Chapter
3
Operating Instructions
CLV 480 Bar Code Scanner
3-8
©
SICK AG · Division Auto Ident · Germany · All rights reserved
8 010 080/O824/10-02-2005
Product description
In object polling mode, the CLV automatically detects the beginning and the end of the ob-
ject located in the reading field without any help of external sensors. The minimum temporal
distance between two consecutive objetcs must not fall below 70 ms when the objects are
moved on the conveyor belt.
Tracking mode (in combination with the OTS 400 Omni Tracking System)
In tracking mode with the OTS 400 Omni Tracking System,
max. 20 objects
can simultane-
ously be located in the reading field (following each other), i. e. the CLV must be able to clear-
ly assign the bar codes to the objects (
). As default, a reading pulse sensor at the
beginning of the reading field controls the starting of the reading process. The end of the
reading field is determined by the parametrized object release point in the OTC 400 Omni
Tracking Controller. In this way, the size of the reading field is clearly determined.
In order to track the transport of the objects in the reading field, a regularly-timed pulse is
required. This is generated by an external incremental encoder for the OTC 400 which re-
gularly supplies a pulse at least every 10 mm (0.39 in) of movement in conveying direction.
As a result, the the distance between the reading pulse sensor and the object release point
is clearly time-mapped in the CLV. Fluctuations when approaching the conveyor or decrea-
ses in speed due to heavy load with numerous conveyor obejcts are also recorded. An in-
ternal clock in the CLV also allows operation at a constant conveyor speed. A gap of at least
50 mm (1.97 in) is necessary for the clear separation of consecutive objects. The reading
result for an object is output by the OTC 400 after the back edge of the object passes the
object release point. Alternatively, the reading process can be started with a command
strings via the data interface.
3.2.3
Scan procedure variants
Line scanner (standard device)
Generates a scan line; due to the V-principle of the beam generation, the reading field height
(the useful length of the scan line for evaluation purposes) is dependent on the reading
distance.
Line scanner with oscillating mirror
The oscillating mirror also deflects the scan line perpendicularly to the scan direction at both
sides around the neutral position with a low oscillating frequency. As a result, the CLV can
also scan larger areas for bar codes. Due to the V-principle of beam generation, the reading
field height is dependent on the reading distance.
Fig. 3-4:
CLV in stand-alone configuration (start/stop mode) and in tracking mode
Start/stop mode
Tracking mode