Siemens Simatic S7-200 System Manual page 234

Instruction Set
Network 18
3
INT
Network 19
SMW68
==
500
Network 20
SMW68
==
1000
Network 21
1 cycle
500 ms
Q0.0
4 cycles or 4 pulses
Figure 10-18 Example of a Pulse Train Output (continued)
10-46
LAD
PTO 0 interrupt routine
MOV_W
If current cycle time
is 500 ms, then set
EN
cycle time of 1000 ms
1000 IN OUT SMW68
and output 4 pulses.
PLS
EN
0 Q0.x
RETI
MOV_W
If current cycle time
is 1000 ms, then set
EN
cycle time of 500 ms
500 IN OUT SMW68 and output 4 pulses.
PLS
EN
0 Q0.x
RETI
Timing Diagram
1 cycle
1000 ms
4 cycles or 4 pulses
Interrupt 3
occurs
Network 18
INT 3
Network 19
LDW= SMW68, 500
MOVW 1000, SMW68
PLS 0
CRETI
Network 20
LDW= SMW68, 1000
MOVW 500, SMW68
PLS 0
Network 21
RETI
Interrupt 3
occurs
S7-200 Programmable Controller System Manual
C79000-G7076-C230-02
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