Trigger - Matrox 4Sight User Manual

120 Chapter 10: Matrox Meteor-II for Matrox 4Sight
Master mode In master mode, Matrox Meteor-II /Multi-Channel
generates (using the PSG) the horizontal and/or vertical
(TTL) synchronization signals and supplies them to the video
source. This allows the video source to synchronize to the
board.

Trigger

Matrox Meteor-II /Multi-Channel accepts an external trigger
input which allows image acquisition to be synchronized to
external events. The board can operate in one of two modes, and
the selected mode is specified by the DCF.
Matrox Meteor-II /Multi-Channel can operate 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
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
Matrox Meteor-II /Multi-Channel can also operate in
asynchronous reset mode. In this mode, the digitizer resets the
camera to begin a new frame when the trigger signal is received.
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.
1. The polarity of the active and inactive levels of the trig-
ger signal are software programmable.
1
edge to capture a
1
.