Short summary

Name	`ARRAY_LENGTH` , `ARRAY_LENGTH_2D` , `ARRAY_LENGTH_3D` , `ARRAY_LENGTH_4D`
→POU type	→function
Category	IEC-block, MemoryEnh
Conform to →IEC-standard	not defined in IEC-standard
Graphical interface	, , ,
Available since	Version 3.2.5 (for library `Standard`) – initial variant

Functionality

The block returns the size (the number of the elements) of the connected →array variable.

No check of invalid dimensions

When these blocks are used, logi.CAD 3 does not check whether the connected array variable is of the correct dimension. For instance, when you connect a two-dimensional a rray variable with the input of ARRAY_LENGTH (here a one-dimensional a rray is required), it will not be possible to successfully build the application and load it onto the PLC.
Therefore, use other means (e.g. specify a unique name of the variable) so that you can easily detect that the connected array variable and the user block are matching regarding the dimension.

Inputs, outputs, return value

`ARRAY_LENGTH`	Identifier	→Data type	Description
In-outs (VAR_IN_OUT):	`IN`	`ARRAY [*] OF` `REAL`, `LREAL`, `USINT`, `UINT`, `UDINT`, `ULINT`, `SINT`, `INT`, `DINT`, `LINT`, `TIME`, `BOOL`, `BYTE`, `WORD`, `DWORD`, `LWORD`, `STRING`, `CHAR`, `DATE_AND_TIME`, `DATE`, `TIME_OF_DAY` or a →user-defined data type	a one-dimensional a rray of variable length
Return value:	–	`UDINT`	number of the elements of the array

`ARRAY_LENGTH_2D`	Identifier	→Data type	Description
In-outs (VAR_IN_OUT):	`IN`	`ARRAY [,] OF` `REAL`, `LREAL`, `USINT`, `UINT`, `UDINT`, `ULINT`, `SINT`, `INT`, `DINT`, `LINT`, `TIME`, `BOOL`, `BYTE`, `WORD`, `DWORD`, `LWORD`, `STRING`, `CHAR`, `DATE_AND_TIME`, `DATE`, `TIME_OF_DAY` or a →user-defined data type	a two-dimensional a rray of variable length
Outputs:	`DIM1`	`UDINT`	number of the elements in dimension 1
Outputs:	`DIM2`	`UDINT`	number of the elements in dimension 2
Return value:	–	`UDINT`	number of all elements of the array

`ARRAY_LENGTH_3D`	Identifier	→Data type	Description
In-outs (VAR_IN_OUT):	`IN`	`ARRAY [,,*] OF` `REAL`, `LREAL`, `USINT`, `UINT`, `UDINT`, `ULINT`, `SINT`, `INT`, `DINT`, `LINT`, `TIME`, `BOOL`, `BYTE`, `WORD`, `DWORD`, `LWORD`, `STRING`, `CHAR`, `DATE_AND_TIME`, `DATE`, `TIME_OF_DAY` or a →user-defined data type	a three-dimensional a rray of variable length
Outputs:	`DIM1`	`UDINT`	number of the elements in dimension 1
	`DIM2`	`UDINT`	number of the elements in dimension 2
	`DIM3`	`UDINT`	number of the elements in dimension 3
Return value:	–	`UDINT`	number of all elements of the array

`ARRAY_LENGTH_4D`	Identifier	→Data type	Description
In-outs (VAR_IN_OUT):	`IN`	`ARRAY [,,,] OF` `REAL`, `LREAL`, `USINT`, `UINT`, `UDINT`, `ULINT`, `SINT`, `INT`, `DINT`, `LINT`, `TIME`, `BOOL`, `BYTE`, `WORD`, `DWORD`, `LWORD`, `STRING`, `CHAR`, `DATE_AND_TIME`, `DATE`, `TIME_OF_DAY` or a →user-defined data type	a four-dimensional a rray of variable length
Outputs:	`DIM1`	`UDINT`	number of the elements in dimension 1
	`DIM2`	`UDINT`	number of the elements in dimension 2
	`DIM3`	`UDINT`	number of the elements in dimension 3
	`DIM4`	`UDINT`	number of the elements in dimension 4
Return value:	–	`UDINT`	number of all elements of the array

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

The calculated values are evaluated by using the Assert block .

FUNCTION_BLOCK ExampleArrayLength
  VAR
    arrayVar1D : ARRAY [1..5] OF INT;
    arrayVar2D : ARRAY [2..5, 3..5] OF INT;
    arrayVar3D : ARRAY [1..6, 1..7, 1..8] OF INT;
    Dim1Var2, Dim2Var2, Dim1Var3, Dim2Var3, Dim3Var3 : UDINT;
    result1D, result2D, result3D : UDINT;
    eno1, eno2, eno3 : BOOL;
  END_VAR
  
  result1D := ARRAY_LENGTH(in:=arrayVar1D, ENO=>eno1);
  ASSERT(result1D=5);
  ASSERT(eno1);
  
  result2D := ARRAY_LENGTH_2D(in:=arrayVar2D, DIM1=>Dim1Var2, DIM2=>Dim2Var2, ENO=>eno2);
  ASSERT(result2D=12);
  ASSERT(Dim1Var2 = 4);
  ASSERT(Dim2Var2 = 3);
  ASSERT(eno2);
  
  result3D := ARRAY_LENGTH_3D(in:=arrayVar3D, DIM1=>Dim1Var3, DIM2=>Dim2Var3, DIM3=>Dim3Var3, ENO=>eno3);
  ASSERT(result3D=336);
  ASSERT(Dim1Var3 = 6);
  ASSERT(Dim2Var3 = 7);
  ASSERT(Dim3Var3 = 8);
  ASSERT(eno3);
 
  (* The usage of the ARRAY_LENGTH_4D block is similar to the other blocks. *)
  
END_FUNCTION_BLOCK

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.