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The information contained in this document pertains to a dual use product controlled for export by the Export Administration
Regulations (EAR). Diversion contrary to US law is prohibited. US Department of Commerce authorization is not required prior to
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loading different symbology files. Refer to the Application Note written to address the individual
topic of interest for more information.
External Sync:
The Tau SWIR camera provides options for external synchronization and triggering. The
camera is in “Free Run” mode whenever the External Sync is Disabled. Options for the synchronized event
(integration, data readout, video output) are discussed below. When an option other than Free Run is
selected, a warning dialog will appear telling the user that an external synchronization source (3V to 3.3V
square wave) must be connected before using the new external sync mode.
Integration Priority:
Probably the most common synchronization task is to control the
start
of the FPA
integration period with an external signal. The Slave - Integration Priority mode offers the most flexibility
for accomplishing this.
Figure 29 illustrates the camera level timing of this mode. The externally provided frame sync controls the
start of the integration period, which causes scene charge to be collected for the length of time that has been
programmed by the user. The delay between external sync and the start of integration is 650ns±70ns. At
the end of the integration period, the FPA readout process begins for the integration period just ended. This
is shown in the lower part of the figure which includes the Camera link frame and line valid signals.
The duration of the readout process is determined by the user selected window size – all pixels in this
window must be read out. At a time that is approximately the selected integration time
prior to the end of
read out
it is possible to start the next integration period (i.e
. integrate while read
). This is indicated in the
figure by the end of the lockout period; at that point the camera will accept another frame sync input. As
illustrated here, the user waits a short period before issuing the sync – at that time, the integration period
and lockout period begin again. During the lockout period, the camera will ignore any external syncs.
