Evaluation; Use As A Starting Alarm Of Machines - Pfannenberg DS5-SIL Instructions De Service

Proof tests and their proof can only be carried out by authorised electrical technical personnel.

4.4. Evaluation

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 acoustic warning signal channel is
to be assessed as a function of the machine. The safe condition is reached when the acoustic warning system
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. 5.
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 fig-
urative sense, clearly tested more than it is required (T
tem 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 ele-
ments of the machine control for the reaching of the safe condition. The latter was not taken into account in the
analysis.
Warning signal
Fig. 5 Starting alarm
Fig. 6 Safety relevant block diagram
PFH
G
SFF
DC
MTTFd
λDiagDU
λDiagDD
λDiagS
HFT
Architecture type IEC/EN61508
Suitability of the system for use in safety chains until
Category (DIN EN ISO13849)
PL (DIN EN ISO13849
Datei/ file name:085501958e.docx
Sounder
Action
Diagnosis
Seite / page: 25 / 52
<<T ). Test functions in the superior control sys-
Test required
Requirement
Control
Diagnosis
channel
3,9 x 10
Safety
relais
Maschine start
-9
1/h
99 %
94,9 %
>100 Years
4 Fit
73 Fit
7460 Fit
0
B
SIL 2
2
d
Zeichnungsnr./ Drwg-no.: 30007-008-13e