Note: Whilst the MIDI In function allows for Trigger 2 to read incoming MIDI Data and play Trigger samples, SSD5 is a better-suited plugin for this sort of application. Users can download the Free version here. https://ssd5-free.dl.drumclassroom.net/
For more information on the difference between Trigger 2 and SSD5, refer to this article.
1. In Digital Performer, create one new midi track, and one new audio track (Under "project in menu bar).
Select your audio track. Click the small triangle next to the output meter to bring up the inserts. Click on the one of the effect slots and load Trigger.
2. Double-click the newly inserted Trigger 2 plugin. Go to the settings page in Trigger 2, and check MIDI in. Set the channel and note according to preference.
3. In Browser, load up an instrument, make sure audition is set to "on". Click on one of the instrument slots, and ensure the instrument plays.
4. Go to your midi track. Select the output "Where it says O", and change it to the following: "Trigger 2: Name of Audio Track : Insert A: Insert A- (Channel Number selected in Step 2)".
5. Switch your Window Set to MIDI mode. Here, you will be able program MIDI patterns to use with Trigger, using the note that you select in your Trigger Settings page in step 2.