IIoT integration with SCADA in SCADA systems - Step-by-Step Execution

Process Flow - IIoT integration with SCADA

IIoT Devices Collect Data

↓

Data Sent via Protocols (MQTT/OPC-UA)

↓

SCADA System Receives Data

↓

SCADA Processes and Visualizes Data

↓

Operator Monitors and Controls

↓

Commands Sent Back to IIoT Devices

Data flows from IIoT devices to SCADA via protocols, SCADA processes and visualizes it, then operators can control devices.

Execution Sample

SCADA systems

1. IIoT device sends sensor data via MQTT
2. SCADA subscribes and receives data
3. SCADA updates dashboard
4. Operator sends control command
5. Command sent back to IIoT device

This sequence shows how IIoT devices communicate with SCADA and how control commands flow back.

Process Table

Step	Action	Data/Command	System State	Output/Result
1	IIoT device sends data	Temperature=75°F	Data in MQTT broker	Data published to topic
2	SCADA subscribes to topic	Temperature=75°F	SCADA receives data	Data available for processing
3	SCADA updates dashboard	Temperature=75°F	Dashboard shows 75°F	Operator sees updated value
4	Operator sends command	Set Fan Speed=High	Command queued in SCADA	Command ready to send
5	SCADA sends command to IIoT device	Set Fan Speed=High	IIoT device receives command	Fan speed set to High
6	IIoT device confirms action	Fan Speed=High	SCADA receives confirmation	Operator notified of success
7	Monitoring continues	Temperature=75°F	Continuous data flow	Real-time updates ongoing

💡 Continuous loop; stops when system is turned off or communication lost

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	After Step 5	After Step 6	Final
Temperature	N/A	75°F	75°F	75°F	75°F	75°F	75°F	75°F
Fan Speed Command	None	None	None	None	High	High	High	High
SCADA Dashboard	Empty	Empty	Shows 75°F	Shows 75°F	Shows 75°F	Shows 75°F	Shows 75°F + Confirmation	Shows 75°F + Confirmation

Key Moments - 3 Insights

Why does SCADA need to subscribe to a topic before receiving data?

SCADA subscribes to the MQTT topic to listen for messages. Without subscribing, it won't receive the IIoT device data. See execution_table step 2 where SCADA subscribes and then receives data.

How does the operator's command reach the IIoT device?

The operator sends a command to SCADA, which queues and then sends it to the IIoT device. This is shown in steps 4 and 5 where the command moves from operator to SCADA to device.

What happens if the IIoT device does not confirm the command?

SCADA will not receive confirmation, so the operator won't see success notification. This can cause alerts or retries. Step 6 shows confirmation; without it, the system knows the command failed.

Visual Quiz - 3 Questions

Look at the execution table, at which step does SCADA update the dashboard with new data?

A Step 2

B Step 3

C Step 4

D Step 5

💡 Hint

Check the 'Action' and 'Output/Result' columns for dashboard updates.

According to the variable tracker, what is the fan speed command after step 4?

A None

B Low

C High

D Medium

💡 Hint

Look at the 'Fan Speed Command' row under 'After Step 4' column.

If the IIoT device never confirms the command, which step's output will not occur?

A Step 6 output

B Step 3 output

C Step 5 output

D Step 2 output

💡 Hint

Check the 'Output/Result' column for step 6 about confirmation.

Concept Snapshot

IIoT devices send data via protocols like MQTT or OPC-UA to SCADA.
SCADA subscribes to receive and process this data.
SCADA visualizes data on dashboards for operators.
Operators send control commands back through SCADA to IIoT devices.
Confirmation from devices ensures command success.
This loop enables real-time monitoring and control.

Full Transcript

This visual execution shows how IIoT devices integrate with SCADA systems. First, IIoT devices collect sensor data and send it using protocols such as MQTT. SCADA subscribes to these data topics to receive the information. Once SCADA gets the data, it updates its dashboard so operators can see real-time values. Operators can then send control commands through SCADA, which forwards them to the IIoT devices. The devices confirm the commands, and SCADA notifies the operator. This cycle continues for ongoing monitoring and control.