Author Topic: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)  (Read 124812 times)

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Offline Gyro

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #550 on: January 30, 2020, 07:46:38 pm »
Nice job.  :-+

Looking forward to seeing whether you can get useable accuracy and noise level at 2mV/div.

Chris
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Offline bhowden

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #551 on: February 01, 2020, 02:39:39 am »
Hopefully this does not seem like I am trying to hyjack this thread.  This is a continuation of my thread on the main testgear forum.  Basically I have been trying to use single triggering on an OWON VDS 1022 DSO to test a quadrature encoder.  Quick summary is that I loaded Florentbr's replacement SW from git hub and all my troubles disappeared.  Single triggering now works exactly as it should.  My issue with both quadrature channels rising at the same time persists.  Also, if I turn the encoder backward, both channels fall at the same time followed by B rising followed by A rising. 

In the triggering menu there is a combo box that lets you set a delay time from a few ns up to seconds.  Can anybody explain what this is and how you would use it?

Brian
 

Offline Gyro

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #552 on: February 01, 2020, 02:15:20 pm »
That's really good news Brian. I am away from home at the moment so I am only able to play with the florentbr sans scope but clearly from your results,  there is a significant improvement in single trigger.

With regard to the trigger holdoff.  This is normally used in repetitive triggering situations (Auto or Normal - I can't think of single trigger use case) to prevent the scope from triggering again within a certain period of time. This is helpful in obtaining a stable trace on 'awkward' signals where there is another transition that could also cause triggering, causing the visible display to 'jitter' between the two resulting views. https://en.wikipedia.org/wiki/Oscilloscope#Holdoff should give you a fuller explanation. The better analog scopes used to have it too.

I'm not sure about your encoder results, it's beginning to sound like a physical anomaly of the encoder itself, though it's difficult to see how the same thing could happen in both directions. Are you sure you have the pinout correct? - I'm just trying to imagine what it would look like if you had one of the outputs accidentally grounded instead of the wiper. Maybe you can post a datasheet link.

Chris
« Last Edit: February 01, 2020, 02:22:51 pm by Gyro »
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Offline bhowden

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #553 on: February 01, 2020, 08:25:14 pm »
I believe you might be onto something here!  I whipped up a quick arduino sketch to just poll as quickly as possible and record the states and times and sure enough, the sketch showed exactly what the scope was showing.  When I worked out the pin out I just used an ohm meter and did a continuity check looking for the common lead but with 5 seconds more thought I think you are correct and that was too simplistic a test.  At some point, A is probably feeding through ground to B and my test was probably fatally flawed.  They are just cheap Chinese encoders so I am not sure a data sheet is available but I will have a closer look.  Thanks again.

Brian
 

Offline bhowden

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #554 on: February 01, 2020, 10:06:27 pm »
Bingo!  Sure enough, I was not using the correct pin out (I did warn you it was probably a stupid mistake on my part).  There is no part number on the encoder but trial and error switching pins did come up with a combination that works properly.  The only bright side is I now know much more about the scope.  Thanks again for you help and patience.

Brian
 

Offline Gyro

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #555 on: February 02, 2020, 10:09:45 am »
Glad you got it sorted Brian.  :-+

Anonymous encoder pinouts aren't the easiest thing to decode - at least we know what it looks like if you mistake an output for the wiper now. I tried to work it out in my head but didn't get past the 'everything will go off (high) at some point. Glad I could help anyway.

Chris
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Offline lotas

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #556 on: February 06, 2020, 12:46:40 pm »
Hello! I found a new driver libusb-win32-bin v1.2.7.1 (09/18/2019)
 

Offline Ben23

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #557 on: February 14, 2020, 10:01:16 am »
Hi everyone. I joined this forum just to say a big thankyou to everyone who's contributed to this thread. I've read the whole thing (and now my head is spinning a bit) and it helped to cement my decision to get a VDS1022I. The fact that there is such an active community supporting the product and continuing to improve the software for it played a big part in that decision.

I do have one newbie question that I don't think has been answered in this thread so far. I've noticed that there are a few clones of the VDS out there now, that look identical in every way but lack the Owon logo on the case. I've ordered what should be a legitimate Owon just to be on the safe side. But it's got me thinking that I should at least check that I've been sent the Isolated version that I ordered, rather than just trusting the silkscreening on the case. To do so (without opening it), would I be correct in thinking that I just need to check with a meter that there isn't a dead short / low resistance between the outer part of the BNCs (or the ground clip of a probe connected to them) and any of the pins of the USB socket?

Thanks.
« Last Edit: February 14, 2020, 10:02:52 am by Ben23 »
 

Offline Gyro

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #558 on: February 14, 2020, 11:24:03 am »
Hi Ben, welcome to the forum.

It is nice, particularly more recently, that the community has picked up from purely H/W analysis, to S/W enhancements too, Linux versions etc.

A good question, no I don't think it has been asked specifically before. Yes, a simple continuity test between the probe ground clips (or the ground tab adjacent to the cal output) and the USB connector (shell and ground contact) will be sufficient to confirm that it is an Isolated version. If you want a bit more certainty, you could add a few more volts, say, a 9V battery in series, but as the idea of the galvanic isolation is to break ground loops, rather than the dodgy practice of floating the scope at high voltages, there is no need to worry. The isolation components are rated for several hundred volts, so there's no risk involved in a simple continuity test.

As far as I can tell, they VDS1022 hasn't been "cloned" as such. There is a PeakTek re-brand that came up a few pages back, but it's the same H/W from the same OEM (still Owon AAFIK).

Chris.
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Offline Ben23

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #559 on: February 15, 2020, 08:25:19 pm »
Thanks Gyro. I received my scope today, it's definitely the isolated version and I've got it working great on my ancient Macbook Pro using the florentbr Github repo, with just the minor change to the installer as per this issue.

I read in the online manual that:
Quote
When the  attenuation  switch  is  set  to  1X,  the  probe  will  limit  the  bandwidth of the oscilloscope in 5MHz. To use the full bandwidth of the oscilloscope, the switch must be set to 10X.

I haven't seen this discussed before. It doesn't make any sense to me - surely all the switch does is reduce the voltage to a tenth of what it would have been (and, in software, multiply all the readings by ten). I don't see that the scope itself either knows or cares whether that attenuation is on, all it cares about is the voltage it sees. So why would it affect the bandwidth?

As for clones, I was just judging on the basis of listings like this one, where you have what is obviously the same design in every respect but lacks the Owon logo. I guess they are still made by Owon but "white label" for reselling...

Cheers
« Last Edit: February 15, 2020, 08:27:30 pm by Ben23 »
 

Offline Gyro

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #560 on: February 15, 2020, 10:10:44 pm »
Hmm, I've never seen a 'white label' one. From the look of it, it's no cheaper than a genuine one, so I suspect that it is original H/W.

Glad you've got it working as advertised, and on a Macbook.

The scope probe X1 / X10 thing is common to all scopes and all switchable scope probes. Basically, in X1, the probe tip exhibits the full capacitance of the probe cable plus the input capacitance of the scope (probably about 100pF in total) and the scope 1M ohm input resistance. This limits the useable bandwidth of the probe to very low frequencies, certainly not above audio - depending on the source impedance.

In the X10 position, the probe is configured as a 10M Ohm high impedance voltage divider, 9M Ohms in the probe tip (plus a bit of capacitance) combined with the 1M ohm input resistance of the scope. The Input capacitance at the probe tip is reduced by approximately the same ratio (around 10-15pF), making it suitable for high frequency use with minimal circuit loading.

Do a forum search of variations of 'scope probe switchable, X1,X10' etc. and you will get loads of hits. It's a fairly common question.

The X1 position is pretty useless unless you need a bit of extra low frequency sensitivity, but you could just as easily use a BNC clip lead and get the same performance. It is best practice to keep the probes switched to X10 (there is a probe division menu in the scope s/w [EDIT: Channel Menu, Probe Rate] so that all the readings come out correctly), for the reason above, and to provide additional useful protection to the scope inputs. The switches tend to be a reliability liability too, I don't know why switchable probes are so common (you can get dedicated X10 probes... and X100 probes for high voltage or low loading use).

Don't forget to adjust the probe compensation trimmers to give a proper square wave on the X10 setting, using the scope Cal output, before using them in anger. That should be documented in the manual too.
« Last Edit: February 16, 2020, 01:43:36 pm by Gyro »
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Offline Ben23

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #561 on: February 16, 2020, 06:37:20 pm »
Very interesting, thanks Gyro. For voltages within the range that can be safely read by both 1X and 10X, I would have expected 1X to be the better choice. I clearly have a lot of learning to do! I did notice I got cleaner traces of the test signal in 10X than 1X.

I've done the probe compensation, thanks.

How close should the 5V test output be to 5V? It's reading as 4.800V on mine (Vamp). I also have a slight difference / DC offset of about 80mV between the two channels' readings, which repeated Auto Calibration runs haven't fixed (it's the channels that are reading differently, not the probes, as the same channel remains higher when the probes are swapped), so I'm wondering whether I need to go into that hidden menu to manually tweak it...

Edit: The difference between the channels appears to be differing amounts of noise, as it's still present when nothing is connected, and always reads roughly the same amount in percentage terms. i.e. if the display is set to 5V/div, it will read say 200-400mV of noise, whereas if it's set to 5mV/div, it will read 0.2-0.4mV.
« Last Edit: February 16, 2020, 07:16:48 pm by Ben23 »
 

Offline Gyro

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #562 on: February 16, 2020, 07:42:14 pm »
Glad it helped.  :)

The 5V test output is derived from the USB supply (well at least the isolated DC-DC converter which isolates the USB on the VDS1022I). As such, it is not that well regulated and will vary a bit with USB port voltage, USB cable drop etc. That's not an issue in practice - it is intended purely as a nice clean square wave for probe compensation rather than a voltage calibration source. It does sound a little bit low though.

The auto calibration (as I understand it) uses mainly factory calibration settings which are stored in Flash memory in the unit for amplitude, and concentrates mostly on voltage zero and zero offset adjustments. Yes, you can use the hidden calibration menu to fine tune the settings (I found that I can improve slightly on the Autocal on my unit), and FlorentBR's description makes the differentiation between Zero amplitude and Zero offset settings clearer than we previously understood. You can use a PSU+DMM to calibrate the V/div settings (one time where using X1 probe setting is useful because the highest range becomes 5V/div rather than 50V/div).

Don't get too hung up on the noise measurement values changing as you change ranges - remember that, like most DSOs, the scope uses an 8 bit ADC (ie. 256 discrete levels full scale - negative max to positive max of the range), so will never be as DC accurate as an average DMM. When you change ranges, the significance of a couple of ADC bits changing is scaled accordingly in the readout. ie. you see the same couple of bits interpreted as 0.4mV on the lowest range and 400mV on the highest.

For absolute voltage accuracy, a DMM will always be superior, but for seeing what a signal actually looks like, you can't beat the scope.
Chris

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Offline Ben23

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #563 on: February 16, 2020, 11:20:27 pm »
For absolute voltage accuracy, a DMM will always be superior

You haven't seen my DMM ;)
 

Offline Gyro

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #564 on: February 17, 2020, 11:21:06 am »
I'm willing to bet that it has more than 8 bit resolution though.  :)
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Offline Nullarbor

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #565 on: February 18, 2020, 07:51:05 pm »
Hello again. I am still enjoying my Owon 1022, but seem to have a "problem" with the TTL external input for triggering.

I can't get it to work - don't know if it's my ineptness or something else.

Has anyone here tried using the EXT as a trigger? Any ideas?

My input signal is a square wave 32us wide and goes from 0v to +9.6v and back down again.

 

Offline Gyro

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #566 on: February 18, 2020, 08:53:27 pm »
A quick thought - have you been into the Utility menu and set the 'Multi' to Trigger In? I think it defaults to trigger out.
Chris

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Offline cosmin1

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #567 on: February 23, 2020, 10:36:07 am »
Hi guys.
Thanks for tones of info i could find in this topic. It answered a lot of my questions and i'm almost convinced to buy the 1022i.
I would appreciate more customizable skin and trace color, to look better like the real oscilloscopes.

That's why i also find interesting the Loto OSCA02, but there isn't any info about it. This means isn't worth the money?
Price is 20$ more than the Owon.

« Last Edit: February 23, 2020, 11:19:03 am by cosmin1 »
 

Offline Gyro

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #568 on: February 23, 2020, 12:37:59 pm »
That's a new one, I haven't seen it before. As you say, there doesn't seem to be much info around. I found a youtube video on it...

...which indicates that it 100Msps like the Owon (don't know if that's per channel or shared). It adds basic 6 bit logic analyser / GPIO capability, data logging (which could be useful), and a 48k buffer (Owon is 5k).  Basic edge triggering only. I don't think it has galvanic isolation though, but I was skipping through the video a bit.

He is raving about the UI in the video, comparing it with the Hantek 6022, I don't think he mentioned the Owon at all. I'm not a fan of on-screen virtual knobs, but that's a personal preference thing. It looks fairly understandable though. He seems to think that FFT and Autoset button are unique features? Huh?  Something screwy seems to happen when he switches from sinewave to squarewave at 1MHz too (15:48), he has to wind down his generator frequency to get it to display. I'm not sure what the flashing warning triangle is about?

I'd be interested to see a teardown to see how much it's doing on board and how much in the PC -  it must be doing something because it mentions the 48k buffer, whereas Hantek claims 1MB, but that's just the arbitrary size of the buffer in the PC that it streams data into in realtime (so effectively the Hantek has none on the device).

It's probably worth you starting a new thread to discuss it so that replies on the different scopes don't get confused.


P.S. Here's a manufacturer video, looks quite good but you need some patience...

https://youtu.be/mUM9R6rnH90
« Last Edit: February 23, 2020, 01:35:04 pm by Gyro »
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Offline cosmin1

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #569 on: February 26, 2020, 05:36:13 pm »
Hello.
As i said, i already ordered the Owon VDS1022i.
Now i just want to install the florentbr's version software with customizable trace colour, to play with it and familiarize myself with the menus.

I follow exactly the indications in Readme file, but all i get is the next error and no app is installing.

## Install
Download and extract the following archive: 
https://github.com/florentbr/OWON-VDS1022/archive/master.zip
Right click on `install-win.cmd` and select "Run as administrator". 
The script installs the drivers, copies the files, registers for uninstall and creates a menu entry.


Am i doing something wrong?
My OS is Windows7 64bit.

« Last Edit: February 26, 2020, 05:53:18 pm by cosmin1 »
 

Offline Gyro

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #570 on: February 26, 2020, 05:42:46 pm »
I think you mean florentbr's s/w.  :)

P.S.   F:\  looks a bit strange unless you have lots of drives?

P.P.S. It may be because you don't have any hardware to attach yet. I'm not sure how I would go about manually installing a driver in device manager if the hardware wasn't already connected. I think it will also automatically pick up the driver from Camomille's installation when you plug it in.
« Last Edit: February 26, 2020, 05:54:27 pm by Gyro »
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Offline Gyro

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #571 on: February 26, 2020, 07:07:29 pm »
My Application Shortcut is:

%JAVA_HOME%\bin\javaw.exe -Djava.library.path="C:\Program Files\OwonVdsTiny\lib" -Duser.dir="%APPDATA%\OwonVdsTiny" -cp "C:\Program Files\OwonVdsTiny\jar\*" com.owon.vds.tiny.Main

(It should have been put as an entry in your start menu by the installer script)
« Last Edit: February 26, 2020, 07:13:17 pm by Gyro »
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Offline Gyro

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #572 on: February 26, 2020, 07:16:52 pm »
I was hoping that it had got that far before failing to install the driver. Sorry, I wouldn't have a clue where to start with remote access.
Chris

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Online indman

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #573 on: February 26, 2020, 07:50:18 pm »
cosmin1 Unzip,copy this file in folder OWON-VDS1022-master and run my modified install-win.cmd without installing the driver. Show me the black window after running this script.
« Last Edit: February 26, 2020, 08:26:35 pm by indman »
 
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Offline cosmin1

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Re: OWON VDS1022I Quick Teardown (versus the Hantek 6022be)
« Reply #574 on: February 26, 2020, 08:59:35 pm »
Oh yeaaaaaaaaaaaah!
That's what i'm talking about.  :clap:

So the old install-win was bad.
Now everything's different. Thank you very much!
I suppose now i can uninstall the original 1.0.30, right?
« Last Edit: February 27, 2020, 08:04:53 am by cosmin1 »
 


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