Equipments (Devices) > PLC200 > Program > String > STR_FIND

Block that searches for the last occurrence of one STRING in another, returning the position of this occurrence.

Ladder Representation

STR_FIND_LAST_block

Block Structure

Variable Type	Name	Data Type	Description
VAR_INPUT	EN	BOOL	Block enabling
	STR1	STRING	STRING where the search will be performed
	STR2	STRING	STRING to be searched
VAR_OUTPUT	DONE	BOOL	Output enabling
VAR_OUTPUT	POS	BYTE	Position where STR2 was found

Operation

This block remains active as long as EN is at TRUE level, updating the value of POS according to the input parameters.

A search in STR1 is performed, from its last position, by an occurrence of STR2.

If it is found, it inserts into the POS the occurrence of this position, while DONE forwards to the next Ladder block the value of EN when ending the operation.

If it is not found, DONE remains FALSE and POS remains unchanged.

NOTE!

POS is treated with index "based one". That is, POS = 1 references the first position of STR.

Compatibility

Device	Version
PLC300	2.10 or higher

Block Flowchart

STR_FIND_LAST_flowchart

Example in Ladder

STR_FIND_LAST_example01

In the example above, a search is done by STR2 in STR1 from its final position. Since STR2 is found in position 4, POS receives 4. The block ends successfully, the DONE output is activated.

STR_FIND_LAST_example02

In the example above, a search is done by STR2 in STR1 from its final position. Since STR2 is found in position 2, POS receives 4. The block ends successfully, the DONE output is activated.

STR_FIND_LAST_example03

In the example above, a search is done by STR2 in STR1 from its final position. Since STR2 is not found, POS remains unchanged and the DONE output is disabled.

Example in ST

The example below displays the instructions for applying the example above in the ST language.

VAR

STR1 : STRING := '2232';

STR2 : STRING := '1';

POS : BYTE;

END_VAR

POS := FB_STR_FIND_LAST(

EN:=DI1,

STR1:=STR1,

STR2:=STR2,

Done=>DO1);