Garmin VHF 215 AIS Technical Reference for Garmin NMEA 2000 Products - Page 6

Linear Backbone Construction The backbone is the main communication path of the NMEA 2000 network, so it is extremely important to construct the backbone properly. An improperly constructed backbone may prevent the network from functioning, or you may experience unexpected performance. The backbone consists of a combination of T-connectors and cables, terminated on both ends. All Tconnectors must connect to the sides of one another either directly or through a backbone cable extension. The top of a T-connector is used to connect a device or power to the network only, and the backbone cannot route through the top of a T-connector. NMEA 2000 Network with Correct Linear Backbone Construction Female terminator installed correctly The terminator must connect to the side of the last T-connector in the backbone. NMEA 2000 devices and power NMEA 2000 drop cables and network power cables must connect to the top of a T-connector, and never to the sides. Backbone cable If needed, the backbone can be extended using a cable connected to the sides of a T-connector. The maximum length of a single backbone cable is 100 m (328 ft.) Male terminator The terminator must connect to the side of the last T-connector in the backbone. NMEA 2000 Network with Incorrect Linear Backbone Construction NMEA 2000 devices and power NMEA 2000 drop cables and network power cables must connect to the top of a T-connector, and never to the sides. Male terminator installed incorrectly The terminator must connect to the side of the last T-connector in the backbone, and cannot connect to the top of a T-connector. Female terminator installed correctly Backbone cable installed correctly T-connector installed incorrectly T-connectors must connect to one another using the sides only, never the top. 6