Siemens Simatic S7-200 System Manual page 208

Instruction Set
Counter Example
I4.0
I3.0
I2.0
Figure 10-7
10-20
LAD
C48
CU CTUD
CD
R
4 PV
Timing Diagram
I4.0
Up
I3.0
Down
I2.0
Reset
3
2
C48
1
(current)
0
C48
(bit)
Example of Counter Instruction for LAD and STL
STL
LD I4.0 //Count Up Clock
LD I3.0 //Count Down Clock
LD I2.0 //Reset
CTUD C48, 4
5 5
4 4 4
3
S7-200 Programmable Controller System Manual
C79000-G7076-C230-02
0