Auxiliary Signals; Trigger - Matrox CronosPlus Installation And Hardware Reference

Auxiliary signals

Auxiliary signals are non-video signals that can be used to synchronize with, react
to, and/or cause external events. Matrox CronosPlus has three TTL auxiliary input
signals, four TTL auxiliary output signals, and one opto-isolated auxiliary signal.
The opto-isolated auxiliary input signal can be used to trigger image acquisition.
The other auxiliary signals can only be used to transmit or receive
application-specific user output or input.

Trigger

You can use the opto-isolated auxiliary input signal as a signal to trigger image
acquisition. The trigger is synchronous to the incoming video stream, and is
received through an opto-coupler that isolates the rest of the circuitry from outside
surges.
Matrox CronosPlus 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 two ways:
• Edge-triggered monoshot acquisition: The acquisition interface waits for the
rising/falling edge to capture a single frame.
• Level-sensitive "continuous" acquisition: The acquisition interface grabs
continuously while the level of the trigger is high/low.
❖ The polarity of the active and inactive levels of the trigger signal is software
programmable.
The trigger signal's negative component (OPTOTRIG-) is usually connected to
the ground of the trigger source.
To enable grabbing upon a trigger, use the MIL-Lite function MdigControl() with
M_GRAB_TRIGGER_STATE
MdigControl() with M_GRAB_TRIGGER_SOURCE.
*. As of MIL 10.
*
. To set the signal used to trigger the grab, use
Auxiliary signals 25