Bit-shift instructions
94
Part II IEC Instructions
SHR
Shift bits to the right
To add an enable input and enable output to the instruction, select [With EN/ENO] from the
"Instructions" pane (LD, FBD or IL editor). To reuse an instruction select "Recently used" from the
context menu or press <Ctrl>+<Shift>+<v> in the programming window.
Bit shift to the right, zero-filled on left:
15 . . 12 11 . . 8 7 . . 4 3 . . 0
DT0 1 0 1 0 0 1 1 0 1 1 0 0 1 0 1 1
15 . . 12 11 . . 8 7 . . 4 3 . . 0
DT0 0 0 0 0 1 0 1 0 0 1 1 0 1 1 0 0
Bit
Bit
Source register
Target register
(n = 4 bits)
The 4 most significant bits are filled with 0s.
PLC types
Availability of SHR (see page 1330)
Data type I/O Function
1st input input value
2nd input number of bits by which the input value is shifted to the right
ANY_BIT
output as input result
If the second input variable N (the number of bits to be shifted) is of
the data type DWORD, then only the lower 16 bits are taken into
account.
The number of steps may vary depending on the PLC and parameters
used, see also Table of Code Intensive Instructions in the online help.
Description
SHR shifts a bit value by a defined number of positions (N) to the right and fills the vacant positions
with zeros.
Data types
Example
In this example, the same POU header is used for all programming languages. For an example
using IL (instruction list), please refer to the online help.
POU header
All input and output variables used for programming this function have been declared in the POU
header.
This example uses variables. You can also use a constant for the input variable.
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