12.2010 Configuration and Connection Examples
Siemens AG 6SE7087-6QX70 (Version AM)
SIMOVERT MASTERDRIVES Compendium Motion Control 2-49
♦ Determination of diagnostic coverage
Parameter Value Comment
DC(channel1) 99 %
Testing of –K1 via –K3 in feedback circuit of –A2
every time the protective door is closed
DC(channel2) 90 %
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
avg
94.5 % → average
)2channel( MTTF
1
)1channel( MTTF
1
)2channel(MTTF
DC
)1channel( MTTF
DC
DC
dd
d
2
d
1
avg
+
+
=
♦ Determination of Performance Level
• Structure of SRP/CS according to Category 3
• MTTF
d
is high
• DC
avg
is average
• 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
-8
/ h.
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
comm
on cause failure (CCF) of the safety function" apply.
A sufficient total of 65 points is thus achieved.
Measures against
common cause
failure (CCF) of the
safety function