Type ConversionBeginnerIEC 61131-3

INT_TO_REAL (Integer to Real Conversion)

Converts 16-bit integer to 32-bit floating-point real value.

The INT_TO_REAL function converts an integer value (INT, 16-bit signed) to a floating-point real value (REAL, 32-bit IEEE 754). This conversion is essential when integer values from counters, analog inputs (raw counts), or recipe parameters need to be used in floating-point calculations such as PID control, scaling, or engineering unit conversions. The conversion is always exact for INT values since REAL has sufficient precision to represent all INT values.

Parameters

Inputs

Name	Type	Description
IN	INT	Integer value to convert (-32768 to 32767)

Outputs

Name	Type	Description
OUT	REAL	Floating-point equivalent

Ladder Logic Example

// Ladder Logic - INT_TO_REAL (Analog Scaling)
//
// |----[INT_TO_REAL]----[DIV]----[MUL]----|
// | IN: Analog_Raw      Scale calculation |
// | OUT: Raw_Real        for engineering  |

Structured Text Example

// Convert raw analog (0-27648) to engineering units
Raw_Real := INT_TO_REAL(Analog_Raw);
Temperature := (Raw_Real / 27648.0) * 100.0;
// 0-27648 raw -> 0.0-100.0 degrees

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Platform-Specific Implementation

Siemens (TIA Portal)

Use CONVERT instruction or INT_TO_REAL in TIA Portal SCL.

Allen-Bradley (Studio 5000)

Implicit conversion in most cases, or use COP instruction.

CODESYS

Use INT_TO_REAL() function in ST. Automatic in some contexts.

Common Applications

Analog input scaling
Counter value in calculations
Recipe parameter conversion
PID input preparation
HMI display formatting

Frequently Asked Questions

What is INT_TO_REAL (Integer to Real Conversion) in PLC programming?

Converts 16-bit integer to 32-bit floating-point real value. The INT_TO_REAL function converts an integer value (INT, 16-bit signed) to a floating-point real value (REAL, 32-bit IEEE 754). This conversion is essential when integer values from counters, analog inputs (raw counts), or recipe parameters need to be used in floating-point calculations such as PID control, scaling, or engineering unit conversions.

What are common applications of INT_TO_REAL (Integer to Real Conversion)?

INT_TO_REAL (Integer to Real Conversion) is commonly used for: Analog input scaling, Counter value in calculations, Recipe parameter conversion, PID input preparation, HMI display formatting.

How do I use INT_TO_REAL (Integer to Real Conversion) in different PLC platforms?

Siemens: Use CONVERT instruction or INT_TO_REAL in TIA Portal SCL. Allen-Bradley: Implicit conversion in most cases, or use COP instruction. CODESYS: Use INT_TO_REAL() function in ST. Automatic in some contexts.