In the EEROS library you will find a directory with examples. Open a shell in the build directory of your EEROS library and run examples/controlsystem/BlockTest3. This examples shows how single blocks can be instantiated. They can be named and their inputs and outputs can be connected to other blocks. The signals in between can be named as well.

The output signals of a newly created block carries a value of NaN (Not a Number). Please note that any block will output a meaningful value only after its run method processes its input values and inner state and finally writes its resulting values to its outputs.