BSL PRO 4 Manual - Biopac

Part B — Acquisition Functions 155External Trigger requires a TTL signal from a third-party device such as a stimulator, pump, presentationprogram or force plate.3) Choose Pos Edge or Neg Edge from the menu to indicate whether you want a positive or negative edgeto trigger the acquisition. Look at the nature of the signal to determine which is most appropriate.‣ A Positive edge occurs when the signal begins below the threshold and crosses above it.‣ A Negative edge occurs when the signal begins above the threshold and drops below it.4) Set the Trigger level by keying in a value or by moving the scroll bar to adjust the threshold value.When setup is complete, close the Set up Triggering window and click the button to begin acquisitionas soon as the trigger is activated.The dialog box shown above is set to begin acquisition when a level of 25.00 mV is reached on analogchannel 4.BSL PRO Manual