How to Use Signal Builder in Simulink: Step-by-Step Guide

In Simulink, use the Signal Builder block to create and manage multiple input signal waveforms for simulation. Open the block, draw or import signals, and connect it to your model to simulate different input scenarios easily.

Syntax

The Signal Builder block is added from the Simulink library and used as a source block in your model. Its basic usage involves:

• Signal Builder block: The block that holds multiple signal groups.
• Signal groups: Sets of waveforms you can switch between during simulation.
• Waveforms: Defined by points in time and amplitude values.

You open the block to create or edit signals and then connect its output to other blocks in your model.

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Open Simulink Library Browser -> Sources -> Signal Builder
Drag and drop the Signal Builder block into your model
Double-click the block to open the Signal Builder editor
Create or import waveforms by adding points or drawing
Connect the block output to your model inputs

Example

This example shows how to create two different signal groups in Signal Builder and simulate a simple model that uses these signals as input.

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1. Open Simulink and create a new model.
2. Add a <code>Signal Builder</code> block from Sources.
3. Add a <code>Scope</code> block from Sinks.
4. Connect the output of Signal Builder to the input of Scope.
5. Double-click Signal Builder to open it.
6. Create two groups: "Group 1" with a sine wave and "Group 2" with a square wave.
7. Close Signal Builder.
8. Run the simulation and observe the waveform in Scope.
9. Switch between groups in Signal Builder to see different inputs.

Output

Scope window shows the selected waveform (sine or square) depending on the active group in Signal Builder.

Common Pitfalls

• Not connecting the Signal Builder output to the model input, so no signal is fed.
• Forgetting to create or activate signal groups before simulation.
• Using incompatible time vectors or overlapping points causing unexpected waveforms.
• Not saving changes in Signal Builder before running simulation.

Always verify your signal shapes in the editor and ensure the correct group is active.

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Wrong way:
- Connect Signal Builder but do not create any waveforms.
- Run simulation and get zero or flat signals.

Right way:
- Open Signal Builder.
- Add waveforms with proper time and amplitude.
- Save and close.
- Run simulation to see expected signals.

Quick Reference

Action	Description
Add Signal Builder block	From Simulink Library Browser under Sources
Open Signal Builder	Double-click the block to edit signals
Create signal groups	Use the editor to add multiple waveform sets
Draw or import waveforms	Define time and amplitude points or draw manually
Connect output	Link Signal Builder output to model inputs
Switch groups	Select different signal sets during simulation
Run simulation	Observe signals in connected scopes or blocks

Key Takeaways

Use the Signal Builder block to create and manage multiple input signals easily.

Always open the block to draw or import waveforms before simulation.

Connect the Signal Builder output to your model inputs to feed signals.

Create multiple signal groups to test different scenarios in one model.

Verify and save your signals in the editor before running simulations.