Communication environment in which full duplex terminals work. Any data sent to the host is echoed back to the device that sent the data. Edge Trigger mode The laser only turns on or off when you pull the trigger–it completely ignores the trigger release. Thus, if you pull the trigger, it will go on and stay on when you release the trigger. Pulling the trigger a second time will cause the laser to go off. If the laser is on, the timeout and number of decodes per trigger event operate normally and will turn the laser off. Edge Trigger mode is most often used in remote triggering applications. See also Level Trigger mode. edge triggering A scanner trigger configuration that makes the laser turn on after you pull the trigger and stay on until you pull it a second time. Simply releasing the trigger does not turn the laser off. If the laser is left on, the scanner timeout turns the laser off. Contrast with level triggering.