Products > Test Equipment
REVIEW - Rigol DS2072 - First Impressions of the DS2000 series from Rigol
Circlotron:
Had a super close look at the screen with my watchmaker's loupe.
The grid is 400 pixels top to bottom. (screen is 480 of course)
Thinnest trace when using large average number is 2 pixels wide. (not always, see next post)
The trace pointer can be moved in 1 pixel increments - 400 steps
The two pixel wide trace can only be moved in two pixel increments - 200 steps. (8 bit D/A?)
What happens is the pointer may be pointing to the lower line of the trace. Wind the pointer up one pixel and it points to the upper line of the trace (the trace does not move). Wind the pointer up one pixel further and the trace moves up two pixels so the pointer is now pointing to the lower line of the trace again.
At 1V per div one pixel is worth 20mV. The pointer can move in 20mV steps but the trace can only move in 40mV steps. There will always be some ambiguity with the measured voltage vs trace position if the trace is not an odd number of pixels wide, or if the trace pointer moves in different size steps to the trace.
Circlotron:
Okay, so you can get a 1 pixel wide trace in some circumstances. See pic.
Notice though that the blue trace has a minimum resolution of 2 vertical pixels (1 LSB?) whereas the trace pointer can be moved 1 pixel at a time. Whether a 1 pixel wide trace can be moved 1 pixel at a time with the pointer though remains to be seen.
Galaxyrise:
--- Quote from: Circlotron on January 27, 2014, 01:51:31 pm ---Okay, so you can get a 1 pixel wide trace in some circumstances. See pic.
--- End quote ---
High Res Acquisition, right?
marmad:
--- Quote from: Circlotron on January 27, 2014, 01:17:18 am ---Having a further look at this offset business - at about 1 or 2 pixels below halfway up the screen there is a point where the pointer and the trace line up perfectly. The further you go up or down the screen the greater the offset between the pointer and the trace, positive offset up the screen and negative offset down the screen. What's more, if you have the peak voltage reading turned on, at 1V/div it shows 40mV at 1 div, 80 mV at 2 div etc. So the scope is actually reading some kind of voltage.
--- End quote ---
This is normal and listed in the specifications: "DC Offset Accuracy: ±0.1 div ± 2 mV ± 1% offset value"
I suggest you do some reading on DC offset in DSOs - and how it's specified.
marmad:
--- Quote from: Circlotron on January 27, 2014, 12:35:28 pm ---The trace pointer can be moved in 1 pixel increments - 400 steps
The two pixel wide trace can only be moved in two pixel increments - 200 steps. (8 bit D/A?)
--- End quote ---
Discussed many many times in this thread: the DS2000 (and DS1000Z) map 200 ADC values to the 400 pixel high waveform display area.
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