Chapter
10
Operating Instructions
CLV 490 Bar Code Scanner
10-82
©
SICK AG · Division Auto Ident · Germany · All rights reserved
8 008 796/0000/25-06-2002
Appendix
Reading field height
Length of the
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scan line that is available for detecting the bar code in the reading plane.
Due to the V-principle of beam generation, the reading field height is dependent on the
reading distance.
Reading interval
Timeslot in which the CLV activates the laser diode and attempts to detect valid bar codes
from the information read. The reading interval may be shorter than the external reading pul-
se, depending on the selected output mode for the reading result.
Reading pulse
Clock pulse applied externally to the CLV to trigger the internal
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reading interval. Can be
supplied by a photoelectric reflex switch or a command from the host on the serial inter-
face.
Reading range (DOF)
Depth of field about the focal point of the laser beam on two sides. The extent of the reading
range depends on the resolution and reading distance.
Reading result
Electronic representation of the data content of the read bar code together with the
Ö
rea-
ding diagnosis data in one
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data output string that is generated after the reading pulse has
elapsed. The reading result on the terminal interface has a fixed format (content and output
format); the reading result on the host interface can be configured separately for Good
Reads and No Reads. Special characters can also be added if necessary.
Result status output
Function of the four "Result 1" ... "Result 4" switching outputs in Reading mode. Signals the
status of the reading result without indicating its contents (e. g. Good Read). You can assign
a status to each output on the D
EVICE
F
UNCTION
tab in CLV. The "Read Result" LED is linked
to the "Result 2" output.
Scan line
See line scanner.
Sending point
Point at which the reading result is output with respect to the start of the
Ö
reading pulse
and the internal
Ö
reading interval.
Separator
Data block in the reading result on the
Ö
host interface. Used to separate the data content
of the bar codes. Can be attached to the bar code as a prefix or suffix. Contains reading
diagnosis data and/or constants (e. g. letters), depending on the configuration. The error
status ST is output in the seperator by default.
SICK network
Special, high performance network of max. 31 CLVs with high data transfer rates on the
RS 485 interface. The CLVs are coordinated (polling) and connected to the host via the CLX
200 Network Controller.