Function-Call Subsystems
A function-call subsystem is a subsystem that another block
can invoke directly during a simulation. It is analogous to a function
in a procedural programming language. Invoking a function-call subsystem
is equivalent to invoking the output methods (see Block Methods) of
the blocks that the subsystem contains in sorted order (see How Simulink Determines the Sorted Order).
The block that invokes a function-call subsystem is called the function-call
initiator. Stateflow, Function-Call Generator, and S-function
blocks can all serve as function-call initiators.
To create a function-call subsystem, drag a Function-Call Subsystem block from the
Ports & Subsystems library into your model and connect a function-call
initiator to the function-call port displayed on top of the subsystem. You
can also create a function-call subsystem from scratch by first creating
a Subsystem block in your model
and then creating a Trigger block
in the subsystem and setting the Trigger block's Trigger
type to function-call.
You can configure a function-call subsystem to be triggered
(the default) or periodic by setting the Sample time type of
its Trigger port to be triggered or periodic,
respectively. A function-call initiator can invoke a triggered function-call
subsystem zero, once, or multiple times per time step. The sample
times of all the blocks in a triggered function-call subsystem must be set
to inherited (-1).
A function-call initiator can invoke a periodic function-call
subsystem only once per time step and must invoke the subsystem periodically.
If the initiator invokes a periodic function-call subsystem aperiodically,
the simulation is halted and an error message displayed. The blocks
in a periodic function-call subsystem can specify a noninherited sample
time or inherited (-1) sample time. All blocks
that specify a noninherited sample time must specify the sample time.
For example, if one block specifies 0.1 as the
sample time, all other blocks must specify a sample time of 0.1 or -1. If
a function-call initiator invokes a periodic function-call subsystem
at a rate that differs from the sample time specified by the blocks
in the subsystem, the simulation halts and an error message appears.
For more information about function-call subsystems, see Function-Call Subsystems.
 | Triggered and Enabled Subsystems | | Conditional Execution Behavior |  |
Learn more about Simulink through this collection of videos, articles, technical literature and the Getting Started with Simulink Guide.
Get this Simulink Kit
Store 
