Shift And Rotate; Shift Instructions - Siemens SIMATIC S7 System Manual

Table 7- 139 ENO status for the MUX and DEMUX instructions
ENO Condition
1 No error
0 MUX: K is greater than the number of inputs -1
DEMUX: K is greater than the number of outputs -1
7.10

Shift and Rotate

7.10.1

Shift instructions

Table 7- 140 SHR and SHL instructions
LAD / FBD SCL
out := SHR(
in:=_variant_in_,
n:=_uint_in);
out := SHL(
in:=_variant_in_,
n:=_uint_in);
For LAD and FBD: Click the "???" and select the data types from the drop-down menu.
1
Table 7- 141 Data types for the parameters
Parameter Data type
IN Byte, Word, DWord
N UInt
OUT Byte, Word, DWord
● For N=0, no shift occurs. The IN value is assigned to OUT.
● Zeros are shifted into the bit positions emptied by the shift operation.
● If the number of positions to shift (N) exceeds the number of bits in the target value (8 for
● ENO is always TRUE for the shift operations.
S7-1200 Programmable controller
System Manual, 11/2011, A5E02486680-05
Byte, 16 for Word, 32 for DWord), then all original bit values will be shifted out and
replaced with zeros (zero is assigned to OUT).
Result OUT
MUX: Selected IN value is copied to OUT
DEMUX: IN value is copied to selected OUT
No ELSE provided: OUT is unchanged,

ELSE provided, ELSE value assigned to OUT

No ELSE provided: outputs are unchanged,

ELSE provided, IN value copied to ELSE

Description
Use the shift instructions (SHL and SHR) to shift the bit pattern of
parameter IN. The result is assigned to parameter OUT.
Parameter N specifies the number of bit positions shifted:
SHR: Shift bit pattern right

SHL: Shift bit pattern left

Description
Bit pattern to shift
Number of bit positions to shift
Bit pattern after shift operation
100BBasic instructions
7.10 Shift and Rotate
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