IS_VALID block

Short summary

Name	`IS_VALID`
→POU type	→function
Category	IEC-block, Numeric
Conform to →IEC-standard	no restrictions
Graphical interface
Available since	version 1.35.0 (for Neuron Power Engineer)

Functionality

The block checks the validity of the value entered at input IN.

In case of valid ANY_REAL values, the block returns the value TRUE (or an equivalent). In the case that the value is "Not-a-Number" (NaN) or infinite ("+Inf", "-Inf"), the block returns the value FALSE (or an equivalent).

Inputs, return value

	Identifier	→Data type	Description
Inputs:	`IN`	`REAL`, `LREAL` (corresponds to →generic data type `ANY_REAL`)	input value
Return value:	–	`BOOL`

Input EN and output ENO are available when →calling the block. See "Execution control: EN, ENO" for information on input EN and output ENO.

See:

"Blocks for safe logic" whether this block is supported for developing safety-relevant applications.
"Highlighting safe logic in the FBD-editor" for the effects when using the block as a block for safe logic.

Example for usage within ST-editor

PROGRAM Test

VAR

      result1, result2 : BOOL;

   END_VAR

   result1 := IS_VALID(IN := REAL#1234.567e8);          (* The variable 'result1' evaluates to 'TRUE'. *)

   result2 := IS_VALID(IN := LREAL#1234.56789e-123);    (* The variable 'result2' evaluates to 'TRUE'. *)

END_PROGRAM

When creating your application within the ST-editor, enter a call of a block by typing the text as requested by the syntax or use Content Assist.