2015 Twin 150's - connecting to Garmin

[c6mcfall]

Want to display engine data on the Garmin but unsure on what all I need. There is a bus that has (3) connections for Devices + (2) bus connections. One has a terminator and the other has a connection into the bus (guessing that's power???) I know I'd need a NMEA2000 starter kit to extend the NMEA 2000 network form the Garmin but do I need another Yamaha "Bus"? to get the bus connected to the NMEA 2000 network? Wish they'd just put what you need in the dang manuals..

Thanks in advance