Bus Creator

Create bus from input signals

• Library:

• Simulink / Commonly Used Blocks

  Simulink / Signal Routing

  HDL Coder / Signal Routing

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Description

The Bus Creator block combines a set of input signals into a bus. You can connect any signal types to the input ports, including other buses. You can access signals in a bus by using a Bus Selector block.

Elements of a bus must have unique names. By default, each element of the bus inherits the name of the signal connected to the Bus Creator block. If duplicate names are present, the Bus Creator block appends the port number to all input signal names. For signals that do not have names, the Bus Creator block generates names in the form signaln, where n is the port number connected to the signal. You can refer to signals by name when you search for their sources or select signals for connection to other blocks. For signal naming guidelines, see Signal Names and Labels.

Ports

Input

Port_1 — Input signal to include in bus

scalar | vector | matrix | array | bus

Input signal to include in the bus, specified as a scalar, vector, matrix, N-D array, or bus.

The number of input ports is driven by the Number of inputs parameter.

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

Output

Port_1 — Output bus

virtual bus | nonvirtual bus

Output bus composed of the combined input signals, specified as a virtual or nonvirtual bus. For more information on the types of buses, see Types of Composite Signals.

Data Types: bus

Parameters

Number of inputs — Number of input signals

2 (default) | integer

Number of input signals, not fewer than two, specified as an integer. Increasing the number of inputs adds empty input ports to the block. Before you simulate the model, make sure that an input signal is connected to each input port.

When you modify the Number of inputs parameter, click Refresh to update the list of signals.

Tip

If all input ports are already connected, you can add an input port to the Bus Creator block by connecting another signal line to it.

Interactively adding a port updates the Number of inputs parameter and adds the new signal to the list of signals in the bus.

Programmatic Use

Block Parameter: Inputs

Type: character vector

Values: integer greater than or equal to 2, comma-separated list of signal names

Default: '2'

By default, the Inputs parameter specifies the number of inputs. When you use it to specify the names of signals in the bus, the number of inputs matches the number of signal names you specify.

Signals in the bus — List of input signals

list of signal names

List of input signals to combine into a bus. You can view all signals entering the block, including the signals contained in nested buses. An arrow next to a signal indicates that an input signal is a bus. To display the contents of that bus, click the arrow.

To rearrange the signals in the output bus, use the Up and Down buttons. You can select multiple top-level adjacent signals in the Signals in the bus list to reorder or remove.

To find the source of any signal entering the block, select the signal in the Signals in the bus list and click the Find button. Simulink^® highlights the icon of the source, opening the subsystem that contains the signal source, if necessary.

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

Programmatic Use

Block Parameter: Inputs

Type: character vector

Values: integer greater than or equal to 2, comma-separated list of signal names

Default: '2'

By default, the Inputs parameter specifies the number of inputs. When you use it to specify the names of signals in the bus, the number of inputs matches the number of signal names you specify.

Filter by name — Search term for filtering displayed input signals

text

Search term for filtering displayed input signals, 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 signals by regular expression

off (default) | on

Option to filter the displayed input signals by regular expression.

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

Dependencies

To access this parameter, click the Show filtering options button to the right 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 signals appear in a hierarchical tree.

Dependencies

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

Output data type — Data type of output bus

'Inherit: auto' (default) | 'Bus: <object name>' | <data type expression>

Data type of the output bus.

If you select 'Bus: <object name>', specify a Simulink.Bus object. The Bus object must be accessible when you update the diagram or simulate the model. To define a Bus object using the Bus Editor, click the Show data type assistant button , and then click the Edit button.

If you select '<data type expression>', specify an expression that evaluates to a data type. Do not specify a Bus object as the expression.

Programmatic Use

Block Parameter: OutDataTypeStr

Type: character vector

Values: 'Inherit: auto' | 'double' | 'single' | 'int8' | 'uint8' | 'int16' | 'uint16' | 'int32' | 'uint32' | 'int64''uint64''boolean' | 'fixdt(1,16,0)' | 'fixdt(1,16,2^0,0)' | 'Enum: <class name>' | 'Bus: <object name>'

Default: 'Inherit: auto'

Require input signal names to match signals above — Check that input signal names match names listed in dialog box

off (default) | on

Check that the input signal names match the names listed in the Block Parameters dialog box. If the signal names do not match, Simulink returns an error.

Tip

The Require input signal names to match signals above parameter might be removed in a future release. To enforce strong data typing, consider using the Override bus signal names from inputs parameter.

Dependencies

If you select Override bus signal names from inputs, the Simulink software ignores the Require input signal names to match signals above setting.

If you change the Number of inputs programmatically, this parameter reverts to 'off'.

Rename selected signal — New name for selected input signal

'' (default) | character vector

New name for the selected input signal. See Signal Names and Labels for signal name guidelines.

Dependencies

To display this parameter, enable the Require input signal names to match signals above parameter.

Override bus signal names from inputs — Option to override names from Simulink.Bus object with input signal names

on (default) | off

By default, the Bus Creator block overrides the names specified by the Simulink.Bus object and uses the input signal names as the output bus element names.

To inherit bus element names from the Bus object, clear this parameter. Clearing the parameter:

• Enforces strong data typing.

• Avoids having to enter a signal name multiple times: in the Bus object and in the model. Entering the name multiple times can accidentally create signal name mismatches.

• Supports the array of buses requirement to have consistent signal names across array elements.

Alternatively, you can enforce strong data typing by checking that input signal names match the Bus object element names.

• Keep the Override bus signal names from inputs check box selected.

• Set the Element name mismatch configuration parameter to error.

Dependencies

To display this parameter, set the Output data type parameter to a Bus object.

Programmatic Use

Block Parameter: InheritFromInputs

Type: character vector

Values: 'on' | 'off'

Default: 'on'

Output as nonvirtual bus — Output nonvirtual bus

off (default) | on

Output a nonvirtual bus instead of a virtual bus.

All signals in a nonvirtual bus must have the same sample time, even if the elements of the associated Bus object specify inherited sample times for some elements. Any operation resulting in a nonvirtual bus containing signals with different sample rates generates an error. To change the sample time of a signal or bus that has a different sample time than the other nonvirtual bus input signals, use a Rate Transition block. For details, see Modify Sample Times for Nonvirtual Buses.

To generate code that uses a C structure to define the structure of the bus that this block creates, enable this parameter.

Dependencies

To display this parameter, set the Output data type parameter to a Bus object.

Programmatic Use

Block Parameter: NonVirtualBus

Type: character vector

Values: 'on' | 'off'

Default: 'off'

Model Examples

Group Signal Lines Within a Component

Group signals into a virtual bus using Bus Creator blocks.

Open Model

Create Nonvirtual Buses with Bus Creator Blocks

Configure a Bus Creator block to output a nonvirtual bus.

Open Model

Simplify Bus Interfaces in Subsystems

Convert an interface that uses Inport, Bus Selector, Bus Creator, and Outport blocks to use In Bus Element and Out Bus Element blocks.

Open Model

Simulink Bus Signals

Introduces you to the following Simulink® bus signal capabilities: Bus Creator, Bus Selector, and Bus Assignment blocks

Open Model

Block Characteristics

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

Tips

For buses at subsystem and model interfaces, you can use Out Bus Element blocks instead of a Bus Creator block with an Outport block. Out Bus Element blocks:

• Reduce signal line complexity and clutter in a block diagram.

• Make it easier to change the interface incrementally.

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.