MEMSET block

Short summary

Name

MEMSET

→POU type

→function

Category

IEC-block, MemoryEnh, block with internal error diagnostic

Conform to →IEC-standard

(plus) not defined in IEC-standard

Graphical interface

Available since

  • version 1.35.0 (for Neuron Power Engineer) – initial variant

  • version 2.0.9 (for library Standard) – graphical interface with in-out variable

  • version 3.5.0 (for library Standard) – restriction "no function blocks with generic data type"

Functionality

The block initializes bytes of the input value with a specified value.

You enter the input value at input IN and the value for the initialization at input VAL. At input LEN, enter the numer of bytes to be initialized in the input value.
By default, value 0 is specified for the initialization and for the number of bytes.

Special cases: 

  • In case of LEN = 0, the block automatically calculates the number of bytes to initialize in the input value.

  • If the value for LEN is > than the maximally possible size of the input value IN, the block initializes until the maximally possible size of the input value. In this case, the output ENO is set to value FALSE.

  • If a STRING element with a length is connected to IN, the length of the STRING buffer is used. The length of the STRING buffer is determined by the declaration.
    STRING elements with a length are STRING variables declared by you; see "Declaration of STRING variables (incl. access)".  

  • If a STRING element without a length is connected to IN, the length of the STRING buffer is also used. However, the length of the STRING buffer is determined by the resulting value.
    STRING elements without a user-defined length are resulting, if you are using STRING functions or →character string literals.

Inputs, outputs

 

Identifier

→Data type

Description

In-outs (VAR_IN_OUT):

IN

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 , a →user-defined data type or a →function block
Restriction: In case of →array data types, only one-dimensional arrays are allowed.

Further restriction: In the case of function blocks, no function blocks with a →generic data type are allowed. As a result of this restriction, you cannot use the following blocks as input of the current block: LIMITER_O, LIMITER_U, FORCEMRK, MAX_HOLD, MIN_HOLD, and →vendor-function blocks that have been declared with a generic data type.
If you use instances of these function blocks anyway, a linker error will occur when building the application.

input value

Inputs:

VAL

USINT

value for initialization; default value = 0
 

LEN

UDINT

the number of bytes to set to VAL; default value = 0

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:

Internal error diagnostic for block 

The block checks the value connected to the inputs before it is executed.
If the value for LEN is > than the maximally possible size of the input value IN, the output ENO of the block is set to value value FALSE (or an equivalent).

Example for usage within ST-editor

PROGRAM Test
    VAR
        Var1, Var2 : BYTE := 0;
        Var3, Var4 : DINT := 0;      
    END_VAR
    MEMSET(IN := Var1, VAL := 16#0A, LEN := 1);     (* The variable 'Var1' evaluates to '10'. *)
    MEMSET(IN := Var2, VAL := 16#0C, LEN := 1);     (* The variable 'Var2' evaluates to '12'. *)
    MEMSET(IN := Var3, VAL := 16#0C, LEN := 1);     (* The variable 'Var3' evaluates to '12'. *)
    MEMSET(IN := Var4, VAL := 16#0A, LEN := 3);     (* The variable 'Var4' evaluates to '657930'. *)
END_PROGRAM

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.