Technical specifications
6.4 Technical specifications
Extension Units KPxx
Operating Instructions, 05/2019, A5E43600360-AC
89
6.4.3
Reaction times and safety characteristics for fail-safe operation
The table below shows the safety characteristics and reaction times from the emergency
stop button of the Extension Unit to the X1 PROFINET interface of the communication
module.
Configured operating mode
In accordance with IEC 61508
1oo1
1oo2
Safety Integrity Level
SIL2
SIL3
Mode of operation
high and low demand mode high and low demand mode
Meantime to Restoration (MTTR)
100 h
100 h
Probability of a dangerous failure per
hour (PFH)
< 6 × 10
-10
1/h
< 3 × 10
-10
1/h
Probability of a dangerous failure on
demand (PFD)
< 8 × 10
-5
< 8 × 10
-5
Diagnostic test interval
15 ms
15 ms
Proof Test Interval
1 x per year
1 x per month
Lifetime
20y
20y
In accordance with IEC 13849-1
Meantime to Failure (MTTFd)
high
high
Meantime to Restoration (MTTR)
100 h
100 h
Diagnostic Coverage (DCavg)
high
high
Performance level
d
e
Category
3
4
All values are based on the SN 29500:2005 and an ambient temperature of 60 °C.
Note
Times
The specified times do not include the times of the applicable safety relay or the safety
program (PROFIsafe), including the PNIO cycle time and F-monitoring time.
Use the following table for calculation of the total reaction time: S7Safety_RTTplus.xlsm
https://support.industry.siemens.com/cs/#document/93839056?lc=en-US