Omron ZFX-C User Manual page 101

Note
Guidelines for setting detection size and detection interval
• Detection size
Determine the detection size roughly according to the size of the defect to be detected.
Setting a smaller detection size results in stronger detection sensitivity, while setting a larger detection size results
in weaker detection sensitivity.
Detection size
Sensitivity
Processing time
When a larger detection size is set, the difference with elements that are not defects decreases as the density of
elements other than defects also is included in the calculation at (2). In other words, the more background that is
included in the detection area, the weaker the detection sensitivity becomes.
• Detection interval
Determine the detection interval roughly according to the size of the defect and the detection size.
The larger the detection interval that is set, the shorter the processing time becomes.
When the detection area is greater than the defect, set a smaller detection interval.
When the defect is greater than the detection area, set a slightly larger detection interval.
When a small detection interval is set, elements overlapping the edge of the defect also are included in the com-
parison, and so the defect value decreases, which results in less stable detection of the defect.
Possible output results
The following values can be output when expressions are set.
Item
Judgment result
Defect
Maximum density
Minimum density
Number of defects
Defect position
Reference position
Position difference
For details on reference position, position difference p.50
98
Setting Measurement Items
(1)
Defect
Stronger
Longer
Description
The judgment result is output. (0:OK, -1:NG, -2: not measured)
Measured extent of defects is output. (0 to 255)
The maximum density value inside the measurement region is output.
(0 to 255)
The minimum density value inside the measurement region is output.
(0 to 255)
The number of defects having an extent of defects at or exceeding the
judgment condition is output. (0 to 255)
The X, Y coordinates of the defect position are output.
(-9999.999 to 9999.999)
The X, Y coordinates of the defect position when the measurement
region is drawn are output. (-9999.999 to 9999.999)
The difference obtained by "measurement position - reference
position" is output. (-9999.999 to 9999.999)
(2)
Weaker
Shorter
Message
Judge (JG)
Defect (F)
Max. density (GH)
Min. density (GL)
Number of defects
(N)
Position X, Y
(X, Y)
Reference X, Y
(SX, SY)
Position dif. X, Y
(DX, DY)
ZFX-C User's Manual