Oscilloscope One Shot Behavior

We’d like to get your feedback on how best to handle the case where you have a scope setup to do a one shot and can make changes to the trigger conditions while the scope is looking for a trigger.

Let’s say you have a one shot set for a rising edge at 3V and don’t see the trigger fire. While the scope is waiting for the trigger you adjust the trigger to 3.5V. While you made your adjustment the old trigger condition (3V) was met.

Do you want the scope to:

  • Stop on the previous trigger condition
  • Stop on the newly set trigger condition
  • Something else, I’ll explain in the comments

0 voters

Depends how you want to update the trigger condition. A couple of possibilities come to mind:

1/ a value is updated in an edit control: use the old value until the new value is entered (enter pressed or the control loses focus)
2/ the value is updated by dragging a slider or threshold line: use the current value (the position of the slider thumb or threshold line right now) as the live value

Option 2 is expected behavior while changing the trigger level knob on a dedicated scope and should be the same for single shot and all other triggered modes. A common application is to “fish” for the wanted trigger point by slowly changing the threshold until the wanted trigger point is found. Using a slider or dragging a threshold line work much better for that than trying a whole bunch of values in an edit control.

Of course having all three (slider, dragable threshold line and edit control) synced together would be best of all.



Thanks Peter for your feedback and suggestions this is very helpful!