For general information and notes about shape comparison, refer to the
parison” (“Shape”) switching mode
chapter.
6.4.4.2.2
Teachable settings (“Teach”)
For the “Shape comparison” (“Shape”) analog 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 scaling of the analog output.
Teach function
Description
Reference object
length (“Length
Ref. Object”)
You can use the “Reference object length” (“Length Ref. Object”) teach
function to teach in the length of the reference object.
Reference object
shape (“Shape
Ref. Object”)
You can use the “Reference object shape” (“Shape Ref. Object”) teach
function to teach in the shape of the reference object. Then the shape that
is taught in corresponds to the “target shape” and serves as a basis for the
shape comparison.
Q
a
Good Teach
In the factory setting, a match level of 100% with 20 mA or 10 V is output
with the “Shape comparison” (“Shape”) analog mode. Alternatively, after the
length and shape of the reference object have been taught in, it is also
possible to teach in the desired match level to be output with 20 mA or 10 V
instead.
With this teach you can have one to as many good objects as desired move
past the sensor. Based on the good objects that move past it, the sensor
automatically saves the value of the lowest match as upper scaling of the
analog output.
Q
a
Bad Teach
In the factory setting, a match level of 0% with 4 mA or 0 V is output with the
“Shape comparison” (“Shape”) analog mode. Alternatively, after the length
and shape of the reference object have been taught in, it is also possible to
teach in the desired match level to be output with 4 mA or 0 V instead.
With this teach you can have one to as many bad objects as desired move
past the sensor. Based on the good objects that move past it, the sensor
automatically saves the value of the highest match as lower scaling of the
analog output.
6.4.4.2.3
Manual settings
Setting
Description
Reference object
length (“Length
Ref. Object”)
You can use the “Reference object length” (“Length Ref. Object”) setting to
set the length of the reference object in milliseconds.
Reference object
shape (“Shape
Ref. Object”)
The shape of the reference object cannot be entered manually. Accordingly,
the teach function for teaching in the shape of the reference object (
"Teachable settings (“Teach”)", page 55
) is available also for the manual
settings.
Shape trigger
threshold (“Self
Trigger”)
The beginning and end of the object is detected directly by the sensor for
teaching in the length and shape of the reference object as well as for the
shape comparison function. This detection is based on the difference in
height between the background (e.g. a conveyor belt) and the object; it is
called the shape trigger threshold – “Self Trigger”. This trigger threshold is
set by default to a height of 25 mm. You can manually adjust this height
threshold in millimeters to detect even smaller objects or hide larger height
fluctuations of the background.
Good object
shape tolerance
Q
a
(“Q
a
Good Tol‐
erance”)
The good object shape tolerance Q
a
(“Q
a
Good Tolerance”) setting can be
used to manually define the match level to be assigned to the upper scaling
of the analog output in the form of a percentage. To enable estimation of
the match level of various objects and setting of useful scaling based on
this, it is advisable to measure some objects in
Run
mode and observe the
results of the shape comparison.
OPERATION
6
8017154/1AVV/2021-03-24 | SICK
O P E R A T I N G I N S T R U C T I O N S | DT50-2 Pro
55
Subject to change without notice
