DS2072 bug? Incorrectly negative cursor delta = negative frequency displayed

• DS2072 bug? Incorrectly negative cursor delta = negative frequency displayed
  Posted by Circlotron on 06 Jan, 2014 12:21
• Check out this screen shot. Only noticed it long after I did the measurement. Cursor A is left and cursor B is right, presumably because of the time positions in the box. Notice delta X is minus 960uS not plus. Also the inverse of this negative period is displayed as minus 1.042kHz. A bug?

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• #1 Reply
  Posted by Altemir on 06 Jan, 2014 13:37
• Yes. This is bug. dT=Tb-Ta. Bug is absent on page 151 from User's guide: http://www.batronix.com/pdf/Rigol/UserGuide/DS2000_UserGuide_EN.pdf (see bottom picture)
  What You will see, when Ta with minus and Tb with plus?
  

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• #2 Reply
  Posted by bogdan546 on 06 Jan, 2014 16:27
• 500us-(-500us)=1.000ms is correct, but at first it should be 960us 
  
• #3 Reply
  Posted by Circlotron on 10 Jan, 2014 02:27
• Perhaps a related matter is this statement at the bottom of page 66 of the User's Guide ->
  
  "In the horizontal direction, the screen can display a maximum of 700 points with the leftmost as 350 and the rightmost as -350."
  
  Left is negative number and right is positive number. This would indicate the age of the data point rather than the time of occurrence as is usual. Maybe the firmware writer got it right in his own mind, just different to the rest of the world.
  
• #4 Reply
  Posted by Altemir on 10 Jan, 2014 04:47
• On MSO4024 fw00.02.00.00.04 I have no this bug.
• #5 Reply
  Posted by marmad on 10 Jan, 2014 14:04
• Quote from: Circlotron on 06 Jan, 2014 12:21

  Check out this screen shot. Only noticed it long after I did the measurement. Cursor A is left and cursor B is right, presumably because of the time positions in the box. Notice delta X is minus 960uS not plus. Also the inverse of this negative period is displayed as minus 1.042kHz. A bug?
  

  Perhaps - but you're running older firmware. The cursor box looks different in the latest version - and no negative error in my image:
  
  
  
  
  BTW, you'd likely get quicker/more responses/information if you posted these issues in the "REVIEW - Rigol DS2072 - First Impressions of the DS2000 series from Rigol" thread then creating separate threads for each question.

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