Communication network topology in SCADA systems - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a star topology where all nodes connect to a central hub.

SCADA systems

topology = {'hub': ['node1', 'node2', 'node3'], 'type': '[1]'}

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

Aring

Bmesh

Cstar

Dbus

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 'ring' or 'bus' which connect nodes differently.

A star topology connects all nodes to a central hub.

2fill in blank

medium

Complete the code to add a new node to a mesh topology.

SCADA systems

mesh_nodes = ['node1', 'node2', 'node3']
mesh_nodes.[1]('node4')

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

Aappend

Bremove

Cpop

Dclear

Attempts:

3 left

💡 Hint

Common Mistakes

Using remove() or pop() which delete elements.

Use append() to add a new node to the list.

3fill in blank

hard

Fix the error in the code to correctly check if a node is in a bus topology.

SCADA systems

bus_nodes = ['node1', 'node2', 'node3']
if 'node4' [1] bus_nodes:
    print('Node found')

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

Anot in

Bin

Cis

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'is' or '==' which compare identity or equality, not membership.

Use 'in' to check membership in a list.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension mapping nodes to their connection count in a mesh.

SCADA systems

connections = {node: len([1]) for node in [2]

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

Amesh_nodes

Cbus_nodes

Dstar_nodes

Attempts:

3 left

💡 Hint

Common Mistakes

Using different node lists causing wrong counts.

Each node connects to all nodes in mesh_nodes, so use mesh_nodes for both.

5fill in blank

hard

Fill all three blanks to filter nodes with more than 2 connections in the topology dictionary.

SCADA systems

filtered = {node: count for node, count in topology.[1]() if count [2] [3]

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

Aitems

B>

C2

Dkeys

Attempts:

3 left

💡 Hint

Common Mistakes

Using keys() which returns only keys, not pairs.

Use items() to get node-count pairs, then filter counts greater than 2.

Practice

1. Which communication network topology connects all devices to a single central device?

easy

A. Star topology

B. Ring topology

C. Bus topology

D. Mesh topology

Solution

1. Step 1: Understand the central device role

   In star topology, all devices connect to one central device like a hub or switch.

2. Step 2: Compare with other topologies

   Ring connects devices in a circle, Bus uses a single cable, Mesh connects devices directly to many others.

3. Final Answer:

   Star topology -> Option A

4. Quick Check:

   Central device connection = Star topology [OK]

Hint: Central device means star topology [OK]

Common Mistakes:

• Confusing ring with star because both have connections
• Thinking bus has a central device
• Mixing mesh with star topology

2. Which of the following is the correct way to describe a bus topology?

easy

A. Devices connected to a single communication line

B. Devices connected in a closed loop

C. Devices connected to a central hub

D. Devices connected directly to every other device

Solution

1. Step 1: Define bus topology

   Bus topology connects all devices along a single communication line or cable.

2. Step 2: Eliminate other options

   Closed loop is ring, central hub is star, direct connections to all is mesh.

3. Final Answer:

   Devices connected to a single communication line -> Option A

4. Quick Check:

   Single line connection = Bus topology [OK]

Hint: Bus topology uses one main cable line [OK]

Common Mistakes:

• Confusing ring (closed loop) with bus
• Thinking bus has a central hub
• Mixing mesh with bus topology

3. Given a SCADA network with devices connected so each device links to exactly two others forming a closed loop, what topology is this?

medium

A. Star topology

B. Bus topology

C. Ring topology

D. Tree topology

Solution

1. Step 1: Analyze device connections

   Each device connects to exactly two others forming a closed loop, which matches ring topology.

2. Step 2: Confirm topology type

   Star has central hub, bus is a single line, tree has branches, so ring is correct.

3. Final Answer:

   Ring topology -> Option C

4. Quick Check:

   Closed loop with two neighbors = Ring topology [OK]

Hint: Closed loop with two neighbors means ring topology [OK]

Common Mistakes:

• Choosing star because devices are connected
• Confusing bus with ring
• Thinking tree topology forms a loop

4. A SCADA system uses a mesh topology but experiences frequent communication failures. Which is the most likely cause?

medium

A. Devices connected in a closed loop

B. Single point of failure at central hub

C. Devices connected in a single line

D. Broken link between two devices reduces redundancy

Solution

1. Step 1: Understand mesh topology features

   Mesh topology has multiple connections for redundancy, so a broken link reduces this redundancy.

2. Step 2: Identify failure cause

   Single point failure applies to star, single line is bus, closed loop is ring, so broken link in mesh is likely cause.

3. Final Answer:

   Broken link between two devices reduces redundancy -> Option D

4. Quick Check:

   Mesh failure due to broken link = Broken link between two devices reduces redundancy [OK]

Hint: Mesh fails if links break, losing redundancy [OK]

Common Mistakes:

• Blaming central hub in mesh (no hub exists)
• Confusing bus or ring issues with mesh
• Ignoring link redundancy in mesh

5. You need to design a SCADA communication network that must remain operational even if multiple device connections fail. Which topology best fits this requirement?

hard

A. Bus topology

B. Mesh topology

C. Ring topology

D. Star topology

Solution

1. Step 1: Identify topology with highest fault tolerance

   Mesh topology connects devices with multiple links, so it can handle multiple failures without losing communication.

2. Step 2: Compare other topologies

   Bus fails if main cable breaks, star fails if central hub fails, ring fails if one link breaks.

3. Final Answer:

   Mesh topology -> Option B

4. Quick Check:

   Multiple failure tolerance = Mesh topology [OK]

Hint: Multiple failures? Choose mesh topology [OK]

Common Mistakes:

• Choosing star assuming central hub is fail-safe
• Selecting ring ignoring single link failure risk
• Picking bus despite single cable vulnerability