FCM_User Reference Manual.pdf.pdf - 第216页

Pr oduc t Ch ang e Ov er User Re f eren ce Manu al 4022 591 960 82 6-24 FCM M ult ifle x 02.02 ■ Rea d the [Av erage grey leve l in area] v alue for fiducial and its backgr ound ■ U se a value in between as the [Threshol…

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4022 591 96082 User Reference Manual
02.02 FCM Multiflex 6-23
Product Change Over
NOTE: It is possible - but not recommended - to set the >/LJKW /HYHO@ and
>7KUHVKROG@ manually as in nearly all cases the correct settings will be
supplied automatically by selecting >7HDFK@.
Before setting the threshold value for the binary algorithm, first the grey levels of
the fiducial and its background have to be determined. Proceed as follows:
■ Select
[Measure Greylevel] to determine the grey levels of the fiducial and its
background
SCREEN 6-15
■ Select with the tracker ball and the sliders a spot with a representative grey level
in the fiducial and one in the background
SCREEN 6-16
Product Change Over
User Reference Manual 4022 591 96082
6-24 FCM Multiflex 02.02
■ Read the [Average grey level in area] value for fiducial and its background
■ Use a value in between as the
[Threshold] level to be set
NOTE: In demanding situations some try-outs may be required, e.g. reset camer-
aposition (if background is out of view), selection of another fiducial etc.
Algorithm
There are 2 options for the fiducial detection algorithm:
■ Select
[Algorithm]
SCREEN 6-17
NOTE: Please notice that the optimum algorithm is calculated by the automatic
teach function! So there is no point for changing this setting manually.
NOTE: The quicker binary algorithm requires a good image, no spots and damages.
If you are in doubt, make some trial measurements.
The following parameters are effected by the selected algorithm:
• [Threshold]
• [Tolerance]
• [Polarity]
• [Smallest Enclosing Rectangle]
• [Area of Interest]
• [Area of Fiducial]
This is indicated in the description of the parameter concerned.
binary quick but less reliable
interpolation slower but more reliable
4022 591 96082 User Reference Manual
02.02 FCM Multiflex 6-25
Product Change Over
Area of Interest
■ Select [Area of Interest]
The [Area of Interest] determines where the system will search for the fiducial.
In this way fiducial-like elements - like certain print patterns - can be avoided.
NOTE: It is recommended to make the area of interest not larger then necessary.
A large area of interest will increase the time required for measurement.
SCREEN 6-18
■ Toggle with <F5> between [Move] and [Resize] as necessary, and
■ Position and resize the area of interest with the arrow keys or by means of the
tracker ball and the sliders
The X and Y value indicate the centre of the search area with respect to the centre
of the field of view of the BVM camera.
Area of Fiducial
■ Select [Area of Fiducial]
This menu box gives the surface area of the fiducial in mm
2
.
SCREEN 6-19