•
Omis
sion of optional signals for controlling the “Reset required” light, the “Restart
required” light, and the brake of a drive
NOTE
Opt
ional signals do not need to be included if the risk analysis indicates that they
are not required. The application must still comply with the required safety level,
however. It is the responsibility of the user to provide proof that this is the case.
The current flow diagram must be adjusted accordingly (see "Safety controller pin
assignment", page 26 and see "Signal for optional safe brake control",
page 30)
4.7 Notes on fault detection
As a general rule, any fault occurring at the bar code brings about the safe state of the
s
afety system.
Owing to the system’s internal sensing behavior, a snapshot of the bar code is
assessed as part of the cycle of the system’s internal processing time. This means that,
depending on the drive speed, not every single point on the bar code is assessed.
If a fault occurs at a point on the bar code and no snapshot has been generated for
that point, the system will not detect this fault. This is not critical to safety if correct bar
codes can be read again in good time. If read faults are present across a longer dis‐
tance, the system will switch to the safe state. Compliance with the response times (see
"Response times", page 80) is ensured.
4.7.1 Illegible bar codes
If bar codes are incorrect or if some bar codes have been affixed incorrectly by 180°, it
w
ill not be possible to detect them at a speed of more than 3,700 mm/s in the case of
a length of up to five continuous bar codes (5 x 30 mm = 150 mm). If the length is
more than 150 mm, the system will switch to the safe state.
4.7.2 Bar code gaps
If the following values are exceeded, the system will switch to the safe state.
Speed of more than Gap not detected
1,000 m/s Up to the length of three bar codes (max. bar
code gap =
90 mm)
2,500 m/s Up to the length of four bar codes (max. bar
code gap =
120 mm)
3,200 m/s Up to the length of five bar codes (max. bar
code gap = 150 mm)
4 PROJECT PLANNING
20
O P E R A T I N G I N S T R U C T I O N S | Safe Linear Positioning 8020941/12O9/2019-08-05 | SICK
Subject to change without notice
To Next Page
Loading...
Need help?
General
