This flow shows how a sensor's physical signal is classified as analog or digital, converted, sent to SCADA, and then processed.
Execution Sample
SCADA systems
Analog signal: 4-20mA current loop
Digital signal: ON/OFF switch
SCADA reads and displays values
Shows how analog and digital signals are read and processed by SCADA.
Process Table
Step
Signal Type
Input Signal
Conversion
SCADA Data Received
Action
1
Analog
Temperature varies continuously
4-20mA current proportional to temp
Current value (e.g. 12mA)
Display temperature value
2
Digital
Switch ON or OFF
Binary 1 or 0
1 (ON) or 0 (OFF)
Trigger alarm or status
3
Analog
Pressure varies continuously
Voltage signal 0-10V
Voltage value (e.g. 5V)
Display pressure value
4
Digital
Pump running or stopped
Binary 1 or 0
0 (OFF)
Show pump stopped
5
End
-
-
-
No more signals to process
💡 All signals processed and converted for SCADA display or control
Status Tracker
Variable
Start
After Step 1
After Step 2
After Step 3
After Step 4
Final
Signal Type
None
Analog
Digital
Analog
Digital
Processed
Input Signal
None
Temperature
Switch
Pressure
Pump status
All signals read
Converted Signal
None
4-20mA
Binary
0-10V
Binary
Converted values
SCADA Data
None
12mA
1
5V
0
Data ready for use
Key Moments - 3 Insights
Why does analog data use a range of values instead of just ON or OFF?
Analog data represents continuous changes, like temperature, so it uses a range (e.g., 4-20mA) to show different levels, as seen in execution_table rows 1 and 3.
How does digital data represent information differently from analog?
Digital data uses only two states (1 or 0) to represent ON or OFF conditions, like a switch, shown in execution_table rows 2 and 4.
What happens if an analog signal is read as digital by mistake?
The continuous information would be lost, only ON/OFF states would be seen, causing incorrect SCADA data, which is why correct conversion is important as shown in the conversion column.
Visual Quiz - 3 Questions
Test your understanding
Look at the execution table, what SCADA data is received at step 3 for the analog pressure signal?
A12mA current value
B5V voltage value
CBinary 1
D0 (OFF)
💡 Hint
Check the 'SCADA Data Received' column at step 3 in the execution_table
At which step does the SCADA system receive a digital signal representing a switch ON state?
AStep 2
BStep 1
CStep 3
DStep 4
💡 Hint
Look for 'Digital' signal type and '1 (ON)' in SCADA Data Received column
If the pump status changed from OFF to ON, how would the SCADA data change at step 4?
AFrom 5V to 12mA
BFrom 1 to 0
CFrom 0 to 1
DNo change
💡 Hint
Check the SCADA Data Received for digital signals in step 4 and consider ON=1, OFF=0
Concept Snapshot
Analog vs Digital Data Points in SCADA:
- Analog signals vary continuously (e.g., 4-20mA current)
- Digital signals have two states: ON (1) or OFF (0)
- SCADA converts and reads these signals accordingly
- Analog shows range values; digital shows discrete states
- Correct conversion ensures accurate monitoring and control
Full Transcript
This visual execution shows how SCADA systems handle analog and digital data points. Sensors read physical signals that are either continuous (analog) or discrete (digital). Analog signals like temperature or pressure are converted into current or voltage ranges (e.g., 4-20mA or 0-10V) and sent to SCADA. Digital signals like switches or pump status are converted into binary 1 or 0. The execution table traces each step, showing input signals, their conversion, and what SCADA receives. Variable tracking shows how signal types and values change step-by-step. Key moments clarify common confusions about continuous vs discrete signals. The quiz tests understanding by referencing specific steps and data values. The snapshot summarizes the key differences and processing rules for analog and digital data points in SCADA systems.