ARRAY_LENGTH block

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, Neuron Power Engineer does not check whether the connected array variable is of the correct dimension. For instance, when you connect a two-dimensional array variable with the input of ARRAY_LENGTH (here a one-dimensional array 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 array 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 array 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 array 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 array 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.