Trigger - Matrox 4Sight User Manual

Matrox Meteor-II /Standard grab section
The video decoder also features automatic gain control (AGC).
However, you can disable this feature (MIL-Lite MdigControl()
with
M_GRAB_AUTOMATIC_INPUT_GAIN
and adjust the gain manually (MdigControl() with
M_GRAB_INPUT_GAIN

Trigger

Matrox Meteor-II /Standard accepts an external trigger input
which allows image acquisition to be synchronized to external
events. The trigger is synchronous to the incoming video stream
and it is received through an opto-coupler that helps isolate the
rest of the circuitry from surges. Matrox Meteor-II /Standard
operates in next valid frame/field mode. When in this mode, the
digitizer waits for the next valid frame or field (as specified by
the DCF file) before commencing the grab. This trigger mode
functions in one of three ways:
Edge-triggered monoshot acquisition: The VIA (Video
Interface Asic) waits for the rising/falling* edge to capture a
single frame.
Edge-triggered continuous acquisition: The VIA waits
for the rising/falling* edge to start a continous grab.
Level-sensitive "continuous" acquisition: The VIA grabs
continuously while the level of the trigger is high/low*.
* The polarity of the active and inactive levels of the trigger
signal are software programmable.
Trigger signals connected to the OPTOTRIG- and OPTOTRIG+
input pins, pass through an opto-coupler, a device that protects
the board from outside surges; OPTOTRIG- is usually
connected to the ground of the trigger source. The voltage
difference across OPTOTRIG+ and OPTOTRIG- must be
between 4.05 V and 9.16 V for logic high, and between -5.0 V
and 0.8 V for logic low. Refer to Appendix D for the pinouts of
these signals on your board.
).
115
set to
M_DISABLE
)