LEN block

Short summary

Name	`LEN`
→POU type	→function
Category	Standard (non-safe), String
Conform to →IEC-standard	currently restricted (IEC demands data type `ANY_STRING` for the input, hence the following data type is demanded as well: `WSTRING`. Currently, this data type is not supported for the block.)
Graphical interface
Available since	version 1.30.0 (for Neuron Power Engineer) - initial variant version 3.8.0 (for library `Standard (non-safe)`): block moved in this library

Functionality

The block determines the length of a string.

At input IN, enter the string for which the length should be determined.

Neuron Power Engineer determines the character positions within a string as follows: 1, 2, ..., n. 1 corresponds to the leftmost character position and n to the length of the string.
Three-character combination of the dollar sign ($) followed by two hexadecimal digits are evaluated as single character. Example: The string '$B15' (corresponds to '±5') consists of 2 characters. See →character string literal for more examples for those combinations.

Inputs, return value

	Identifier	→Data type	Description
Inputs:	`IN`	`STRING`	input value
Return value:	–	`USINT`, `UINT`, `UDINT`, `ULINT`, `SINT`, `INT`, `DINT` or `LINT` (corresponds to →generic data type `ANY_INT`)

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, result3, result4 : INT;

    END_VAR

    result1 := LEN(IN := 'ASTRING');       (* The variable 'result' evaluates to '7'. *)

    result2 := LEN(IN := '$B15');          (* The variable 'result' evaluates to '2'. *)

    result3 := LEN(IN := 'ABC$00D');       (* The variable 'result' evaluates to '3'. Reason: The character string is terminated at position 4 because of '$00'. *)

    result4 := LEN(IN := '');              (* The variable 'result' evaluates to '0'. *)

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.