Avery Dennison ALS 204, Service And Installation Manual

Page: 80 / 224

80
5 O
PERATION
5.1 A
UTOMATIC DISPENSING SPEED ADJUSTMENT
ALS
20X
256
– m=4: double-phase operation; rising and falling
edge of each pulse is counted. Thus, a sensor pulse
can be decoded into four counting steps (Applica-
tion: Labeller in double-phase mode)
g: gear ratio
– Is required, if the rotary encoder is flanged directly
to the motor axle, and if a reduction gear is switched
between motor and drive axle of the conveyor. In
this case rules: g>1.
– See “Rotary encoder at the motor axle” on page 76.
v: max. speed
Maximum dispensing speed, which should be
reached by the labeller.
Limits
f
limit
: max. frequency
The maximum admissible signal-input-frequency is
20 kHz. This is dependent on the galvanic
separation and a digital filter for noise suppression.
If the specific output frequency of the
rotary encoder
is lower, than this value must be entered here.
x
limit
: min. resolution
– Minimum admissible resolution, referred to the con-
veyor belt distance which must be measurable.
– The resolution should be at least 0.2 mm, to avoid
significant deterioration of the dispensing accuracy
on the product.
c
limit
: run length counter
The labeller counts the steps between product
photoelectric sensor and dispensing edge. Because
of the counter register being 16 bit wide (including
polarity sign) and no overflow being allowed, the
max. counter value is 2
15
-1 = 32767.
Calculations
Size Symbol Calculation Note
W heel circumference
Max. speed 1000 mm = 1 m; 60 s = 1 min
Resolution ok, if
Frequency ok, if
Max. distance product sensor
to dispensing edge
U U
π
d
⋅
=
π
3 1415926
,
=
v v
mm
s
---------
v
m
min
---------
1000
60
------------ ⋅
=
x x
U
p m g
⋅ ⋅
------------------- =
x x
limit
≤
f f
v p g
⋅ ⋅
U
----------------- =
f f
limit
≤
a a x c
limit
⋅
=