Siemens SIMATIC S5 Manual page 123

S5-115F Manual
Setting a counter "S" and counting down "CD"
Example:
When input I 4.1 is switched on (set), counter 1 is set to the count 7. Output Q 2.5 is now "1".
Every time input I 4.0 is switched on (count down), the count is decremented by 1.
The output is set to "0" when the count is "0".
Timing Diagram
1
0
1
0
7
0
1
0
S C 1
STL
A I 4.0
CD C 1
NOP 0
*
A I 4.1
L KC 7
S C 1
NOP 0
*
NOP 0
*
NOP 0
*
A C 1
= Q 2.5
* NOP 0 is required if the program is to be represented in LAD or CSF in the PG 635, PG 670, PG 675, PG 685, PG 695 or
PG 750 programmers. NOP 0 operations are automatically assigned when programming in LAD and CSF.
EWA 4NEB 811 6149-02
I 4.0
I 4.1
C 1
Q 2.5
Time
S C 1
CSF
C 1
I 4.0
CD
CU
I 4.1
S
KC 7
CV BI
DE
Q 2.5
R Q
STEP 5 Operations
Circuit Diagram
I 4.1
KC 7
R S CI
I 4.0
I I I I
CQ
0
Q 2.5 Count
LAD
C 1
I 4.0
CD
CU
I 4.1
S
KC 7
CV BI
DE
R Q
Binary
16 bits
Q 2.5
3-27