A function block composite is a group of function blocks that works together. The function block composite holds an algorithm, or a portion of an algorithm, that you want to use again. Function block composites are similar to a subroutine in a software program that you call and use in multiple locations.
You build the function block composite once, store it in your Function Block Library, and reuse it as necessary for different loops and applications throughout your process or for other processes.
For an example, suppose you want to define an algorithm for a simple loop using function blocks. You could use a Splitter function block to generate two outputs and send them to two different Analog Output function blocks that convert the values and send the signal to field devices through output parameters. The following figure shows the function block composite diagram for this example.
