Clock (Clock-Pulse Generator) - Siemens SIMATIC S5-90U System Manual

S5-90U/S5-95U
8.5.3

Clock (Clock-Pulse Generator)

This subsection describes how to program a clock-pulse generator.
Example: A clock-pulse generator can be implemented using a self-clocking timer that is followed
in the circuit by a binary scaler. Flag F 2.0 restarts timer T 7 each time it runs down,
i.e., flag F 2.0 is "1" for one cycle each time the timer runs down. The pulses of flag
F 2.0 applied to the binary scaler result in a pulse train with pulse duty factor 1:1 at
output Q32.5. The period of this pulse train is twice as long as the time value of the
self-clocking timer.
Timing Diagram
Signal states
1
0
1
0
T
STL
AN F 2.0
L KT 010.1
SD T 7
NOP 0
NOP 0
NOP 0
A T 7
= F 2.0
***
A F 2.0
F 2.0
AN F 3.0
F 3.0
S Q 32.5
A F 2.0
F 2.0
A F 3.0
F 3.0
R Q 32.5
NOP 0
F 2.0
***
AN F 2.0
Q 32.5
A Q 32.5
S F 3.0
F 2.0
AN F 2.0
Q32.5
AN Q 32.5
R F 3.0
NOP 0
EWA 4NEB 812 6115-02b
F 2.0
Q32.5
Time
T
CSF
T 7
T 0
F 2.0
KT 10.1 TV
BI
DE
R F 2.0
Q
Q 32.5
&
S
&
R Q
F 3.0
&
S
&
R Q
STEP 5 Operations
Circuit Diagram
G
F 2.0
F 3.0
Q32.5
LAD
F 2.0
T 7
T 0
TV BI
KT 10.1
DE
R Q
Q32.5
F 2.0 F 3.0
S
F 2.0 F 3.0
R Q
F 2.0 Q 32.5
F 3.0
S
F 2.0 Q32.5
R Q
F 2.0
( )
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