How to implement a "Generalisation" in SCL

Question

Is it possible for a generalisation in UML to be implemented in Simatic SCL code (or Structured text code)?

The definition of a Generalisation in UML:

A generalisation is a relationship between a morew general classifier and a 
more specific classifier. Each Instance of the specific classifier is also an
indirect instance of the general clasifier. Thus, the specific classifier
inherits the features of the more general classifier.

Features specified for instances of the general classifier are implicitly
specified for instances of the specific classifier. Any constraint applying
to instances of the general classifier also applies to instances of the 
specific classifier.

Answer 1

In general the answer to this is no, not really. All means of programming PLCs (ladder, ST, FBD, etc) are generally only very lightly abstracted from the actual machine code. They are closer to assembly wrappers than to anything we would think of as a modern development language. Structured Text is closer to very primitive Pascal - it lacks most any sort of object oriented features.

The notion is that PLCs and PLC programmers have long since been used to an approach of extreme micromanagement when it comes to developing programs for them. The reasons for this are many - some more valid than others. Scott Whitlock wrote a good bit here outlining some of those reasons. A big one is that maintenance guys on the factory floor are often the ones trying to troubleshoot the machines and having clear, non-abstract, state-machine information available to them is much more valuable than the need for an elegant, minimal formulation to stroke the ego of the system developer.

PLC programming is a ruthlessly practical industry. If you have the choice between something 10% more practical and something 90% more elegant, the practical solution will always win.

With that said - there are some who are playing in this area. I suggest a quick read of this article for some examples of trying to make ST work a bit like you are suggesting. Still, I would be cautious before putting anything like this to work in a real factory with real machines that need to be both safe and reliably making money.