Increment And Decrement Instructions; Increment Word, Decrement Word; Increment, Decrement Example - Siemens Simatic S7-200 CPU 210 System Manual

5.6

Increment and Decrement Instructions

Increment Word, Decrement Word

L
A
INC_W
D
EN
IN
DEC_W
EN
IN
S
INCW
T
L
DECW

Increment, Decrement Example

I0.0
Figure 5-6 Example of Increment/Decrement Instructions
S7-200 Programmable Controller, CPU 210
C79000-G7076-C235-01
The Increment Word and Decrement Word instructions add or
subtract 1 to or from the input word.
Operands:
OUT
In ladder:
OUT
In STL:
Increment and decrement word operations are signed
OUT
(16#7FFF > 16#8000).
OUT
When programming in ladder, if you specify the address for IN
to be the same address as OUT, you can reduce the amount of
memory required.
These instructions affect the following Special Memory bits:
SM1.0 (zero); SM1.1 (overflow); SM1.2 (negative)
LAD
INC_W
EN
MW0 IN OUT MW0
DEC_W
EN
MW2 IN OUT MW2
Application
Increment Word
MW0 125
increment
MW0 126
IN: T, C, MW
OUT: T, C, MW
IN + 1 = OUT
IN - 1 = OUT
OUT + 1 = OUT
OUT - 1 = OUT
STL
Network
LD I0.0
INCW MW0
DECW MW2
Decrement Word
MW2 5000
decrement
MW2 4999
Instruction Set
5-9