LE (Less Than or Equal)
Returns TRUE when first input is less than or equal to second input.
The LE (Less Than or Equal) comparison function returns TRUE when the first input is less than or equal to the second input. It is used for maximum limit checks, upper boundary validation, and ensuring values stay within acceptable ranges.
Parameters
Inputs
| Name | Type | Description |
|---|---|---|
| IN1 | ANY_NUM | First value |
| IN2 | ANY_NUM | Second value |
Outputs
| Name | Type | Description |
|---|---|---|
| OUT | BOOL | TRUE when IN1 <= IN2 |
Ladder Logic Example
// Ladder Logic - LE Comparison // // |----[LE]---( Within_Limit )----| // | IN1: Motor_Speed | // | IN2: Max_Speed (1800) |
Structured Text Example
Within_Limit := (Motor_Speed <= Max_Speed);
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Platform-Specific Implementation
Siemens (TIA Portal)
Use CMP <= instruction in TIA Portal.
Allen-Bradley (Studio 5000)
Use LEQ (Less Than or Equal) instruction.
CODESYS
Use <= operator in ST or LE function block.
Common Applications
- Maximum speed limiting
- Upper boundary checks
- Capacity limit verification
- Dosage limit control
Frequently Asked Questions
What is LE (Less Than or Equal) in PLC programming?
Returns TRUE when first input is less than or equal to second input. The LE (Less Than or Equal) comparison function returns TRUE when the first input is less than or equal to the second input. It is used for maximum limit checks, upper boundary validation, and ensuring values stay within acceptable ranges.
What are common applications of LE (Less Than or Equal)?
LE (Less Than or Equal) is commonly used for: Maximum speed limiting, Upper boundary checks, Capacity limit verification, Dosage limit control.
How do I use LE (Less Than or Equal) in different PLC platforms?
Siemens: Use CMP <= instruction in TIA Portal. Allen-Bradley: Use LEQ (Less Than or Equal) instruction. CODESYS: Use <= operator in ST or LE function block.
Related Function Blocks
LT (Less Than)
Returns TRUE when first input is strictly less than second input.
View Reference →GE (Greater Than or Equal)
Returns TRUE when first input is greater than or equal to second input.
View Reference →EQ (Equal)
Returns TRUE when both inputs are exactly equal.
View Reference →GT (Greater Than)
Returns TRUE when first input is strictly greater than second input.
View Reference →NE (Not Equal)
Returns TRUE when two compatible operands compare unequal at execution.
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