Overlapped Exposure Readout Trigger (Mode 14) - FLIR GRASSHOPPER 3 Series Technical Reference

7.1.6

Overlapped Exposure Readout Trigger (Mode 14)

Overlapped Exposure Readout mode is a vendor- unique trigger mode that is very similar to Standard External
mode, but allows for triggering at faster frame rates. This mode works well for users who want to drive exposure
start with an external event. However, users who need a precise exposure start should use
Trigger (Mode 0).
In the figure below, the trigger may be overlapped with the readout of the image, similar to continuous shot (free-
running) mode. If the trigger arrives after readout is complete, it starts as quickly as the imaging area can be
cleared. If the trigger arrives before the end of shutter integration (that is, before the trigger is armed), it is dropped.
If the trigger arrives while the image is still being read out of the sensor, the start of exposure is delayed until the
next opportunity to clear the imaging area without injecting noise into the output image. The end of exposure
cannot occur before the end of the previous image readout. Therefore, exposure start may be delayed to ensure
this, which means priority is given to maintaining the proper exposure time instead of to the trigger start.
2/10/2017
©2013-2017
FLIR Integrated Imaging
Solutions Inc. All rights reserved.
Figure 7.5: Trigger Mode 14 ("Overlapped Exposure/Readout Mode")
Registers—TRIGGER_MODE: 830h
Presence
ON
Polarity
Source
Value
Mode
Parameter
Grasshopper
[0] 1
[6] 1
[7] Low/High
[8-10] GPIO Pin
[11] Low/High
[12-15] Trigger_Mode_14
[20-31] None
®
3 PGE Technical Reference
7 Image Acquisition
Standard External
48