The block represents the fundamental component of Simulation Studio simulation models. All blocks in the base template are either directly or indirectly derived from a base block class. The base block class implements the message handling protocols and defines how blocks communicate with each other through ports. Each block is responsible for creating any ports it needs to perform the functionality required by the block. From a GUI perspective, ports completely define the interface to most blocks. Port management and related port message handling are two vital functions required of all blocks.

For the most part, blocks communicate with other blocks by using links between ports. When using the Simulation Studio GUI, you can create a link from an output port only to an input port of compatible type. If you have multiple links on a given port, logic in the port determines which connections are used and in what order. The default behavior is to use the connections in the order in which they were created.