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4.4. Evaluations
4.4.1. Use as a starting alarm of machines
For use as a starting alarm of machines, the function of the generation of the optical warning signal channel
is to be assessed as a function of the machine. The safe condition is reached when the optical warning sys-
tem works reliably. The diagnosis channel monitors this function and, upon failure, leads in the safe condition
via a safety loop. This architecture is illustrated schematically in Fig. 7 .
Starting alarms and similar uses are architectures that can normally be attributed to the 'high demand mode'.
Immediately before switching on the machine or entering the dangerous condition, an automatic function test
must be carried out by a superior control system, such as described in section 4.8. Only after a successful
test can there be an approval. This automatic test ensures that the function of the monitoring channel is, in
the figurative sense, clearly tested more than it is required (T
control system and corresponding measures for fault messages must be in accordance with the functional
safety according to IEC/EN61508
The safety loop is made up of diagnosis channel with recording, evaluation of the dangerous condition and
elements of the machine control for the reaching of the safe condition. The latter was not taken into account
in the analysis.
Warning signal
Action
(Mensch)
Fig. 7 Starting alarm
Fig. 8 Safety relevant block diagramm
PFH
SFF
DC
MTTFd
λ
Diagnosis switch
DU
λ
Diagnosis switch
DD
λ
Diagnosis switch
S
HFT
Category (DIN EN ISO13849)
Architecture type
Suitability of the system for use in safety chains until
PL (DIN EN ISO13849)
*
The lifetime of the flashtube is to be observed as specified in the technical data. The number of executed flashes is pivotal for the
lifetime. This is to be taken into account in the respective use.
085501930i_de-en-fr.docx
File name:
Requirement
Control
Flashing light
Diagnosis
channel
Diagnosis
Safety parameters for starting alarms
21 / 44
<<T
). Test functions in the superior
Test
required
24V DC
230V AC
-10
4,27 x 10
4,99 x 10
99,7
99
>100
0,5
42,5
82
0
2
B
SIL 2
d
Safety
relais
Maschine start
Start
-10
(1/h)
99,6
%
99
%
>100
years
0,5
Fit
49,4
Fit
85,3
Fit
0
2
B
SIL 2
d
Drwg-no.: 30084-004-5i
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