Automatic vs manual mode switching in SCADA systems - Visual Side-by-Side Comparison

Process Flow - Automatic vs manual mode switching

Start

↓

Check Mode Switch Request

↓

Is Automatic Mode?

Yes→System Controls Process Automatically

↓

Monitor & Adjust

↓

Loop Back to Check

↓

Is Manual Mode?

Yes→Operator Controls Process

↓

Monitor & Adjust

↓

Loop Back to Check

The system checks if the mode switch request is automatic or manual, then either controls the process automatically or lets the operator control it, looping back to monitor continuously.

Execution Sample

SCADA systems

mode = 'automatic'
if mode == 'automatic':
    control_process_automatically()
else:
    operator_controls_process()

This code switches control based on mode: automatic mode runs automatic control, manual mode lets operator control.

Process Table

Step	Variable 'mode'	Condition Checked	Branch Taken	Action
1	'automatic'	mode == 'automatic' ?	True	Call control_process_automatically()
2	N/A	N/A	N/A	System controls process automatically
3	N/A	N/A	N/A	Monitor and adjust process
4	N/A	N/A	N/A	Loop back to check mode switch request

💡 Continuous loop; system keeps monitoring and controlling based on mode

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
mode	undefined	'automatic'	'automatic'	'automatic'	'automatic'

Key Moments - 2 Insights

Why does the system keep looping back to check the mode?

Because the system must continuously monitor if the mode changes, as shown in execution_table rows 3 and 4 where it monitors and loops back.

What happens if the mode is 'manual' instead of 'automatic'?

The else branch runs operator_controls_process(), letting the operator control the process manually, which is the opposite branch of step 1 in the execution_table.

Visual Quiz - 3 Questions

Look at the execution_table, what action is taken at step 1 when mode is 'automatic'?

A Loop back to check mode

B Call operator_controls_process()

C Call control_process_automatically()

D Stop the system

💡 Hint

Check the 'Action' column in execution_table row 1

At which step does the system monitor and adjust the process?

A Step 3

B Step 2

C Step 1

D Step 4

💡 Hint

Look at the 'Action' column in execution_table row 3

If mode changes to 'manual', which branch will the system take at step 1?

A True branch to automatic control

B False branch to manual control

C No branch, system stops

D System restarts

💡 Hint

Refer to the condition and branch taken in execution_table row 1

Concept Snapshot

Automatic vs Manual Mode Switching:
- System checks mode continuously
- If mode is 'automatic', system controls process automatically
- If mode is 'manual', operator controls process
- Always monitor and adjust process
- Loop back to check mode changes

Full Transcript

This visual execution shows how a SCADA system switches between automatic and manual modes. The system starts by checking the mode variable. If the mode is 'automatic', it runs automatic control functions. Otherwise, it lets the operator control the process manually. After controlling, the system monitors the process and loops back to check the mode again. This loop ensures the system always responds to mode changes and keeps the process running safely.