI:CLK:EDGE   TRIG_SPI:CLK:EDGE   Command / Query
TRSPI:CLK:TIM   TRIG_SPI:CLK:TIME   Command / Query
TRSPI:MOSI   TRIG_SPI:MOSI      Command / Query
TRSPI:MISO   TRIG_SPI:MISO      Command / Query
TRSPI:CSTP   TRIG_SPI:CSTYPE      Command / Query
TRSPI:CS   TRIG_SPI:CS      Command / Query
TRSPI:NCS   TRIG_SPI:NCS      Command / Query
TRSPI:TRTY   TRIG_SPI:TRTY      Command / Query
TRSPI:DLEN   TRIG_SPI:DATA_LEN   Command / Query
TRSPI:BIT   TRIG_SPI:BIT      Command / Query
TRSPI:TRTY   TRIG_SPI:TRTY      Command / Query
TRSPI:DATA   TRIG_SPI:DATA      Command?
TRSPI:CLK:SL            Command?
TRSPI:FRAM            Command?


TRUART:RX   TRIG_UART:RX      Command / Query
TRUART:TX   TRIG_UART:TX      Command / Query
TRUART:TRTY   TRIG_UART:TRTY      Command / Query
TRUART:CON   TRIG_UART:CONDITION   Command / Query
TRUART:QUAL   TRIG_UART:QUALIFIER   Command / Query
TRUART:DATA   TRIG_UART:DATA      Command / Query
TRUART:BAUD   TRIG_UART:BAUD      Command / Query
TRUART:DLEN   TRIG_UART:DATA_LEN   Command / Query
TRUART:PAR   TRIG_UART:PARITY   Command / Query
TRUART:STOP   TRIG_UART:STOP      Command / Query
TRUART:POL   TRIG_UART:POLARITY   Command / Query
TRUART:BIT   TRIG_UART:BIT      Command / Query


TRCAN:CANH   TRIG_CAN:CANH      Command / Query
TRCAN:CANL   TRIG_CAN:CANL      Command / Query
TRCAN:TRTY   TRIG_CAN:TRTY      Command / Query
TRCAN:CON   TRIG_CAN:CONDITION   Command / Query
TRCAN:ID   TRIG_CAN:ID      Command / Query
TRCAN:IDL   TRIG_CAN:ID_LEN      Command / Query
TRCAN:DATA   TRIG_CAN:DATA      Command / Query
TRCAN:DAT2   TRIG_CAN:DATA2      Command / Query
TRCAN:BAUD   TRIG_CAN:BAUD      Command / Query


TRLIN:SRC   TRIG_LIN:SOURCE      Command / Query
TRLIN:CON   TRIG_LIN:CONDITION   Command / Query
TRLIN:ID   TRIG_LIN:ID      Command / Query
TRLIN:DATA   TRIG_LIN:DATA      Command / Query
TRLIN:DAT2   TRIG_LIN:DATA2      Command / Query
TRLIN:DLEN   TRIG_LIN:DATA_LEN   Command / Query
TRLIN:ERR:ID   TRIG_LIN:ERR:ID      Command / Query (typo)
TRLIN:ERR:CHK   TRIG_LIN:ERR:CHECK   Command / Query
TRLIN:ERR:SYNC   TRIG_LIN:SYNC      Command / Query (typo)
TRLIN:ERR:PAR   TRIG_LIN:ERR:PAR   Command / Query
TRLIN:BAUD   TRIG_LIN:BAUD      Command / Query
TRLIN:STAN   TRIG_LIN:STANDARD   Command / Query


TRQL      TRIG_QUALIFY_LIMIT   Command / Query
TRQT      TRIG_QUALIFY_TYPE   Command / Query
TRQS:SR      TRIG_QUALIFY_SET:SOURCE   Command / Query
TRQS:LV      TRIG_QUALIFY_SET:LEVEL   Command / Query
TRQE:SR      TRIG_QUALIFY_EDGE:SOURCE   Command / Query
TRQE:LV      TRIG_QUALIFY_EDGE:LEVEL   Command / Query
TRQE:SL      TRIG_QUALIFY_EDGE:SLOPE   Command / Query


TRDP      TRIG_DROP      Command / Query
TRNR      TRIG_NOISEREJ      Command / Query
TRWT      TRIG_WINDOW_TYPE   Command / Query
TRHD      TRIG_HOLDOFF      Command / Query
TRHDS      TRIG_HOLDOFF_START   Command / Query
TRPL      TRIG_PATTERN_LIMIT   Command / Query
TRTY      TRIG_TYPE      Command / Query
TRSR      TRIG_SOURCE      Command / Query
TRST      TRIG_STATUS      Command / Query
TRFSM      TRIG_FSM      Command / Query
TRPH      TRIG_PATTERN_HOLDOFF   Command / Query
TRPT      TRPT         Command / Query
TRSE      TRIG_SELECT      Command / Query
TRMD      TRIG_MODE      Command / Query
TRWI      TRIG_WINDOW      Command / Query
TRPA      TRIG_PATTERN      Command / Query


SET50
ARM      ARM_ACQUISITION
TRLV?      TRIG_LEVEL?
SAST?      SAMPLE_STATUS?
 

Online Rerouter

  • Super Contributor
  • ***
  • Posts: 4087
  • Country: au
  • Question Everything... Except This Statement
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1378 on: May 29, 2019, 08:27:19 pm »
Hmm, looks like the voltmeter and measurement histogram, and zone triggering features are buried in there too, however they don't seem to have menus. looks promising. Any word on them Performa01? or are they staying 5000 exclusive?
« Last Edit: May 29, 2019, 08:31:40 pm by Rerouter »
 

Offline Performa01

  • Frequent Contributor
  • **
  • Posts: 787
  • Country: at
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1379 on: May 29, 2019, 10:07:29 pm »
Hmm, looks like the voltmeter and measurement histogram, and zone triggering features are buried in there too, however they don't seem to have menus. looks promising. Any word on them Performa01? or are they staying 5000 exclusive?
I cannot  tell for sure, but Histograms and Zone trigger are most definitely midrange (SDS5000X) features and I would be surprised I we'd ever get them in the entry level instruments.

The DVM is just a marketing gag anyway, brought up by the big brands, even though I have to say it is very nicely implemented on the SDS5000X, with histogram and trend plots, but at the end of the day, it is just a very special way to represent automatic measurements.

BTW, I'm glad to report that I've just got a reply from Siglent R&D that they have identified the USB issue and we can expect a fix with the next firmware release!

 

Offline SMB784

  • Regular Contributor
  • *
  • Posts: 170
  • Country: us
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1380 on: May 29, 2019, 10:46:36 pm »
Any word on whether or not the WiFi bug fixes address the fact that the scope has trouble connecting to WiFi networks with spaces or special characters in the name? Does DHCP actually automatically update the IP address? WiFi connectivity has been a serious hindrance for this scope in my experience.
"Anything will lase if you hit it hard enough."

-Arthur L. Schawlow
 

Online Rerouter

  • Super Contributor
  • ***
  • Posts: 4087
  • Country: au
  • Question Everything... Except This Statement
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1381 on: May 29, 2019, 11:08:13 pm »
Performa01, any news on if they can fix the remaining SCPI command Typo's for the next version, I can see they have fixed up a few such as SYSTem:Error? Command, but not all, In case it was lost and buried, Current List remaining on latest version:

:Bandwidth_Limit? only is implemented for C1, and not C2-C4, equally it only returns the result for C4 (short from :BWL is correct and working)
MATH: CURSOR_VALUE? Contains a Space unlike all other similar commands
C3:INVERT_SET? is missing, instead its currently C4:INVERT_SET? (short form C3:INVS is correct and working)
HISTORY_LIST? is missing, instead its currently HISTORY_LIST (short form HSLST? is correct and working)
DIGITAL:LOW8_SWICHT, typo in name, should be DIGITAL:LOW8_SWITCH
DIGITAL:HIST_MODE is a query and should be DIGITAL:HIST_MODE?
C5:COUPLING? typo in name, should be C4:COUPLING?
DIGITAL:RESET_DDR is a query and should be DIGITAL:RESET_DDR?
TRIG_LIN::SYNC typo in name, should be TRIG_LIN:ERR:SYNC
TRIG_LIN:ERR:_ID typo in name, should be TRIG_LIN:ERR:ID

Edit:
EX5:TRIG_LEVEL command and query is currently a duplicate of EX:TRIG_LEVEL, I know this doesnt apply to this model, but likely means it exists in the higher models.
CURSOR_DISPLAYE, typo in command, should be CURSOR_DISPLAY
« Last Edit: May 31, 2019, 11:36:17 pm by Rerouter »
 
The following users thanked this post: Performa01

Offline rf-loop

  • Super Contributor
  • ***
  • Posts: 3042
  • Country: fi
  • Starting with DLL21
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1382 on: May 30, 2019, 07:31:57 pm »
Bode Plot II  what is first time published with FW 6.1.33 is really big step to right direction.

As also noted by @Performa01 and @tautech  there is some new functions and also many other improvements.

BodePlot II is now an amazingly good and versatile tool especially considering the Price Range.
I have also feel that they will still develop it better later.

Although it is astoundingly good it still needs some finishing and UI fine tuning to improve operating ergonomics. Yet, even if it were not developed any more, it is a good real tool. It is not just an extra line to the sales brochure. It is a real tool with significant real value. But it need Siglent Signal generator.

BodePLot II Basic limits are same with first generation BodelPlot.
10Hz - 120MHz (or less if generator max is less),  1 phase reference/DUT input level reference and it can handle simultaneously 3 DUT outputs with Phase and Amplitude.
Minimum span is 500Hz and max full span.
In Linear step sweep mode it can use 10 - 500 data points for span in use. (with 500Hz min span, 1Hz step)
In Linear step sweep mode user set center and span and steps in this span.
In Decade (log) sweep mode it can set for down to 2  - up to 275204396 points/decade what can give up to ~500pts for used span. In this mode user set start and stop frequency and points/decade.

It can run in
Channel Gain:Auto mode (better dynamic, slow. It automatically adjust scope input V/div setting during whole sweep depending DUT output level) 
Channel Gain:Hold mode (faster but max dynamic range is less, this mode keep previously set channel V/div settings constant)

Sweep mode can be Simple or Variable level. In variable level mode it use user defined table for sweep level profile. Profile can have max 10 data pairs, for freq and level.

It need perhaps BodePlot II  User Reference Manual  (not these simple nonsense User Manuals). There is so many things, what may confuses an inexperienced user, or if experience is from different device and imagines it to work like another. Of course it can be used with a try-oops-try method but many times it leads to frustration and then barking that it works wrong.

Here is very simple example what do not give lot of information but perhaps show small improvement.
I have adjusted reference (Ch1)  and DUT out (Ch4) Phase difference to zero with sweep starting freq with this DUT setup connected. (It can try adjust using channel Deskew as I did for this image)



XTAL test



Probe 1x compare



Image trace is ugly but it is just only for show max dynamic range using BodePlot maximal level set (6Vpp). During sweep I have adjusted attenuation between DUT-IN and DUT-OUT and attenuation was made using resistors and pot etc with BobPease style (because this I have used low freq) and beginning and end of trace no signal at all. (Ch4 input disconnected). Level steps are random dB's.

Looks like promise about more than 110dB range is not exaggerated.

One more example, now used minimum span, 500Hz with 500 data points (1Hz resolution)



Due to amount of sample points and quite narrow min span this is quite nice tool for example selecting optimal Crystal's for Crystal ladder filters. It have enough frequency resolution for this. (as can see also in this image)

Trace goes bit over top and bottom. Of course it can set for 20dB div also when it is running and  it display what is out of top and bottom. Also it can movce up and down changing reference position. THese display settings can do when it is running. Most other things can do only when stopped. It is nice if Siglent add some setting between 10 and 20dB/div so that whole dynamic range can also look in one image  with better fit to screen height.





After some unknown time more...
« Last Edit: June 01, 2019, 03:17:45 am by rf-loop »
If practice and theory is not equal it tells that used application of theory  is wrong or the theory itself is wrong.
It is much easier to think an apple fall to the ground than to think that the earth and the apple will begin to move toward each other and collide.
 
The following users thanked this post: Performa01, rigol52

Offline rf-loop

  • Super Contributor
  • ***
  • Posts: 3042
  • Country: fi
  • Starting with DLL21
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1383 on: May 30, 2019, 07:36:31 pm »
Reserved for continue BP II  because here is so many other discussions about this and that and those and so on...
It may take time before I can more tests and examples. 

Just continue common discussion below this...   
« Last Edit: May 30, 2019, 07:58:10 pm by rf-loop »
If practice and theory is not equal it tells that used application of theory  is wrong or the theory itself is wrong.
It is much easier to think an apple fall to the ground than to think that the earth and the apple will begin to move toward each other and collide.
 

Online Rerouter

  • Super Contributor
  • ***
  • Posts: 4087
  • Country: au
  • Question Everything... Except This Statement
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1384 on: May 30, 2019, 07:58:47 pm »
The dynamic measurement I believe only uses full steps of the Vdiv, in reality they could probably use a sliding scale approach with the fine Vdiv to always keep the signal at about 80% of the ADC scale (maximum resolution) but I agree that would make it take even longer.

My experience with bodeV1 was that the phase had a nasty rollover situation, where if a signal was sat at about 180 degrees offset it would jump top to bottom of the screen despite only 1 degree variance in phase shift. Kind of wondering if there is now a way to unroll the phase shift so once it moves past 180 degrees it keeps counting in that direction. e.g. 190 degrees shift. or atleast set a reference phase offset (currently working onsite so have not dug into this in person yet)
 

Offline rf-loop

  • Super Contributor
  • ***
  • Posts: 3042
  • Country: fi
  • Starting with DLL21
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1385 on: May 30, 2019, 08:14:04 pm »
The dynamic measurement I believe only uses full steps of the Vdiv, in reality they could probably use a sliding scale approach with the fine Vdiv to always keep the signal at about 80% of the ADC scale (maximum resolution) but I agree that would make it take even longer.

My experience with bodeV1 was that the phase had a nasty rollover situation, where if a signal was sat at about 180 degrees offset it would jump top to bottom of the screen despite only 1 degree variance in phase shift. Kind of wondering if there is now a way to unroll the phase shift so once it moves past 180 degrees it keeps counting in that direction. e.g. 190 degrees shift. or atleast set a reference phase offset (currently working onsite so have not dug into this in person yet)

Why "believings"...  you can see it even in this XTAL example image what is snap shot just at this position where it use 7.8mV/div (during sweep it change).
Fact, for level measurement they use fine variable V/div.

After 180 degree it jump. So user need keep track about these jumps and with human intelligence position these parts of phase draws to right position if need. There is no internal mechanism for keep track about this so reliably that it can keep always right phase over many phase turns. And I can not see even reason why to start "nutting" and try develop this kind of system.
Also test setup destroy this phase very easy. How to compensate it automatically. It is made for intelligent users who also think and not only give all thinking to machine. Example there is DUT and then example 2m cable delay. Then user sweep from 1MHz to 120MHz. How about DUT phase shift and total phase shift. It come some amount complex system if start also compensate this automatically. Of course all is possible as long as there is no limit in bank balance.
« Last Edit: May 30, 2019, 08:34:03 pm by rf-loop »
If practice and theory is not equal it tells that used application of theory  is wrong or the theory itself is wrong.
It is much easier to think an apple fall to the ground than to think that the earth and the apple will begin to move toward each other and collide.
 

Online Rerouter

  • Super Contributor
  • ***
  • Posts: 4087
  • Country: au
  • Question Everything... Except This Statement
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1386 on: May 30, 2019, 08:21:23 pm »
Good to see, and I agree I missed it, been digging to far in the other direction has skewed my thinking a little
 

Offline rf-loop

  • Super Contributor
  • ***
  • Posts: 3042
  • Country: fi
  • Starting with DLL21
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1387 on: June 01, 2019, 01:47:22 am »

My experience with bodeV1 was that the phase had a nasty rollover situation, where if a signal was sat at about 180 degrees offset it would jump top to bottom of the screen despite only 1 degree variance in phase shift. Kind of wondering if there is now a way to unroll the phase shift so once it moves past 180 degrees it keeps counting in that direction. e.g. 190 degrees shift. or atleast set a reference phase offset (currently working onsite so have not dug into this in person yet)

This is quite complex problem and I can not see easy way what do not then rise up some problem  when used in many kind of situations. When device under test output is low it is very difficult to detect reliable phase due to noise. Also it need note that there is no continuous reference and dut output. There is not 1 point where these signal can  "agglutinate" when BP start and after then start continuously follow both and calculate phase shift even over many full turns. I can not find how to do it with this kind of machine without some extra hardware.
If add hysteresis then loose accuracy. If add level limiter what user can set so that it do not try measure phase when signal level is under this limit then it do not draw anything in this area.
But always if work under 20MHz, it is important to use channels BW limit. Specially if there exist quite low levels. Like example in my previous image where is 60kHz xtal and dynamic range around 85dB.
If practice and theory is not equal it tells that used application of theory  is wrong or the theory itself is wrong.
It is much easier to think an apple fall to the ground than to think that the earth and the apple will begin to move toward each other and collide.
 

Offline Performa01

  • Frequent Contributor
  • **
  • Posts: 787
  • Country: at
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1388 on: June 01, 2019, 08:28:33 am »
Bode Plot II might be able to provide even more dynamic range if an amplifier is to be measured, or if it’s used for measurements with passive structures that can tolerate the increased power.

Attached there is the measurement of an MI (Marconi Instruments) TF 2154 RF amplifier, capable of delivering some 25dBm (300mW) output power with 27dB gain and 1.5MHz to 520MHz bandwidth.

With the current version of Bode Plot II, we can only measure up to 120MHz, so we are unable to examine the high frequency roll-off of the amplifier and just get a lowpass filter response.

First a relative measurement (Vout/Vin):


SDS1104X-E_TF2175_Bode_120MHz_27dB_Rel

This bode plot shows 60dB dynamic range, only because the start frequency is far outside the specified bandwidth.

The measurement confirms that we indeed get the specified gain of 27dB within the passband.

The phase response within the passband appears not flat, hence does not match the amplitude response. This is simply because no attempt was made to compensate for the additional signal delay from input to output of the amplifier.

Now let’s have a look at the absolute output (Vout):


SDS1104X-E_TF2175_Bode_120MHz_27dB_Abs

Output power within the passband is measured as 21dBm. Since the generator level has been set to 0dBm and the amplifier was fed through a resistive 2-way power splitter (6dB loss), the input power was at -6dBm, which not only proves (again) that the specified gain of 27dB is actually achieved but also the absolute output power has been accurately measured by the scope.

Up to 120MHz an amplifier like this wouldn’t provide any real benefit, since e.g. the SDG6052X can deliver close to 24dBm at 120MHz, which is just about 1dB less than the max. output of the Marconi TF 2175. On the other hand, the current version of the Bode Plot II only allows a max. generator amplitude of 19.5dBm, so we could gain another 5dB with the TF 2175 after all.

Should Siglent give us a 500MHz version of the Bode Plot II for the SDS5000X though, the benefit of such an amplifier would be huge, since the output of the SDG6052X is limited to some 0dBm at 500MHz – so we’d gain at least 24dB at that frequency!
 

Online tautech

  • Super Contributor
  • ***
  • Posts: 15022
  • Country: nz
  • Taupaki Technologies Ltd. NZ Siglent Distributor
    • Taupaki Technologies Ltd.
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1389 on: June 01, 2019, 10:29:18 am »
Getting to know Bode plot II in latest firmware 6.1.33............

Let's revisit a previous one I'd done with firmware 6.1.20R1
https://www.eevblog.com/forum/testgear/siglent-sds1204x-e-released-for-domestic-markets-in-china/msg1435854/#msg1435854

Again I'll use the bandpass filter tutorial from here:
https://www.electronics-tutorials.ws/filter/filter_4.html

This is what we should see:


And this exact passive 1KHz to 30KHz bandpass filter:


10 pts/decade for ~30s sweep time.


Max 179 pts/decade for ~2 minute sweep time
Avid Rabid Hobbyist
 

Offline plurn

  • Regular Contributor
  • *
  • Posts: 89
  • Country: au
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1390 on: June 01, 2019, 11:51:54 pm »
...

FFT:
- better structured UI
- selectable FFT length for easier setup without the need to change the max. record length in the Acquire menu
- up to 8 markers
- configurable search for peaks and harmonics
- table view for the search results

There are still some minor issues that will be sorted with the next update.
...

How awesome is the new FFT in firmware version 6.1.33? Answer = very awesome.

The ability to put markers with measurements on harmonics is very useful - seems to be just one step away from calculating total harmonic distortion (THD) for us. It does not seem to calculate THD yet though.

I don't really know how it is able to show so much dynamic range in FFT with an 8 bit scope. I have normal mode selected in acquire settings and in FFT. Is ERES/averaging on all the time or something for FFT even in normal mode? See attached picture - why is there so much dynamic range shown? Scope is looking at my audio amplifier that is outputting a 477Hz sine wave. If it is valid dynamic range that is very useful.



Note - there is a good possibility that I have set up something wrong and or misunderstood.
Edit: it does seem to calculate some of the harmonics frequencies wrong sometimes though. For example the 4th harmonic should be 1908Hz rather than 2.05kHz.
« Last Edit: June 02, 2019, 12:00:31 am by plurn »
 

Offline Performa01

  • Frequent Contributor
  • **
  • Posts: 787
  • Country: at
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1391 on: June 02, 2019, 02:56:16 am »
How awesome is the new FFT in firmware version 6.1.33? Answer = very awesome.

The ability to put markers with measurements on harmonics is very useful - seems to be just one step away from calculating total harmonic distortion (THD) for us. It does not seem to calculate THD yet though.

I don't really know how it is able to show so much dynamic range in FFT with an 8 bit scope. I have normal mode selected in acquire settings and in FFT. Is ERES/averaging on all the time or something for FFT even in normal mode? See attached picture - why is there so much dynamic range shown? Scope is looking at my audio amplifier that is outputting a 477Hz sine wave. If it is valid dynamic range that is very useful.
c should be 1908Hz rather than 2.05kHz.
Well, the FFT itself hasn’t changed at all. It’s just the markers and the table that have been added.

Normal mode is the right one for FFT and in fact you should stick to that. The ADC is only 8-bit, but a long FFT improves the S/N-ratio a lot, because the frequency domain is divided into bins where each of them covers only a narrow chunk out of the frequency spectrum, which in turn reduces the noise accordingly.

You should not confuse S/N-ratio with dynamic range though. Even with a low noise level like this, the single tone 1st order dynamic range would only be some 50dB, as is to be expected for an 8bit system.

Thankfully, the single tone test >50dB below the reference level isn’t a very realistic test scenario anyway, so we should look at the much more important dual tone 1st order dynamic test, where the amplitude of the first (reference) tone is close to the reference level and can thus act as a near ideal dither for the much weaker 2nd tone. This implicitly provides a major resolution enhancement. We are going to verify right now that there is actually much more dynamic range than what can originally be expected from just 8 bits…

I’ve also noticed that you did not setup your FFT very well, thus giving away a lot of its potential.
I suggest you have a closer look to the FFT chapter in my review document (parts 6 & 7) here:

https://www.eevblog.com/forum/testgear/siglent-sds1104x-e-in-depth-review/msg1371782/#msg1371782

This will answer most of your questions and also contains a number of tables for assistance with the optimum setup of the FFT for most practical purposes. However, when I wrote that document, the FFT length selection was not available, so now this can be used instead of adjusting the record length limit in the [Acquire] menu.

First let’s check the FFT at higher frequencies, around 30MHz:


SDS1104X-E_FFT_128kpts_Dynamic_30MHz

To analyze a signal in the frequency domain, we need a sample rate that is at least twice as high, hence >60MSa/s is required for 30MHz. As you can see, I’ve chosen 100MSa/s which is accomplished by selecting 128k FFT length at a timebase of 100µs/div.

Next I’ve adjusted the center frequency to 30MHz and the horizontal scale to 1MHz/div, so I can watch the frequency span from 25 to 35MHz.

I feed two signals into CH.4 of the scope:

1.   30MHz, 14dBm
2.   31MHz, -66dBm

Normally, I do not use the vertical scale of 20dB/div, but in this case the whole picture shall be revealed at once. With a total display range of 160dB, the setting of the reference level is not critical anymore, so it has been set to 40dBm in order to give some headroom.

I’ve set a 16x averaging to get more stable measurements together with a nicely condensed noise floor. This is not strictly required for higher signal levels, but a valuable tool to make measurements both clearer and look nicer, especially for low level / high dynamic range measurements.

From the peak table we can see that the measurement is not too far off from the true levels. Most importantly, the weak 2nd tone is fairly accurately measured as -66.2dBm. The total dynamic range in this scenario is >80dB and the noise floor is below -70dBm.

Now for the low frequency (audio) stuff:


SDS1104X-E_FFT_512kpts_Dynamic_500Hz_01

To analyze signals in the audio range, we can assume a bandwidth of 50kHz maximum, which requires a sample rate >100kSa/s. Consequently, I’ve chosen 100kSa/s which is accomplished by selecting 512k FFT length at a timebase of 500ms/div. Note that we’ve now got a frequency resolution of only 190mHz which allows a very precise analysis of what’s going on.

Next I’ve adjusted the center frequency to 500Hz and the horizontal scale to 50Hz/div, so I can watch the frequency span from 250 to 750Hz.

I feed two signals into CH.4 of the scope:

1.   440Hz, 14dBm
2.   500Hz, -56dBm

This time I’ve used a vertical scale of 10dB/div, which hides the noise floor and limits the display range to 80dB, but that is usually not an issue as is demonstrated with the next screenshot. By simply shifting the reference level by 20dB to 0dBm, we can see the signals down to -80dBm and the noise floor gets visible again. The stronger 1st tone is still accurately measured, since other than on a real SA, the reference level here is really nothing more than a display setting.


SDS1104X-E_FFT_512kpts_Dynamic_500Hz_02

From the peak table we can see that the measurements are once again pretty accurate. The total dynamic range in this scenario is “only” >70dB and the noise floor is below -75dBm.

But we can indeed lower the 2nd tone by another 10dB and see if this still works:


SDS1104X-E_FFT_512kpts_Dynamic_500Hz_03

We can see that accuracy begins to degrade now for the weak 2nd tone, but still very usable. All in all an 80dB dynamic range is not too bad for only 8 bits.

You may notice some spurious signals here at ~560Hz and 680Hz – these are imperfections from the generator due to the external signal mixing without proper isolation between the generator outputs. To prove that, I’ve switched off the output for the 2nd signal and now everything is clean:


SDS1104X-E_FFT_512kpts_SpurTest_500Hz

Marker 2 now happens to show the level of the noise floor at -77dBm.

You mentioned automatic distortion measurements … I wouldn’t rule out that we’ll get that someday ;)
« Last Edit: June 02, 2019, 06:05:51 am by Performa01 »
 
The following users thanked this post: Gabri74, plurn

Online graybeard

  • Regular Contributor
  • *
  • Posts: 63
  • Country: us
  • Senior III-V RF/mixed signal/device engineer
    • Chris Grossman
1st use of Bode Plot II
« Reply #1392 on: June 02, 2019, 06:20:27 am »
I just tried out the new Bode Plot II with my SDS1104X-E and SDG2042X with a 50KHz lowpass filter I had in my drawer.  I connected both the scope and AWG to a WiFi range extender/router in my lab and assigned them both fixed IP addresses within my local subnet.  The scope immediately recognized the SDG2042X. 

I tried setting the upper frequency to 120MHz, but the it set the upper frequency to 40Mhz which is the upper limit for my SDG2042X.  I set the frequency sweep range from 10Hz to 40MHz with 12 points/decade.  I set the output of the AWG to 5Vp-p with a 50Ω output impedance.  I did this all on the scope without touching the AWG.

The 50KHz lowpass filter is designed to be used on a scope.  It has a 100KΩ input impedance and is designed for a 1MΩ load.  It has a nominal gain of ½ (-6dB).

I connected the output of the filter to channel 3 of the SDS1104X-E.  On the input I put a BNC tee.  One side of the tee was connected to the output 1 of the SDG2042X.  The other side was connected to a 50Ω feed-through termination on the channel 2 input of the SDS1104X-E.

I then turned on the bode plot and it made a very nice response curve of the filter.   I was auto plot ranges were not perfect, so after it ran through the response once I manually set some of the limits for a nicer plot.



I then used the cursor to find the 3dB point of the filter which turned out to be 54.5KHz.



The Bode Plot will be very useful for a variety of measurements.  However it does not replace a sweep generator and detector probe for making IF stage adjustments becasue it is far to slow, but will be excellent for a precise measurement of the adjusted stage(s) once done.   

This is a pretty damn nifty feature for such a reasonably priced oscilloscope.  I am somewhat annoyed that the seemingly arbitrary low frequency limit of 10Hz.  It would be nice to be able to go a couple of decades lower down to 100mHz.  Even so, I am very happy with my purchase.

In looking at it further the 10Hz low frequency cutoff is because the Bode Plot mode uses the scopes AC input coupling and 10Hz is high enough not to be rolled off by the input high pass in AC mode.   Although it would be nice to go lower in frequency, the 10HZ limit now makes sense.
« Last Edit: June 02, 2019, 11:34:31 am by graybeard »
 

Online graybeard

  • Regular Contributor
  • *
  • Posts: 63
  • Country: us
  • Senior III-V RF/mixed signal/device engineer
    • Chris Grossman
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1393 on: June 02, 2019, 06:40:01 am »
You mentioned automatic distortion measurements … I wouldn’t rule out that we’ll get that someday ;)

The usefulness of FFT feature for distortion measurements will be very limited by the 8 bit ADC that digitizes the signal.  High fidelity audio measurements require a minimum of 16 bits, and preferably 24 bits.
« Last Edit: June 02, 2019, 06:42:21 am by graybeard »
 
The following users thanked this post: Performa01, plurn

Offline Performa01

  • Frequent Contributor
  • **
  • Posts: 787
  • Country: at
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1394 on: June 02, 2019, 08:23:59 am »
You mentioned automatic distortion measurements … I wouldn’t rule out that we’ll get that someday ;)

The usefulness of FFT feature for distortion measurements will be very limited by the 8 bit ADC that digitizes the signal.  High fidelity audio measurements require a minimum of 16 bits, and preferably 24 bits.
Excellent objection!

I should really have pointed out that despite the fact that we can get a rather decent dynamic range up to 80dB, the linearity is still no better than what a fast 8-bit ADC can deliver. If it’s a very good one, then we can hope for an INL of no more than +/- 1LSB.

Let’s check that, with an ultralow distortion 1kHz sinewave:


SDS1104X-E_FFT_Harmonics_1kHz

As can be seen, the strongest distortion component is the 2nd harmonic at some -57.7dBc. This alone would cause a distortion figure of 0.13%. While this proves that an 8-bit system certainly isn’t suited for high fidelity audio testing, it at least indicates that the ADCs in the SDS1000X-E aren’t bad at all and the INL is <1 LSB indeed.

This would still be enough for general purpose audio and maybe also some other applications.

After all, most DMMs offer a bunch of fancy functions as well, even though they are far inferior when compared to a dedicated instrument for the same purpose. Yet users demand it (quite obviously even professionals, because otherwise lab bench DMMs would not provide frequency and even capacitance measurement).
 
The following users thanked this post: plurn

Offline plurn

  • Regular Contributor
  • *
  • Posts: 89
  • Country: au
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1395 on: June 02, 2019, 04:10:44 pm »
...

Hi Performa01,

Thank you so much for providing all of this information, and instructions for optimising set up for FFT.

I am not surprised that I did not setup my FFT very well. My method for setting it up so far has been by "twiddling the dials" until it looks about right. I will study the FFT part of your review and your post to try and understand this better.

My twiddling the dials method also explains why I thought FFT had improved with this firmware version. When I have used the FFT in the past, I got much less dynamic range and just accepted it as a limitation of an 8 bit oscilloscope. I would have just had it set up even less optimised.

I do find the new markers and the table to be a big convenience. It will save a lot of time compared to trying to measure peaks/harmonics individually.
 
The following users thanked this post: Performa01

Offline testian

  • Regular Contributor
  • *
  • Posts: 54
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1396 on: June 03, 2019, 05:42:00 am »
Does anybody know how to set the WiFI password if the necessary character is not in selectable?
I am missing the "

I already digged a bit in the file system and found:
 /usr/bin/siglent/usr/wifi/wpa.conf
But it does not affect the password used when connecting.


Changing the password on all other devices is not really an option for me.
 
The following users thanked this post: tek2232

Offline HendriXML

  • Frequent Contributor
  • **
  • Posts: 467
  • Country: nl
    • KiCad-BOM-reporter
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1397 on: June 03, 2019, 09:05:12 am »
In that case it would be nice if a hexadecimal version of the password was supported.
“I ‘d like to reincarnate as a dung beetle, ‘cause there’s nothing wrong with a shitty life, real misery comes from high expectations”
 

Online tautech

  • Super Contributor
  • ***
  • Posts: 15022
  • Country: nz
  • Taupaki Technologies Ltd. NZ Siglent Distributor
    • Taupaki Technologies Ltd.
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1398 on: June 05, 2019, 05:43:42 pm »
Does anybody know how to set the WiFI password if the necessary character is not in selectable?
I am missing the "
Confirmed and reported.

The latest 6.1.33 firmware otherwise has given us a significant improvement in WiFi performance if my old beta SDS1104X-E unit is anything to go by.  :phew:
WiFi connection seems very stable now and range is now much improved with the TL_WN725N dongle.
Avid Rabid Hobbyist
 

Offline Old Printer

  • Frequent Contributor
  • **
  • Posts: 494
  • Country: us
Re: Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes
« Reply #1399 on: June 06, 2019, 05:19:32 am »
Does anybody know how to set the WiFI password if the necessary character is not in selectable?
I am missing the "
Confirmed and reported.

The latest 6.1.33 firmware otherwise has given us a significant improvement in WiFi performance if my old beta SDS1104X-E unit is anything to go by.  :phew:
WiFi connection seems very stable now and range is now much improved with the TL_WN725N dongle.

My WIFI was poor to non existent with that dongle over about 25 feet but I did have the "Remember IP Address" setting wrong. I went straight to a Ethernet connection rather than mess around with it, and all problems disappeared. I have not used the web interface since, so I look forward to seeing if the firmware update makes a difference. Foe my location running a wire was the easiest alternative.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf