es 75 MFD to be installed and upgrading older ST70 autopilot

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum tbeson,

The SeaTalkng spur port of a/c/e/eS/gS-Series MFD is designed to be interfaced backbone spur socket of a SeaTalkng T-Piece, SeaTalkng 5-Way Connector, or SeaTalkng Inline Terminator via an appropriate length SeaTalk to SeaTalkng Spur Cable. Unlike the a/c/e/eS/gS-Series MFDs, ST70 Autopilot Control Heads, and ST70 Multifunction Instrument Displays, the i40 Instrument Displays feature a SeaTalk rather than a SeaTalkng communications interface. The i40 Instruments may be interfaced to a SeaTalkng backbone via an E22158 SeaTalk to SeaTalkng Converter Kit. The SeaTalkng Converter may be interfaced to the currently installed backbone by connecting one of the Converter's blue backbone sockets to the blue backbone socket of a SeaTalkng T-Piece or SeaTalkng 5-Way Connector within the presently installed SeaTalkng backbone networking your autopilot's components to one another.