Chapter
10
Operating Instructions
CLV 45x Bar Code Scanner
10-36
©
SICK AG · Division Auto Ident · Germany · All rights reserved
8 009 139/K949/06-06-2002
Appendix
Line scanner with oscillating mirror: Fence-type bar code positioning
Fig. 10-23: Line scanner with oscillating mirror: Calculating the number of scans for fence-type bar
code positioning
v
l
LH
l
CW
l
C
10°
Line scanner with oscillating mirror: Lateral reading at object
Calculation for
standard decoder!
Specified values:
Number of scans n = ?
Transporting speed v = 0.5 m/s
Code length with idle zone l
C
= 100 mm
Code length under 10
°
:
Reading area height l
LH
= 500 mm
Scanning frequency f = 600 Hz
Bar code 100 % readable, all scans on the code
Codefenster s = l
LH
- l
C
1. Dwell time of the bar code
in the reading area:
l
CW
100 mm
cos 10
-------------------------
102 mm
=
=
t
s
v
---
=
t
l
LH
l
CW
–
(
)
v
-----------------------------
=
t
0.5
0.102
–
(
)
0.5 m/s
----------------------------------------
=
t = 796 ms
f
SW
1
t
----
=
f
SW
1
0.796 s
-----------------------
=
n
600 Hz
1.26 Hz
----------------------
=
n
f
f
SW
----------
=
f
SW
= 1.26 Hz
n = 476
3. Number of possible scans
(approximation):
2. Required oscillating mirror
frequency:
