Find String (FIND)

The FIND instruction locates the starting position of a specified string within another string.

Available Languages

Ladder Diagram

Function Block

This instruction is not available in function block.

Structured Text

FIND (Source,Search,Start,Result);

Operands

There are data conversion rules for mixed data types within an instruction. See Data conversions.

Ladder Diagram and Structured Text

Operand	Type	Format	Description	Notes
Source	ANY_STRING	Tag	The string to search in	String types are: default STRING data type with max 82 length of characters for the string. any new string type you created with configurable length of characters for the string.
Search	ANY_STRING	Tag	The string to find
Start	SINT INT DINT	Immediate tag	The position in Source to start the search	Enter a number between 1 and the DATA size of the Source.
Result	DINT SINT INT	Tag	The position in Source where search string was found

See Structured Text Syntax for more information on the syntax of expressions within structured text.DescriptionThe FIND instruction searches the Source string for the Search string. If the instruction finds the Search string, the Result shows the starting position of the Search string within the Source string. Otherwise the Results is zero.Affects Math Status FlagsNoMajor/Minor Faults

A minor fault will occur if:	Fault Type	Fault Code
The LEN value of the string tag is greater than the DATA size of the string tag.	4	51
The Start value is invalid, or the Source string is empty.	4	56

None specific to this instruction. See Common Attributes for operand related faults.

Execution

Ladder Diagram

Condition	Action
Prescan	N/A
Rung-condition-in is false	N/A
Rung-condition-in is true	The instruction executes.
Postscan	N/A

Structured Text

Condition	Action
Prescan	See Prescan in the Ladder Diagram table
Normal execution	See Rung-condition-in is true in the Ladder Diagram table.
Postscan	See Postscan in the Ladder Diagram table

Example

A message from a

MessageView

terminal contains several pieces of information. The backslash character (\) separates each piece of information. To locate a piece of information, the FIND instruction searches for the backslash character and records its position in find_pos.

Ladder Diagram

Structured Text

IF MV_read.EM THEN

FIND(MV_msg,find,1,find_pos);

MV_read.EM := 0;

END_IF;