Run and Trigger Options
There are two modes of capturing images, both controlled from the main Video form:
SnapShot. This captures a single image as quickly as possible after you click the button. The Movie form will then appear with the captured image.
Run. This will capture a sequence of images according to the timing you have specified on the Capture tab. The checkbox indicates whether a Run is active. Once a Run is started, there must be a Trigger at some point to define the final timing. You can always manually Trigger by checking the box. Run allows you to Abort the run before completion.
If you are in a Run, you have the option of having the pump run automatically (assuming a pump is present). These options are setup on the Pump tab.
The Trigger is an event which fixes the final timing of the Movie images. There will be a certain number of images captured prior to the Trigger and a certain number after, both set on the Capture tab. A number of things can cause a Trigger. If more than one Trigger event occurs, all those after the first are ignored.
Sources of Trigger events include:
Checkbox on Video form. The user manually triggers by clicking the checkbox .
Video Trigger. This is setup on the Capture tab. The user specifies a single point in the image to make a gray scale, i.e., brightenss, measurement. A blue cross-hair will appear at the point.
Video Trigger by Z<120. Z stands for gray scale. The overall gray scale range is 0 to 255. 120 is approximately in the middle, so this says trigger if the measured gray scale is darker than this mid value.
Video Trigger by delta Z>60. The current gray scale value is measured and stored when you click the point. If this changes, in either direction, by more than 60, cause a Trigger.
Trigger at Pump Completion. If the pump is run, its stopping will cause a Trigger.