Siglent Technical Support join in EEVblog

[boggis the cat]

Tautech has already responded with the reason for this behaviour, but I thought I should add this.

Note that the "Pk-Pk[1]=3.10V" and "Ampl[1]=3.02V" indications have an "=" symbol here:

1Xprobe - 500mVdiv:

While when the signal has been exceeded, as below, you get an above maximum reported (with ">"): "Pk-Pk[1]>784.00mV" and "Ampl[1]>780.00m".

1Xprobe - 100mVdiv:

This is handy to realise, as the 'scope is letting you know that there is a problem.

Perhaps it would be useful to have a more obvious 'flag' to let the user know when this condition occurs.  Some other 'scopes give an "***" type of indication instead of giving the maximum, but my preference would be for some form of separate 'overload condition' indication.

[Performa01]

I'd like to clarify a few things about overdriving the scope input stage, as this topic comes up quite often:

As most high(er) bandwidth scopes, the Siglent SDS1000X-E have a split path input buffer. That means there is a separate signal path for low frequencies down to DC in order to ensure reasonable high DC accuracy and offset stability, which a wide bandwidth / high impedance buffer cannot provide on its own.

Overdriving the DC path is straight forward and just results in clipping outside the visible screen area, so no problems here.
Overdriving the AC path - put in simple terms - causes a differentiation of the input signal rather than clipping.
When both signals are combined at the output of the split path buffer, this causes significant signal distortion. It gets particularly bad if the overdrive is asymmetrical, because this causes a an offset shift between both signal paths.

See also this thread, where a similar topic has been discussed:
https://www.eevblog.com/forum/testgear/is-this-the-siglent-compensation-issue-of-else/msg1467994/#msg1467994

Some more hints:

1. The specified input offset range does not indicate the amount of overdrive that can be tolerated, just the input offset voltage that can be compensated by means of the vertical position control. The overdrive is always the signal portion outside the visible screen area, hence related to the signal amplitude, which isn't affected by the position control.

The buffer input can handle some +/-500mV without noticable distortion, so you can overdrive the 500uV/div range quite severly and even asymmetrically while still being able to view the pulse flat without significant distotion, but this is not generally so.

The true rule of thumb is to make sure that the input buffer does not see more than +/-500mV in order to avoid signal distotions.

This means that the distortion free input range is about
+/-500mV up to 118mV/div
+/-5V from 120mV/div to 1.18V/div
+/-50V for 1.2V/div up to 10V/div

The numbers above have to be multiplied by the probe attenuation factor of course, so they are ten times higher for a 10x probe for example.

This means that at 200mV/div we still get a significant overdrive tolerance of +/-5V, but at 1V/div it is still only +/-5V, hence almost no headroom left.

2. The automatic amplitude measurements currently indicate overrange (>) as soon as a single sample falls outside the visible screen area, so they are just an indication for parts of the signal might not be visible, but no overdrive warning. Just stick with the rule of thumb given above and you're unlikely to ever run into problems with signal fidelity.

[evgen.05]

Hello! Found a strange behavior of my SDS1202x-e. Same signal. Just Sampling 500/1GS/s. Why amplitude is different?

[tautech]

Hello! Found a strandge behavior of my SDS1202x-e. Same signal. Just Sampling 500/1GS/s. Why amplitude is different?

At a glance it looks like aliasing.....take note of the timebase setting vs frequency indicator.
Adjust to fastest timebase then see what you measure.

[evgen.05]

It doesn't matter. Just turn on second channel - amplitude is higher

[tautech]

It doesn't matter. Just turn on second channel - amplitude is higher

Yep, mine's the same. I have my suspicions why but I'd rather someone more knowledgeable explain than me talk out of my ar*se.

It's Nyquist related and with half the sample rate with 2 channels active quite evident.
So not being able to shut eyes and leave it till the morning it was best to get it out of my mind.

HP sig gen @ ~80 MHz
SDS1104X-E (2x 1Gsa/s ADC's)





Channels 1 and 4 use an ADC each.
So with sufficient sampling rate measurements remains the same.
SDS1202X-E was checked with the same signal @ 80 MHz and the measurement change was minute, maybe 2 mV.
Maybe I should've checked 1202X-E at higher frequencies to see when 2 channels active 'really' makes a difference but you can do that.

[Performa01]

1GSa/s -> both ADCs combined in interleaved mode provide 5 samples per signal period.
500MSa/s -> single ADC provides just 2.5 samples per signal period.

With only few samples per waveform period, signal reconstruction cannot be very accurate anymore and 2.5 or 5 samples per waveform period is a significant difference. Not great, but that's how it is if you go close to the limits.

Yet I assume the amplitude is within the specified +2/-3dB in both cases - what is the suppopsed actual signal amplitude?

[Stu5]

Performa1, Boggis, & Tautech - thanks for your responses, that is very useful for my understanding.

See also this thread, where a similar topic has been discussed:
https://www.eevblog.com/forum/testgear/is-this-the-siglent-compensation-issue-of-else/msg1467994/#msg1467994

I had actually read this thread already. Just to clarify, in my case the distortion is at the bottom of the square wave which is at 0V (so I can see this with zero vertical offset), whereas in the above thread the signal is being offset by a long way to see the top. For me it also seems to extend over a much longer timescale - in the above thread, the effect seems to last less than 60ns.
Are we saying that the high part of the square wave is causing the overdrive problem which affects the part of the signal (near 0V) which we can see?

Before this I was using a fairly basic OWON VDS1022 PC oscilloscope, and this didn't show the effect. Are you still sure it is due to being over-driven?

[radiolistener]

I'm using SDS1102X and found some strange thing.
I connected input to the adafruit Si5351 module ( https://learn.adafruit.com/adafruit-si5351-clock-generator-breakout/overview ) with 0.5 m coaxial cable with SMA connectors. The oscilloscope input is switched to 50 Ohm mode. And Si5351 programmed for 10 MHz output.

Si5351 has a good square wave output with fast rise time = 1 ns. So, it looks like good way to test oscilloscope bandwidth

10 MHz:


500 kHz:


There is strange distortion on the top, I tried 1 m cable and it leads to increase delay of the distortion.
So, it looks like impedance mismatch which leads to pulse reflection in the cable.

Can someone test other SDS1102X with a fast 1 ns pulse source?
Is it ok to get such reflection on the oscilloscope?

[Performa01]

Performa1, Boggis, & Tautech - thanks for your responses, that is very useful for my understanding.

See also this thread, where a similar topic has been discussed:
https://www.eevblog.com/forum/testgear/is-this-the-siglent-compensation-issue-of-else/msg1467994/#msg1467994

I had actually read this thread already. Just to clarify, in my case the distortion is at the bottom of the square wave which is at 0V (so I can see this with zero vertical offset), whereas in the above thread the signal is being offset by a long way to see the top. For me it also seems to extend over a much longer timescale - in the above thread, the effect seems to last less than 60ns.
Are we saying that the high part of the square wave is causing the overdrive problem which affects the part of the signal (near 0V) which we can see?

Before this I was using a fairly basic OWON VDS1022 PC oscilloscope, and this didn't show the effect. Are you still sure it is due to being over-driven?

It does not matter whether the top or bottom of the waveform is observed when the opposite part of it falls outside the +/-500mV window after the attenuators.

It depends on the signal frequency what the distortion looks like. It gets generally much worse with lower frequencies. The signal freqeuency was 10kHz in that other thread.

Just to illustrate that, here’s my test signal at 100Hz and 2.5Vpp amplitude, measured at a vertical gain setting of 1V/div:


Test Signal 100Hz@1V

Now increase the vertical gain to 120mV/div:


Test Signal 100Hz@120mV

Even though the input is heavily overdriven by 2V beyond the top of the visible screen area, there is not much signal distortion and only minor offset shift.

Now increase the vertical gain just a tad to 118mV/div:


Test Signal 100Hz@118mV

See? This is because of the low frequencies get clipped, whereas the higher frequencies just get an offset. Because of this the two signal portions don’t fit together anymore.

Now let’s try a higher signal frequency, 1kHz at the exact same settings otherwise:


Test Signal 1kHz@118mV

Looks much better already, doesn’t it?

Now the same test at 10kHz:


Test Signal 10kHz@118mV

Distortion is almost gone. This is because now even the fundamental of the input signal is processed by the HF part of the input buffer. There is still an offset shift, but this gets less with shorter signal periods of course and is already almost negligible here.

Finally 100kHz:


Test Signal 100kHz@118mV

Bingo! No noticeable signal distortion and also no offset shift anymore.

[Performa01]

I'm using SDS1102X and found some strange thing.
I connected input to the adafruit Si5351 module ( https://learn.adafruit.com/adafruit-si5351-clock-generator-breakout/overview ) with 0.5 m coaxial cable with SMA connectors. The oscilloscope input is switched to 50 Ohm mode. And Si5351 programmed for 10 MHz output.

Si5351 has a good square wave output with fast rise time = 1 ns. So, it looks like good way to test oscilloscope bandwidth

…

There is strange distortion on the top, I tried 1 m cable and it leads to increase delay of the distortion.
So, it looks like impedance mismatch which leads to pulse reflection in the cable.

Can someone test other SDS1102X with a fast 1 ns pulse source?
Is it ok to get such reflection on the oscilloscope?

I don’t have a SDS1102X, but SDS2304X is similar with regard to the 50 ohm input, which isn’t a good match above some 100MHz.

Here’s the test with 10MHz square wave, 1ns rise time, 1.5Vpp amplitude and internal 50 ohm termination of the scope:


SDS2304X Square 10MHz 1ns 50ohm internal

Here is the similar situation, but with an external 10dB in-line attenuator at the scope input and the generator level increased to 4.5Vpp:


SDS2304X Square 10MHz 1ns 50ohm internal + 10dB Att

As can be seen, the situation improves significantly with this.

Of course, much higher frequency content can be seen in my screenshots, because the SDS2304 happens to have 375MHz/3dB bandwidth at 200mV/div vertical gain setting.

[Joel_l]

I went to use my spectrum analyzer today and noticed the time and date or off. when I go to set date, I cant change anything. I can change the date format OK but the date or time, no. I expect that pressing the function button would scroll through the fields and the knob would change them. Nothing happens.

I recently updated to 1.2.9.1, but I don't recall trying to change anything in previous versions.

Am I missing something?

Thanks

Update: I did a reset and then the time and date test showed on the display and I was able to key in the correct data. Certainly does not work as the "help" menu suggest.

[Dino2018]

My experiences with SHS1102 (firmware 3.01.02.02R7):
The hardware is quite good but the software is too buggy.

Problems I have found so far:
All the mathematic functions and the "Trend Plot mode" ignore the set probe attenuation (X10, X100...) its X1 regardless the settings.

If I pres Run/Stop the applied (Low pass) filter is turned off and must be reactivated in the menu.

Sometimes when saving a BMP the waveforms disappear (everything else is saved).

I'd like to use inverted screen but some texts are difficult to read as they have almost the same color as the background.

If I record a Trend Plot it's very difficult to read the cursors. For example if the recording is 20min long and I want to measure values of both inputs in the same time (voltage and current at 11min:22sec).

It's almost impossible to move the cursor through longer Trend Plots or zoom to a specific point in the trend. I'm recording trends overnight but it's useless if I can't read the data afterwards as the device is practically frozen.

I have send my complaints to the distributor and he forwarded it to the prodecer but we didn't get any response (it's already 5 months).

[tautech]

My experiences with SHS1102 (firmware 3.01.02.02R7):
The hardware is quite good but the software is too buggy.

Problems I have found so far:
All the mathematic functions and the "Trend Plot mode" ignore the set probe attenuation (X10, X100...) its X1 regardless the settings.

If I pres Run/Stop the applied (Low pass) filter is turned off and must be reactivated in the menu.

Sometimes when saving a BMP the waveforms disappear (everything else is saved).

I'd like to use inverted screen but some texts are difficult to read as they have almost the same color as the background.

If I record a Trend Plot it's very difficult to read the cursors. For example if the recording is 20min long and I want to measure values of both inputs in the same time (voltage and current at 11min:22sec).

It's almost impossible to move the cursor through longer Trend Plots or zoom to a specific point in the trend. I'm recording trends overnight but it's useless if I can't read the data afterwards as the device is practically frozen.

I have send my complaints to the distributor and he forwarded it to the prodecer but we didn't get any response (it's already 5 months).

Welcome to the forum.

Please see reply:
https://www.eevblog.com/forum/testgear/siglent-technical-support-join-in-eevblog/msg1464559/#msg1464559

I have no further updates at this time.

[DazA1]

@Dino2018

I asked the same question and was told a new firmware was going to be released around mid May. Its 1st of June today so maybe soon we will have these issues fixed?

I found the same issues with my scope and i decided to put together a pdf (see post 934 of this thread).

I hope this gets sorted but i am not getting my hopes up these issues have been around for a long time.

[Siglent America]

We are currently finishing up the editing on the documentation. I expect it will be posted in a week (hopefully less).

[tautech]

New SHS1000 and SHS800 series firmware is now available on Siglent websites.
Release Date 06.07.18

SHS800 owners.
Warning:
Be sure to select correct version to suit your model.

https://www.siglenteu.com/service-and-support/firmware-software/handheld-oscilloscopes/

At this time only the SHS820 (200 MHz) and SHS1000 firmware is up on the US site.
https://www.siglentamerica.com/service-and-support/firmware-software/handheld-oscilloscopes/

Further info SHS800: 60, 100, 150 MHz models
Changelog
1. The probe attenuation factor is considered in the trend diagram mode.
2. Digital filtering state remains even in scope stop state.
3. The switchboard can record the configuration of the math waveform.
4. The Math waveform takes into account the probe coefficient configuration.
5. Improved Win10/EasyScope connectivity.
6. Improved vertical cursor measurements when changing scales on fixed/stopped waveforms
7. Enabled self-calibration under Normal or Single mode.
8. Improved edge trigger performance for single and normal mode
9. Increased Single trigger data depth in long storage mode(from 20kto2Mpts).
10. Increased stability of trend map transfer of CSV data to USB memory devices > 4 GB
11. Optimize the display algorithm of multi-meter trend chart and oscilloscope trend chart. Solves the slow response of keys after long recording time.
12. Enhanced FFT data usage. Long storage features 40 times the corresponding frequency points used in ordinary storage.
13. Improved read/write timeout to the U disk.
14. Time stamp information added to the saved CSV file.

Update instructions
Very important ! READ THEM please !
CFG (configuration) file are to be installed too so take care that instructions are followed.

[DazA1]

  WARNING!!!!       WARNING!!!!

Just updated my Firmware on a SHS1062 with this file and it looks like its been bricked!!!!

It reported the firmware update successful and told me to power cycle the unit.

When i pressed the power button i heard the relay click but nothing on the screen. Disconnecting and reconnecting the battery has made no difference.

Any ideas??

[BillB]

Aw man, that's a bummer.  Now I'm afraid to upgrade mine.   

[DazA1]

The irony of my scope being bricked is not lost on me considering i was one the people for a long time requesting these issues to be fixed.

I was so pleased to read the list of changes i just wanted to get it updated 

[Performa01]

The irony of my scope being bricked is not lost on me considering i was one the people for a long time requesting these issues to be fixed.

I was so pleased to read the list of changes i just wanted to get it updated 

Really sorry to read about the troubles. Have you contacted Siglent support already?

If not, just use the contact form on the linked webpage.

https://www.siglentamerica.com/contact-us/

And please keep us updated. Best of luck!

[BillB]

In spite of DazA1's difficulties, I decided to provide another data point and upgrade my SHS806.  I am happy to report that it upgraded without a problem, so it seems the SHS806,08,10's firmware is safe. 

The release notes implied EasyScope capability on Windows 10 with the new EasyScopeX version (that I installed and tested with the SDS1000X-E update).  However, as this is USB, the previous EasyScope 3 software used custom USB drivers rather than NI.  These drivers do not install on Windows 10 Pro 1803; the inf installer complains that the third-party inf does not contain a digital signature.

I did have EasyScope 3 running on a Windows 7 machine connected to this SHS806, so I know its possible.  The documentation regarding how EasyScopeX might support the SHS806 in a Windows 10 64bit system is lacking. 

Thanks Siglent and you Siglent support guys on this forum for being so responsive!
 

[DazA1]

I have not noticed these lines on the screen before? I needed a bright light and the screen to be just at the right angle to make them visible. The thicker group of lines at the bottom seem to be the same width as Siglents GUI. They change a little bit when the power button is pressed and stay on screen even when the battery is disconnected.

Instead of the firmware update failing has my screen gone bad? The last image on the screen was the "Please power cycle" message which was on a completely white background something the screen to my knowledge has never displayed before. Could this have stressed the screen somehow? (going from an entirely white screen to then off)

The only problem with the idea that it's the screen not the Firmware update is that i can't hear the relays when pressing the CH1 & CH2 buttons?

Any ideas? (i really wanted to play around with these Firmware updates)

[mojoe]

I know this reply is months later, but I've started a new job and moved across the country since my previous post. I finally got the two power supplies unboxed and just finished replacing the binding posts with the new ones that Siglent sent me in January.

The first one took a little while to figure out the best way to disassemble things, without taking too much apart. The second one only took about 15 minutes. The new binding posts fit my banana plugs much firmer, so I'm happy.

When I had the supplies apart, I noted how very nicely everything was laid out, and how clean the boards were. There was no sign of rust or rough edges on the metal. I didn't bother to see what brand caps were used, but overall, the insides looked to be very good quality.

Thanks to Siglent for sending me the new binding posts.

[tautech]

I know this reply is months later, but I've started a new job and moved across the country since my previous post. I finally got the two power supplies unboxed and just finished replacing the binding posts with the new ones that Siglent sent me in January.

The first one took a little while to figure out the best way to disassemble things, without taking too much apart. The second one only took about 15 minutes. The new binding posts fit my banana plugs much firmer, so I'm happy.

When I had the supplies apart, I noted how very nicely everything was laid out, and how clean the boards were. There was no sign of rust or rough edges on the metal. I didn't bother to see what brand caps were used, but overall, the insides looked to be very good quality.

Thanks to Siglent for sending me the new binding posts.

Glad you have it sorted.
There's a mod that can be done that allows short and shouldered banana plugs to be used plus some discussion on lengths that seem best to use with SPD3kX models.
https://www.eevblog.com/forum/testgear/siglent-spd3303x-e-binding-post-issues-solved/