Set Parameter

R2026b

Set values on ROS parameter server

• 

Set Parameter block

To add a block to a model, double-click the canvas and start typing the block name. Then, select the block from the list.

Libraries:
ROS Toolbox / ROS

Description

The Set Parameter block sets the Value input to the specified name on the ROS parameter server. The block uses the ROS node of the Simulink^® model to connect to the ROS network. This node is created when you run the model and is deleted when the model terminates. If the model does not have a node, the block creates one.

Ports

Input

Value — Parameter value

scalar | logical | uint8 array

Parameter value from the ROS network. The value depends on the Data type parameter.

Length — Length of string parameter

integer

Length of the string parameter, specified as an integer. This length is the number of elements of the uint8 array or the number of characters in the string that you cast to uint8.

Note

When casting your string parameters to uint8, ASCII values 0–31 (control characters) return an error due to their incompatible character type.

Dependencies

To enable this port, set the Data type to uint8[] (string).

Parameters

Source — Source for specifying the parameter name

Select from ROS network | Specify your own

Source for specifying the parameter name as one of the following:

• Select from ROS network — Use Select to select a parameter name. The Data type parameter is set automatically. You must be connected to a ROS network.

• Specify your own — Enter a parameter name in Name and specify its data type in Data type. You must match a parameter name exactly.

Name — Parameter name

string

Parameter name to get from the ROS network, specified as a string. When Source is set to Select from ROS network, use Select to select an existing parameter. You must be connected to a ROS network to get a list of parameters. Otherwise, specify the parameter and data type.

Parameter name strings must follow the rules of ROS graph names. Valid names have these characteristics:

• The first character is an alpha character ([a-z|A-Z]), tilde (~), or forward slash (/).

• Subsequent characters are alphanumeric ([0-9|a-z|A-Z]), underscores(_), or forward slashes (/).

Data type — Data type of your parameter

double | int32 | boolean | uint8[] (string)

Data type of your parameter, specified as a string.

Note

The uint8[] (string) data type is an array of ASCII values corresponding to the characters in a string. When getting string parameters, you can create a MATLAB Function (Simulink) block to compare the string to a desired parameter value. For more information, see ROS Parameters in Simulink.

Data Types: double | int32 | Boolean | uint8

Programmatic Use: Add Block

To add the block programmatically, use the add_block function with one of these library block paths as the source.

"robotlib/Set Parameter"

Example: add_block("robotlib/Set Parameter","myModel/myBlock",MakeNameUnique="on")

Extended Capabilities

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

Version History

Introduced in R2019b