Varex Imaging 2315NDT, Руководство пользователя

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USER
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ANUAL
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2315NDT v2 CMOS X-ray Detector User Manual
19.1.7 Continuous readout - Pre-programmed Exposure
Figure 17 Continuous readout - Pre-programmed exposure, two images example timing
In Pre-programmed exposure, the detector receives a trigger and grabs a pre-determined
number of images that can have different detector exposure times (see Figure 17 ). The number
of images (maximum of 4) and the detector exposure time of each image have to be previously
set by software (SCap or API). This acquisition only works with Software trigger and External
edge trigger source. In SCap, this mode is selected using Configuration > Exposure Mode >
Pre-programmed Exposure .
19.2 Readout Mode ‘Idle’
The v2 detectors can be programmed to be used with a readout mode ‘Idle’. This means that
once the detector is powered on, the sensor doesn’t read out the dark current but waits for a
request to come in to start the images acquisition.
In this way the synchronization between image request (trigger) and actual image acquisition is
immediate, but the first image will have accumulated dark current and hence it will be noisy or
even saturated. This image usually needs to be discharged.
Triggering the detector is the attempt to synchronize the detector to other devices, for example,
other X-ray sources that have their specific schemes of radiating X-ray pulses. In Idle readout
mode there are two trigger sources available:
•
Software Trigger (see Section 19.2.1 ).
•
External Edge Trigger (see Section 19.2.2 ).
(The signal levels on the trigger connectors are shown in Table 9 on page 16 ).
Once the detector is rightfully triggered, an image is acquired.
Due to the nature of the Idle readout mode, where the frame exposure time is determined by the
distance between two triggers, only the ‘Expose and read’ exposure mode is available in Idle
readout.