Chapter
4
Operating Instructions
CLV 490 Bar Code Scanner
4-12
©
SICK AG · Division Auto Ident · Germany · All rights reserved
8 008 796/0000/25-06-2002
Installation
4.4.3
Mounting the sensors for detecting the object distance
If the dynamic focus control function of the CLV is triggered by external sensors, suitable
sensors must be mounted in the vicinity of the CLV.
operation from above. The sensors must be arranged in such a way that all of the potential
object heights are classified uniquely and overlapping reading ranges occur that can be for-
med with the depths of field of the CLV. A maximum of five switching inputs are available for
this purpose. A max. of 32 switching states for 8 distance configurations (reading ranges)
can be implemented using the internal assignment table (combinations). Photoelectric reflex
switches, for example, can be used to detect the object distance. In the default setting, all
five "IN 0 ... IN 4" switching inputs are selected for dynamic focus control.
1.
The depths of field of the CLV for the bar code resolution in question is shown in the
graphs in
Chapter 10.2 Specification diagrams, Page 10-1
table focus positions for overlapping reading ranges.
2.
Mount distance sensors (e. g. photoelectric reflex switches) one above the other in a
row at the mounting location to measure the object distance (see also assignment
). It is advisable to mount these distance sensors opposite the
direction of motion of the conveyor belt at approx. 100 mm in front of the reading pulse
sensor.
3.
Connect the distance sensors to the "IN 0 ... IN 4" switching inputs on the CLV via the
AMV/S 60 Connection Module (see
Chapter 5.5.7 Connecting the switching inputs,
4.
Set the focus positions for the required reading ranges on the R
EADING
C
ONFIGURATION
tab in the "CLV-Setup" program. To do so, click the D
ISTANCE
C
ONFIGURATION
/A
SSIGNMENT
T
ABLE
button and edit the required entries in the dialog box that is then displayed.
5.
Chapter 4.3.2 Adjusting the CLV, Page 4-8
, choose the standard deco-
der and start Percentage Evaluation mode temporarily.
6.
Check the reading quality in all distance configurations while the conveyor belt stationary.
7.
Then check the distance detection function in Reading mode under realistic conditions.
To do so, monitor the reading result in the Terminal Emulator as described in
Chapter 4.4.2 Mounting the external reading pulse sensor, Page 4-10
Default: Focus position F 1 up to F 8 = 1 200 mm.
Fig. 4-11:
Mounting example for object distance detection
DC1
DC2
DC8
LS1
LS2
LS7
h2
h7
h1
Reading distance
DC = Distance Configuration
Object distance