SIGMATEK SNC 021, Руководство пользователя

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SNC 021 S-DIAS SAFETY SNC INCREMENTAL ENCODER
Page 12 02.12.2019
2.3 Safety-Relevant Parameters
Input Module
2-channel application
Safety parameters for two
connected incremental encoders,
which monitor one another in the SNC
021
1-channel application
Safety parameters for one
connected incremental encoder, which
is monitored
in the SNC 021
SNC 021
including CPU modules
SCP 011/SCP 111
PFH
D
= 3.51E-09 (1/h)
MTTF
D
= 580 years
DC = 99.00 %
SFF = 99.63 %
PFH
D
=3.42E-09 (1/h)
MTTF
D
= 803 years
DC = 97.82 %
SFF = 99.57 %
PL e / CAT 4 according to EN/ISO 13849
SIL 3 according to EN 62061
PL d / CAT 2 according to EN/ISO 13849
SIL 3 according to EN 62061
The application for a specific PL,
category or SIL-CL requires a risk
analysis of the end-use application to
determine whether two incremental
encoders are sufficient.
These safety parameters were calculated
for the SNC 021 when used with a
incremental encoder. The safety
parameters of the entire machine must
be determined in the end application.
Reason for SIL 3 with single-channel use:
Because the high SFF value is greater than 99 %, SIL 3 can be accepted with a hardware
tolerance (HFT) of 0 according to EN 62061.
1-channel and 2-channel application:
The application for a specific PL, category or SIL-CL requires a correct
installation. Please note any normative requirements of the end application
(machine) for installation and selection of encoders.
The use of the specified parameters requires a risk analysis of the end
application, by which whether 2 incremental encoders is sufficient must be
determined.
For two-channel application, both incremental encoders must be monitored in
the application (SCP 011/111).