Xtium2-CL MX4 User's Manual
Xtium2-CL MX4 Reference
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Supported Events and Transfer Methods
Listed below are the supported acquisition and transfer events. Event monitoring is a major
component to the Trigger-to-Image Reliability framework.
Acquisition Events
Acquisition events pertain to the acquisition module and provide feedback on the image capture
phase.
Event
Description
External Trigger
(Used/Ignored)
Generated when the external trigger pin is asserted, which indicates the start of
the acquisition process. There are two types of external trigger
events: ‘Used’ or
‘Ignored’. Following an external trigger, if the event generates a captured image,
an External Trigger Used event will be generated
(CORACQ_VAL_EVENT_TYPE_EXTERNAL_TRIGGER). If there is no captured image,
an External Trigger Ignored event will be generated
(CORACQ_VAL_EVENT_TYPE_EXTERNAL_TRIGGER_IGNORED). An external trigger
event is ignored if the event rate is higher than the possible frame rate of the
camera.
Start of Frame
Event generated during acquisition, with the detection of the start of a video frame
by the board acquisition hardware. The Sapera event value is
CORACQ_VAL_EVENT_TYPE_START_OF_FRAME.
End of Frame
Event generated during acquisition, with the detection of the end of a video frame
by the board acquisition hardware. The Sapera event value is
CORACQ_VAL_EVENT_TYPE_END_OF_FRAME.
Data Overflow
The Data Overflow event indicates that there is not enough bandwidth for the
acquired data transfer without loss. Data Overflow would occur with limitations of
the acquisition module and should never occur.
The Sapera event value is CORACQ_VAL_EVENT_TYPE_DATA_OVERFLOW.
Frame Valid
Event generated on detection of the start of a video frame by the board acquisition
hardware. Acquisition does not need to be active; therefore, this event can verify a
valid signal is connected. The Sapera event value is
CORACQ_VAL_EVENT_TYPE_VERTICAL_SYNC.
Pixel Clock
(Present/Absent)
Event generated on the transition from detecting or not detecting a pixel clock
signal. The Sapera event values are CORACQ_VAL_EVENT_TYPE_NO_PIXEL_CLK
and CORACQ_VAL_EVENT_TYPE_PIXEL_CLK.
Frame Lost
The Frame Lost event indicates that an acquired image failed to transfer to on-
board memory. An example is if there are no free on-board buffers available for
the new image. This may be the case if the image transfer from onboard buffers to
host PC memory is not sustainable due to bus bandwidth issues or no host buffers
are available to receive an image.
The Sapera event value is CORACQ_VAL_EVENT_TYPE_FRAME_LOST.
External Line Trigger
Too Slow
Event which indicates that the detected shaft encoder input tick rate is too slow for
the device to take into account the specified shaft encoder multiplier value. The
Sapera event value is
CORACQ_VAL_EVENT_TYPE_EXT_LINE_TRIGGER_TOO_SLOW.
Line Trigger Too Fast
Event which indicates a previous line-trigger did not generate a complete video
line from the camera. Note that due to jitter associated with using shaft encoders,
the acquisition device can delay a line trigger if a previous line has not yet
completed. This event is generated if a second line trigger comes in while the
previous one is still pending. This event is generated once per virtual frame. The
Sapera event value is CORACQ_VAL_EVENT_TYPE_LINE_TRIGGER_TOO_FAST.
Shaft Encoder
Reverse Count
Overflow
Event which indicates that the shaft encoder has travelled in the opposite direction
expected and that the number of pulses encountered during that travel has
exceeded the acquisition device counter. The acquisition device will thus not be
able to skip the appropriate number of pulses when the expected direction is
detected. The Sapera event value is
CORACQ_VAL_EVENT_TYPE_SHAFT_ENCODER_REVERSE_COUNT_OVERFLOW.
