Functions without fixed runtime behaviour

[joels]

Hi,

I am working on a safety system in WinCC OA. The WinCC OA notes advise against using functions which do not have a defined and fixed runtime behaviour (such as dynContains()).

I was wondering what other functions do not have a defined and fixed runtime behaviour and should therefore be avoided to meet safety requirements. For example, would using dynlen() and len() have the same issues?

Thanks,
Joel

[Gertjan van Schijndel]

That advice seems to be only for datapoint functions. I guess that advice only allows functions that take O(1) time (big O notation).
The duration of 'dynContains' takes for a sorted list O(log n) or O(n) for an unsorted list.
The functions 'dynlen'/'mappinglen' take O(1) time, so they do not have the same issue.