SHR block

Short summary

Name	`SHR`
→POU type	→function
Category	Standard (safe), Bitstring
Conform to →IEC-standard	currently restricted (IEC demands `ANY_INT` for the input `N` and an error handling in case of values < `0` for input `N`.) more possible than defined in IEC-standard (IEC demands `ANY_BIT` only for the input `IN` and the return value.)
Graphical interface
Available since	version 1.10.0 (for Neuron Power Engineer) – initial variant: `ANY_BIT` for input `IN` and return value version 1.23.0 (for Neuron Power Engineer) – enhancement: `ANY_INT` for input `IN` and return value version 3.8.0 (for library `Standard (safe)`): block provided in this library

Functionality

The block returns the result of a bitwise shift to the right.

At input IN, enter the value to be shifted. At input N, enter the bits to right-shift the value. The bits cleared on the left are filled with 0.

Deviation from IEC-standard

If a negative value is connected to the input N, Neuron Power Engineer does not treat this as an error but performs an opposite shift, hence a shift to the left. This behavior is a deviation from the →IEC-standard that specifies that values < 0 for the input N are an error.

Compare: "SAR block" for an arithmetic shift to the right.

Inputs, return value

	Identifier	→Data type	Description
Inputs:	`IN`	`BOOL`, `BYTE`, `WORD`, `DWORD` or `LWORD` (corresponds to →generic data type `ANY_BIT`) and `USINT`, `UINT`, `UDINT`, `ULINT`, `SINT`, `INT`, `DINT` or `LINT` (corresponds to →generic data type `ANY_INT`)	input value
Inputs:	`N`	`INT`	number of bits to shift
Return value:	–	`BOOL`, `BYTE`, `WORD`, `DWORD` or `LWORD` (corresponds to →generic data type `ANY_BIT`) and `USINT`, `UINT`, `UDINT`, `ULINT`, `SINT`, `INT`, `DINT` or `LINT` (corresponds to →generic data type `ANY_INT`)

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

PROGRAM Test

VAR

        result1, result2 : BYTE;

    END_VAR

    result1 := SHR(IN := 16#40, N := 1);       (* The variable 'result1' evaluates to '16#20'. *)

    result2 := SHR(IN := 16#80, N := 1);       (* The variable 'result2' evaluates to '16#40'. *)

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.