Behaviour of stopped Photo Eyes (possible bug)

[FelixMoehlmann]

[ FlexSim 23.1.2 ]

Hi everyone,

one of our clients recently requested help with a problem in a model in which they use the following 'feature':

If a Photo Eye is stopped by calling object.stop() on it, it will automatically stop any newly arriving item. When it gets resumed, the item is resumed as well.

A reference to the stopped item is stored in a node in the PEs attribute tree under stats. The issue is that this reference is not cleared after the item is resumed. This then leads to the item being resumed every time the Photo Eye is switched out of a stopped state. At one point in the client's model this lead to the item seemingly ignoring the processing time on a station as demonstrated in the attached model.

PE_StopResume_Bug_23_1.fsm

This looks like a bug, at least if this is actually a feature rather than some deprecated functionality as the missing documentation might suggest.

[jason_lightfoot_adsk · Accepted solution]

This looks like some 'spill-over' from the station functionality but was not fully implemented. I can't say I understand why stopping a sensor as a concept should stop the item, but for now if this is how they want to implement it they can use a station instead of the photoeye which will clear the item references correctly, whereas a decision point and photo-eye will not.

I'll send this into the devs to review.

[Matthew_Gillespie]

@Felix Möhlmann

This issue is fixed in 23.0.9 and 23.1.3 released today.