Bus Selector

Select elements from incoming bus

• Library:

• Simulink / Commonly Used Blocks

  Simulink / Signal Routing

  HDL Coder / Signal Routing

• 

Description

The Bus Selector block outputs the elements you select from the input bus. The block can output the selected elements separately or in a new virtual bus.

Ports

Input

Port_1 — Input bus

virtual bus | nonvirtual bus

Input bus, which can be virtual or nonvirtual.

For arrays of buses, you must use a Selector block to select the bus that you want to use with the Bus Selector block.

Data Types: bus

Output

Port_1 — Selected bus elements of input bus

signal | message

Selected bus elements of an input bus.

For each output element, this block uses a separate port from the top to the bottom of the block. If the block is rotated, see Port Location After Rotating or Flipping for the port order of various block orientations.

Data Types: single | double | half | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | string | Boolean | fixed point | enumerated | bus
Complex Number Support: Yes

Parameters

Elements in the bus — List of elements in input bus

list of element names

List of elements in the input bus from which to select output elements.

If you change an element name while the Block Parameters dialog box is open, you can see the updated name by clicking Refresh.

To highlight the source of an element entering the block, select the element in the list and click Find.

Programmatic Use

Block Parameter: InputSignals

Type: cell array

Values: element names

Filter by name — Search term for filtering displayed input elements

text

Search term for filtering displayed input elements, specified as text. Do not enclose the search term in quotation marks. The filter does a partial string search.

To access the filtering options, click the Show filtering options button to the right of the Filter by name box.

Enable regular expression — Option to filter displayed input elements by regular expression

off (default) | on

Option to filter the displayed input elements by regular expression.

When this parameter is enabled, entering t$ in the Filter by name box displays all elements whose names end with a lowercase t (and their immediate parents). For details, see Regular Expressions.

Dependencies

To access this parameter, click the Show filtering options button on the right side of the Filter by name box.

Show filtered results as a flat list — Option to display filtered results as a flat list

off (default) | on

Option to display filtered results as a flat list that uses dot notation to reflect the hierarchy of buses. By default, the filtered elements appear in a hierarchical tree.

Dependencies

To access this parameter, click the Show filtering options button on the right side of the Filter by name box.

Selected elements — Selected elements of input bus

list of elements names

The selected elements of the input bus.

To specify an output element, select an element from the Elements in the bus list, and then click the Select button. The element is added at the end of the Selected elements list. To add elements below an existing element, select an element in the Selected elements list before you click Select. Elements are added below the element you selected.

If you select multiple elements from the Elements in the bus list, the order in which you select them is the order in which Simulink^® inserts them in the Selected elements list.

If an output element listed in the Selected elements list is not an input to the Bus Selector block, the element name starts with three question marks (???).

To change the order of the output bus elements, use the Up and Down buttons. Port connectivity with downstream blocks is maintained when you change the element order.

To remove bus elements from the block output, use the Remove button. You can select multiple contiguous elements to move or remove.

Tip

In the Simulink Editor, as you draw a new line close to the output side of a Bus Selector block when all output ports are already connected, Simulink:

• Adds a port

• Prompts you to specify the element to be selected

You cannot use this automatic port addition approach if:

• A bus input is not connected to the Bus Selector block.

• You do not specify an element in response to the prompt that appears when you draw a line close to the Bus Selector block icon.

• You select the Output as virtual bus parameter.

Programmatic Use

Block Parameter: OutputSignals

Type: character vector

Values: character vector in the form of 'signal1,signal2'

Default: none

Output as virtual bus — Option to output selected elements as virtual bus

off (default) | on

Option to output the selected elements as a virtual bus.

By default, the block outputs each of the selected elements from a separate output port that is labeled with the corresponding bus element name. When this parameter is enabled, the block outputs the selected elements from one port, grouped in a virtual bus.

The output bus is virtual. To convert the output to a nonvirtual bus, insert a Signal Conversion block after the Bus Selector block. Set the Signal Conversion block Output parameter to Nonvirtual bus and set the Data type to a Simulink.Bus object.

When the Selected elements list includes only one element and you enable Output as virtual bus, then that element is not wrapped in a bus. For example, if the element is a bus, the output element is that bus. If the element is not a bus, the output element is not a bus.

Programmatic Use

Block Parameter: OutputAsBus

Type: character vector

Values: 'on' | 'off'

Default: 'off'

Model Examples

Simplify Bus Interfaces in Subsystems and Models

Convert a subsystem or model interface that uses Inport, Bus Selector, Bus Creator, and Outport blocks to use In Bus Element and Out Bus Element blocks.

Explore Simulink Bus Capabilities

Explore Simulink bus capabilities.

Open Model

Block Characteristics

Data Types	Boolean | bus | double | enumerated | fixed point | half | integer | single | string
Direct Feedthrough	yes
Multidimensional Signals	yes
Variable-Size Signals	yes
Zero-Crossing Detection	no

Tips

For buses at subsystem and model interfaces, you can use In Bus Element blocks instead of an Inport block with a Bus Selector block. In Bus Element blocks:

• Reduce line complexity and clutter in a block diagram.

• Make it easier to change the interface incrementally.

• Allow access to a bus element closer to the point of usage, avoiding the use of a Bus Selector and Goto block configuration.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using Simulink® Coder™.

Actual data type or capability support depends on block implementation.

HDL Code Generation

Generate Verilog and VHDL code for FPGA and ASIC designs using HDL Coder™.

HDL Coder™ provides additional configuration options that affect HDL implementation and synthesized logic.

To learn more about using buses for HDL code generation, see Buses (HDL Coder) and Use Bus Signals to Improve Readability of Model and Generate HDL Code (HDL Coder).

HDL Architecture

This block has a single, default HDL architecture.

HDL Block Properties

ConstrainedOutputPipeline	Number of registers to place at the outputs by moving existing delays within your design. Distributed pipelining does not redistribute these registers. The default is 0. For more details, see ConstrainedOutputPipeline (HDL Coder).
InputPipeline	Number of input pipeline stages to insert in the generated code. Distributed pipelining and constrained output pipelining can move these registers. The default is 0. For more details, see InputPipeline (HDL Coder).
OutputPipeline	Number of output pipeline stages to insert in the generated code. Distributed pipelining and constrained output pipelining can move these registers. The default is 0. For more details, see OutputPipeline (HDL Coder).

PLC Code Generation
Generate Structured Text code using Simulink® PLC Coder™.

Fixed-Point Conversion

Design and simulate fixed-point systems using Fixed-Point Designer™.

Actual data type or capability support depends on block implementation.