Read Parameter

R2026b

Read PX4 system parameters

• 

Read 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:
UAV Toolbox Support Package for PX4 Autopilots / PX4 Utility Blocks

Description

Add-On Required: This feature requires the UAV Toolbox Support Package for PX4 Autopilots add-on.

The Read Parameter block reads the specified PX4 system parameter, and provides its value as output.

The block supports all parameters listed in PX4 Parameter Reference page. You can also use custom parameters that you define by following the guidelines.

During Normal mode simulation, the block outputs zeroes.

During Connected I/O simulation, this block reads data from the peripherals of the hardware.

Examples

Read PX4 System Parameters from PX4 Autopilot

Read system parameters from PX4^® autopilot using Read Parameter block.

• Open Model

Ports

Output

Data — Value of the parameter

scalar

Value of the specified PX4 system parameter

Data Types: int32 | float

Status — Status of the received parameter value

0 | 1

The Status output indicates if the parameter that you specified is valid or not. A value of 0 indicates that the parameter handle is valid, and a value of 1 indicates that the parameter handle is invalid.

Data Types: Boolean

Parameters

Parameter Name — Name of the PX4 parameter

SL_FLOAT_PARAM (default) | One of the parameter

Enter the name of the PX4 system parameter.

Note

The Parameter Name that you enter in this field must match one of the PX4 parameters; otherwise, the Status port outputs 1, indicating that the parameter handle is invalid.

Data Type — Data type of the PX4 parameter

FLOAT (default)

Select the data type of the parameter that you entered in the Parameter Name field.

Note

If the Data type that you select in this field does not match the actual data type of the PX4 parameter, the values read may lead to data type mismatch.

Sample time — Interval at which the block reads values

0.5 (default) | any non-negative value that is a multiple of 0.5 | -1

Enter the time interval at which the block reads values from the uORB network.

When you set this parameter to -1, Simulink^® determines the best sample time for the block based on the block context within the model.

Programmatic Use: Add Block

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

"px4Utilslib/Read Parameter"

Example: add_block("px4Utilslib/Read Parameter","myModel/myBlock",MakeNameUnique="on")

Version History

Introduced in R2018b