Siemens SIMATIC S5 Manual page 285

Reaction times in the ET 200 distributed I/O system
Calculating the
typical reaction
time t
R
Calculating the
worst-case
reaction time t
R
C-18
The reaction time t for a typical situation is calculated below. The values
R
used are those calculated in the worked example in the preceding section.
Table C-13 Calculating the typical reaction time
Reaction time
Medium
t
I/O
DP slave (input) DP l (i t)
t
I/Obus
t t
slave slave
t
IM 318
t
DP
DP master and
t
cons
SINEC L2-DP SINEC L2-DP
t
prog
bus
t
DP
t
IM 318
DP slave DP l
t
I/Obus
(output) t (output) t
slave slave
t
I/O
The worst-case reaction time t
Table C-14 Calculating the worst-case reaction time t
Reaction time
Medium
t
I/O
DP l DP slave
t
I/Obus
(input) t (input) t
slave slave
t
IM 318
t
DP
DP master and
t
cons
SINEC L2 DP SINEC L2 DP
t
bus prog
t
DP
t
IM 318
DP slave DP l
t
I/Obus
(output) t (output) t
slave slave
t
I/O
Time (ms) Factor
(typical)
0.0
0.0
0.0
3.67
0.0
100.0
3.67
0.03
0.33
5.0
t
R
is calculated below:
R
R
Time (ms) Factor (typical)
0.0
0.0
0.0 (1+t
I/Obus
3.67
0.0
100.0
3.67
0.03 (1+t
I/Obus
0.33
5.0
ET 200 Distributed I/O System
Final value
(ms)
1 0.0
1 0.0
1 0.0
0.5 1.835
2 0.0
1.5 150.0
0.5 1.835
1 0.03
1 0.33
1 5.0
= 159.03
Final value
(ms)
1 0.0
1 0.0
/t ) 0.0
DP
1 3.67
2 0.0
2 200.0
1 3.67
/t ) 0.03
DP
2 0.66
1 5.0
t = 213.03
R
EWA 4NEB 780 6000-02a