Matrox Matrox Radient eV-CXP, Установка и справочник по оборудованию, Страница: 37 / 70

Auxiliary signals 37
Next valid frame and asynchronous reset modes
Matrox Radient eV-CXP can operate in two modes: next valid frame mode or
asynchronous reset mode. In next valid frame mode, the board waits for the next
valid frame (as specified by the DCF file) before starting the grab.
In asynchronous reset mode, the board resets the video source to begin a new frame
when a trigger signal is received. The board can send an exposure signal to reset
the video source.
Exposure timers
Matrox Radient eV-CXP has four 16-bit exposure timers, which operate on a
125 MHz internal clock. These timers can each generate an exposure output signal
with up to two pulses.
Exposure output signals allow you to control the exposure time and other external
events related to the video source (such as a strobe). An exposure output signal
can be output on any of the auxiliary output signals or auxiliary I/O signals in
output mode. An exposure signal can also be sent to a video source as a CoaXPress
GPIO signal.
To output an exposure signal, use the MIL-Lite function MdigControl() with
M_GRAB_EXPOSURE... .
Trigger signals
You can use any of the auxiliary input signals of Matrox Radient eV-CXP (or
auxiliary I/O signals in input mode) as a trigger. A trigger signal can be used to
initiate image acquisition, or prompt an on-board event.
Note that only one auxiliary input signal can be rerouted to a CoaXPress trigger
signal, per video source, at a time.
Timing requirements
When you use an external signal as a trigger, the pulse width of the signal must
be at least 16 nsec (2 clock periods at 125 MHz).
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Note that these timing requirements apply for any auxiliary input signal.
To enable grabbing upon a trigger, use the MIL-Lite function MdigControl() with
M_GRAB_TRIGGER ; to set the source of the signal used to trigger the grab, use
MdigControl() with M_GRAB_TRIGGER_SOURCE. To start an exposure
timer upon a trigger, use MdigControl() with
M_GRAB_EXPOSURE_SOURCE .