Siemens Simatic S7-200 System Manual page 236

Instruction Set
Network 60
Network 61
SM0.0
VW100
SMW80
Network 62
Enable interrupt
I0.1
I0.0
Q0.1
10% duty cycle
Figure 10-19
10-48
LAD
(Program continued from previous page.)
1
Begin interrupt routine when
INT
I0.0 makes the transition from
off to on.
Increase the pulse width by
ADD_I
the value in VW100.
EN
IN1
IN2 OUT SMW80
Change pulse width.
PLS
EN
1 Q0.x
Disable rising edge interrupt.
DTCH
EN
0 EVENT
RETI
Timing Diagram
VW100 = 4000
50% duty cycle
Interrupt 1 occurs
(cycle time = 10,000 ms)
Example of High-Speed Output Using Pulse Width Modulation (continued)
Network 60
INT 1
Network 61
LD SM0.0
+I VW100, SMW80
PLS 1
DTCH 0
Network 62
RETI
VW100 = -2000
Enable interrupt
50% duty cycle 30% duty cycle
Interrupt 1 occurs
S7-200 Programmable Controller System Manual
C79000-G7076-C230-02
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