Download Chapter 6: Matrox Pulsar hardware reference

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Chapter 6: Matrox Pulsar hardware reference
Trigger
Matrox Pulsar accepts an external trigger input which allows
image acquisition to be synchronized to external events. The
board accepts either a TTL or an RS-422 external trigger signal.
The TTL level signal must have a maximum amplitude of 5 V.
A signal over 2 V is considered high, while anything less than
0.8 V is considered low. The transition of 0.8 V to 2 V is
considered to be the rising edge.
The trigger signal’s pulse width must be greater than one pixel.
You can determine the pulse width by taking the inverse of the
pixel frequency. For example, if the pixel frequency is
12.27 MHz, the pulse width is 1/12.27 MHz ≈ 82 nanoseconds.
▲ Warning
The trigger signal on Matrox Pulsar is not buffered or
conditioned. The circuits on Matrox Pulsar are sensitive to
static electricity and surges. Be careful about what is hooked
up to the board since there is no circuit protection.
There are different ways to provide some protection. For
example, you can add an opto-coupler to your TTL trigger
source. This would help isolate the rest of the circuitry from
surges.
Exposure
Matrox Pulsar also has two software and hardware
re-triggerable timers whose outputs drive the EXPOSURE
signals of the 50-pin digital connector. These timers allow you
to control the video source exposure time or other related
external events.
The controls for the trigger, timers, and all video source settings
are configured in the DCF file; however, you can change the
trigger mode, exposure time, input-signal gain, and LUT
palette, using the MIL-Lite command MdigControl().