Data Translation 18729, User Manual

Page: 27 / 128

Chapter 2
10
Triggers
DT3120 board can accept one of the following trigger sources:
• A software trigger
−
The board can acquire a frame when a
software command is issued.
• An external trigger
−
By attaching a digital signal to connector J1
on the board, you can synchronize frame acquisitions with
external events.
By default, the external trigger is disabled. Through software,
you can enable the external trigger.
You program the trigger source for the acquisition using software.
You can specify whether to start image acquisition when the board
detects either a low-to-high edge (rising-edge) transition or a
high-to-low edge (falling-edge) transition.
The incoming external trigger is forwarded to the device driver as an
interrupt. The interrupt is processed by the device driver to start the
acquisition, if desired.