Model hierarchy and navigation in Simulink - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to open a Simulink model named 'myModel'.

Simulink

open_system('[1]')

Drag options to blanks, or click blank then click option'

AmyModel

Bsimulink

Cmodel

Dsystem

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to put the model name in quotes.

Using the wrong model name.

Using open instead of open_system.

The function open_system('myModel') opens the Simulink model named 'myModel'.

2fill in blank

medium

Complete the code to get the list of blocks inside the model 'myModel'.

Simulink

blocks = find_system('[1]', 'SearchDepth', 1)

Drag options to blanks, or click blank then click option'

AmyModel

BmyModel/Subsystem

CSubsystem

Droot

Attempts:

3 left

💡 Hint

Common Mistakes

Using a subsystem name instead of the model name.

Not specifying the model name as a string.

Using 'root' which is not a valid model name.

find_system('myModel', 'SearchDepth', 1) returns blocks at the top level of 'myModel'.

3fill in blank

hard

Fix the error in the code to get the parent system of block 'myModel/Subsystem1/BlockA'.

Simulink

parent = get_param('[1]', 'Parent')

Drag options to blanks, or click blank then click option'

AmyModel/Subsystem1

BmyModel/Subsystem1/BlockA

CBlockA

DmyModel

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the parent system path instead of the block path.

Using only the block name without the full path.

Confusing block and system names.

get_param('myModel/Subsystem1/BlockA', 'Parent') returns the parent system of the block.

4fill in blank

hard

Fill both blanks to create a list of all subsystems inside 'myModel' at any depth.

Simulink

subsystems = find_system('[1]', 'BlockType', '[2]')

Drag options to blanks, or click blank then click option'

AmyModel

BSubsystem

CBlock

DSystem

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Block' or 'System' instead of 'Subsystem' for BlockType.

Using a subsystem path instead of the model name.

Not specifying BlockType parameter.

find_system('myModel', 'BlockType', 'Subsystem') finds all subsystems inside the model.

5fill in blank

hard

Fill all three blanks to create a dictionary mapping subsystem names to their number of blocks inside 'myModel'.

Simulink

counts = {sys: len(find_system(sys, '[1]', '[2]')) for sys in find_system('[3]', 'BlockType', 'Subsystem')}

Drag options to blanks, or click blank then click option'

ASearchDepth

B1

CmyModel

DBlockType

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'BlockType' instead of 'SearchDepth' for depth control.

Using wrong model or subsystem names.

Not limiting search depth causing incorrect counts.

This code counts blocks at depth 1 inside each subsystem found in 'myModel'.

Practice

1. What is the main purpose of using model hierarchy in Simulink?

easy

A. To automatically generate code from the model

B. To increase the simulation speed by skipping blocks

C. To break a large model into smaller, manageable parts

D. To change the color scheme of the model

Solution

1. Step 1: Understand model hierarchy concept

   Model hierarchy means dividing a big model into smaller parts called subsystems or referenced models.

2. Step 2: Identify the main benefit

   This division helps manage complexity and makes the model easier to understand and develop.

3. Final Answer:

   To break a large model into smaller, manageable parts -> Option C

4. Quick Check:

   Model hierarchy = smaller parts [OK]

Hint: Think 'big to small parts' for model hierarchy [OK]

Common Mistakes:

• Confusing hierarchy with simulation speed
• Thinking hierarchy changes model appearance
• Assuming hierarchy auto-generates code

2. Which Simulink command is used to open a subsystem from the current model window?

easy

A. open_system('subsystem_name')

B. close_system('subsystem_name')

C. save_system('subsystem_name')

D. run_system('subsystem_name')

Solution

1. Step 1: Recall command to open subsystems

   The command open_system('name') opens the specified subsystem or model window.

2. Step 2: Verify other commands

   close_system closes, save_system saves, and run_system runs simulations, not open.

3. Final Answer:

   open_system('subsystem_name') -> Option A

4. Quick Check:

   Open subsystem = open_system [OK]

Hint: Use open_system to open any model part [OK]

Common Mistakes:

• Using close_system to open models
• Confusing save_system with open_system
• Assuming run_system opens models

3. Given the following commands in Simulink:

open_system('topModel/subsystem1')
open_system('topModel/subsystem1/subsubsystemA')

What will be the result?

medium

A. Both subsystem1 and subsubsystemA windows open

B. Only subsystem1 window opens

C. Only subsubsystemA window opens

D. An error occurs because subsubsystemA is nested

Solution

1. Step 1: Understand open_system behavior

   Each open_system command opens the specified model or subsystem window independently.

2. Step 2: Analyze nested subsystem opening

   Calling open_system on a nested subsystem opens that window even if parent is already open.

3. Final Answer:

   Both subsystem1 and subsubsystemA windows open -> Option A

4. Quick Check:

   open_system opens each specified window [OK]

Hint: Each open_system call opens its target window [OK]

Common Mistakes:

• Thinking nested subsystems open automatically
• Assuming error on nested subsystem open
• Believing only one window opens at a time

4. You try to navigate to a subsystem using open_system('model//subsystem') but get an error. What is the likely cause?

medium

A. Subsystem does not exist in the model

B. Incorrect path syntax with double slashes

C. Model is not loaded in memory

D. open_system cannot open subsystems

Solution

1. Step 1: Check path syntax

   The path uses double slashes //, which is invalid in Simulink paths.

2. Step 2: Understand correct path format

   Paths should use single slashes / to separate model and subsystem names.

3. Final Answer:

   Incorrect path syntax with double slashes -> Option B

4. Quick Check:

   Use single slash in paths [OK]

Hint: Use single slash '/' in subsystem paths [OK]

Common Mistakes:

• Using double slashes in paths
• Assuming open_system can't open subsystems
• Ignoring model load status

5. You have a large Simulink model with many nested subsystems. To improve navigation and clarity, which approach is best?

hard

A. Use only one big subsystem without nesting

B. Flatten all subsystems into one level to avoid hierarchy

C. Disable hierarchy navigation commands

D. Use model referencing to separate parts into independent models

Solution

1. Step 1: Understand model referencing benefits

   Model referencing breaks large models into separate files, improving clarity and reusability.

2. Step 2: Compare alternatives

   Flattening or using one big subsystem reduces clarity and manageability; disabling navigation removes helpful tools.

3. Final Answer:

   Use model referencing to separate parts into independent models -> Option D

4. Quick Check:

   Model referencing = better clarity and navigation [OK]

Hint: Use model referencing for big, nested models [OK]

Common Mistakes:

• Flattening hierarchy reduces clarity
• Using one big subsystem is hard to manage
• Disabling navigation commands hurts workflow