Piranhs HS-xx Detailed Getting Started Guide
10
DALSA Corp.
03-32-10147-01
11.
If you are planning to use an external EXSYNC source to generate your
frame rate, enter
sem 3
to operate the camera in an externally controlled
frame rate, otherwise skip to Part 4. This mode accepts an external trigger on
the falling edge of CC1.
12.
Enter
svm 1
and observe that the test pattern displayed by the framegrabber
returns to the original ramp. This indicates that the camera is receiving the
external trigger.
If the captured test pattern doesn’t change, check:
•
The shaft encoder connection
•
That the shaft encoder is generating pulses and is rotating
•
The framegrabber configuration file for the CC1 line.
Part 4: Focusing and Aligning the Camera in
Area Mode
1.
Enter
sem 7
to return to an internally generated frame rate.
2.
Enter
svm 0
to select real video for output. The test pattern should now be
replaced by a real image.
3.
It may be necessary to adjust the gain or light level to observe an image on
the screen. If you need to adjust the video output, use the command
sag
0 i
where
i
is the gain value in a range from -10 to +10dB.
•
If you are using the minimum gain value and the framegrabber still
shows a white image, you will need to increase the camera’s frame
rate. Use the command
ssf f
where
f
is the new frame rate in Hz
or reduce the light.
•
If you using the maximum gain and the image is still dark you will
need to add more light.
•
If you have a highly reflective aperture where the blacks are washed
out and the edge of the image is clipped at white, reduce the
number of stages
stg
i
, where
i
is the number of stages, until the
bloomed part of the image is eliminated. If you reduce the number
of stages, you will have to create another framegrabber
configuration file to handle the reduced image height. When using
fewer stages it is important that the direction be identical to the TDI
direction so that the same portion of the image sensor is used. If you
are using the TDI camera in both directions, then the aperture needs
to be adjusted so that is not part of the field of view.
4.
Using a test alignment object, position the camera to required magnification
(field of view) necessary for your system (for example, 600 dpi will require
that there is 3000 pixels measured between 5 inches on the test target). Use
the framegrabber tools to measure this distance.
5.
Focus the lens. The black to white transition should occur in as few pixels as
possible.
6.
Align the camera so that it is square to the test target. If there is a 10 row tilt
in the line over 1000 pixels then this will result in about a 1 pixel blurring (96
stage operation) in TDI mode of operation. See diagram for good alignment
definitions.
Readout is triggered by an
EXSYNC pulse. EXSYNC pulses
arriving during readout of the
test pattern are ignored.
