State Writer

Write to a block state

• 

Libraries:
Simulink / Signal Routing

Description

The State Writer block sets the state of a supported state owner block.

State Writer blocks can write state to these state owner blocks:

• Discrete State-Space

• Discrete-Time Integrator

• Delay

• Unit Delay

• Discrete Transfer Fcn

• Discrete Filter

• Discrete FIR Filter

• Integrator

• Second-Order Integrator

• Outport of conditional subsystem blocks such as Enabled Subsystem, Triggered Subsystem, and Function-Call Subsystem

• S-Function with multiple discrete states

  To configure an S-Function block as a state owner block, each data type work vector must be declared as a discrete state vector using ssSetDWorkUsedAsDState and named using ssSetDWorkName or ssSetDWorkRTWIdentifier in mdlInitializeSizes.

Tip

You can determine whether a block is a supported state owner block by the value of the block's IsStateOwnerBlock parameter. The expression

get_param(blk,'IsStateOwnerBlock')

where blk is a block name or handle, returns 'on' if the block is a supported state owner block and 'off' otherwise.

To add a State Reader or State Writer block to your model, click a state owner block to highlight it. Then, from the current block tab of the Simulink^® toolstrip, click Reader-Writer. From the menu, select State Reader Block or State Writer Block.

Note

The current block tab of the toolstrip might be labeled with the name of the highlighted block, for example, Outport, or it might be labeled Block, depending on the type of block you highlight.

If the state owner block has multiple states, then the State Reader or State Writer block dialog opens. Select a state from the State Owner Selector Tree.

Note

Before adding a State Reader or State Writer block for a Second-Order Integrator block, you must explicitly name the states. See Specifying the State Names.

After you create a State Reader or State Writer block, a badge appears above the state owner block, and the name of the state owner block appears next to the State Reader or State Writer block.

A State Reader or State Writer block cannot remain in the same system as its state owner block. After you create a State Reader or State Writer block, cut and paste it to move it to the desired location within the model hierarchy.

Alternatively, you can add a State Reader or State Writer block to your model from the Simulink Library Browser, then set the State owner block parameter from the block parameters dialog.

Note

When you create a library block with a State Reader or State Writer block, you must also include the corresponding state owner block in the library block. In addition to custom library blocks created using the workflow mentioned in Create Custom Library, Simulink treats model components created using Subsystem Reference block as a one-block library.

You can select a State Reader or State Writer block or a corresponding state owner block to highlight blocks related to it. To show a related block in an open diagram or new tab, pause on the ellipsis that appears after selection. Then, select Related Blocks from the action bar. When multiple blocks correspond to the selected block, a list of related blocks opens. You can filter the list of related blocks by entering a search term in the text box. After you select a related block from the list, window focus goes to the open diagram or new tab that shows the related block.

Examples

Initialize, Reset, and Terminate State of Simulink Block

Use the Initialize Function, Reset Function, and Terminate Function blocks to respond to events in a Simulink model.

• Open Model

Reading and Writing States with the Initialize Function and Terminate Function Blocks

In this example, the Initialize Function block uses the State Writer block to set the initial condition of a Discrete Integrator block to 10.

• Open Model

Limitations

The State Writer block does not support resettable states inside an Enabled Subsystem block. You must use a Reinitialize Function block to implement resettable states inside an Enabled Subsystem block. An external signal received at the enable port of the Enabled Subsystem triggers the execution of the Reinitialize Function block inside the subsystem. For more information on configuring Reinitialize Function block settings, see Reinitialize States of Blocks in Subsystem.

Ports

Input

In — State value

scalar | vector

State value written to a state owner block.

When writing to a state owner block with an input scalar, the scalar value is expanded to match the dimension of the state. All elements of the state are set to the same value.

Data Types: single | double | half | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | fixed point

Parameters

State owner block — Name of state owner block

none (default)

Name of state owner block whose state this block is writing. To change the state owner block, select a block from the State Owner Selector Tree.

Note

If the name of a state owner block contains a slash (/), the slash appears as two slashes (//) in the State Writer block parameters dialog. This notation distinguishes the slash in the block name itself from slashes that separate names at different levels of the model hierarchy.

Programmatic Use

Block Parameter: StateOwnerBlock

Type: character vector

Value: '' | '<model path/block name>'

Default: ''

Block Characteristics

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

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

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