Signal labeling in Simulink - Mini Project: Build & Apply

Signal labeling

📖 Scenario: You are working on a Simulink model that processes sensor data. To keep your model clear and easy to understand, you want to label the signals with meaningful names.

🎯 Goal: Label the signals in your Simulink model with exact names to improve readability and documentation.

📋 What You'll Learn

Create a Simulink model with three signals named exactly as specified

Assign the exact signal labels to each signal

Use the signal label property to name the signals

Display the signal labels in the model

💡 Why This Matters

🌍 Real World

In real-world Simulink models, labeling signals clearly helps engineers understand data flow and maintain complex systems.

💼 Career

Signal labeling is a key skill for control engineers, embedded systems developers, and anyone working with model-based design.

1

Create signals in Simulink model

Create three signals in your Simulink model named inputSignal, processedSignal, and outputSignal.

Simulink

% Create three signals named inputSignal, processedSignal, and outputSignal
% Your code here

Hint

Use Simulink.Signal to create signal objects with the exact variable names.

2

Assign labels to signals

Assign the signal label "Input Data" to inputSignal, "Processed Data" to processedSignal, and "Output Data" to outputSignal using the Label property.

Simulink

% Assign labels to the signals
% Your code here

Hint

Use the Label property of each signal object to assign the exact label strings.

3

Connect signals to blocks and apply labels

Connect the signals inputSignal, processedSignal, and outputSignal to the respective blocks in your Simulink model and ensure the signal labels are applied to the signal lines.

Simulink

% Connect signals to blocks and apply labels
% Your code here

Hint

Use set_param to assign the signal labels to the ports of blocks with the exact block and port names.

4

Display signal labels in the model

Print the signal labels of inputSignal, processedSignal, and outputSignal to the MATLAB command window using disp.

Simulink

% Print the signal labels
% Your code here

Hint

Use disp to print each signal's Label property exactly.

Practice

1. What is the main purpose of signal labeling in Simulink models?

easy

A. To increase the simulation speed

B. To change the signal data type automatically

C. To name signals for easier understanding and debugging

D. To create new signal blocks

Solution

1. Step 1: Understand signal labeling purpose

   Signal labeling is used to name signals clearly in a model.

2. Step 2: Identify benefits of labeling

   Labels help with debugging, documentation, and collaboration by making signals easier to recognize.

3. Final Answer:

   To name signals for easier understanding and debugging -> Option C

4. Quick Check:

   Signal labeling = Naming signals [OK]

Hint: Labels make signals easy to identify quickly [OK]

Common Mistakes:

• Thinking labels change signal data types
• Assuming labels speed up simulation
• Confusing labeling with creating blocks

2. Which method correctly adds a label to a signal in Simulink?

easy

A. Right-click the signal and select 'Add Label'

B. Double-click the signal line and type the label

C. Drag a Label block from the library

D. Use the 'Signal Properties' dialog to rename the block

Solution

1. Step 1: Review ways to add labels

   In Simulink, double-clicking a signal line allows direct editing of its label.

2. Step 2: Compare options

   Right-click does not have 'Add Label' option; Label block is separate; renaming block is different from labeling signal.

3. Final Answer:

   Double-click the signal line and type the label -> Option B

4. Quick Check:

   Double-click signal line = Add label [OK]

Hint: Double-click signal line to label it fast [OK]

Common Mistakes:

• Trying to add label via right-click menu
• Confusing signal label with block name
• Dragging unrelated blocks to label signals

3. Given this Simulink model snippet, what label will appear on the signal after running this code?

signal = Simulink.Signal();
signal.CoderInfo.StorageClass = 'ExportedGlobal';
signal.Description = 'Speed signal';
signal.SignalName = 'vehicle_speed';

medium

A. vehicle_speed

B. Speed signal

C. ExportedGlobal

D. Simulink.Signal

Solution

1. Step 1: Understand signal properties

   The 'SignalName' property sets the label shown on the signal line in Simulink.

2. Step 2: Identify label from code

   Here, 'SignalName' is set to 'vehicle_speed', so this is the label that appears.

3. Final Answer:

   vehicle_speed -> Option A

4. Quick Check:

   SignalName property = label shown [OK]

Hint: SignalName property sets the visible label [OK]

Common Mistakes:

• Confusing Description with label
• Using StorageClass as label
• Assuming class name shows as label

4. You tried to label a signal by typing on the line, but the label does not appear. What is the most likely cause?

medium

A. The signal is inside a masked subsystem without label visibility enabled

B. The model is not saved

C. The signal line is too short to display the label

D. The signal data type is incompatible with labeling

Solution

1. Step 1: Consider label visibility rules

   Signals inside masked subsystems may hide labels unless visibility is enabled.

2. Step 2: Evaluate other options

   Signal length does not prevent labeling; saving model does not affect label display; data type does not block labels.

3. Final Answer:

   The signal is inside a masked subsystem without label visibility enabled -> Option A

4. Quick Check:

   Masked subsystem hides labels by default [OK]

Hint: Check masked subsystem label visibility settings [OK]

Common Mistakes:

• Blaming signal length for missing label
• Thinking saving model shows labels
• Assuming data type affects labeling

5. You have multiple signals named 'speed' in different subsystems. How can you label them uniquely to avoid confusion in a large Simulink model?

hard

A. Use the same label 'speed' for all signals to keep consistency

B. Disable signal labels to reduce clutter

C. Rename the blocks instead of labeling signals

D. Add subsystem name as prefix to each signal label, e.g., 'Engine_speed'

Solution

1. Step 1: Understand labeling best practice

   Unique labels help distinguish signals, especially with same base names in different subsystems.

2. Step 2: Apply prefix naming

   Adding subsystem name as prefix (e.g., 'Engine_speed') uniquely identifies each signal.

3. Step 3: Evaluate other options

   Using same label causes confusion; renaming blocks does not label signals; disabling labels removes helpful info.

4. Final Answer:

   Add subsystem name as prefix to each signal label, e.g., 'Engine_speed' -> Option D

5. Quick Check:

   Unique labels = prefix subsystem name [OK]

Hint: Prefix labels with subsystem names for uniqueness [OK]

Common Mistakes:

• Using identical labels causing confusion
• Confusing block names with signal labels
• Removing labels to avoid clutter