HMI screen layout principles in SCADA systems - Mini Project: Build & Apply

HMI Screen Layout Principles

📖 Scenario: You are designing a simple Human-Machine Interface (HMI) screen for a factory control system. The screen will show the status of three machines and allow operators to see if they are running or stopped.

🎯 Goal: Build a basic HMI screen layout using a dictionary to represent machine statuses, add a configuration for alert threshold, filter machines that need attention, and display the filtered list.

📋 What You'll Learn

Create a dictionary called machines with three machines and their statuses ('running' or 'stopped')

Add a variable called alert_status set to 'stopped' to filter machines needing attention

Use a dictionary comprehension to create alert_machines with only machines matching alert_status

Print the alert_machines dictionary to show machines needing attention

💡 Why This Matters

🌍 Real World

HMI screens in factories show machine statuses clearly so operators can quickly see which machines need attention.

💼 Career

Understanding how to organize and filter data for HMI layouts is important for automation engineers and SCADA system developers.

1

Create the initial machine status dictionary

Create a dictionary called machines with these exact entries: 'Machine1': 'running', 'Machine2': 'stopped', 'Machine3': 'running'.

SCADA systems

# Create the machines dictionary with exact statuses
# Your code here

Need a hint?

Use curly braces to create a dictionary with keys as machine names and values as their statuses.

2

Add the alert status configuration

Add a variable called alert_status and set it to the string 'stopped'.

SCADA systems

machines = {'Machine1': 'running', 'Machine2': 'stopped', 'Machine3': 'running'}
# Set alert_status to 'stopped'
# Your code here

Need a hint?

Simply assign the string 'stopped' to the variable alert_status.

3

Filter machines needing attention

Use a dictionary comprehension to create a new dictionary called alert_machines that includes only machines from machines whose status matches alert_status.

SCADA systems

machines = {'Machine1': 'running', 'Machine2': 'stopped', 'Machine3': 'running'}
alert_status = 'stopped'
# Create alert_machines dictionary with machines matching alert_status
# Your code here

Need a hint?

Use dictionary comprehension syntax: {key: value for key, value in dict.items() if condition}

4

Display the machines needing attention

Write a print statement to display the alert_machines dictionary.

SCADA systems

machines = {'Machine1': 'running', 'Machine2': 'stopped', 'Machine3': 'running'}
alert_status = 'stopped'
alert_machines = {name: status for name, status in machines.items() if status == alert_status}
# Print alert_machines dictionary
# Your code here

Need a hint?

Use print(alert_machines) to show the filtered dictionary.