Use the Trigger TTL action to insert TTL triggers into an experiment macro to initiate specific events from various components during your experiment.
From the Actions tab on the Design tab, select Trigger TTL as the action and then select Options. The TTL Action Options window is displayed.
Enter the appropriate channel in the TTL Channel field.
Enter the desired pulse duration (in msec) for this TTL trigger in the Pulse Duration field.
Click the Done button.