Fishfinder, radar, and cartography features cannot be shared among the system's MFDs when they have been networked via a SeaTalkng / NMEA 2000 backbone alone. Proper installation would require that the MFD's be interfaced to one another or to a HS5 RayNet Network Switch via an appropriate length of RayNet (F) to RayNet (F) Cable. One of the MFDs will be interfaced to the backbone and will be the only MFD within the system (even though others may be interfaced to the backbone) which will communicate with the backbone. This MFD will be designated as the system's Data Master. The system's Data Master MFD will share data from the system's backbone to the system's other networked MFDs. All MFDs must be operating with the same version of software ... in this case LightHouse II v19.03 software is recommended.