In either sensor orientation (left or right) the measured position increases as the web moves from left to right.
Note:
If no sensor bit is set or if no web bit is set then the value in the sensor position output register is
meaningless.
Sensor Orientation
Completely open
Fully covered
Left sensor orientation
Number of pixels
0
Right sensor orientation
0
Number of pixels
Note:
The output when the web completely covers the sensor or when the web is completely outside the
sensor window would be different based on the sensor orientation.
Note:
If a single web (with two edges) is seen by the sensor, then the width of the web can be obtained by
taking the difference between right and left edge positions.
Note:
If a single web (with two edges) is seen by the sensor, then the centerline of the web can be obtained
by taking the average of left and right edge position.
Sensor 1/Sensor 2 Coverage
The sum of individual widths of webs is provided as the coverage value. Individual width is defined as the
region between two rising edges on an image captured. When one web with two edges is present, the
coverage value will equal the web width. When multiple webs are present, then the coverage value would
correspond to the sum of individual widths.
Note:
When only one web (with both edges within the sensor field of view) is presented to the sensor the
coverage value will be the same as the web width, The coverage value is computed based on edges seen
by the controller. Hence, based on the controller settings if multiple contrasting features on the web are
seen, then coverage value will not be the same as the web width.
Note:
The complement of coverage is the gaps. So if a web is completely covering a sensor's viewing area,
then a gap in the web can be detected by seeing a drop in coverage value. Sum of all gaps = Number of
Pixels - Coverage.
Note:
This measurement is an instantaneous raw measurement for each sensor. Enabling and disabling the
filter in the controller will have no effect on the measurement output.
Quality Factor Registers
The quality of the sensor measurement from the two sensors are provided in this register. Higher numbers
correspond to good quality measurement while a low number indicates lower quality. The value of the
quality factor ranges from 0 to 256. The eight most significant bits of register 6 correspond to the 8-bits
quality factor from sensor 1 while the eight least significant bits correspond to the quality factor of sensor 2.
Content subject to change without notice
SCU5: Sensor and Web Guide Controller User Manual v 3.6| Page 50
Copyright © 2021 Roll-2-Roll Technologies LLC
+1-888-290-3215