CH_A set to Not Used. Triggering on CH_B as [Level below 2.6V]. With this configuration I would expect the trigger point to be the falling edge of the pulse i.e. as it transitions from above 2.6V to below 2.6V. However, it triggers on the rising edge instead. If I change the trigger to [Above 2.6V] it triggers on the rising edge as expected. If I change the trigger to [Falling below 2.6V] then it triggers correctly. When I introduce CH_A in the logic I get even more unexpected results. It's as though the trigger point is when the requested condition is no longer met?