Hey guys,
I have a Rigol DS1054Z and I've been playing around with some filters today. I was comparing the output of the first filter on CH1 versus the output of the second filter on CH2. I was getting "strange" output on the second filter, so I made the second filter equal to the first filter and to my surprise, the output was not equal on the scope.
Scope version information:
![](http://bitshift.co.za/forum-files/rigol-bug/a-software-version.png)
CH1 @ 1V per division and CH2 @ 1V per division triggering off CH3. Math A-B is on at 1V per division.
![](http://bitshift.co.za/forum-files/rigol-bug/b-ch1-ch2-1v.png)
CH1 @ 2V per division and CH2 @ 2V per division triggering off CH3.
![](http://bitshift.co.za/forum-files/rigol-bug/c-ch1-ch2-2v.png)
CH1 @ 500mV per division and CH2 @ 500mV per division triggering off CH3. I forgot to turn the math function on here but the A-B operation reflects the difference between to the two wave forms.
![](http://bitshift.co.za/forum-files/rigol-bug/d-ch1-ch2-500mv.png)
Note the difference in wave form. The probes are physically connected to the same point in the circuit:
![](http://bitshift.co.za/forum-files/rigol-bug/probes-connected.jpg)
I first suspected probe compensation so I checked both probes:
CH1 compensation:
![](http://bitshift.co.za/forum-files/rigol-bug/e-ch1-compensation.png)
CH2 compensation:
![](http://bitshift.co.za/forum-files/rigol-bug/f-ch2-compensation.png)
CH1 & CH2 & CH3 compensation side by side @ 1V per division:
![](http://bitshift.co.za/forum-files/rigol-bug/g-ch1-ch2-ch3-compensation-side-by-side.png)
![](http://bitshift.co.za/forum-files/rigol-bug/probe-compensation.jpg)
CH1 & CH2 compensation side by side @ 500mV per division:
![](http://bitshift.co.za/forum-files/rigol-bug/h-ch1-ch2-compensation-side-by-side.png)
Note the difference in amplitude of the square wave. I tried two different probes connected to channel 2 but the same issue was present. I tried the self calibration feature of the scope but again the problem persisted. Just to be sure, I then tried switching CH2 with CH3 and the results were correct.
CH1 @ 1V per division and CH3 @ 1V per division triggering off CH2.
![](http://bitshift.co.za/forum-files/rigol-bug/i-ch1-ch3-1v.png)
CH1 @ 500mV per division and CH3 @ 500mV per division triggering off CH2.
![](http://bitshift.co.za/forum-files/rigol-bug/j-ch1-ch3-500mv.png)
This issue only happens when switching from 1V per division to 500mV per division and lower on CH2. I can't decide whether this is a hardware or software bug since there are no relay clicks when you change from 1V to 500mV per division. Any ideas on what the issue could be?