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Outport - Create output port for subsystem or external output

Library

Ports & Subsystems, Sinks

Description

Outport blocks are the links from a system to a destination outside the system.

Simulink software assigns Outport block port numbers according to these rules:

Outport Blocks in a Subsystem

Outport blocks in a subsystem represent outputs from the subsystem. A signal arriving at an Outport block in a subsystem flows out of the associated output port on that Subsystem block. The Outport block associated with an output port on a Subsystem block is the block whose Port number parameter matches the relative position of the output port on the Subsystem block. For example, the Outport block whose Port number parameter is 1 sends its signal to the block connected to the topmost output port on the Subsystem block.

If you renumber the Port number of an Outport block, the block becomes connected to a different output port, although the block continues to send the signal to the same block outside the subsystem.

When you create a subsystem by selecting existing blocks, if more than one Outport block is included in the grouped blocks, Simulink software automatically renumbers the ports on the blocks.

The Outport block name appears in the Subsystem icon as a port label. To suppress display of the label, select the Outport block and choose Hide Name from the Format menu.

Outport Blocks in Conditionally Executed Subsystems

When an Outport block is in an enabled subsystem, its initial output value can be either explicitly specified, or inherited from its input signal.

Specifying Initial Conditions

To explicitly specify an initial output value:

  1. Select Dialog in the Source of initial output value drop-down list.

  2. Specify the Initial output parameter.

If you select Dialog, you can also specify what happens to the output when the subsystem is disabled, using the Output when disabled drop-down menu. Select either:

Inheriting Initial Conditions

The initial output value of the outport block can be inherited from the following sources:

The procedure you use to inherit the initial conditions of the Outport block differs depending on whether you are using classic initialization mode or simplified initialization mode.

To inherit initial conditions in classic initialization mode:

  1. Select Dialog in the Source of initial output value drop-down list.

  2. Set the Initial output parameter to [] (empty matrix).

  3. Click OK.

To inherit initial conditions in simplified initialization mode:

  1. Select Input signal in the Source of initial output value drop-down list.

  2. Click OK.

    The Initial output and Output when disabled parameters are disabled, and the values are both inherited from the input signal.

For more information on classic and simplified initialization mode, see Underspecified initialization detection.

Outport Blocks in a Top-Level System

Outport blocks in a top-level system have two uses: to supply external outputs to the workspace, which you can do by using either the Configuration Parameters dialog box or the sim command, and to provide a means for analysis functions to obtain output from the system.

Connecting Buses to Root Level Outports

A root level Outport of a model can accept a virtual bus only if all elements of the bus have the same data type. The Outport block automatically unifies the bus to a vector having the same number of elements as the bus, and outputs that vector.

If you want a root level Outport of a model to accept a bus signal that contains mixed types, you must select the Outport's Specify properties via bus object parameter and set the Outport's Bus object for validating input bus parameter to the name of a bus object that defines the type of bus that the Outport produces. If the bus signal is virtual, it will be converted to nonvirtual, as described in Automatic Bus Conversion. See Using Bus Objects more information.

An Outport in a conditionally executed subsystem that is connected to a bus that contains mixed data types cannot be configured to reset and have initial values specified.

Data Type Support

The Outport block accepts complex or real signals of any data type supported by Simulink software. An Outport block can also accept fixed-point and enumerated data types if the block is not a root-level output port. The complexity and data type of the block's output are the same as those of its input. For a discussion on the data types supported by Simulink software, see Data Types Supported by Simulink in the Simulink documentation.

The elements of a signal array connected to an Outport block can be of differing complexity and data types except in the following circumstance: If the output port is in a conditionally executed subsystem and the initial output is specified, all elements of an input array must be of the same complexity and data types.

Typical Simulink data type conversion rules apply to an output port's Initial output parameter. If the initial output value is in the range of the block's output data type, Simulink software converts the initial output to the output data type. If the specified initial output is out of the range of the output data type, Simulink software halts the simulation and signals an error.

Parameters and Dialog Box

The Main pane of the Outport block dialog box appears as follows:

The Signal Attributes pane of the Outport block dialog box appears as follows:

Show data type assistant

Display the Data Type Assistant.

Settings

The Data Type Assistant helps you set the Output data type parameter.

See Specifying Block Output Data Types for more information.

Command-Line Information

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

Port number

Specify the port number of the block.

Settings

Default: 1

This parameter controls the order in which the port that corresponds to the block appears on the parent subsystem or model block.

Command-Line Information

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

Icon display

Specify the information to be displayed on the icon of this input port.

Settings

Default: Port number

Signal name

Display the name of the signal connected to this port (or signals if the input is a bus).

Port number

Display port number of this port.

Port number and signal name

Display both the port number and the names of the signals connected to this port.

Command-Line Information

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

Source of initial output value

Select the source of the initial output value of the Outport block.

Settings

Default: Dialog

Dialog

The initial output value is specified by the Initial output parameter on the dialog.

Input signal

The initial output value is inherited from the input signal.

Tips

Dependencies

This parameter applies only if the Outport resides in an Enabled Subsystem.

Selecting Dialog enables the following parameters:

Command-Line Information

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

Output when disabled

Specify what happens to the block output when the subsystem is disabled.

Settings

Default: held

held

Output is held when the subsystem is disabled.

reset

Output is reset when the subsystem is disabled.

Tips

Dependencies

Command-Line Information

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

Initial output

For conditionally executed subsystems, specify the block output before the subsystem executes and while it is disabled.

Settings

Default: [ ]

Simulink software does not allow the initial output of this block to be inf or NaN.

Tips

Dependencies

Command-Line Information

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

Specify properties via bus object

Use a bus object to define the structure of the bus that is input or output by this block.

Settings

Default: Off

On

Use a bus object to define the structure of the bus that is input or output by this block.

Off

Do not use a bus object to define the structure of the bus that is input or output by this block.

Tips

Selecting this parameter is required if the bus is nonvirtual (including a nonvirtual bus that was converted from a virtual bus as described in Automatic Bus Conversion) and is optional otherwise.

Dependencies

This parameter enables Bus object for validating input bus.

This parameter enables Output as nonvirtual bus in parent model.

Command-Line Information

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

Bus object for validating input bus

Specify the name of the bus object that defines the structure that a bus must have to connect to this port.

Settings

Default: BusObject

A bus object is an instance of class Simulink.Bus that is defined in the base workspace.

Tips

At the beginning of a simulation or when you update the model's diagram, Simulink software checks whether the bus connected to this port has the specified structure. If not, Simulink software displays an error message.

Dependencies

Specify properties via bus object enables this parameter.

Command-Line Information

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

Output as nonvirtual bus in parent model

Select this parameter if you want the bus emerging in the parent model to be nonvirtual. The bus that is input to the port can be virtual or nonvirtual, regardless of the setting of Output as nonvirtual bus in parent model.

Settings

Default: Off

On

Select this parameter if you want the bus emerging in the parent model to be nonvirtual.

Off

Clear this parameter if you want the bus emerging in the parent model to be virtual.

Tips

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. Any bus operation that would result in a nonvirtual bus that violates this requirement generates an error. Therefore, if you select this option all signals in the bus must have the same sample time. You can use a Rate Transition block to change the sample time of an individual signal, or of all signals in a bus, to allow the signal or bus to be included in a nonvirtual bus.

Dependency

Specify properties via bus object enables this parameter.

Command-Line Information

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

Port dimensions (-1 for inherited)

Specify the dimensions that a signal must have in order to be connected to this Outport block.

Settings

Default: -1

Valid values are:

-1

A signal of any dimensions can be connected to this port.

N

The signal connected to this port must be a vector of size N.

[R C]

The signal connected to this port must be a matrix having R rows and C columns.

Dependency

Clearing Specify properties via bus object enables this parameter.

Command-Line Information

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

Variable-size signal

Specify the type of signals allowed out of this port.

Settings

Default: Inherit

Inherit

Allow variable-size and fixed-size signals.

No

Do not allow variable-size signals.

Yes

Allow only variable-size signals.

Dependencies

When the signal at this port is a variable-size signal, the Port dimensions parameter specifies the maximum dimensions of the signal.

Command-Line Information

Parameter: VarSizeSig
Type: string
Value: 'Inherit'| 'No' | 'Yes'
Default: 'Inherit'

Sample time (-1 for inherited)

Enter the discrete interval between sample time hits or specify another appropriate sample time such as continuous or inherited.

Settings

Default: -1

By default, the block inherits its sample time based upon the context of the block within the model. To set a different sample time, enter a valid sample time based upon the table in Types of Sample Time.

See also How to Specify the Sample Time in the online documentation for more information.

Command-Line Information

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

Lock output data type setting against changes by the fixed-point tools

Select to lock the output data type setting of this block against changes by the Fixed-Point Tool and the Fixed-Point Advisor.

Settings

Default: Off

On

Locks the output data type setting for this block.

Off

Allows the Fixed-Point Tool and the Fixed-Point Advisor to change the output data type setting for this block.

Command-Line Information

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

See Also

For more information, see Fixed-Point Tool and Fixed-Point Advisor in the Simulink Fixed Point documentation.

Signal type

Specify the numeric type of the signal output by this block.

Settings

Default: auto

auto

Output the numeric type of the signal that is connected to its input.

real

Output a real-valued signal. The signal connected to this block must be real. If it is not, Simulink software displays an error if you try to update the diagram or simulate the model that contains this block.

complex

Output a complex signal. The signal connected to this block must be complex. If it is not, Simulink software displays an error if you try to update the diagram or simulate the model that contains this block.

Command-Line Information

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

Sampling mode

Specify the sampling mode (Sample based or Frame based) that the input signal must match.

Settings

Default: auto

auto

Accept any sampling mode.

Sample based

The output signal is sample-based.

Frame based

The output signal is frame-based.

Tips

To generate frame-based signals, you must have the Signal Processing Blockset product installed.

Command-Line Information

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

Minimum

Specify the minimum value that the block should output.

Settings

Default: []

The default value, [], is equivalent to -Inf. Simulink software uses this value to perform:

Tip

This number must be a double scalar value.

Command-Line Information

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

Maximum

Specify the maximum value that the block should output.

Settings

Default: []

The default value, [], is equivalent to -Inf. Simulink software uses this value to perform:

Tip

This number must be a double scalar value.

Command-Line Information

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

Data type

Specify the output data type of the external input.

Settings

Default: Inherit: auto

Inherit: auto

A rule that inherits a data type

double

Data type is double.

single

Data type is single.

int8

Data type is int8.

uint8

Data type is uint8.

int16

Data type is int16.

uint16

Data type is uint16.

int32

Data type is int32.

uint32

Data type is uint32.

boolean

Data type is boolean.

fixdt(1,16,0)

Data type is fixed point fixdt(1,16,0).

fixdt(1,16,2^0,0)

Data type is fixed point fixdt(1,16,2^0,0).

Enum: <class name>

Data type is enumerated.

<data type expression>

The name of a data type object, for example Simulink.NumericType

Tips

This parameter can also be an expression that evaluates to a data type, for example, float('single')

Command-Line Information

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

Mode

Select the category of data to specify.

Settings

Default: Inherit (Constant, Data Type Conversion, Discrete Time Integrator, Gain, Inport, Outport, Product, Saturation, Sum, Switch), Built in (Logical Operator, Relational Operator)

Inherit

Inheritance rules for data types. Selecting Inherit enables a second menu/text box to the right. The following list is the possible values, which can vary by block:

  • Inherit from 'Constant value' (Constant block default)

  • Inherit via internal rule (Discrete-Time Integrator, Gain, Product, Sum, Switch block default)

  • Inherit via back propogation (Data Type Conversion block default)

  • auto (Inport, Outport block default)

  • Logical (see Configuration Parameters: Optimization)

  • Same as first input

  • Same as input (Saturation block default)

  • Same as accumulator

Built in

Built-in data types. Selecting Built in enables a second menu/text box to the right. The following list is the possible values, which can vary by block:

  • double (Constant, Data Type Conversion, Discrete-Time Integrator, Gain, Inport, Outport, Product, Saturation, Sum, Switch block default)

  • single

  • int8

  • uint8

  • int16

  • uint16

  • int32

  • uint32

  • boolean (Logical Operator, Relational Operator block default)

Fixed point

Fixed-point data types.

Enumerated

Enumerated data types. This option is available on some blocks. Selecting Enumerated enables a second menu/text box to the right. The following list is the possible values, which can vary by block:

  • <class name>

Expression

Expressions that evaluate to data types. Selecting Expression enables a second menu/text box to the right. The following list is the possible values, which can vary by block:

  • <data type expression>

Dependency

Clicking the Show data type assistant button enables this parameter.

Command-Line Information

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

See Also

See Using the Data Type Assistant in the Simulink User's Guide.

Signedness

Specify whether you want the fixed-point data as signed or unsigned.

Settings

Default: Signed

Signed

Specify the fixed-point data as signed.

Unsigned

Specify the fixed-point data as unsigned.

Dependencies

Selecting Mode > Fixed point enables this parameter.

Command-Line Information

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

See Also

See Specifying a Fixed-Point Data Type in the Simulink User's Guide for more information.

Word length

Specify the bit size of the word that holds the quantized integer.

Settings

Default: 16

Minimum: 0

Maximum: 32

Large word sizes represent large values with greater precision than small word sizes.

Dependencies

Selecting Mode > Fixed point enables this parameter.

Command-Line Information

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

See Also

See Specifying a Fixed-Point Data Type in the Simulink User's Guide for more information.

Scaling

Specify the method for scaling your fixed-point data to avoid overflow conditions and minimize quantization errors.

Settings

Default: Best precision (Constant), Binary point (Data Type Conversion, Discrete-Time Integrator, Gain, Inport, Outport, Product, Saturation, Sum, Switch), Integer (Logical Operator, Relational Operator)

Binary point

Specify binary point location.

Slope and bias

Enter slope and bias.

Best precision

Specify best-precision values. This option appears for some blocks.

Integer

Specify integer. This setting has the same result as specifying a binary point location and setting fraction length to 0. This option appears for some blocks.

Dependencies

Selecting Mode > Fixed point enables this parameter.

Selecting Binary point enables:

Selecting Slope and bias enables:

Command-Line Information

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

See Also

See Specifying a Fixed-Point Data Type in the Simulink User's Guide for more information.

Fraction length

Specify fraction length for fixed-point data type.

Settings

Default: 0

Binary points can be positive or negative integers.

Dependencies

Selecting Scaling > Binary point enables this parameter.

Command-Line Information

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

See Also

See Specifying a Fixed-Point Data Type in the Simulink User's Guide for more information.

Slope

Specify slope for the fixed-point data type.

Settings

Default: 2^0

Specify any positive real number.

Dependencies

Selecting Scaling > Slope and bias enables this parameter.

Command-Line Information

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

See Also

See Specifying a Fixed-Point Data Type in the Simulink User's Guide for more information.

Bias

Specify bias for the fixed-point data type.

Settings

Default: 0

Specify any real number.

Dependencies

Selecting Scaling > Slope and bias enables this parameter.

Command-Line Information

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

See Also

See Specifying a Fixed-Point Data Type in the Simulink User's Guide for more information.

Characteristics

Sample Time

Inherited from the driving block

Dimensionalized

Yes

Multidimensionalized

Yes

Virtual

Yes, when the block resides in a subsystem block and not at the root level of a model

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

See Also

Inport

  


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