NOTE
The teaching in and measurements for the shape comparison must be carried out at
a constant process speed, and thus a constant movement speed of the measuring
object.
For the shape comparison to function flawlessly, it is absolutely necessary to either
set (
see "Manual settings", page 39
) or teach in (
see "Teachable settings (“Teach”)",
) the object length to make optimum use of the sensor's internal memory and
thus achieve a meaningful result.
The object length of the object to be compared may correspond to the length of the
reference object at maximum. If a shape to be compared is longer than the reference
shape, but matches this shape for the length of the reference shape, then very high
match levels can be achieved due to the time-limited viewing range (or “reference
object length”).
Only one reference object can be taught in for the shape comparison (length, shape
and shape trigger threshold). For example, if a shape has been taught in for output
Q
1
and another shape is taught in for Q
2
, then the preceding shape is overwritten. It
is possible to set the outputs for the match level of this one shape so that they are
independent of each other.
Depending on the speed setting selected for the sensor and the transport speed of the
measuring object, the following minimum detectable object lengths or reference object
times are recommended for the shape comparison.
Table 8: Minimum detectable object lengths and reference object times
Speed setting Min. time the
object is in
front of the
sensor
Min. object
length at
0.2 m/s
Min. object
length at
0.5 m/s
Min. object
length at
1.0 m/s
Min. object
length at
2.0 m/s
Super-fast
40 ms
0.01 m
0.02 m
0.04 m
0.08 m
Fast
160 ms
0.03 m
0.08 m
0.16 m
0.32 m
Medium
400 ms
0.08 m
0.20 m
0.40 m
0.80 m
Slow
1200 ms
0.24 m
0.60 m
1.20 m
2.40 m
Super-slow
3600 ms
0.72 m
1.80 m
3.60 m
7.20 m
NOTE
The values displayed in the table refer to the laser class 2 variants of DT50-2 Pro. In the
case of devices with laser class 1, the values are to be multiplied by a factor of 2.
NOTE
The switching mode and the settings can be changed by executing a teach function by
means of a multifunctional input (
see "Multifunctional input (“MF Input”)", page 57
IO-Link (
see "Operation via IO-Link", page 21
6.4.1.4.2
Teachable settings (“Teach”)
For the “Shape comparison” (“Shape”) switching mode it is necessary to teach in the
length and shape of the reference object. In addition, you have the option of teaching in
the switching threshold of the shape comparison.
Teach function
Description
Reference object
length
You can use the “Reference object length” (“Length Ref. Object”) teach
function to teach in the length of the reference object.
6
OPERATION
38
O P E R A T I N G I N S T R U C T I O N S | DT50-2 Pro
8017154/1AVV/2021-03-24 | SICK
Subject to change without notice