Siemens S7-400 Service Manual download pdf (Page 139)

Shift and Rotate Instructions

Ladder Logic (LAD) for S7-300 and S7-400 Programming

A5E00706949-01

11-5

11.1.4 SHL_W Shift Left Word

Symbol

SHL_W

OUT

ENO

Parameter Data Type Memory Area Description

EN BOOL I, Q, M, L, D Enable input

ENO BOOL I, Q, M, L, D Enable output

IN WORD I, Q, M, L, D Value to shift

N WORD I, Q, M, L, D Number of bit positions to shift

OUT WORD I, Q, M, L, D Result of shift instruction

Description

SHL_W (Shift Left Word) is activated by a logic "1" at the Enable (EN) Input. The

SHL_W instruction is used to shift bits 0 to 15 of input IN bit by bit to the left. Bits

16 to 31 are not affected. The input N specifies the number of bits by which to shift.

If N is larger than 16, the command writes a "0" at output OUT and sets the bits

CC 0 and OV in the status word to "0". N zeros are also shifted in from the right to

fill vacated bit positions. The result of the shift instruction can be scanned at output

OUT. The CC 0 bit and the OV bit are set to "0" by SHL_W if N is not equal to 0.

ENO has the same signal state as EN.

lacesN

OUT

The vacated places

are filled with zeros.

These six bits

are lost.

0000

15... ...8 7... ...0

1111 0101 0101

0101000011 0100 00001101

Status word

BR CC 1 CC 0 OV OS OR STA RLO /FC

writes: x x x x - x x x 1

1 2 ... 134 135 136 137 138 139 140 141 142 143 144 ... 227 228

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Siemens S7-400 Service Manual Page 139