Siemens SIMATIC S5 Manual page 269

Reaction times in the ET 200 distributed I/O system
C.1 Reaction times with IM 308-C as DP master
Reaction times in
ET 200
Importance
C-2
Fig. C-1 shows the reaction times of the ET 200 distributed I/O system. The
aggregate reaction time is the mean reaction time which elapses between the
switching of an input and the associated switching of an output:
t
prog
t
slave
Figure C-1 Reaction times in the ET 200 distributed I/O system
Table C-1 shows the relative importance of the reaction times introduced in
the above illustration. The individual reaction times are described in detail
below.
Table C-1 Importance of reaction times in the ET 200 distributed I/O system
Ser. Reaction time
No.
1 ... of application
program in the CPU
2 ... between IM 308-C
and CPU
3 ... on the
SINEC L2-DP bus
4 ... within the slave
t
cons
t
DP
Abbreviation
t Important for access to process
prog
image, otherwise negligible
t Depends on length of application
cons
program
t Important if bus configuration is
DP
large, baud rate is low and/or
data telegrams are extensive
t ET 200U, S5-95U: very
slave
important
ET 200B, ET 200C: less
important
t
slave
t
DP
Importance
ET 200 Distributed I/O System
EWA 4NEB 780 6000-02a