Learn Schneider-ecostruxure-unitypro - 10 Code Examples & CST Typing Practice Test

Schneider EcoStruxure Control Expert (formerly Unity Pro) is an IEC 61131-3 compliant PLC programming environment used for developing, configuring, testing, and maintaining Schneider Electric Modicon PLCs across industrial automation systems.

View all 10 Schneider-ecostruxure-unitypro code examples →

Hello World Output in Unity Pro (ST)TON On-Delay Timer (ST)CTU Up Counter (ST)Move Value (ST MOV Equivalent)Analog Scaling (0-27648 -> 0-100%)Motor Start/Stop Seal (ST)Rising Edge Detection (R_TRIG)FOR Loop Summing Registers PID Function Block Example PWM Output Example (ST)

Learn SCHNEIDER-ECOSTRUXURE-UNITYPRO with Real Code Examples

Updated Nov 27, 2025

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Code Sample Descriptions

Hello World Output in Unity Pro (ST)

IF %I0.0 THEN
    %Q0.0 := TRUE;
ELSE
    %Q0.0 := FALSE;
END_IF;

A basic Structured Text example that turns ON %Q0.0 when %I0.0 is TRUE.

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TON On-Delay Timer (ST)

TON_1(IN := %I0.1, PT := T#5s);
IF TON_1.Q THEN
    %Q0.1 := TRUE;
END_IF;

Standard TON timer usage in Unity Pro ST.

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CTU Up Counter (ST)

CTU_1(CU := %I0.2, PV := 10);
IF CTU_1.CV >= 10 THEN
    %Q0.2 := TRUE;
END_IF;

Counting rising pulses on %I0.2. After reaching 10, %Q0.2 turns ON.

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Move Value (ST MOV Equivalent)

%MW10 := %MW0;

Moves the value of %MW0 to %MW10.

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Analog Scaling (0-27648 -> 0-100%)

Scaled := (REAL(%IW0) * 100.0) / 27648.0;

Unity analog inputs use 0-27648 for 0-20 mA or 0-10V.

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Motor Start/Stop Seal (ST)

IF %I0.3 THEN
    M_Start := TRUE;
END_IF;
IF %I0.4 THEN
    M_Start := FALSE;
END_IF;
%Q0.3 := M_Start;

Classic latch logic using %I0.3 start and %I0.4 stop.

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Rising Edge Detection (R_TRIG)

R_TRIG_1(CLK := %I0.5);
IF R_TRIG_1.Q THEN
    %Q0.4 := TRUE;
END_IF;

Using Unity’s built-in R_TRIG function block.

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FOR Loop Summing Registers

Sum := 0;
FOR i := 0 TO 9 DO
    Sum := Sum + %MW[i];
END_FOR;

Sum %MW0 through %MW9.

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PID Function Block Example

PIDAT_1(
    PV := %MW100,
    SP := %MW200,
    KP := 1.0,
    TI := 2.0,
    TD := 0.0,
    MAN := FALSE,
    OUT => %MW300
);

Calling the PIDAT block in Unity Pro for process control.

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PWM Output Example (ST)

IF Ramp >= 100 THEN
    Ramp := 0;
END_IF;
IF Ramp < Duty THEN
    %Q0.5 := TRUE;
ELSE
    %Q0.5 := FALSE;
END_IF;
Ramp := Ramp + 1;

Generating PWM by comparing a ramp counter against duty cycle.

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Frequently Asked Questions about Schneider-ecostruxure-unitypro

What is Schneider-ecostruxure-unitypro?

What are the primary use cases for Schneider-ecostruxure-unitypro?

Programming Modicon M340, M580, M221, Premium, and Quantum PLCs. Industrial automation logic development. SCADA integration via Modbus, Ethernet/IP, and Schneider protocols. Safety-critical control sequences. Batch process automation

What are the strengths of Schneider-ecostruxure-unitypro?

Rich industrial-grade toolset. Strong diagnostics, traces, and breakpoints. Supports complex multi-PLC systems. Excellent for large-scale automation. Robust communication configuration

What are the limitations of Schneider-ecostruxure-unitypro?

Windows-only environment. Steeper learning curve for beginners. Expensive licensing. Can feel slow with very large projects. Not ideal for non-Modicon hardware

How can I practice Schneider-ecostruxure-unitypro typing speed?

CodeSpeedTest offers 10+ real Schneider-ecostruxure-unitypro code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.

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Code Sample Descriptions

Hello World Output in Unity Pro (ST)

IF %I0.0 THEN
    %Q0.0 := TRUE;
ELSE
    %Q0.0 := FALSE;
END_IF;

A basic Structured Text example that turns ON %Q0.0 when %I0.0 is TRUE.

Let’s Try →

TON On-Delay Timer (ST)

TON_1(IN := %I0.1, PT := T#5s);
IF TON_1.Q THEN
    %Q0.1 := TRUE;
END_IF;

Standard TON timer usage in Unity Pro ST.

Let’s Try →

CTU Up Counter (ST)

CTU_1(CU := %I0.2, PV := 10);
IF CTU_1.CV >= 10 THEN
    %Q0.2 := TRUE;
END_IF;

Counting rising pulses on %I0.2. After reaching 10, %Q0.2 turns ON.

Let’s Try →

Move Value (ST MOV Equivalent)

%MW10 := %MW0;

Moves the value of %MW0 to %MW10.

Let’s Try →

Analog Scaling (0-27648 -> 0-100%)

Scaled := (REAL(%IW0) * 100.0) / 27648.0;

Unity analog inputs use 0-27648 for 0-20 mA or 0-10V.

Let’s Try →

Motor Start/Stop Seal (ST)

IF %I0.3 THEN
    M_Start := TRUE;
END_IF;
IF %I0.4 THEN
    M_Start := FALSE;
END_IF;
%Q0.3 := M_Start;

Classic latch logic using %I0.3 start and %I0.4 stop.

Let’s Try →

Rising Edge Detection (R_TRIG)

R_TRIG_1(CLK := %I0.5);
IF R_TRIG_1.Q THEN
    %Q0.4 := TRUE;
END_IF;

Using Unity’s built-in R_TRIG function block.

Let’s Try →

FOR Loop Summing Registers

Sum := 0;
FOR i := 0 TO 9 DO
    Sum := Sum + %MW[i];
END_FOR;

Sum %MW0 through %MW9.

Let’s Try →

PID Function Block Example

PIDAT_1(
    PV := %MW100,
    SP := %MW200,
    KP := 1.0,
    TI := 2.0,
    TD := 0.0,
    MAN := FALSE,
    OUT => %MW300
);

Calling the PIDAT block in Unity Pro for process control.

Let’s Try →

PWM Output Example (ST)

IF Ramp >= 100 THEN
    Ramp := 0;
END_IF;
IF Ramp < Duty THEN
    %Q0.5 := TRUE;
ELSE
    %Q0.5 := FALSE;
END_IF;
Ramp := Ramp + 1;

Generating PWM by comparing a ramp counter against duty cycle.

Let’s Try →

Frequently Asked Questions about Schneider-ecostruxure-unitypro

What is Schneider-ecostruxure-unitypro?

What are the primary use cases for Schneider-ecostruxure-unitypro?

What are the strengths of Schneider-ecostruxure-unitypro?

Rich industrial-grade toolset. Strong diagnostics, traces, and breakpoints. Supports complex multi-PLC systems. Excellent for large-scale automation. Robust communication configuration

What are the limitations of Schneider-ecostruxure-unitypro?

Windows-only environment. Steeper learning curve for beginners. Expensive licensing. Can feel slow with very large projects. Not ideal for non-Modicon hardware

How can I practice Schneider-ecostruxure-unitypro typing speed?

CodeSpeedTest offers 10+ real Schneider-ecostruxure-unitypro code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.