The GPS100 doesn't actually compute and transmit the twilight AM time over an NMEA 2000 network. However, the DSM200 and DSM250 receive enough information from the GPS100 (time and position) to compute the twilight AM time. You display the twilight AM time on a DSM200 or DSM250 in the following way. Enter menu mode, scroll to "Favorite Screen Setup..." and press enter. Scroll to the favorite screen where you would like to view the twilight AM time and press enter. Scroll to "Data:" and press enter. Scroll to "Time" and press enter. Scroll to "Twilight AM" and press enter. Press the back key three times to exit menu mode and return to the normal viewing mode. Scroll through your screens to the favorite screen you selected for twilight AM time.