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X64 Xcelera-HS PX8 Reference
X64 Xcelera-HS PX8 User's Manual
CVI/CCF File Parameters Used
Shaft Encoder Enable = X, where:
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If X = 1, Shaft Encoder is enabled
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If X = 0, Shaft Encoder is disabled
Shaft Encoder Pulse Drop = X, where:
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X = number of trigger pulses ignored between valid triggers
Shaft Encoder Pulse Multiply = X, where:
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X = number of trigger pulses generated for each shaft encoder pulses
Shaft Encoder Direction = X, where:
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X = 0, Ignore direction
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X = 1, Forward steps are detected by pulse order A/B (forward motion)
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X = 2, Forward steps are detected by pulse order B/A (reverse motion)
For information on camera configuration files see the Sapera Acquisition Parameters Reference
Manual (OC-SAPM-APR00).
Virtual Frame Trigger for Line Scan Cameras
When using line scan cameras a frame buffer is allocated in host system memory to store captured
video lines. To control when a video line is stored as the first line in this “virtual” frame buffer, an
external frame trigger signal is used. The number of lines sequentially grabbed and stored in the
virtual frame buffer is controlled by the Sapera vertical cropping parameter.
Virtual Frame Trigger Timing Diagram
The following timing diagram shows an example of grabbing 10 video lines from a line scan camera
and the use of a virtual frame trigger to define when a video line is stored at the beginning of the
virtual frame buffer. The virtual frame trigger signal (generated by some external event) is input
on the X64 Xcelera-HS PX8 trigger input.
Virtual frame trigger can be 24V industry standard, TTL 5V or RS-422 and be rising or falling
edge active, active high or low, or double pulse rising or falling edge.
Virtual frame trigger control is configured for rising edge trigger in this example.
Virtual frame trigger connects to the X64 Xcelera-HS PX8 via the External Trigger Input 1 & 2
balanced inputs:
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Trigger Input #1 on connector J1: pin 1 (+) and 9 (-)
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Trigger Input #1 on connector J4: pin 19 (+) and pin 20 (-)
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Trigger Input #2 on connector J4: pin 21 (+) and 22 (-) for input #2
Camera control signals are output to the camera to trigger at all times in order to keep the
camera running and avoid bad acquired lines at the beginning of a virtual frame.
The camera control signals are either based on timing controls input on one or both X64
Xcelera-HS PX8 shaft encoder inputs or line triggers generated internally by the X64 Xcelera-HS
PX8.
The number of lines captured is specified by the Sapera vertical cropping parameter.
