New oscilloscope from Fnirsi DPOS350P

[Ivont]

Has anyone tried a resonant circuit.  The phase is erratic.      I don't know if the gain is true, but the chart does not change and is stable.

[BillyO]

The gain is (sort of) accurate, the phase is nutsy-coocoo.  There are at least two problems here.  First problem is that the phase is 180 degrees out of whack.   Second problem is that there is no averaging being done.  Every other 'real' scope I have had the pleasure of using to do Bode plots does several runs and presents the average of those runs.  This method naturally reduces the error caused by the juxtaposition between stimulus and sample and produces a more relevant plot.

I have little 'faith' that this will ever be fixed.  So, my advice is to ignore the phase plot and accept the amplitude plot, but with a small grain of salt.

[Ivont]

I pray to God.    But the thing that annoys me the most is that at least they could have made it when it's fully charged show some kind of indicator and when it's discharged it also glows red or whatever. Two days ago the generator went haywire.  After a reboot, it went.  When I measure from the generator, the flickering is only fixed on a falling edge.

[ptluis]

The gain is (sort of) accurate, the phase is nutsy-coocoo.  There are at least two problems here.  First problem is that the phase is 180 degrees out of whack.   Second problem is that there is no averaging being done.  Every other 'real' scope I have had the pleasure of using to do Bode plots does several runs and presents the average of those runs.  This method naturally reduces the error caused by the juxtaposition between stimulus and sample and produces a more relevant plot.

I have little 'faith' that this will ever be fixed.  So, my advice is to ignore the phase plot and accept the amplitude plot, but with a small grain of salt.

Finally you reach the conclusion that this feature is bad implemented. I told you many posts before, and that's why I've always insisted that buyers return the device back, kind of a message to Fnirsi "if you don't fix this, you keep it". Like i said before, if nobody complains fnirsi don't care and nobody get their scopes fixed. If the creator comes here to read messages he already know what people dislike. Don't expect a firmware fix because it's not their way of working. Too bad!

[Ivont]

But this is very unworthy.  I am writing to them to refund my money because I can't use it, but these people don't believe in God until they face the harsh fate.  Every intelligent person should know that it is not money that will help them, but kindness.  They will have to spend the money they earn on something else.

[Grandchuck]

Maybe what Fnirsi should do is open up this scope and let people play with the firmware. There are well over 3000 replies on the Fnirsi-1013D thread (people there are playing with the firmware).

Do lots of extra sales result from this kind of activity?  What do you think?

[Ivont]

This is what I was told by AliExpress, the official store of Fnirsi. "Firmware update: Our R&D team is evaluating related functional upgrades, but we don’t have a specific release timeline yet. We’ll keep you updated if there’s any progress.  [Angel]"

[BillyO]

Finally you reach the conclusion that this feature is bad implemented.

I have always held this conclusion.  The amplitude is fairly accurate, the phase is not and It could hugely benefit from averaging.

Because the amplitude plot is fairly good, the mode is not totally useless and you can still get some good use out of it as long as the phase angle is not important to you.

[Ivont]

Can also the test signal, it does not start at the same degrees every time.    There is a start from which the start frequency and end are set.    Or samples with a difference, on each iteration without waiting to take the next sample.    For amplitude this is not so important, but for phase it is of great importance.

[Ivont]

When I turn on the oscilloscope and the internal generator is on square waves, I switch to measure a resonant circuit, but when I return to the oscilloscope mode, the displayed signal is a sine wave, with the starting frequency that I set in the resonant circuit measurement mode. To clear the sine wave, and accept the signal that is square, I have to repeat the square wave button, even though it shows that it is pressed.

[Ivont]

Does anyone know about this.    I believe the Fnirsi will never expose themselves.  They will fix all the mistakes.    They will improve this oscilloscope.    Another question is whether "some" people will be able to use it.

[BillyO]

What are the precise steps to reproduce this problem?

[Ivont]

I turn on the oscilloscope, everything is as it should be.  I go into a resonant circuit analysis menu, and when I go back to oscilloscope mode, I see this.

[BillyO]

Okay, same thing happens to me.  I guess when you go into the Bode plot mode it sets the generator to sine, otherwise it would not work.  So, again I'm guessing you want it to go back to a square wave, or whatever you had it set at before going into the Bode plot, when you exit back to scope mode?

Honestly, I would never have seen this as a problem.  It's just two taps on the screen to get it back.  It must be a special use case you have.   Just asking, but why is this a problem for what you are doing?

[Ivont]

Maybe it doesn't hurt, but it shouldn't.  The return is made by selecting again in the generator.

[BillyO]

Maybe it doesn't hurt, but it shouldn't.

Are there not far more important things for them to work on?  Like phase angle and averaging in the Bode plot mode?  (Just as an example)

[Ivont]

Yes, that's right. And that's what I told them, and I've sent them pictures.  On their site, I downloaded the firmware, but it didn't help, because it seems to be the same.

[cluca1969]

It would be helpful if your photo of the oscilloscope menu was in English.

[Ivont]

the symbols are the same.

[cluca1969]

Maybe, but not for me. I'm not a native English speaker either, but I try my best to respect my fellow forum members and to think and express myself in a common language that everyone can understand. I don't know what you're trying to prove by posting a picture with writing in another language unknown to most of the people on this forum ?

[Aldo22]

Maybe, but not for me. I'm not a native English speaker either, but I try my best to respect my fellow forum members and to think and express myself in a common language that everyone can understand. I don't know what you're trying to prove by posting a picture with writing in another language unknown to most of the people on this forum ?

Google can translate that.
Here's Romanian. No idea if it makes sense.   

[BillyO]

the symbols are the same.

Romanians have not used Cyrillic since the mid-1800's.

[Ivont]

You know it.  I don't mind who chose which language in the oscilloscope.  I have no such rights to dictate.

[Ivont]

the symbols are the same.

Romanians have not used Cyrillic since the mid-1800's.

I meant the icons.  moreover, it talks about the language I have selected on my oscilloscope.  It never occurred to me that anyone would pay attention to the language.  This probably means that someone has some personal problems.  I don't speak Russian either, but I understand it better and that was the reason until I got to know the features.

[PlainName]

this error which you will see in the picture if you look carefully

Well I don't know what the error is and I've looked closely. Is it because the generator is set to squarewave but the display of same is a sine? I only think this because the discussion is about the generator not remembering its setting, but that in itself wouldn't be too bad (lots of things seem to do that), so I can only think that it is much worse and showing you that it is doing one thing but actually doing another?

Do I get the prize? There was a prize, wasn't there? Otherwise why make it a secret that only the super-attentive will notice? You could have given a clue, or even a white-on-white spoiler if it hurt too much to just say what the problem was or what the screen is showing.