Advantages and background info about the MultiPhase function.
MultiPhase is available since firmware version 1.44f17 (17-OCT-2017).
Some product effects have a phase with strong variations or drifts. MultiPhase much improves the detection performance and stability at such situations.
NOTE: MultiPhase can only be used with BD metal detectors with conveyor and photo sensor. Products must pass the photo sensor one by one. Each product must reliably interrupt the photo sensor beam.
Note: MultiPhase cannot be used for bulk products.
Note : Other settings have to be made before using the MultiPhase.
Refer to ‘HowTo: MultiPhase Checklist’ for this purpose.
MultiPhase = off versus MultiPhase = on
Metal detection, MULTIPHASE = off
Signal is checked if it exceeds the limits of the teacharea. If yes, it is a metal detection. Limits of the teacharea are adjusted by OPTIMIZE TOL. X and TOL. Y.
Metal detection, MULTIPHASE = on
Signal is rotated forth and back until it best fits into the teacharea. Maximum rotation angle is set by MULTIPHASE +/-.
Signal is checked if it exceeds the limits of the teacharea. If yes, it is a metal detection. Limits of the teacharea are adjusted by OPTIMIZE TOL. X and TOL. Y and MULTIPHASE TOL. X* and TOL. Y*.
Preconditions for using MultiPhase
With MULTIPHASE = on : If any precondition or setting for MultiPhase is not fulfilled, a yellow warning message Preconditions for MultiPhase not fulfilled is shown.
Preconditions are shown in ‘HowTo: MultiPhase Checklist’.
MultiPhase is active when:
1/ PRODUCT MENU > ADVANCED MENU > MULTIPHASE = ON
and
2/ the warning Preconditions for MultiPhase not fulfilled does not appear:
ADVANTAGES OF MULTIPHASE
Product only, with MULTIPHASE = off
• The phase angle of a product signal changes during production.
• Possible reasons are variation in product consistency or temperature.
• This leads to false metal detections. The product is uncontaminated.
Product only, with MULTIPHASE = on
• The signal is rotated forth and back until it best fits into the teacharea.
• The rotated signal now fits correctly inside the teach area. No more false detection.
Product + Metal, with MULTIPHASE = off
Same product as above, with phase drift + metal contamination.
Product + Metal, with MULTIPHASE = on
The product with metal still gets reliably detected.
Thus using MultiPhase has the dual benefit of reducing false rejects while at the same time maintaining reliable metal detection.
DISPLAY UPDATE
2D and bar display:
With MULTIPHASE = on the screen content appears delayed. The signal only appears once the product has completely passed through the sensor head tunnel.
The amount of delay depends on the conveyor speed and the length of the product.
Oscilloscope display:
Is the same for MULTIPHASE = on/off and will always display the data in realtime.
VIBRATION FILTER
With MULTIPHASE = on, the VIBRATION FILTER is always automatically set OFF.
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