EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: Boscoe on October 21, 2015, 02:46:37 pm
-
When a manufacturer quotes 50,00 waveform updates per second what is actually happening when the display is only being refreshed less than 60Hz?
Also if a scope doesn't have a graded intensity display how would you effectively display 1Gsa/a (for example) of information?
Thanks
-
Combine multiple acquired waveforms into one trace.
-
Combine multiple acquired waveforms into one trace.
So, the display update rate is still low (~60 fps)? Do they specify this rate?
-
The 'waveform update rate' is actually a bit of a misnomer these days, as what it really means is the trigger rate (i.e. how many triggers a scope can process per second). Back in the old days with analog scopes the trigger rate was identical to the rate the waveform was refreshed on the screen. However, DSOs capture the waveform into the sample memory, and depending on the settings the waveform on the display of a DSO might only show a part of the captured waveform.
-
Combine multiple acquired waveforms into one trace.
So, the display update rate is still low (~60 fps)? Do they specify this rate?
If a display would be updated 50000 times per second you'd miss 99.9% of the signals. Your eyes can keep up with about 5 updates per second so what you want is that each acquisition stays on screen for at least 200ms. In old analog scopes the phosphor takes care of keeping the trace longer on the display. A DSO needs to combine many acquisitions into one trace on the screen where the oldest acquisition fades away.