Siemens SIMATIC S5 Manual page 273

Reaction times in the ET 200 distributed I/O system
C.2.1 Reaction time t
Definition
Table C-5 Reaction time t
Reaction time
t for accessing
prog
process image
At the start of the application program cycle, the process image of the in-
puts is transferred to the PII.
At the end of the application program cycle, the process image of the out-
puts is transferred from the PIO to the outputs address area.
If you access the process image, t
program.
For calculating cycle time and reaction time, see the system manual
S5-90U/S5-95U Programmable Controller, Chapter. 6)
t for direct access
prog
(load/transfer com-
mands)
If you access the address areas directly using load/transfer commands,
reaction time t
C-6
prog
t is the reaction time of the application program in the CPU. There are
prog
two cases for t :
prog
(S5-95U)
prog
Caused by
S5-95U
Application program
PII
OB 1
PIO
Application program
PII
OB 1
L PY 59
:
:
:
T PY 64
PIO
is negligible.
prog
Input
data
Address areas:
Inputs
Outputs
Output
data
equals the duration of the application
prog
Address areas:
Input
data
Inputs
Output
data
Outputs
Importance
very important
negligible
ET 200 Distributed I/O System
EWA 4NEB 780 6000-02a