The standard plugins in Dragstone works in a simple way: each one of them represents a single piece of hardware, service or logical handling of data. They are all represented as grey boxes on your screen.
But there are circumstances where Dragstone needs to represent an ecosystem of external hardware. This is represented with blue plugins that come in two flavors: master and slave. Master is the the one with more rounded corners and slaves are the square ones.
In order for Dragstone to know what Slave belongs what Master, a connection has to be dragged between the TO MASTER output from the Slave and the TO SLAVE input on the Master. This should reflect your hardware setup in real life because there are scenarios where you own more controllers/hubs and have different hardware connected to each of them!
Example of Ecosystem reflecting real life hardware setup
In the below example the first picture shows how the setup is made in real life and on the second picture how it is reproduced in Dragstone.