Basler A640F, User Manual

Page: 27 / 188

Basic Operation & Standard Features
BASLER A640
f
3-5
DRAFT
3.2.4 Controlling Exposure Start with a Software Trigger
Exposure start can be controlled by sending a software trigger command to the camera via the
1394 bus. The Trigger Mode control register (see page
4-32 ) is used to enable the ability to start
image exposure with a software trigger. The Software Trigger control register (see page 4-27 ) is
used to set the software trigger.
If you are triggering the camera with a software trigger, only the programmable exposure mode is
available. In programmable mode, exposure starts when the Trigger field of the Software Trigger
control register is set to 1. The length of the exposure is determined by the shutter setting as
described in Section
3.2.1 . The Trigger field will self clear shortly after exposure start. Figure 3-3
illustrates programmable exposure with a software trigger.
Figure 3-3: Programmable Exposure with a Software Trigger
Enabling the Software Trigger Feature
To enable the software trigger feature:
• Set the On/Off field of the Trigger Mode control register to 1 to enable triggering.
• Set the Trigger Source field of the Trigger Mode control register to 7 to select software trig-
gering.
• Set the Trigger Mode field of the Trigger Mode control register to 0 to select the programma-
ble exposure mode.
Using the Software Trigger Feature
To use the software trigger feature, the camera must be set for continuous-shot operation. If more
precise control of exposure start time is desired, you should also monitor the Trigger Ready signal
and you must base the timing of the software trigger on the state of the Trigger Ready signal. (See
Section
3.2.8 for more information on the Trigger Ready signal.)
The following descriptions assume that you are using a software trigger to start exposure and that
you are monitoring the Trigger Ready signal.