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Mux - Combine several input signals into vector

Library

Signal Routing

Description

The Mux block combines its inputs into a single vector output. An input can be a scalar or vector signal. All inputs must be of the same data type and numeric type. The elements of the vector output signal take their order from the top to bottom, or left to right, input port signals. See How to Rotate a Block for a description of the port order for various block orientations. To avoid adding clutter to a model, Simulink software hides the name of a Demux block when you copy it from the Simulink library to a model. See Mux Signals for information about creating and decomposing vectors.

Note   The Mux block allows you to connect signals of differing data and numeric types and matrix signals to its inputs. In this case, the Mux block acts like a Bus Creator block and outputs a bus signal rather than a vector. The MathWorks discourages using mux blocks to create bus signals, and may not support this practice in future releases. See Avoiding Mux/Bus Mixtures for more information.

The Mux block's Number of Inputs parameter allows you to specify input signal names and sizes as well as the number of inputs. You can use any of the following formats to specify this parameter:

• Scalar

  Specifies the number of inputs to the Mux block. When this format is used, the block accepts scalar or vector signals of any size. Simulink software assigns each input the name signalN, where N is the input port number.

• Vector

  The length of the vector specifies the number of inputs. Each element specifies the size of the corresponding input. A positive value specifies that the corresponding port can accept only vectors of that size. For example, [2 3] specifies two input ports of sizes 2 and 3, respectively. If an input signal width does not match the expected width, Simulink software displays an error message. A value of -1 specifies that the corresponding port can accept scalars or vectors of any size.

• Cell array

  The length of the cell array specifies the number of inputs. The value of each cell specifies the size of the corresponding input. A scalar value N specifies a vector of size N. A value of -1 means that the corresponding port can accept scalar or vector signals of any size.

• Signal name list

  You can enter a list of signal names separated by commas. Simulink software assigns each name to the corresponding port and signal. For example, if you enter position,velocity, the Mux block will have two inputs, named position and velocity.

The MathWorks encourages using Vector Concatenate blocks rather than Mux blocks to combine vectors. The primary exception is the creation of a vector of function calls, which requires a Mux block. In future releases, Mux blocks may have no unique capabilities and may be deprecated.

If you want to create a composite signal, in which the constituent signals retain their identities and can have different data types, use a Bus Creator block rather than a Mux block. Although you can use a Mux block to create a composite signal, The MathWorks discourages this practice. See Avoiding Mux/Bus Mixtures for more information.

Data Type Support

The Mux block accepts real or complex signals of any data type supported by Simulink software, including fixed-point and enumerated data types.

For a discussion on the data types supported by Simulink software, see Data Types Supported by Simulink in the Simulink documentation.

Parameters and Dialog Box

Number of inputs

Specify number and size of inputs.

Settings

Default: 2

You can enter a comma-separated list of signal names for this parameter field.

Command-Line Information

See Block-Specific Parameters for the command-line information.

Display option

Specify the appearance of the block in the model.

Settings

Default: bar

bar

Displays the block in a solid foreground color

none

Mux appears inside the block

signals

Displays signal names next to each port

Command-Line Information

See Block-Specific Parameters for the command-line information.

Characteristics

Virtual

Yes For more information, see Virtual Blocks in the Simulink documentation.

See Also

Demux

Multiport Switch

Outport

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