When you are new to something, it always helps to get a mental picture of how that something works.  Since I learned Simulink over 10 years ago, I have developed my own mental model of Simulink models.  Today I want to present a mental model for the three basic components in Simulink block diagrams, ports, blocks and signals.

Something Familiar

A good mental model is something to which you are already familiar.  I like to compare Simulink diagrams to programs written in a procedural language like MATLAB or C.  My favorite is MATLAB, so that is usually how I think.

Ports

Ports are the input and output arguments for the function.

Blocks

When I think about blocks, I think of them as algorithmic components of the programs.  A block like the Gain or Product is a function that operates on inputs and produces an output.

Signals

Signal lines pass the value output from one block to the next block.  I think of signal lines as the variables in a program.

Generating Code

With my intuition in hand, I read the generated code so I can compare and refine my mental model.  The result is here:

In this case, I made a couple tweaks to the code generation settings for readability and interface. 

What do you think?

How does your mental model of a block diagram compare to mine?  Leave a comment here and share it with me.