Meaning of the checkboxes "Edges on bright background / reflector only" and "Edges on dark background only" of the AS30-Prime

Those checkboxes are also accessible via the ISDU264, which can be seen in the AS30s IODD information document. Note that this ISDU is a record of 8 bits. Bit 2 and 3 are the equivalent to check the boxes using the SOPAS ET user interface. Note that the subindices are not writable and callable each. However, the 8 bits (1 byte) of Index 264 has to be written or read. 

Both functions are useful just after a

• "Teach-in bright background / external illumination / reflector"
  or
• "Teach-in dark background"

Those teach-in possibilities have the purpose of bringing a light or dark background to a defined, smoothed high or low level.

In the following, the mentioned checkbox functions will be explained in detail. 

If you would like to try out the functions mentioned below yourself, please consider the following:

• First, perform a Factory Reset to make sure all settings are default.
• Set the "Background" setting to "Proximity".
• "Middle" as sensitivity setting is sufficient.
• The sensor can be positioned without any angle. Consider the measuring distance specified in the sensor data sheet.

Attached to this article, you can find the PDF-File "AS30_Function_Test_Paper_SICK_AG_Support.pdf". It can be used to get a better understanding of different functions. In order to use it, it has to be printed out in color mode. The resolution should be >300 dpi. If available, the quality should be set at least to "Normal", better "Optimal".

As the information box of SOPAS ET claims:

"The background must be a reflector, a white background or the external illumination. Only edges on that background are accepted."

In order to understand this feature easily, the attached test paper can be used. For this test the sensor AS30-EBM534I220A00 (One Edge, 100 mm sensing distance) and the "AS30-OneEdge"-page was used. 

As mentioned before, the bright background must be thought-in before this function can be used. The sensor needs to "know" how the background looks like and will smoothen the signal. For this the paper field "Bright Background" should be used. The light spot must be positioned in the center of the field.

Now, the function can be tested using the field "Test field for Function Edges on bright background / reflector only". The light spot should be positioned inside this dashed field. 

The white part demonstrates the bright background. However, the black field(s) (right part) demonstrates the object which has some brighter parts (gray bars) in its structure. This can be a foil, a web or some other material.

The task now is, that the sensor only detects the left edge between white and black and not the edges between gray and black no matter which edge search direction is set. For this, the checkbox "Edges on bright background / reflector only" can be activated. Below are two examples: activated function, deactivated function. Those are screenshots of the SOPAS ET user interface of the AS30.

Deactivated

Activated

As the information box of SOPAS ET claims:

"The background must be dark, such as dark material or open space. Only edges on that background are accepted."

In order to understand this feature easily, the attached test paper can be used, as well. For this test the sensor AS30-EBM534I220A00 (One Edge, 100 mm sensing distance) and the "AS30-OneEdge"-page was used. 

As mentioned before, the dark background must be thought-in before this function can be used. The sensor needs to "know" how the background looks like and will smoothen the signal. For this the paper field "Dark Background" should be used. The light spot must be positioned in the center of the field.

If both backgrounds -white and black- will be thought-in, the black one has to be performed first.

Now, the function can be tested using the field "Test field for Function Edges on dark background only". The light spot should be positioned inside this dashed field. 

The black part demonstrates the dark background. However, the gray field(s) (right part) demonstrates the object which has some brighter parts (white bars) in its structure. This can be a foil, a web or some other material.

The task now is, that the sensor only detects the left edge between gray and black and not the edges between gray and white. For this, the checkbox "Edges on dark background only" can be activated. Below are two examples: activated function, deactivated function. Those are screenshots of the SOPAS ET user interface of the AS30.

Deactivated

Activated

Playing around using the attached document help to understand the mentioned functions better. Using these functions can improve many applications and allows a better, more stable edge measurement.