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Piranha2 User’s Manual
test pattern pixels (first 2 pixels following the last End-of-line pixel. You may need to turn
the End-of-line sequence “on” by sending the command
els 1
). Any deviation from a
consistent value of these pixels (170DN/85DN) could be an indication of the following:
•
shorted bits
•
stuck bits
•
digital noise pickup on the I/O cable
•
open connection.
To activate the test pattern, use the command
svm 2
. Use the test pattern to verify the
proper timing and connections between the camera and frame grabber.
To receive a complete line of raw video data (without digital processing or test pattern)
through the RS232 port, use the command
gl
. The returned data displays one pixel value
after another and the minimum, maximum, and mean value of the sampled line. Use this
command to ensure the proper video input range.
Probe the output lines with an oscilloscope. Disconnect the digital cable from the camera
and check the digital signals at the output of the camera. Ensure that the correct values
are present. Check all cable connections, especially right at the connector; poor
connections or broken wires will cause randomly changing bits or stuck bits.
Horizontal Lines or Patterns in Image
A faulty or irregular encoder signal may result in horizontal lines due to exposure time
fluctuations; ensure that your exposure time is regular. If you have verified that your
exposure time is consistent and patterns of low frequency intensity variations still occur,
ensure that you are using a DC or high frequency light source.
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