|
PresencePLUS™ Systems FAQs
Inputs and Outputs
|
 |
Q: What happens to the output if you get triggers that are exactly 50 milliseconds apart? |
|
If the output is pulsed, the output will never turn on. However, if the output is latched it will stay on until it changes state, so it will be on for a minimum of 50 milliseconds.
|
|
Q: Can the PresencePLUS sensor trigger continuously? |
|
No. The PresencePLUS needs an input for every inspection. However, if the input is sent through a MAXI-AMP CL5A or an equivalent logic module, the module can convert the input signal to a pulsed signal. Another option is to tie the "output ready" output to the "trigger" input.
|
PresencePLUS™ Systems FAQs
Lens
|
|
Q: How do you lock the lens? |
|
Use the setscrew under the LED ringlight.
|
|
Q: What is the Resolution of the PresencePLUS? |
|
The resolution of the PresencePLUS is dependent upon the application. The resolution or reliability of the PresencePLUS sensor depends upon the lighting, the feature being inspected, and the speed of the part. There are two ways to express resolution. The first is the number of lines per millimeter that the sensor can clearly distinguish. The following graph shows the maximum resolution vs. the sensor-to-object distance for the 8 mm, 12 mm, and 16 mm lenses.
Another way to express resolution is in "inches per pixel". This describes the area of the image represented by each pixel. Use the following equation:
Resolution = Horizontal Field of View / 512
where:
the horizontal field of view (or FOV) = the image width on the sensor, and
512 = the width of the image in pixels.
For example, if the horizontal FOV is 4", the resolution is .008". If you are counting one row of pixels and you could detect a 1-pixel change, that would equal a change of .008".
Decreasing the image size will increase the resolution. To decrease the image size, either reduce the sensor-to-object distance or use a lens with a longer focal length.
Download Lens Calculator (.xls format): enter field of view and distance to get a recommended lens focal length.
Smallest detectable area = ((horizontal FOV x 10) / 512) squared
where:
the horizontal FOV = the width of the image that is viewed on the sensor,
512 = the width of the image array in pixels, and
10 = the smallest detectable object width in pixels
The result will be an area described in the units that were used to describe the horizontal FOV. For example, if the sensor's horizontal FOV is 4" x 3", the smallest area would be:
((4" x 10) / 512) squared = .006" squared
You could detect an object measuring 0.077" x 0.077".
|
|
Q: What is the smallest feature the PresencePLUS can detect?
|
|
A good general rule is that the PresencePLUS can detect a 100-pixel black object on a white background, or a 100-pixel white object on a black background.
|
|
Q: How far does the lens protrude from the front of the sensor?
|
|
1.125" for the 16 mm lens, 1.125" for the 12 mm lens, and .875" for the 8 mm lens.
|
PresencePLUS™ Systems FAQs
PresencePLUS Hardware
|
|
Q: What size is a C-mount lens? |
|
C-mount was a 16 mm movie standard that has a major diameter of 1.000", a thread pitch of 32 per inch, and a flange focal distance of .69". Closed circuit TV cameras and most machine vision systems use this mounting standard.
|
|
Q: What is the size of the PresencePLUS sensor array?
|
|
Each pixel is 7.9 micrometers by 7.9 micrometers. Therefore, an estimate of the total size of the array is 512 (horizontal) x 7.9 micrometers by 384 (vertical) x 7.9 micrometers = 4.045 mm (h) by 3.11 mm (v).
|
|
Q: Does the shutter speed effect the skew on the screen? |
|
No. The image acquisition time is fixed at 30 ms. Changing the shutter speed will only change the degree of blur due to motion.
|
|
Q: Does the PresencePLUS sensor save programs? |
|
The sensor saves the program in EEPROM so it will not be effected by loss of power. On power-up, the sensor initializes itself from the saved EEPROM parameters.
|
|
Q: Why do I get communication errors and strange numbers when I download a program? |
|
Most likely, the program that was downloaded was empty, and had "garbage" in it. To fix the sensor, download the factory default.
|
|
Q: How fast is the PresencePLUS? |
|
50 ms from trigger to output.
|
|
Q: What is the shutter speed? |
|
The exposure time for motion applications is .0625 – 2 ms. The exposure time for index is .0612 – 15 ms.
|
PresencePLUS™ Systems FAQs
PresencePLUS Software
|
|
Q: How does the PresencePLUS calculate the contrast value? |
|
The PresencePLUS finds the greatest grayscale difference between every sixth pixel per row. Then it averages the difference of all the rows. This average number is the focus number.
|
|
Q: What does the "X" mean when I try to use a hot key and nothing happens? |
|
The "X" indicates that the hot key will not work with that screen.
|
|
Q: When do the stats and Pass-Fail numbers reset to zero? |
|
This occurs when the user manually clears them, when the sensor has been "taught" again, or when the sensor is powered down.
|
|
Q: How do I remove my ROI quickly? |
|
In either the Setup Screen or the Quick Start Screen, select the RESET option. This will remove both the ROI and the mask.
|
|
For answers to your PresencePLUS System questions, contact a Banner Applications Engineer:
e-mail: sensors@bannerengineering.com
on-line request form page
telephone: 1-800-809-7043 |
