SQRT

Calculates the square root of Value and stores the result in Result.

Ladder Representation

Block Structure

Variable Type	Name	Data Type	Description
VAR_INPUT	EN	BOOL	Block enabling.
VAR_INPUT	Value	REAL	Reference variable for the operation.
VAR_OUTPUT	Done	BOOL	End of operation.
VAR_OUTPUT	Result	REAL	Variable that stores the operation result.

Operation

When EN is TRUE, the block writes the square root of Value to Result.

If the operation completes without errors, Done is set. If an operation error occurs, Done remains FALSE and Result keeps its previous value.

When EN is FALSE, Result remains unchanged and Done remains FALSE.

Execution Flowchart

Examples

Ladder Example

This example calculates the square root of VALUE and stores the final result in RESULT. The block completes successfully and activates Done.

This example attempts to calculateste the square root of a negative VALUE. The block reports an execution error, leaves RESULT unchanged, and keeps Done disabled.

Structured Text Example

The following Structured Text code applies the same logic shown in the Ladder example.

Structured Text

VAR
    VALUE : REAL := 81.0;
    RESULT : REAL;
END_VAR

RESULT := FB_SQRT(EN:=DI1, Value:=VALUE, Done=>DO1);