Chapter
10
Operating Instructions
CLV 480 Bar Code Scanner
10-42
©
SICK AG · Division Auto Ident · Germany · All rights reserved
8 010 080/O824/10-02-2005
Appendix
Line scanner with oscillating mirror: fence-type bar code arrangement
Fig. 10-31: Line scanner with oscillating mirror: calculating the number of scans for fence-type bar
code positioning
I
c
10
°
I
LM
I
CW
Line scanner with oscillating mirror: side read on object
Calculation for
standard decoder!
Specified values:
Number of scans n = ?
Conveyer velocity v = 0.5 m/s
Code length with blanc zone l
C
= 100 mm (3.94 in)
Code length under 10
°
:
Reading field height l
LH
= 500 mm (19.7 in)
Scanning frequency f = 600 Hz
Bar code 100 % readable, all scans on the code
Code windows = l
LH
- l
C
1. Dwell time of the bar code
in the reading area:
l
CW
100 mm
cos 10
-----------------------------
102 mm (4 in)
=
=
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
(rough estimate):
2. Required oscillating mirror
frequency: