Initial Length (PB)

R2026b

Initial distance between blocks

Since R2024b

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Initial Length (PB) 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:
Simscape / Foundation Library / Translational / Elements

Description

The Initial Length (PB) block provides an initial distance between ports B and F.

Connections B and F are position-based translational conserving ports. Length is positive when port F has a more positive position than port B. The block does not transmit force.

The block has no parameters. You specify length as an initial variable target.

Variables

To set the priority and initial target values for the block variables prior to simulation, use the Initial Targets section in the block dialog box or Property Inspector. For more information, see Set Priority and Initial Target for Block Variables.

Nominal values provide a way to specify the expected magnitude of a variable in a model. Using system scaling based on nominal values increases the simulation robustness. Nominal values can come from different sources, one of which is the Nominal Values section in the block dialog box or Property Inspector. For more information, see Modify Nominal Values for a Block Variable.

Examples

Gravity and Friction in the Position-Based Translational Domain

Configure gravity and friction due to gravity in a mechanical position-based translational network.

• Open Live Script

Ports

Conserving

B — Base port

position-based translational

Position-based translational conserving port that represents the base connection.

Programmatic Use

Port: B

F — Follower port

position-based translational

Position-based translational conserving port that represents the follower connection. For positive length, port F has a more positive position than port B.

Programmatic Use

Port: F

Programmatic Use: Add Block

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

"fl_lib/Translational/Elements/Initial Length (PB)"

Example: add_block("fl_lib/Translational/Elements/Initial Length (PB)","myModel/myBlock",MakeNameUnique="on")

For information about programmatic access to individual block parameters, see the Programmatic Use section of parameter descriptions on this page.

Extended Capabilities

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

Version History

Introduced in R2024b

R2026a: Block name changed from Translational Initial Spacer (PB) to Initial Length (PB)

To improve consistency between translational and rotational domains, the Translational Initial Spacer (PB) block has been renamed to Initial Length (PB). The new block name is consistent with the Initial Relative Angle (AB) block in the Rotational library, introduced in R2026a. The block functionality is unchanged.