Festo CAMC-G-S3 Manual page 245

A Technical appendix
Error acceptance
Change in the signal shape
Swapping of the sin and cos out­
put signal
Supplementary requirements for shaft encoders with incremental and absolute signals
Simultaneous incorrect position
change of incremental and abso­
lute signal
Additional requirements for rotary encoders with synthetically-generated output signals
Any falsification of the output
signal
Additional requirements for linear encoders
Mounting of read head broken
Static offset of the material
measure (e.g. visual code strip)
Damaged material measure (e.g.
visual code strip)
1) Sensitivity and DC in accordance with the parameterised fault limits; specification applies to factory setting
2) Position information is "static" if there is a fault => Fixed commutating position, motor at idle / voltage of a channel static
=> Commutating position changes by max +/-90° of a signal period of an encoder, motor only moves in this range
Festo – GDCP-CAMC-G-S3-EN – 1406NH – English
Fault Error detection by the
exclusion safety module
None Individual signal monitor­
ing and vector length mon­
1)
itoring
Yes Safety module has suffi­
ciently separated signal
processing without multi­
plexer
None None, the safety module
only analyses the ana­
logue sin/cos signals
None Not possible in all cases, if
both output signals are
falsified simultaneously.
Required! Not possible safely.
According However, monitoring of
to manu­ the period of the SOS re­
facturer's quest occurs:
datasheet A switch-off and error
for the en­ message occur after
coder 24 hrs.
Supplementary notes/
comments
In accordance with sec­
tion A.3;
2)
DC > 90%
–
Only for Hiperface in­
terface:
The basic unit carries
out a cyclical plausibil­
ity check, using a
cross-comparison of
the sin/cos signals
with the absolute posi­
tion read via the data
interface
Use fault exclusion for
the encoder, or a
second measuring sys­
tem for position com­
parison.
Use fault exclusion for
the motor - encoder
system, or a second
measuring system for
position comparison.
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