Matrox Solios eA, Установка и справочник по оборудованию, Страница: 93 / 196

Matrox Solios GigE acquisition section 93
Exposure timers
The auxiliary I/O controller has eight exposure timers. Each exposure timer can
generate exposure output signals to control the exposure time and other external
events related to the video source (such as a strobe). The exposure signals can be
output using auxiliary output signals or auxiliary I/O signals in output mode.
The exposure timers are 16-bit timers, allowing each to count up to 65535 clock
ticks before resetting.
The exposure timers can use one of the following as a clock source:
• A clock that is internally generated. Each exposure timer can use one of 17
possible internal clocks, whereby clock n has a frequency of 100/2
n
MHz and n
is a value between 0 and 16, inclusive. Therefore when using the slowest internal
clock, the 16-bit timers can generate an exposure signal with a duration of up to
42.95 secs (active time + delay).
• A clock from an external source. In this case, you must define an auxiliary input
signal (or an auxiliary I/O signal in input mode) as a timer-clock input; the
timer-clock input signal must meet the specification of the auxiliary signal. The
same timer-clock input can be used to clock different timers.
• A clock based on another exposure timer. Two exposure timer groups exist, 1 to 4
and 5 to 8. An exposure timer from group 1 to 4 can be used as a clock source for
a timer from group 1 to 4, but cannot be used as a clock source for a timer from
group 5 to 8, and vice versa.
To output an exposure signal, use the MIL-Lite function MdigControl() with
M_GRAB_EXPOSURE . To specify the clock source of an exposure timer, use
the MIL-Lite function MdigControl() with
M_GRAB_EXPOSURE_CLOCK_SOURCE.