Response times
ET 200S Distributed I/O System - Fail-Safe Modules
Installation and Operating Manual, 08/2008, A5E00103686-07
203
Note
Please note that the Excel files for calculating the maximum response times (
s7fcotia.xls and
s7ftimea.xls) included with the S7 Distributed Safety and S7 F/FH Systems option packages
already support calculation of the extension of the "Maximum response time in the event of a
fault" by the programmed discrepancy time.
Maximum response time of the EM 4 F-DI/3 F-DO DC24V PROFIsafe
Formula for calculating the maximum response time if there is no fault:
maximum response time
without a fault = T
max
+ input delay + short-circuit test time*
*: Short-circuit test time = 2 x input delay
Parameters for the input delay and the short-circuit test are assigned in
STEP 7.
Table D- 7
EM 4 F-DI/3 F-DO DC24V PROFIsafe: Internal Processing Times
Evaluation of the Sensors
minimum internal processing
time T
min
maximum internal
processing time T
max
1oo2
4 ms
9 ms
Maximum response time if a fault occurs:
The table below contains the maximum response times of the F-DI/F-DO module when a
fault occurs, depending on the parameter settings in
STEP 7 and on the sensor evaluation.
Table D- 8
EM 4 F-DI/3 F-DO DC24V PROFIsafe: Maximum Response Time if a Fault Occurs
1oo2 evaluation*
Input Delay
3 ms
Short-circuit test deactivated
14 ms
Short-circuit test activated
22 ms
*: The response times with 1oo2 evaluation also depend on the configured discrepancy behavior:
Provide 0 value: The times defined in the table above apply.
Provide last valid value: The times in the table above are extended by the programmed discrepancy
time.
Note
Please note that the Excel files for calculating the maximum response times (
s7fcotia.xls and
s7ftimea.xls) included with the S7 Distributed Safety and S7 F/FH Systems option packages
already support calculation of the extension of the "Maximum response time in the event of a
fault" by the programmed discrepancy time.
