Siemens Simovert Masterdrives Compendium page 77

12.2010
Parameter
DC(channel1)
DC(channel2)
DC
avg
Measures against
common cause
failure (CCF) of the
safety function
Siemens AG 6SE7087-6QX70 (Version AM)
SIMOVERT MASTERDRIVES
♦ Determination of diagnostic coverage
Value
99 %
90 %
94.5 % → average
♦ Determination of Performance Level
•
Structure of SRP/CS according to Category 3
•
MTTF is high
d
•
DC is average
avg
•
Sufficient measures against common cause failure
According to EN ISO 13849-1:2008 Appendix K, PL e is achieved
with PFHd = 4.29 x 10
In accordance with ISO 13849-1, a minimum of 65 points are required
for SRP/CS from category 2.
The observations stated in subsection 2.4.5.2 "Measures against
common cause failure (CCF) of the safety function" apply.
A sufficient total of 65 points is thus achieved.
Compendium Motion Control
Configuration and Connection Examples
Comment
Testing of –K1 via –K3 in feedback circuit of –A2
every time the protective door is closed
Testing of –K2 and –K3 in feedback circuit of –A1 on
request for Emergency Stop
Faults might accumulate undiscovered between the
requests.
Testing of –K4 in feedback circuit of –A2 every time
the protective door is closed
DC
1
MTTF ( channel
d
=
DC
avg
1
MTTF ( channel
d
-8
/ h.
DC
2
+
) 1 MTTF ( channel ) 2
d
1
+
) 1 MTTF ( channel ) 2
d
2-49