9
05.01
9.4 Application examples
9-367
©
Siemens AG 2012 All Rights Reserved
SIMODRIVE 611 Configuration Manual (PJU) – 02/2012 Edition
Table 9-14
Determining the diagnostic coverage level (DC)
Parameter
Value
Comment
DC (channel 1)
99 %
Testing –K1 via –K3 in the feedback circuit of –A2, as
well as –K6 at –A3 each time the protective door is clo-
sed.
DC (channe 2)
90 %
Testing –K2 and –K3 in the feedback circuit of –A1
when EMERGENCY STOP is requested.
Undetected accumulation of faults is possible between
the requests.
Testing –K4 in the feedback circuit of –A2 each time the
protective door is closed.
DC
avg
94,50 %
→
avergage
MTTF
d
(channel 1)
1
MTTF
d
(channel 2)
1
+
DCavg =
MTTF
d
(channel 1)
DC
1
MTTF
d
(channel 2)
DC
2
+
S
Structure of the SRP/CS corresponding to Category 3
S
MTTF
d
is high
S
DC
avg
is average
S
sufficient measures against common cause failures
Acc. to EN ISO 13849–1:2008 Annex K PLe mit PFH
d
= 4,29 x 10
-8
/ h is
attained.
Measures against common cause failures CCF of the
safety function
According to EN ISO 13849–1 Annex F, for SRP/CS from Category 2, a mini-
mum of 65 points is required.
The considerations according to Chapter 9.4.1 Table 9-9.
This means that in total, the adequate number of 65 points is reached.
Checking the PFH value of the complete safety func-
tion
Table 9-15
PFH value of the complete safety function
Parameter
PFH value
PL
Comment
SENSE
2,47 x 10
-8
/ h
e
Position switches –S4 and –S5
EVALUATE
2 x 5,4 x 10
-11
/ h
e
Safety relays –A2 and –A3
RESPOND
4,29 x 10
-8
/ h
e
Switching elements –K1, –K2, –K3,
–K4, –K5 and –K6
Total
8,59 x 10
-8
/ h
e
<1 x 10
-6
/ h
As a consequence, the requirements regarding PLd with Category 3 for the pro-
tective door safety function are fulfilled.
Determining DC
Determining the
Performance Level
9 Cabinet Design and EMC
02.12
