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Operating Instructions
Chapter
4
C4000 Select
8012247/RI61/2007-11-30
© SICK AG • Industrial Safety Systems • Germany • All rights reserved
27
Configuration
4.4
Floating blanking
Floating blanking functionality permits the C4000 Select safety outputs (OSSDs) to remain
in an active (high) state (e.g. green state) when an object of limited, fixed size is moving in
the protective field of the C4000 Select. The C4000 Select supports one- or two-beam
floating blanking. It is not required that an object be present for the outputs to be active
(high) and only one floating blanking field may exist in a single C4000 Select.
When one-beam floating blanking has been enabled, one beam may be blocked in the pro-
tective field of the C4000 Select without causing a stop condition to occur. When two-
beam floating blanking is enabled, two contiguous beams may be blocked in the protective
field of the C4000 Select without causing a stop condition to occur. When an object that is
larger than the floating blanking configuration of the C4000 Select, or when more than
one object has been detected in the protective field of the C4000 Select, an immediate
stop condition will occur.
The first beam, normally used for synchronization, may be blanked. An algorithm is integra-
ted into the floating blanking function to allow sparks or other small objects to transit
through the protective field without causing a stop condition to occur.
Configuration of floating blanking is accomplished by using three of the DIP switch positi-
ons. A single switch enables or disables floating blanking, while the other two switches
enable either one- or two-beam floating blanking. All three DIP switches must be in the off
position in order for floating blanking to be turned off. Refer to chapter 4 “Configuration”
on page 21 for additional details on DIP switch setting requirements for floating blanking.
When the C4000 Select is used with one or two additional C4000 Select devices via
connection to the extended I/O connection, floating blanking may be independently
configured on any or all of the devices.
A
Yellow
LED in each C4000 Select receiver message center indicates when floating
blanking is active.
Blanked areas require a separate risk analysis!
A blanked area is in principle a hole in the protective field. Check in detail whether and
where blanking is actually required. You must protect the blanked area in another way, e.g.
mechanically. Otherwise, you must take the blanked area into consideration in the calcula-
tion of the safety distance and mount the safety light curtain appropriately.
After modifying the blanking, check the protective field with the test rod. Instructions
can be found in chapter 7.3.3 on page 49.
Floating blanking is not suitable for all applications. Please consult the relevant safety
standards and regulations that apply to your application.
WARNING
Fig. 16: Example of mecha-
nical protection of floating
blanking
Blanked area, sides
protected by
mechanical barriers