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

Block that deletes part of a section of STR, storing the remainder in DST.

Ladder Representation

STR_DELETE_block

Block Structure

Variable Type	Name	Data Type	Description
VAR_INPUT	EN	BOOL	Block enabling
	STR	STRING	Original STRING
	POS	BYTE	Position from which the removal will begin
	LEN	BYTE	Number of characters to be removed from POS
VAR_OUTPUT	DONE	BOOL	Output enabling
VAR_OUTPUT	DST	BYTE	Variable that receives the new STRING

Operation

This block remains active as long as EN is at TRUE level, updating the value of DST according to the input parameters. A section defined by the POS initial position is removed from STR and a LEN size, and the final result is stored in DST.

If POS is outside the allowable range of values (between 1 and the size of STR), DONE receives FALSE and DST remains unchanged.

If successful, the DONE value forwards to the next Ladder block the EN value when the operation is completed.

NOTE!

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

NOTE!

If the size of DST is less than the sum of the number of remaining characters in STR, the resulting value will be truncated.

Compatibility

Device	Version
PLC300	2.10 or higher

Block Flowchart

STR_DELETE_flowchart

Example in Ladder

STR_DELETE_example01

In the above example, as the value of POS is invalid, the block is not completed successfully, and the DONE output is disabled.

STR_DELETE_example02

In the example above, two characters are deleted from position 2 of STR1, and the remaining characters are sent to DST_6. When the block is ended successfully, the DONE output is activated.

STR_DELETE_example03

In the example above, two characters are deleted from position 4 of STR1, and the remaining characters are sent to DST_6. When the block is ended successfully, the DONE output is activated. Note that if POS + LEN is greater than the size of STR1, only the remaining characters are deleted from STR1, without generating an error.

STR_DELETE_example04

In the example above, five characters are deleted from position 3 of STR1, and the remaining characters are sent to DST_6. When the block is ended successfully, the DONE output is activated. Note that if POS + LEN is greater than the size of STR1, only the remaining characters are deleted from STR1, without generating an error.

STR_DELETE_example05

In the example above, one character is deleted from position 1 of STR1, and the remaining characters are sent to DST_2. Since the size of DST_2 is 2, the last character copied is discarded. The block ends successfully, Done output is activated.

Example in ST

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

VAR

STR1 : STRING := 'ABCD';

POS : BYTE := 1;

LEN : BYTE := 1;

DST_2 : STRING;

END_VAR

DST_2 := FB_STR_DELETE(

EN:=DI1,

STR:=STR1,

POS:=POS,

LEN:=LEN,

Done=>DO1);