Real-time data display in SCADA systems - Step-by-Step Execution

Process Flow - Real-time data display

Sensor collects data

↓

Data sent to SCADA server

↓

Server processes data

↓

Update display dashboard

↓

Operator views live data

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Repeat continuously

Data flows from sensors to the SCADA server, which processes and updates the display continuously for live monitoring.

Execution Sample

SCADA systems

while True:
    data = read_sensor()
    processed = process_data(data)
    update_display(processed)
    sleep(1)

This loop reads sensor data every second, processes it, and updates the display in real-time.

Process Table

Step	Action	Data Value	Display Update	Notes
1	Read sensor	Temperature=22.5°C	Display shows 22.5°C	Initial sensor read
2	Process data	Temperature=22.5°C	Display updated to 22.5°C	Data formatted for display
3	Update display	Temperature=22.5°C	Dashboard refreshed	Operator sees current value
4	Wait 1 second	-	-	Pause before next read
5	Read sensor	Temperature=22.7°C	Display shows 22.7°C	New sensor data read
6	Process data	Temperature=22.7°C	Display updated to 22.7°C	Data formatted for display
7	Update display	Temperature=22.7°C	Dashboard refreshed	Operator sees updated value
8	Wait 1 second	-	-	Pause before next read
...	...	...	...	...
N	Loop continues	New sensor data	Display updates continuously	Real-time display ongoing

💡 Loop runs indefinitely to provide continuous real-time updates

Status Tracker

Variable	Start	After 1	After 2	After 3	Final
data	None	22.5°C	22.7°C	22.6°C	Latest sensor value
processed	None	22.5°C formatted	22.7°C formatted	22.6°C formatted	Formatted for display
display	Blank	Shows 22.5°C	Shows 22.7°C	Shows 22.6°C	Always shows latest value

Key Moments - 3 Insights

Why does the display update every second instead of only once?

Because the loop repeats continuously (see execution_table rows 1-8), it reads new data and updates the display every second to show live changes.

What happens if the sensor data is delayed or missing?

The display will show the last processed value until new data arrives, as the loop waits and updates only when new data is read (refer to variable_tracker for data changes).

Why do we process data before updating the display?

Processing formats or filters raw sensor data to make it readable and accurate for the display, ensuring the operator sees clear information (see execution_table step 2 and 6).

Visual Quiz - 3 Questions

Look at the execution table, what is the display showing at step 5?

A No data

B Temperature=22.5°C

C Temperature=22.7°C

D Temperature=22.6°C

💡 Hint

Check the 'Display Update' column at step 5 in the execution_table.

At which step does the system wait before reading new sensor data again?

A Step 4

B Step 2

C Step 3

D Step 1

💡 Hint

Look for the 'Wait 1 second' action in the execution_table.

If the sensor data suddenly stops updating, what will the display show?

A Blank screen

B Last processed value

C Error message

D Random data

💡 Hint

Refer to the key_moments explanation about missing sensor data and variable_tracker for 'data' variable.

Concept Snapshot

Real-time data display in SCADA:
- Continuously read sensor data in a loop
- Process data for clarity
- Update display dashboard every cycle
- Use delays (e.g., 1 second) to pace updates
- Ensures operators see live system status

Full Transcript

In real-time data display for SCADA systems, sensors collect data continuously. This data is sent to the SCADA server, which processes it and updates the display dashboard. The process repeats in a loop, typically every second, to keep the operator's view current. The code example shows a loop reading sensor data, processing it, and updating the display. The execution table traces each step: reading data, processing it, updating the display, and waiting before repeating. Variables like 'data' and 'processed' change values each cycle to reflect new sensor readings. Key moments clarify why updates happen every second, how missing data is handled, and why processing is needed before display. The quiz tests understanding of display values at specific steps, timing of waits, and behavior when data stops. This method ensures operators always see the latest system status live.