This block is currently not supported for usage in safety-relevant applications. When it will be supported sometimes in the future, then the label "safety_unsupported_reallreal" has to be re-inserted again for this page, so that the block appears in the correct section in the chapter "Unsupported system blocks"

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 logi.CAD 3)

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.