Clock Pulse Generator - Siemens Simatic S5-101U Programming Instructions Manual

Clock pulse generator
A clock pulse generator can be con-
s t r u c t e d from a s e l f - c l o c k i n g t i m e r
F 2
0
U
w i t h a T f l i p - f l o p ( b i n a r y s c a l e r )
a t i t s output.
Timer T 7 i s r e s t a r t e d w i t h f l a g
F 2.0 each t i m e i t s t i m e elapses,
i.e.
f l a g F
2.0
has a "1" s i g n a l
f o r one c y c l e each t i m e t h e t i m e
e l apses
.
These pulses from f l a g F
2.g
a c t on
t h e f o l l o w i n g T f l i p - f l o p w i t h t h e
r e s u l t t h a t a p u l s e t r a i n w i t h a
mark-space r a t i o o f 1 : 1
appears
a t output Q 6.6.
The p e r i o d dura-
t i o n of t h i s pulse t r a i n i s t w i c e
as great as t h e t i m e o f t h e s e l f -
c l o c k i n g timer.