Hi Raxis13,
Thank you for testing so thoroughly!
The OpenHantek6022 project started as a linux software to handle Hantek DSOs of the 2000 and the 5000 line, 6022 support was added later. As 6022 is different to 2xxx and 5xxx the program had a lot of compromises. After the original maintainer of the github repo resigned I cloned it and removed all non-6022 stuff – development is still under linux. MacOSX and Windows builds are created by CI (continuous integration) tools travis and appveyor, but untested unless sometimes a short win check in a virtual win7 machine. So I cannot help with win installation.
To the program itself. Its display was designed to resemble a real HW scope so that everybody who had used a scope before (even an old analog non-storage scope) should be familiar with this SW.
Also if you do some checks be sure to know what signals you are using, either by using a well known signal, e.g. from a signal generator or the mains signal (after a transformer, never measure directly the mains voltage!) or by attaching another scope or by measuring with a DMM (digital multi meter).
Now to your questions:
> For the tests I used the 1Mhz square reference signal.Where did you get this signal? From the screen shots I suspect you took the calibration output of the scope and selected 50 Hz. Please look at the Horizontal mini window -> Calibration out. This signal (on the two contacts on the right of the scope) is a square wave 0V/2V with 1 kHz on each program start (to be consistent with the label) but you can select 50 Hz..100 kHz in 1 / 2 / 5 / 10 … steps.
> 1/ Big problems to find a correct adjustment of parameters for a normal display of the signal.Select the “Timebase” accordingly, the “Samplerate” will be adjusted automatically but you can change it without affecting “Timebase” if you want. Select the correct Trigger Mode (Auto = show always a trace, even if not triggered, Normal = show only a triggered trace, Single = take one trace by pressing SPACE. Select the correct Trigger Source = CH1 or CH2 and the wanted Slope (/ = up, \ = down). The trigger level (in Volt) can be adjusted with the small red arrow on the right side, the trigger time position on the screen (0..100%) can be adjusted with the small red arrow on top (as mentioned in your topic 5/).
> 2/ Without a manual, I am very bored with the display values that seemed not in accordance with the signal.
For instance, you can see that there is : Time base 100ms/div ; 50 divisions on the horizontal axis ; 50 periods of this signal 1MHz are visible on the screen = 50 microseconds. So we should have 1 microsecond by div.
Problem, or not?Please look at my screen shots some posts above. The display has 10 time divisions and 8 voltage divisions (the dotted lines, just like a real scope). The default brightness of these lines is quite low, but you can change this in the menu Oscilloscope/Colors. As said the signal is not 1 MHz but (as you can see in the bottom measurement line) CH1 is 50 Hz.
> What means all these values on the bottom of the screen.From left to right:
Channel, coupling (in our case only DC, for MATH it is the function), voltage resolution (e.g. 1V/div), spectrum resolution (e.g. 10dB/div), DC part of the signal (average), AC part of the signal, RMS of the signal, i.e. sqrt( DC² + AC²), frequency of the signal.
> When i move the white markers 1 and 2 at the beginning and at the end of 1 period I found a difference of 20ms. Or normally I should have 1 microsecond. What is wrong?
3/ Sample rate : 10 kSample / sec. Seem very insufficient for a 1 MHz signal
No, 20ms equates the 50 Hz. This is easily sampled with 10 kSamples/s.
> How to use this red cursor, which give a value in percent (10% on the image)?This is the trigger position at 10% of screen width.
6/ If you move a small window (Horizontal, Voltage, Spectrum, Trigger) on the right side, you will have a lot of difficulties to reposition them.
You have to do it only once, the program stores the positions.
5/ No horizontal line for CH1 /CH2 measure cursor
No cursor for amplitude measurements on Spectra.
7/ How to use the sensitive areas Markers, CH1…, On, OFFSelect the channel you want, switch it on and draw a rectangle to measure time and voltage/spectrum differencies. You can see the small red rectangle in the middle of the red trace on your big screen shot, and the measured values 75.57 ms/516.1 mV on the right. Play around to get used to it, I never touched this software region.
8/ FFT – Very interesting. In addition we can use a csv file, with all the results.
Where is defined the width of the signal used for the FFT calculus?
How do you define dB for spectrum? Is-it equal to 10 * log10(Vf/Vmax), with Vf = V for the Fourier
frequence f.The FFT is calculated always over the complete 20 kSamples. You can define the window function in menu Oscilloscope/Analysis.
dB for spectrum is dBV, i.e. 20*log(V(f)/1Vrms), so a 50 Hz sine of 100 mV (rms) gives a peak with -20 dBV at 50 Hz. You can define your reference value in menu Oscilloscope/Analysis e.g. to reference to dBu (=dBm) for audio measurements.
CSV file : what are the units for t, V, f?Simple SI units -> t = seconds, V = Volt, f = Hz
Always 20 000 samples in the csv file regardless of sample rate 10, 50 or 100 kS/s. Is this useful?Yes, this is the max amount of samples we can get in one step (we do oversampling of raw 8-bit samples and average to got always 20000 samples that are real voltage samples (C++ double values).
Validity of the calcul :
- problem : positive values founded lines 102, 302,502… (with control value as indicated on the display image). I repeated the test several times (Timebase 100ms) and I found always the same problem. As you see the spectrum on your screen shot is above 0 dB, it’s clear that you see positive values at 50 Hz, 150 Hz, … (I see that you ticked the X10 probe box on Voltage window but the signal looks like you used a 1:1 probe for the 2Vpp square wave.) This setting is used together with the provided scope probes set to X10 to display the real voltage at the tip of the probe.
But no problem with Timebase 10 or 20 ms.
- with a 1MHz pure square signal we should find the fundamental at 1MHz, then sub harmonics at 3, 5, 7… Mhz. Please say goodbye to 1 MHz, it is 50 Hz with harmonics at 150, 250,...
I intend to compare using CH1 recording with Excel but I have not conclude right now. I need
definitions of units, which are not enough clear for me.
Units see above, simple s, V, Hz
I have to thank you again for your testing.
Regarding the translation - there are already German and Portuguese translation files in the source code but I do not see if it's activated, I can check, but only with low priority.
Martin
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