Good evening, I've just lost a bunch of time trying to debug a problem.

If I go online the values I'm seeing are not possible, and they seem to blink from random gibberish to the real values.

attached is a screenshot, where for example my tag "ts_st_high" is written once at row 31, but at the IF condition is monitored as different.

could it be because of problems decompiling for the online monitoring of nested FBs?

here is my structure, nothing that seems unreasonable to me:

main_OB==>devices_FB(single instance) ==> actuator_FB (mult. inst.)==> alarm_FB (mult. inst.)

the one I'm monitoring is the alarm FB, the other uupper levels are all working as expected.

Interestingly if I open and monitor the FC "ltime_to_sec" I'm seeing the same issue with the same frequency as the alarm FB. Inside the fc the monitored value for return is the same as what i see in the fb.

Across my program all the alarm_FB are showing the same problem, 

all the tags are showing this behaviour, doesnt matter if in, InOut or static

CPU et200sp 1510 tia portal v18 upd2

 to be honest it is difficult to describe the issue, i managed to do a screen capture of the problem. it is visible at line 38

Stefan Arcularius

Your condition of the if and elsif statement is not fulfilled (according to your programming it would only be fulfilled for one CPU cycle, which makes it almost impossible to grab the screenshot at the right moment). Therefore, the values for #ts_st_high, #ts_act and #ts_st_low are displayed in gray color, which means that the value may be wrong.

 as you said the ts_st_high is only written one cycle, as i am saving the time of the rising edge. if i look at this tag in a watch table i see that the value is consistent with what is shown in gray. problem is that in the following if statement, where i compare it with current time it changes, as shown in the video attachment.

Today it is mostly stable, but last friday it was almost always showing random data continously changing.

after several test i am shure the code works correctly, it is only a online visualization problem. last week i was having a problem and lost a bunch of time looking at this, but my issue was somwhere else.

I guess what I'm trying to get to is: has anyone else experienced this behavour? are there any tweaks possible to improve/avoid this?