SICK CLV 421

Chapter 10 Operating Instructions
CLV 42x bar code scanner
10-46 © SICK AG · Division Auto Ident · Germany · All rights reserved 8 009 981/O078/16-08-2004
Appendix
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
pulse, depending on the selected output mode for the reading result.
Reading pulse
Pulse applied externally to the CLV to trigger the internal  reading interval. Can be supplied
by a photoelectric reflex switch or a command from the host on the serial interface.
Reading result
Electronic representation of the data content of the read bar code together with the 
reading diagnosis data in one  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.
Reflector polling
Reading pulse generated automatically by the CLV using a special bar code that serves as
a reflector for the laser beam. The bar code is positioned opposite the CLV. The CLV polls
the reflector at regular intervals. When it is concealed by an object, the CLV starts the
reading interval. It stops the reading interval once it detects the reflector again.
Result status output
Function of the "Result 1" and "Result 2" 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
DEVICE CONFIGURATION tab in the user interface of CLV Setup.
The "Result" LED is linked to the "Result 2" output.
Scan line
See line scanner.
Specification diagrams
Diagrams for reading the resolution-specific depth of field (DOF) for specific focus positions.
Splitter
Data block in the reading result of the  host interface. Used to separate several bar codes
from each other. Contains up to 5 elements, consisting of constants (control characters,
letters, digits). The “Splitter“ block is empty in the default setting of the CLV 42x.
Standard decoder
Tried-and-tested  decoder from the CLV product family. Suitable for applications with an
adequate code height, limited tilt, and high-quality bar code prints.
Storage in the CLV
The application-specific  parameter set can be stored temporarily or permanently in the
CLV. If it is stored temporarily in the RAM, it is lost as soon as the power supply is switched
off. Parameter sets that are stored permanently are transferred to the EEPROM in the CLV
and remain active as the current data record when the power supply is switched off. The
default setting is not affected by this and is stored in a read-only memory (ROM).