Always call BACnet function blocks cyclically

It is very important that all BACnet function blocks are called once per cycle and only once!

Do not call the function blocks in this way:

This would create a BACnet object that is no longer updated if bCondition is FALSE. The object looks faulty to the client trying to access it.

However, it is possible to declare a BACnet object as a variable and not call it at all. In this case the BACnet object is not generated and therefore does not exist in the BACnet server.