The Siglent SDG1000 and SDG800 thread

[tautech]

Hello,
Could anyone verify for me the following issue?
Setting duty to value different than 50% does not affect the shape of the square wave.
... or it is just my lack of knowledge ... 
rgs,
M

SDG1005, firmware 37R2.

Welcome to the forum.

By definition a square wave is symetrical, Hi & Lo being the same time duration. A square wave however can be "offset" and be "riding" on an applied voltage.

What you describe is a "pulse" that can be a continious stream or "triggered" as a single pulse.
It can also be offset and adjusted for: Hi, Lo, and frequency (length of period).

So:
A 50% duty cycle pulse IS a square wave. 

[Owen]

Hello,
Could anyone verify for me the following issue?
Setting duty to value different than 50% does not affect the shape of the square wave.
... or it is just my lack of knowledge ... 
rgs,
M

SDG1005, firmware 37R2.

Squar wave 20-80% works here (SDG1025, Firmware latest - i think 37R2). If Siglent is reading this: Please save the language setting, I don't think anybody likes that new "Please Select Language" feature on every single bootup wether it's in mode "last" or "default".

[tautech]

There has been much discussion on this "feature" lately:
https://www.eevblog.com/forum/testgear/siglent-technical-support-join-in-eevblog/msg631583/#msg631583

Until it changes, just ignore it and proceed with using the equipment, ANY control button or knob will override the boot up language selection menu.

[mmrow]

tautech:

Thanks alot for a quick reply and warm welcoming !

I absolutely agree - a 50% duty cycle pulse IS a square wave 
However I would expected the behaviour can be observed at the screen of generator 

Owen:
Thank you!
... but now I do not understand. Did not work for me with 36R1 as well ...
Do you confirm the change of the duty value anyhow - any button, whatever ?
M

[tautech]

I absolutely agree - a 50% duty cycle pulse IS a square wave 
However I would expected the behaviour can be observed at the screen of generator 

Glad to see WE think alike, but it'll be this way for "general" acceptance.

Please put your country flag in your profile, it really helps when you need local advice. 

[mmrow]

Thanks again tautech.
besides, something I'd like to share with all of you - if already not noticed somewhere on forum. With the newest version of the firmware (i.e. 37R2), the tool button gives another space for improvement - bandwidth update. It seems that everything we need is ... a license key 

[tautech]

besides, something I'd like to share with all of you - if already not noticed somewhere on forum. With the newest version of the firmware (i.e. 37R2), the tool button gives another space for improvement - bandwidth update. It seems that everything we need is ... a license key 

Yes it has been spotted. 
AFAIK it is for future functionality.

[rf-loop]

Hello,
Could anyone verify for me the following issue?
Setting duty to value different than 50% does not affect the shape of the square wave.
... or it is just my lack of knowledge ... 
rgs,
M

SDG1005, firmware 37R2.

User Manual pages 23 - 25.

With SDG1005 you can set Square wave dyty between 20% to 80%.
(definition for Square wave is 50% but using this function can also do other rectangle waves where duty is not 50%)

If it really do not work, it is possible that this function have example hardware failure.

It need carefully test.
SDG1000 service manual:
Duty Cycle Verification for Square.  Page 26.

(I have never seen this failure but I know how this part of circuit works)

Other discussing is if name Square is good or not for this function.
In real it is Rectangle function where special case is Square wave. Rectangle wave with exactly 50% duty is Square wave, what is also SDG's default.

I think Siglent is not alone with this name of this function.

But, please check carefully if it works ok or not. If not, suspected is hardware failure.
What ever is failure type, if it do not work, it is warranty failure case and you need try first contact seller.

[Wmacky]

SDG1000 service manual:
Duty Cycle Verification for Square.  Page 26.

Where is this service manual?  I read it was on the Siglent disk, but no dice?

[TerminalJack505]

SDG1000 service manual:
Duty Cycle Verification for Square.  Page 26.

Where is this service manual?  I read it was on the Siglent disk, but no dice?

See the first post of this thread.

[rf-loop]

Issues (unsolved)
*SQUARE WAVE GLITCH (in brief, the work-aroundis to use the pulse function when working at low frequencies, either that or a hardware mod): https://www.eevblog.com/forum/testgear/siglent-sdg1020-arbitrary-fungen-first-impressions-and-a-possible-signal-glitch/

In the first message in this thread there is still this claim.
Why this totally obsolete disinformation information is still there? This issue is solved long time ago By Siglent.

[mmrow]

rf-lloop:

Square or Rectangle?  There is no my ambition here to work on taxonomy area issues :-)
Just wanted to know if anyone have experienced the issue mentioned ealier - if so, in consequence, to be a proof that is related with firmware bug.
By the way, reading a manual is always a good idea - especially when everything other fails. Yes, I already did follow the methods described in manual - unsuccessfully (ie. "Use the keypad or the knob to input the desired value, choose the unit, and press the corresponding button. The generator will change the waveform immediately.").
Does not affect on the wave neither immediately nor with delay.
To be honest is hard to believe it is a hardware issue - this is an arbitrary type generator.
Anyway, thanks for your assistance ... 
M

[tautech]

Hello,
Could anyone verify for me the following issue?
Setting duty to value different than 50% does not affect the shape of the square wave.
... or it is just my lack of knowledge ... 
rgs,
M

SDG1005, firmware 37R2.

SDG1010 FW 37R2
AWG square wave behaves as expected, select Duty and use either keypad or rotary knob to adjust Duty cycle between 20 & 80 %.
Confirmed on display and with scope.

Try Utilitiy>System>Set to Default and then set the AWG to your desired setup again.

Let us know if that works.

[rf-loop]

rf-lloop:

To be honest is hard to believe it is a hardware issue - this is an arbitrary type generator.
Anyway, thanks for your assistance ... 
M

It is arbitrary generator, yes.
But I know how Square function signal is produced in SDG1000 series.
All units what I have tested with all firmwares this Duty % adjustment have worked and also works with unit what I have in my own demo use.
Square wave works internally so that it still produce Sine wave!  But in this function internal Sinewave do not go to output amplifiers. It go to PECL comparator. Other input of comparator get this Sine and other input get adjustable DC for duty adjust. When DC is middle of sinewave p-p it produce 50% Duty square out and this signal go to output stages.

Pulse function, what also produce rectangle, can also produce 50% duty rectangle signal what is square wave.
Using Pulse function signal is produced totally different way directly by DAC. In many cases (and up to Pulse mode freq top limit, it is perhaps best mode for produce square wave and if want, set it for Duty %, so changing frequency do not affect duty.

Both methods have some advantages and disadvantages. 

If Square function produce without any problem always 50% duty square independent of Duty setting it tell least to me that PECL do not work right or PECL do not get adjustable treshold voltage and problem is there and of course failure can be many kind of, some component, some PCB issue etc.... rare but possible. 

I have experience with these equipments and have also  warranty time repair service and I have also repaired these units in some rare cases. (example in old case when Siglent factory have accidentally installed wrong type of CH2 output ampliviers.) Also I have investigated quite deeply this Square function circuits due to fact that old times there was this "famous" glitch" issue what also was extremely pure hardware issue due to wrong setting of PECL comparator hysteresis setting (+ some cases also internal sinewave noise.) (both of these have been long time ago solved By Siglent)

Of course also FW may do same thing if there is problem with DAC driving what produce adjustable DC to PECL for square duty setting. But as told, I have not yet seen any FW version with this bug. So, if this do not work, my susppect is HW failure.

[rf-loop]

About SDG800 series.
It have, as all SDG models, Sync out signal.

Sync Out signal (front panel BNC)  is qquite fast rising and falling bit over 50ns wide pulse.
Its true rise and fall time is roughly 1.2ns or even bit less.
Signal output impedance is 50ohm and signal level is over 2V (load 50ohm impedance)
Sync Out is limited to work down to 500ns signal cycle period (up to 2MHz).

It is also useful if you need this kind of signal (fixed level, fixed width but frequency nearly zero - up to 2MHz.
Its fast risetime may be some times useful. (it produce lot of high freq harmonics and this group of harmonics may be useful for some works.

It may be useful to know how this Sync Out signal time position is related with CH1 signal output with different functions/modes.


It is somehow explained here
(partially under work and I do not know when they all are ready. Time is not renewable resource and I have it only limited amount.)

attached one sample

[mmrow]

stepping back to sdg100 issue for a moment ... closing of the raised issue.


tautech:
The brilliant idea (with setting to defaults) but I have failed with all exercises, using both channels. Including trial with firmware R31.

rf-loop:
Your detailed explanation convinced me - it can be the hw failure. No doubts.

The good news is that the other functions/options I have already checked seems to be operational. 
I think I will have to survive using your workaround - pulse signal.
Many thanks to you both!
I will stay tuned with this thread - it is very valuable ...
Marek

[Lightages]

Has anyone heard how/when/if the bandwidth upgrade keys can be purchased and how much?

[tautech]

Has anyone heard how/when/if the bandwidth upgrade keys can be purchased and how much?

I have asked Siglent exactly this.
They indicate it is for "future" use.

All we can do for now is wait for an announcement for use of this feature.

[Lightages]

I bet the cost will be just a little bit less than the difference in the model prices originally. I also wonder if the upgrade process will open the firmware to the same kind of hack as the Rigol scopes. Maybe they are working on locking it down before anyone here gets their hands on it.

[nctnico]

Siglent is already using license-key enabled options on the SDS2000 oscilloscopes. No doubt someone will come up with a hack some day.

[tautech]

I bet the cost will be just a little bit less than the difference in the model prices originally. I also wonder if the upgrade process will open the firmware to the same kind of hack as the Rigol scopes. Maybe they are working on locking it down before anyone here gets their hands on it.

Siglent hat off.

Of course we all are aware of this "business model", similar is happening with Hantek, but often I've wondered when hackers might devote their energy/s to Siglent products. Product families from most manufacturers appear to have common HW so it follows that BW is set at factory by programming.
rf-loop has indicated there are differences in the SDG1000 series with componentry tolerances and that dictates the final BW selected at factory. However this may have been addressed to allow a wider range of BW to be programmed after manufacture. 
Don't discount a HW revision either, that permits BW upgrade over the full 1000 series range, that HW might omit the cooling fan in the higher BW models.

As they say: "time will tell".

Siglent hat on.

[dav]

Do these mods:
https://www.eevblog.com/forum/testgear/looking-for-reasonable-dds-function-gererator-need-opinions-please/msg579056/#msg579056
void the 3 years warranty?

[rf-loop]

Do these mods:
https://www.eevblog.com/forum/testgear/looking-for-reasonable-dds-function-gererator-need-opinions-please/msg579056/#msg579056
void the 3 years warranty?

How it can be unclear?

Where is  factory who keep still warranty valid if someone have opened product and done some DIY works inside equipment.  How they can be responsible about failures after this. There is many things, even ESD what may damage equipment if not any other thing. After ESD it even may work normally and after hours or weeks it may accidentally fail just because in history it have get ESD. Of course people may have even more than enough knowledge, experience and skills for do work but how factory really know it and how they can trust it and keep warranty still valid. It is like name and sign on blanko paper.

http://siglenteu.com/shfw.aspx

5. The warranty is void if:

(1) Accidental damage occurs during transportation (please confer with insurance agency or transportation company on the compensation).

(2) Malfunction or damage is caused by misuse according to warnings in the product documentation or using or storing in an environment outside of the specification’s limits.

(3) Surface damage by manmade factors, like burn, distortion by force, etc.

(4) Repaired by anyone who is not from SIGLENT Maintenance Center or an authorized maintenance branch.

(5) Accident damage caused by using a power cord or a power adapter not approved by SIGLENT.

(6) Malfunction or damage caused by natural calamities, like earthquake, lightning strike, etc.

I do not know what is official answer for this particular question but my opinion is: This is the same thing as in the fourth paragraph above.

[ivan747]

Issues (unsolved)
*SQUARE WAVE GLITCH (in brief, the work-aroundis to use the pulse function when working at low frequencies, either that or a hardware mod): https://www.eevblog.com/forum/testgear/siglent-sdg1020-arbitrary-fungen-first-impressions-and-a-possible-signal-glitch/

In the first message in this thread there is still this claim.
Why this totally obsolete disinformation information is still there? This issue is solved long time ago By Siglent.

It's a hardware problem, it's not like Siglent will come to my house to fix it. I will re-word it and place it in the solved section, but still, there are units out there with the problem.

[tautech]

2 items of interest that should be included in this thread.

Siglent announcement of Labview drivers:
https://www.eevblog.com/forum/testgear/siglent-technical-support-join-in-eevblog/msg656874/#msg656874

SPA1010 Power Amp for Siglent SDG waveform generators:
http://www.siglent.com/ENs/prodcut-fjxx.aspx?fjid=1071&id=145&tid=16&T=2

User Manual
http://www.siglent.com/2014EnglishWebsite/Documents/UserManual/SPA1000_UserManual_UM60010-E01A.pdf