Use As Acoustic Warning System With Test Function - Pfannenberg DS5-SIL Instructions De Service

4.4.2.2. Use as acoustic warning system with test function

This evaluation is only applicable for systems with a low demand mode. The test function, as described in section 4.7,
is taken into account. This must be automated and must take place at least ten to one hundred times more often than
the expected requirement rate. The system with test function, including the diagnosis and respective measures in the
fault message, must be in accordance with the requirements of the function safety according to IEC/EN61508.
In the following, a requirement rate less frequent than once a year is assumed (low demand).
Automatic
Test interval
Proof test interval
PFD
mean
SFF
DC
MTTR
λ
, Sounder
D
λ
, Sounder
S
λ
Diagnosis
DU
λ
Diagnosis
S
β (CCF)
λ
complete
DU
λ
complete
S
MTTF
d
HFT
Architecture type
Suitability of the system for
use in safety chains until
Category
(DIN EN ISO13849)
PL (DIN EN ISO13849)
** In the case of a proof test interval of 15 years, >25% of the permitted PFD for SIL2 is already used. The warning system is
only part of a safety chain. This must be considered during system integration.
Datei/ file name:085501929j de-en-fr-it.docx
monthly weekly
(672h) (168h)
1 1
3,55E-04 3,09E-04
99,0 99,1
67,7 71,9
2
page 26 / 68
daily monthly
(24h) (672h)
1 15
2,95E-04 4,46E-03
99,1 99,1
73,1 73,0
48h
243
79
77
7459
10
251
7610
>100
0
B*
2
c
weekly daily
(168h) (24h)
15 15
4,40E- 1/ require-
4,41E-03
03
99,1 99,1
73,3 73,3
2**
Drwg-no.: 30007-008-12j
a
ment
%
%
h
Fit
Fit
Fit
Fit
%
Fit
Fit
a
SIL