This topic is about instrumentation and controls, and in particular how these are being represented in the RDL.
All Instrumentation & Controls classes are, in the top of their class hierarchies, strictly separated by function. In the table below this is shown for the first level in the hierarchy:
Click here for a report showing all 738 subclasses of INSTRUMENTATION FUNCTION.
No combinatory explosion
Since most instrumentation items and all controls are combinations of above functions the number of possible combinations is unmanageable. And they are not required either, because these combinations can be made on-the-fly in a kind of "cafetaria mode", similar to composing your food by selecting food from a counter.
Below two examples are given:
A measuring element of a transmitter, process switch, process gauge, or process-connected recorder is defined with an AssemblyOfAnIndividual template.
Combinations of other functions are done by typing with the applicable functions. Alternatively each function is declared separately. Later these can be combined with two AssemblyOfAnIndividual templates.
Using templates allows for a different choice of for a further specialization later. Just deprecate the old template and create a new one.