Photon Focus DR1-D3360-192-G2-8, Руководство пользователя, Страница: 46 / 119

5 Functionality
The falling edge of the trigger pulse is delayed by the time t
d
−
iso
−
input
which results from the
signal isolator. This signal is clocked into the FPGA which leads to a jitter of t
jitter
. The pulse is
then delayed by t
trigger
−
delay
by the user defined value which can be configured via camera
software. After the trigger offset time t
trigger
−
offset
the exposure is stopped.
In the trigger pulse width controlled exposure mode the image sensor operates
in sequential read out mode (see Section 5.1.5). The maximal frame rate is there-
fore lower than normal as the exposure start is only allowed after the read out
of the previous frame.
5.2.5 Trigger Delay
The trigger delay is a programmable delay in milliseconds between the incoming trigger edge
and the start of the exposure. This feature may be required to synchronize the external strobe
with the exposure of the camera.
5.2.6 Strobe Output
The strobe output is an isolated output located on the power supply connector that can be
used to trigger a strobe. The strobe output can be used both in free-running and in trigger
mode. Strobe settings:
Strobe_Delay Programmable delay delay from the active input trigger edge to the rising edge
of the strobe output signal.
Strobe_PulseWidth Width of the trigger pulse in µ s. A setting of 0 turns off the strobe output.
Strobe_Invert Inverts the strobe output signal. Strobe_Invert=False: strobe signal active high,
Strobe_Invert=True: strobe signal active low.
The strobe output needs a separate power supply. Please see Section 6.5, Fig.
5.14 and Fig. 5.15 for more information.
5.2.7 Burst Trigger
The camera includes a burst trigger engine. When enabled, it starts a predefined number of
acquisitions after one single trigger pulse. The time between two acquisitions and the number
of acquisitions can be configured by a user defined value via the camera software. The burst
trigger feature works only in the mode "Camera controlled Exposure Time".
The burst trigger signal can be configured to be active high or active low. When the frequency
of the incoming burst triggers is higher than the duration of the programmed burst sequence,
then some trigger pulses will be missed. A missed burst trigger counter counts these events.
This counter can be read out by the user.
The burst trigger mode is only available when TriggerMode =On. Trigger source is determined by
the TriggerSource property.
The timing diagram of the burst trigger mode is shown in Fig. 5.18.
.
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