Networked SCADA architecture in SCADA systems - Step-by-Step Execution

Process Flow - Networked SCADA architecture

Field Devices

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Remote Terminal Units (RTUs)

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Communication Network

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SCADA Master Station

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Human-Machine Interface (HMI)

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Data Historian & Control Servers

Data flows from field devices through RTUs over a network to the SCADA master station, where operators monitor and control via HMI.

Execution Sample

SCADA systems

Field Device -> RTU -> Network -> SCADA Master -> HMI

// Data flow example

Shows the path of data from sensors to operator interface in a networked SCADA system.

Process Table

Step	Component	Action	Data State	Next Component
1	Field Device	Senses physical parameter	Raw sensor data	RTU
2	RTU	Collects and formats data	Formatted data packet	Communication Network
3	Communication Network	Transmits data	Data in transit	SCADA Master Station
4	SCADA Master Station	Receives and processes data	Processed data	HMI & Control Servers
5	HMI	Displays data to operator	Visualized data	Operator
6	Operator	Sends control commands	Control commands	SCADA Master Station
7	SCADA Master Station	Sends commands to RTU	Command packets	RTU
8	RTU	Executes commands on field devices	Actuator actions	Field Device
9	Field Device	Performs physical action	Changed physical state	End
10	-	End of cycle	-	-

💡 Cycle completes when field device acts on operator command and new data is sensed.

Status Tracker

Variable	Start	After Step 2	After Step 4	After Step 6	After Step 8	Final
Data	Raw sensor data	Formatted data packet	Processed data	Visualized data	Control commands	Changed physical state
Command	None	None	None	Control commands	Command packets	Actuator actions

Key Moments - 3 Insights

Why does data change format between Field Device and SCADA Master Station?

Data is raw at the field device but must be formatted by the RTU for reliable transmission over the network, as shown in steps 1 and 2 of the execution table.

How does the operator control the field devices remotely?

The operator uses the HMI to send commands that travel back through the SCADA Master Station and RTU to the field devices, as seen in steps 6 to 9.

What role does the communication network play in this architecture?

It transmits data packets between RTUs and the SCADA Master Station, enabling remote monitoring and control, as shown in step 3.

Visual Quiz - 3 Questions

Look at the execution table, what data state is present after the RTU processes sensor data?

A Raw sensor data

B Processed data

C Formatted data packet

D Visualized data

💡 Hint

Check Step 2 in the execution table where RTU formats the data.

At which step does the operator send control commands back into the system?

A Step 5

B Step 6

C Step 4

D Step 7

💡 Hint

Look for the step where the operator action is recorded in the execution table.

If the communication network fails, which step's data state will be missing or stuck?

A Step 3: Data in transit

B Step 5: Visualized data

C Step 2: Formatted data packet

D Step 8: Actuator actions

💡 Hint

The communication network transmits data; check Step 3 in the execution table.

Concept Snapshot

Networked SCADA architecture connects field devices to operators via RTUs and a communication network.
Data flows from sensors to SCADA master station, then to HMI for monitoring.
Operators send commands back through the same path to control devices.
Reliable data formatting and transmission are key for remote control.
Communication network is the critical link between RTUs and SCADA master.
Cycle repeats continuously for real-time monitoring and control.

Full Transcript

Networked SCADA architecture involves field devices sensing data, which is collected and formatted by RTUs. This data travels over a communication network to the SCADA master station, where it is processed and displayed on the HMI for operators. Operators send control commands back through the SCADA master and RTUs to the field devices, which act accordingly. The communication network is essential for transmitting data and commands. This cycle repeats continuously to enable real-time monitoring and control of industrial processes.