18
The
Trigger Settings
dialog box controls the settings of the trigger in the camera.
Normally the camera should be in free-running mode, with
P2 TTL Enable
checked as in
the picture above. That configuration will support both, external and internal
Trigger
modes.
The Camera link group box enables and controls the CC1 trigger input in the camera link
interface of the camera. Typically this is used in the configuration with a frame grabber
board and not with camera running in USB mode.
The
P2 TTL trigger
input is an input on an extra pin of the power connector of the camera.
If you have ordered a power supply with the trigger input option you will have a nine pin
connector where you can apply your trigger.
The
Sync Exp
check box should be left unchecked. It is documented in the detailed
documentation below and is typically not used
The FastCamera supports the following trigger modes:
Free Running
in which the frame rate is determined by the value in the user interface.
Single Edge
in which a frame is taken on each trigger from the digital input selected
below.
Multi Edge
is not supported by the USB software, but provides for a burst of images to
be collected on each trigger.
The
Post-Trigger Frames
field
defines the relative position of the Trigger in the
captured
sequence of video frames
.
The Trigger can mark beginning, end, or somewhere in the
middle of the frames sequence depending on the user application. Its
edit box takes a
number from zero to 65535, which is the number of frames to be taken before stopping
data collection after the trigger is detected (manual, through the software interface or
external, via a cable).
Note:
you can set the post trigger frame count so high that the
trigger image will not be in the camera memory’s circular buffer when writing stops; see the
discussion below about camera memory states.
A value of zero
will cause the camera to
stop immediately after receiving the
Trigger
.
Finally, the
Clk/line
field defines the number of clocks the camera uses to read out each
line from the image sensor. This should normally be set to
160
but can be as low as
135
clocks/line
for the highest rate operation of the camera. It is normally used to slow down
the camera link output of the camera, which is irrelevant for USB operation of the camera.
This setting affects the maximum frame rate you can obtain with the camera. The frame
rate can not exceed the frame readout time which is equal to the
Clk/line
value plus 1
times the number of lines in the image divided by 66,666,666. (I.e. the sensor clock
speed). If you attempt to set the exposure to a larger value than the frame readout time
you will get a flashing effect with overall image brightness changing from frame to frame.
