Operating Instructions
Chapter
6
CLV 490 Bar Code Scanner
8 008 796/0000/25-06-2002
©
SICK AG · Division Auto Ident · Germany · All rights reserved
6-25
Operation
6.5.4
Background teach-in
If the Autofocus function is used in the D
IFFERENTIAL
B
ACKGROUND
or D
IFFERENTIAL
B
ACKGROUND
WITH
T
RACKING
mode, the CLV must first learn the
ambient background
in its reading field to
narrow the reading field even further. When the internal distance profile is set, the reading
field of the CLV must
not contain any objects
. In this mode, the CLV does not output any
reading results.
The Background teach-in function can be started as a device function via CLV 490 (interac-
tively), or press the [F2] key.
Line scanner with oscillating mirror:
In the "Background teach-in" mode, the CLV behaves in the following manner:
–
in "Oscillating" mode (default setting: oscillating with a fixed amplitude), the CLV shuts
off oscillation and positions the scan line under the angle CW = 50 (corresponds to an
angle of deflection below 105
°
). This position cannot be altered.
–
in "One-Shot" mode, the CLV positions the scan line under the angle CW = 50.
–
in "Fixed Position" mode, the scan line’s selected position remains unchanged.
1.
Mount the CLV at the reading station and align it with an object containing a bar code.
2.
Remove the object so that the CLV has an unobstructed view of the background.
3.
Choose CLV 490, D
EVICE
F
UNCTIONS
, B
ACKGROUND
, T
EACH
-
IN
– or –
press the [F2] key.
The E
XECUTE
D
EVICE
F
UNCTIONS
window opens.
Choose B
ACKGROUND
, T
EACH
-
IN
in the
EXECUTE
menue.
The "Device Ready" LED extinguishes. The CLV then scans its background and learns
the ambient background so that it can create a suitable distance profile.
The CLV outputs a message once the teach-in procedure has been successfully com-
pleted (see
The CLV has then learned the ambient background.
Fig. 6-10:
CLV-Setup: Dialog window for running the background teach-in