Battery Monitoring; Retentive/Non-Retentive Flags; Interrupt Processing - Siemens Simatic S5-101U Programming Instructions Manual

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3.2
Battery monitoring
Flag F 63.6 i s used f o r m o n i t o r i n g t h e
The P C must be i n t h e "RUN" s t a t e .
battery.
Flag F 63.6 i s r e s e t by t h e "ERASE PRO-
This f l a g i s s e t by t h e operating system
GRAM" f u n c t i o n o f t h e programner o r by
o f the P C on power recovery and d u r i n g
the user program. The user can t h e r e f o r e
t h e normal scanning c y c l e i f f a i l u r e
determine how t h e P C i s t o r e a c t t o
o f the b a t t e r y backup v01 tage i s detected.
backup b a t t e r y f a i l ure.
The S5-101W has a t o t a l o f 512 f l a g s .
The f l a g area i s subdivided as f o l l o w s :
Retentive f l a g s (F 0.0
...
F 31.7)
-
r e t a i n t h e i r l a s t s t a t e p r i o r t o
-
power-down on power-up ( w i t h backup
b a t t e r y o n l y )
-
r e t a i n t h e i r l a s t s t a t e when t h e
mode i s changed from "STOP" t o "RUN"
( w i t h and w i t h o u t backup b a t t e r y )
-
are r e s e t l i k e t h e n o n - r e t e n t i v e
f l a g s on power-up ( w i t h o u t backup
b a t t e r y )
-
can also be r e s e t b y t h e user p r o -
gram (
"
ERASE PROGRAM" f u n c t i o n ).
By using r e t e n t i v e f l a g s , t h e l a s t
s t a t u s o f the p l a n t o r machine p r i o r
t o t h e P C l e a v i n g t h e "RUN" mode can
be stored. O n r e s t a r t , t h e p l a n t o r
machine can resume operations a t t h e
p o i n t a t which i t was stopped.
Interrupt processing
When an i n t e r r u p t s i g n a l (e.g.
emer-
gency o f f ) from t h e process i s r e -
ceived by the PC, t h e l a t t e r i n t e r -
r u p t s c y c l i c scanning o f t h e user program
and i n i t i t a t e s t h e processing o f a
s p e c i f i c i n t e r r u p t r o u t i n e .
I n t e r r u p t processing w i t h t h e S5-101U
i s defined e x c l u s i v e l y by t h e user pro-
gram so t h a t each i n p u t and o u t p u t can
be used f o r i n t e r r u p t processing.
Non-retentive f l a g s ( F 32.0.. .F 63.7)
-
are r e s e t when t h e P C mode changes
from "STOP" t o "RUN" and on power-up.
Flags F 61.0
-
F 62.7 are reserved
as c o o r d i n a t i n g f l ags f o r operation
i n t h e SINEC L 1 l o c a l area network;
f l a g s F 63.0
-
F 63.7 are reserved
as system f l a g s . Since they are a f -
fected by t h e P C o p e r a t i n g system,
they must n o t be used as f l a g s i n
t h e normal sense.
I n order t o achieve minimum response
times, t h e i n p u t s and outputs are r e -
ferenced d i r e c t , i.e.
o u t s i d e c y c l i c
program scanning. The l o a d / t r a n s f e r
operations "LPB" ( i n p u t s ) and "TPB"
( o u t p u t s ) are a v a i l a b l e f o r t h i s pur-
pose.
A more o r l e s s constant response time
i s achieved i f t h e scanning o f t h e i n -
p u t s programmed by t h e user as i n t e r r u p t
i n p u t s i s u n i f o r m l y d i s t r i b u t e d over
t h e e n t i r e user program. Fig. 6 shows
a user program w i t h i n t e r r u p t processing.

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