The Simulink® Block Data Type Support table includes a complete list of blocks that support variable-size signals.
To view the table:
Open a Simulink model.
Select Help > Simulink > Block Data Types & Code Generation Support > Simulink.
X in the Variable-Size Support column
indicates support for that block.
Control port blocks are in conditionally executed subsystems.
You can set the Propagate sizes of variable-size signals parameter
for these blocks to
when execution is resumed (Action Port), and
when enabling (Enable and Trigger or Function-Call).
Switching blocks support variable-size signals by allowing input signals with different sizes and propagating the size of the input signal to the output signal. You can set the Allow different data input sizes parameter for these blocks on the Signal Attributes pane to either on or off.