Siemens SIMATIC S7-200 - Example of CTUD Counter Instruction for Simatic LAD, FBD, and STL

SIMATIC Instructions
9-26
S7-200 Programmable Controller System Manual
A5E00066097-02
I4.0
Up
LD I4.0 //Count Up Input
LD I3.0 //Count Down Input
LD I2.0 //Reset Input
CTUD C48, 4
Timing Diagram
LAD
STL
I3.0
Down
I4.0
C48
I3.0
4
I2.0
CTUD
CU
R
CD
PV
I2.0
Reset
0
1
2
3
4
5
4
3
4
5
0
C48
(current)
C48
(bit)
C48
CTUD
CU
R
CD
PV+4
I4.0
I3.0
I2.0
FBD
Figure 9-9 Example of CTUD Counter Instruction for SIMATIC LAD, FBD, and STL