Exposure Control and Asynchronous Reset
Many industrial grade cameras allow for asynchronous reset while enabling exposure control. This means that, at some asynchronous instant, the camera is forced to enter into an "Expose-Readout" sequence, called an acquisition phase.
The image seen by the camera during the exposure condition is sent out of the camera during the readout condition. It is often advisable to keep the exposure duration short to remove any blurring effect if the observed scene is in movement.
The figure shows two successive camera cycles. Quite often, it is not possible to overlap the exposure condition of a given cycle with the readout condition of the previous cycle.
Two successive camera cycles