https://forge.codesys.com/forge/talk/Visualization/thread/5dfb639b5f/2020-03-12T09:13:20.270000ZRecent posts to Record discrete changes in a variable with a trace2020-03-12T09:13:20.270000Z2020-03-12T09:13:20.270000Zapplinghttps://forge.codesys.com/u/appling/https://forge.codesys.comf996902b80032014377e1879b63dbcaa05583b22

<div class="markdown_content"><p>Hi everyone!<br/> Basically my question is: Is it possible to have a trace element plot discrete changes in a variable (only one point per record)?</p> <p>I want to record and plot a variable that changes after a certain trigger event happens.<br/> 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.</p> <p>The desired behavior would be, that only one point is plotted in the trace element for every time the trigger has a rising flank.</p> <p>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 (&gt;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.<br/> I cannot use the x-y diagram on the target device, as its version is on 3.5.7.10</p> <p>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. </p> <p>Do you have any ideas on how to make this work?<br/> I hope the screenshots will help illustrate my problem.</p></div>