====== ISNAN ======

{{:en:mervis-ide:35-help:isnan.png}}

===== Function name =====

ISNAN

===== ST call =====

<code st-iec>
PROGRAM ISNAN_DEMO
 VAR
     REAL1,REAL2: REAL;
  END_VAR
 REAL2:= ISNAN(REAL1);
END_PROGRAM
</code>

===== Description =====

Compares the input variable value with NaN (Not-A-Number, i.e. the value does not represent any valid real number). Returns TRUE, if the value is NaN.

===== Inputs =====

|Input|Type    |Description|
|IN   |ANY_REAL|Input value|

===== Outputs =====

|Output|Type|Description |
|=>    |BOOL|Output value|

===== Application example =====

{{:en:mervis-ide:35-help:isnan_example.png}}