Using Simulink

Virtual Blocks

When creating models, you need to be aware that Simulink blocks fall into two basic categories: nonvirtual and virtual blocks. Nonvirtual blocks play an active role in the simulation of a system. If you add or remove a nonvirtual block, you change the model's behavior. Virtual blocks, by contrast, play no active role in the simulation; they help organize a model graphically. Some Simulink blocks are virtual in some circumstances and nonvirtual in others. Such blocks are called conditionally virtual blocks. The following table lists Simulink virtual and conditionally virtual blocks.

Table 4-1: Virtual and Conditionally Virtual Blocks 

Block Name	Condition Under Which Block Will Be Virtual
Bus Selector	Always virtual.
Data Store Memory	Always virtual.
Demux	Always virtual.
Enable Port	Always virtual.
From	Always virtual.
Goto	Always virtual.
Goto Tag Visibility	Always virtual.
Ground	Always virtual.
Inport	Virtual unless the block resides in a conditionally executed subsystem and has a direct connection to an outport block.
Mux	Always virtual.
Outport	Virtual when the block resides within any subsystem block (conditional or not), and does not reside in the root (top-level) Simulink window.
Selector	Virtual except in matrix mode.
Subsystem	Virtual except if the block is conditionally executed and/or the block's Treat as Atomic Unit option is selected.
Terminator	Always virtual.
Test Point	Always virtual.
Trigger Port	Virtual when the outport port is not present.

Block Data Tips

Copying and Moving Blocks from One Window to Another