When a low level (<1.4V) is received the channel output will be turned on and when the level is equal or greater than 1.4V output will be turned off.
To turn of the external trigger capability press System to enter the system utility interface. By default, the “Setting” tab is selected. Press the Up/Down arrow key to switch the parameter focus to “Trig In”, and press the Left/Right arrow key or the knob to enable the trigger input function.