Baumuller BM5-O-SAF-002, Operation Manual, Page: 34 / 182

Requirements for the use of rotary encoders for the safety-related monitoring
Operation Manual Safety Module for b maXX 5000 BM5-O-SAF-002/3
Document no.: 5.11016.03 Baumüller Nürnberg GmbH
34
of 180
7.5
7.5 Requirements for the use of rotary encoders for the safety-related monitoring
The following encoder types can be used for the safety-oriented monitoring with the
Safety Module:
WARNING!
Only encoders, which have a certificate of an EC-type test or which have been
released by Baumüller may be used for the safety-related monitoring.
The following requirements must be complied with.
m
According to the applicable standards in the field of functional safety, encoders have a
tested analog sine-/cosine-interface.
m
The safety integrity level or the performance level of the encoder must be in accor-
dance to a risk reduction of the supported safety functions at minimum.
m
Encoders must have the possibility of a safe shaft connection between encoder shaft
and motor shaft according to EN 61800-5-2, table D.16.
m
Encoders must have the possibility of a safe connection between encoder cabinet and
motor chassis according to EN61800-5-2, table D.16.
m
The safety-relevant parameters must be common to the encoders:
m
Category
m
MTTF
D
per channel (Mean Time to Failure dangerous)
m
DC average (Diagnostic Coverage)
m
PL (Performance-Level)
m
PFH (Probability of Failure per Hour)
m
HFT (Hardware fault tolerance)
m
PFD (Probability of Failure on Demand)
m
SIL (Safety Integrity Level)
m
Encoders should have internal diagnostic functions. The diagnostic functions take
place independently without the excitation by the Safety Module.
m
If present, the encoder-internal diagnostic functions switch the encoder outputs into a
safe status, if errors occur.
m
The maximum lifetime of the encoder must be considered. The encoder must be re-
placed upon completion of its lifetime.
m
Encoders must apply to the appropriate EMC-directives and to the statutory environ-
mental requirements for safety-related components.
DANGER!
The nonobservance of data sheet specifications and the exceeding of specified
encoder data may result in the loss of the safety function. Integration guides and the
encoder’s specification must be strictly adhered to.