Start (Active High)
Reset (Active High)
Counter
Current Value
Figure 9-11
Clock
Internal
Direction
Control
(1 = Up)
Counter
Current
Value
Figure 9-12
S7-200 Programmable Controller System Manual
A5E00066097-02
Counter
Disabled
1
0
1
0
+2,147,483,647
Current
value
0
frozen
-2,147,483,648
Counter value is somewhere in this range.
Operation Example with Reset and Start
Current value loaded to 0, preset loaded to 4, counting direction set to Up.
Counter enable bit set to enabled.
1
0
1
0
3
2
1
0
Operation Example of Modes 0, 1, or 2
Reset interrupt
Reset interrupt
generated
generated
Counter
Counter
Counter
Enabled
Disabled
Enabled
Current
value
frozen
PV=CV interrupt generated
Direction changed within interrupt routine
4
3
2
1
0
SIMATIC Instructions
-1
9-29