| Acquisition triggering |
Thie Triggers window controls options for automatic initiation of recording. This allows the program to wait until some condition is met before it starts sampling data. The 'trigger' is a value for one of the channels; data in that channel must meet the user-set trigger condition -- either exceed or fall below the trigger value -- before LabHelper begins sampling.
The trigger window allows you to:
When all of these options are correctly set, click the 'Triggering OK' button.
When sampling is started (or restarted), the program draws the normal channel display on the screen. It displays the triggering conditions at the top of the screen, along with a continuously updated readout of the current value of the trigger channel (in Chart mode; in Oscilloscope mode there is no trigger channel readout). As soon as the trigger condition is met, normal sampling begins.
Note that you can interrupt trigger scanning and manually initiate sampling from the keyboard. Hitting the spacebar, the 'return' key, or clicking the mouse (or the button) will immediately initiate normal data collection. Hitting the 'esc' key will stop scanning and open the OPTIONS window.
If the trigger condition is constantly met, the computer will continually restart sampling, leaving little time to check the keyboard. To insure a response to the 'tab' or 'escape' key, hold the keys down until the computer does what you want.