There are several reasons to convert a model to use an array of buses (see Benefits of an Array of Buses). For example:
The model was developed before Simulink® supported arrays of buses (introduced in R2010b), and the model contains many subsystems that perform the same kind of processing.
The model has grown in complexity.
Here is a general approach for converting a model that contains buses to a model that uses an array of buses. The method that you use depends on your model. For details about these techniques, see Combine Buses into an Array of Buses and Use Arrays of Buses in Models.
This workflow refers to a stylized example model. The example shows the original modeling pattern and a new modeling pattern that uses an array of buses.
In the original modeling pattern:
The target bus to be converted is named MainBus
, and it
has three elements, each of type BusObject
.
The ScalarAlgorithm1
,
ScalarAlgorithm2
, and
ScalarAlgorithm3
subsystems encapsulate the
algorithms that operate on each of the bus elements. The subsystems all have
the same content.
A Bus Selector block picks out each element of
MainBus
to drive the subsystems.
The construction in the original modeling pattern is inefficient for two reasons:
A copy of the subsystem that encapsulates the algorithm is made for each element of the bus that is to be processed.
Adding another element to MainBus
involves changing the
Bus
object definition and the Bus
Selector block, and adding a subsystem. Each of these changes is
a potential source of error.
To convert the original modeling pattern to use an array of buses:
Identify the target bus and associated algorithm that you want to convert. Typically, the target bus is a bus of buses, where each element bus is of the same type.
The bus that you convert must be a nonvirtual bus. If all elements of the target bus have the same sample time (or if the sample time is inherited), you can convert a virtual bus to a nonvirtual bus.
The target bus cannot have variable-dimensioned and frame-based elements.
Use a Concatenate block to convert the original bus of buses to an array of buses.
In the example, the new modeling pattern uses a Vector
Concatenate block to replace the Bus Creator
block that creates the MainBus
signal. The output of the
Vector Concatenate block is an array of buses, where the
type of the bus is BusObject
. The new model eliminates
the wrapper bus (MainBus
).
Replace all identical copies of the algorithm subsystem with a single For Each subsystem that encapsulates the scalar algorithm. Connect the array of buses to the For Each subsystem.
The new model eliminates the Bus Selector blocks that
separate out the elements of the MainBus
signal in the
original model.
Configure the For Each Subsystem block to iterate over the input array of buses and concatenate the output bus.
The scalar algorithm within the For Each subsystem cannot have continuous states. For additional limitations, see the For Each Subsystem block documentation.