appling - 2020-03-12

Hi everyone!
Basically my question is: Is it possible to have a trace element plot discrete changes in a variable (only one point per record)?

I want to record and plot a variable that changes after a certain trigger event happens.
So far I have tried setting up a trace element for this. Unfortunately, even if I configure the trigger (with a rising flank) and set the option "post trigger samples" to 1, still more then one data point is plotted on the visualization.

The desired behavior would be, that only one point is plotted in the trace element for every time the trigger has a rising flank.

What I have tried so far: I have realized that the trace fills up the predefined buffer no matter what kind of trigger options I configure. As the buffer size is not freely definable I have put the trace into an extra task with a high cycle time (>1s) so that only one data point can be recorded. Unfortunately, this is not a good workaround, as the frequency of recordings will change depending on the monitored process and the task time cannot be set via a variable.
I cannot use the x-y diagram on the target device, as its version is on 3.5.7.10

I also should add that I am using the trace element in the "normal" visualization. I am not using the trace object that can be added to the application tree - to be honest, I do not know how to add that object to any user visualization.

Do you have any ideas on how to make this work?
I hope the screenshots will help illustrate my problem.