Equipments (Devices) > SCA06 > Ladder > Data Transfer

Block that copies an array from a certain position to another array or to itself.

Ladder Representation

ARRAY_COPY_block

Block Structure

Variable Type	Name	Data type	Description
VAR_INPUT	EN	BOOL	Block enabling
	VAR_SRC	Array: BYTE USINT SINT WORD UINT INT DWORD UDINT DINT REAL LREAL	Input Array
	POS_SRC	BYTE USINT WORD UINT	Position of the input array from which the copy will be made
	POS_DST	BYTE USINT WORD UINT	Position of the output array from which it will be replaced
	LEN	BYTE USINT WORD UINT	Number of array positions to be copied
VAR_OUTPUT	ENO	BOOL	End of operation
VAR_OUTPUT	Result	Array: BYTE USINT SINT WORD UINT INT DWORD UDINT DINT REAL LREAL	Output Array

Operation

This block, when it has a value of TRUE in EN, copies LEN values from the POS_SRC position from the input array (VAR_SRC) to the position POS_DST into the destination array (Result).

Comments:

- POS_SRC, POS_DST and LEN input variables only accept positive integers. If a negative value is assigned to any of them, the value zero will be considered.

- The Input Array can be repeated on the output without worrying about data being overwritten.

- If the amount of data to be copied defined by LEN exceeds the last position of the input array, only valid data will be copied to the last position of the input array, thus avoiding any garbage being assigned to the output array.

- If the amount of data to be copied defined by LEN exceeds the last position of the output array, only the data required to complete it will be copied, preventing subsequent memory from receiving unwanted values.

- The block will not execute if LEN has a value greater than the size of the input array.

When EN has FALSE value, Result remains unchanged.

The ENO value forwards to the next Ladder block the EN value after the operation is completed.

NOTE!

•	It is important to notice that not only LEN but also POS_SRC will not exceed the VAR_SRC array's size. The same must be noticed when setting values to POS_DST, related to the output array Result.

•	To learn how to create arrays please go to: Ladder > Editor > Variables > Editing in the Rung

Block Flowchart

Example in Ladder

ARRAY_COPY_example01

ARRAY_COPY_example02

ARRAY_COPY_example03

ARRAY_COPY_example04

In the examples above the value of the variable SRC is copied to DST array, according to source position (POS_SRC), destination (POS_DST) and the lenght to be copied (LEN). The block ends with success and ENO output is activated.

Example in ST

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

VAR

SRC : ARRAY[0..5] OF INT := [1, 2, 3, 4, 5, 6];

DST : ARRAY[0..5] OF INT;

END_VAR

DST := FB_ARRAYCOPY(SRC, 0, 2, 6);