Photon Focus D-2048 CameraLink Series, User Manual

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5 Functionality
Free running The trigger is generated internally by the camera. Exposure starts immediately
after the camera is ready and the maximal possible frame rate is attained, if Constant
Frame Rate mode is disabled. In Constant Frame Rate mode, exposure starts after a
user-specified time (Frame Time) has elapsed from the previous exposure start and
therefore the frame rate is set to a user defined value.
Interface Trigger In the interface trigger mode, the trigger signal is applied to the camera by
the CameraLink
®
interface. Fig. 5.15 shows a diagram of the interface trigger setup. The
trigger is generated by the frame grabber board and sent on the CC1 signal through the
CameraLink
®
interface. Some frame grabbers allow the connection external trigger
devices through an I/O card. A schematic diagram of this setup is shown in Fig. 5.16.
I/O Trigger In the I/O trigger mode, the trigger signal is applied directly to the camera by the
power supply connector (via an optocoupler). A setup of this mode is shown in Fig. 5.17.
The electrical interface of the I/O trigger input and the strobe output is described in
Section 6.1.3.
C a m e r a
S y s t e m P C
M a c h i n e V i s i o n
B
A
D a t a C a m e r a L i n k
P o w e r
E X S Y N C ( C C 1 ) / S o f t t r i g g e r
C a m e r a L i n k
T M
F r a m e G r a b b e r
Figure 5.15: Interface trigger source
5.2.3 Exposure Time Control
Depending on the trigger mode, the exposure time can be determined either by the camera or
by the trigger signal itself:
Camera-controlled Exposure time In this trigger mode the exposure time is defined by the
camera. For an active high trigger signal, the camera starts the exposure with a positive
trigger edge and stops it when the preprogrammed exposure time has elapsed. The
exposure time is defined by the software.
Trigger-controlled Exposure time
In this trigger mode the exposure time is defined by the
pulse width of the trigger pulse. For an active high trigger signal, the camera starts the
exposure with the positive edge of the trigger signal and stops it with the negative edge.
External Trigger with Camera controlled Exposure Time
In the external trigger mode with camera controlled exposure time the rising edge of the
trigger pulse starts the camera states machine, which controls the sensor and optional an
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