SICK CLV 490 Series, Operating Instructions Manual

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Chapter 3 Operating Instructions
CLV 490 Bar Code Scanner
3-8
©
SICK AG · Division Auto Ident · Germany · All rights reserved 8 009 993/O824/20-12-2004
Product description
In autofocus mode and in combination with the OTS 400 Omni Tracking System the CLV can
also use the object height information from the OTS 400 or any other CLV transmitted via
the CAN bus.
3.2.2 Event-controlled dynamic focus control
As an alternative to the autofocus function, the CLV can switch its focus position in response
to certain events and thus dynamically cover a large reading range. A maximum of eight
reading ranges can be defined as distance configurations for this purpose and approached
consecutively in reading mode (see Fig. 3-4 ).
The switch over takes place in response to changes in the object distance (with reads from
above: object height detection). The trigger source for the switchover can be:
•
A signal combination at the "IN 0" to "IN 4" switching inputs, a command on the host
interface/terminal interface or the integrated timer (e. g. for search mode). Additional in
the case of the line scanner with oscillating mirror also the oscillating mirror reversal
points. The distance configurations are assigned to the switchover sequence by means
of a programmable assignment table.
•
In combination with the OTS 400 Omni Tracking System:
Alternatively the object height information from the OTS 400 or any other CLV via the
CAN bus.
The distance measurement of the autofocus function can be additionally used to define the
distance configurations.
3.2.3 Reading modes in stand-alone configuration
Start/stop mode
During the reading process, only one object is located in the reading field in start/stop
mode, i. e. all read bar codes can be clearly assigned to the object. As default, two reading
pulse sensors at the beginning and at the end of the reading field control the starting and
stopping of the reading process ( Fig. 3-5 ). The size of the reading field is determined by the
distance between the two sensors. Alternatively, the reading process can be controlled with
Fig. 3-4: Dynamic focus control: classification of the reading range in distance configurations
1 2 3 5 8 4 6 7
Reading
field height
Focus
position
Reading distance
Focus position
Reading distance
DC = Distance Configuration
DC 1
DC 3
DC 4
DC 6
DC 7
DC 8
DC 2
DC 5