I'm just afraid that the term
waveform update rate has become a new marketing buzz word for scope manufacturers, omitting the fact that the true
waveform processing rate, i.e. the rate at which the scope manages to transfer samples from fast FIFO buffer to DPO buffer, is way more important.
Trigger out proves as much as the hardware trigger frequency counter used by Uni-T I'm afraid...
I'm not sure what you're talking about... you mean the frequency counter on the Uni-T? This has nothing to do with triggers (only the input signal itself) and is nothing like a Trigger Output.
According to the manual it is a hardware frequency counter that counts trigger frequency.
And intensity grading... well... it actually needs _more_ processing than a simple persistence mode as used within low-cost scopes, so this is no indication as well.
Yes!! That's the point - a oscilloscope with intensity-grading has more processing power than one without.
Did you look at the PCB of the Siglent? Do you know what DPO (and fast waveform capture) architecture looks like?
This is definitely a fast DPO - no doubt about that. I'm more curious to see how nicely the UI works - and how well things like segmented memory are implemented.
You're right, but I'd like to distinguish between processing power and processing complexity.
Intensity grading is more complex than simply persistent mode.
To achieve the same waveform processing rate with intensity grading, more processing power is needed.
But a scope featuring intensity grading does not automatically have more processing power. Of course it should, but for simple marketing purposes you can implement intensity grading which is just a software feature and keep your hardware as (cheap) as it was.
Also, you can't tell from the screen update rate, how fast waveform processing is because your
eye trigger (aka shutter speed
) is almost saturated at 50 frames per second.
Just give priority to the UI, e.g. with a dedicated snappy ARM SoC, and the scope feels flashy.
We're talking about 2000....50,000....150,000 waveforms per second. No way that you can verify this by screen refresh rate.
You need some glitch generator - periodic signal + spurious glitches like Dave uses in his reviews - and then watch if the glitch becomes visible at some time or if the scope misses the glitch.