Operating Instructions
Chapter
10
CLP 100 Bar Code Reader
Appendix
8 008 912/0000/21-08-2002
©
SICK AG · Division Auto Ident · Germany · All rights reserved
39
10.4
Calculation of the number of scans
The maximum possible number of scans for a bar code depends on the transporting speed
v.
Figures 10-3
and
display one calculation example each for the possible number of
scans at ladder and fencing positionings of the bar code bars.
Recommended minimum value n = 5
Specified values:
Number of scans n = ?
Transporting speed v = 1.5 m/s
Bar length l
S
= 20 mm
Scanning frequency f = 500 Hz
Coding 100 % readable
Fig. 10-3: Calculation example: Number of scans for ladder positioning of the bar code bars
Recommended minimum value n = 5
Specified values:
Number of scans n = ?
Transporting speed v = 2 m/s
Code length with idle zone l
C
= 150 mm
Reading area height l
LH
= 400 mm
Scanning frequency f = 500 Hz
Coding 100 % readable, all scans on the code
Code window s = l
LH
– l
C
Fig. 10-4: Calculation example: Number of scans for fencing positioning of the bar code bars
I
S
v
v
s
t
---
=
v
l
S
n t
Sc a n
⋅
------------------------
=
with
t
Sc a n
1
f
---
=
v
l
S
n
----
f
⋅
=
n
l
S
v
----
f
⋅
=
n
0.02 m
1.5
m
s
----
-------------------
500
1
s
---
⋅
=
n
6.7
n
⇒
6
=
=
I
C
v
I
LH
v
s
t
---
=
v
l
L H
l
C
–
n t
Sc a n
⋅
------------------------
=
with
t
Sc a n
1
f
---
=
v
l
L H
l
C
–
n
------------------
f
⋅
=
n
l
L H
l
C
–
v
------------------
f
⋅
=
n
0.4
0.15
–
(
)
m
2
m
s
----
-------------------------------------
500
1
s
---
⋅
=
n
63.5
n
⇒
62
=
=
