12.2010 Configuration
and Connection Examples
Siemens AG
6SE7087-6QX70 (Version AM)
SIMOVERT MASTERDRIVES
Compendium Motion Control
2-31
♦
Determination of diagnostic coverage
Parameter
Value
Comment
DC(channel1)
90 %
Testing of -K1 in feedback circuit of –A1
DC(channel2)
90 %
Testing of -K2 in feedback circuit of –A1
DC
avg
90
%
→
average
2)
(channel
DC
1)
(channel
DC
DC
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
.
2.4.5.2
Measures against common cause failure (CCF) of the safety function
In accordance with ISO 13849-1 Appendix F, a minimum of 65 points
are required for SRP/CS from Category 2.
Measure
Points
Physical separation between signal paths:
Separation of wiring in control cabinet
Adequate creepages and clearances on printed circuits.
15
Protection against overvoltage, overcurrent
15
Use of proven components.
5
Diverse technologies are applied as a result of the internal
structure of the elements for Evaluate and React
20
The requirements regarding resistance to all relevant
ambient conditions such as temperature, shock, vibration,
humidity (e.g. as specified in the applicable standards) taken
into consideration.
10
The designers have been trained to detect the reasons for
and effects of common cause failures.
5
Total 70
A sufficient total of 65 points is achieved.
