How do I connect a Yacht Devices tank adapter to a Raymarine C120e over NMEA 2000?
I want to connect a Yacht Devices tank level adapter to my Raymarine chartplotter, which I know as a C120e. What cables and network connections do I need, and how do I get the tank level to appear on the screen?
Answer
Connect the Yacht Devices tank adapter as a spur on a single powered, correctly terminated NMEA 2000 or SeaTalkng backbone, with the Raymarine display on the same network. First confirm the exact Raymarine model and adapter part number: "C120e" is ambiguous, and the display must support tank data as well as the physical connection.
Check the model labels
Read the model label on the back of the plotter or check its system information page. Raymarine sold a C120 Classic, C120W and E120; the later c/e generation includes the c125, c127, e125 and e127. Network sockets and display functions differ between these models.
A later display with a SeaTalkng connection can join an NMEA 2000 network through a suitable adaptor cable. A C120 Classic uses the older SeaTalk2 interface. Do not follow later c/e-series wiring instructions or assume it will display tank-level messages just because a physical connection is possible.
Check the Yacht Devices label too. If it is a YDTA-01 tank adapter, identify whether it has a DeviceNet Micro-C connector or a Raymarine-style SeaTalkng connector. The connector determines which cable you need; either version still requires the correct sender settings.
Use one backbone
NMEA 2000 and SeaTalkng use compatible network communications but different connectors. This connection normally needs a physical adaptor cable rather than a protocol converter.
- Existing SeaTalkng backbone: connect the plotter to a white spur socket. Connect a Micro-C tank adapter to another white spur socket through a SeaTalkng-to-DeviceNet adaptor cable.
- Existing Micro-C backbone: connect the tank adapter to a T-piece, then connect a compatible SeaTalkng plotter to another T-piece through an adaptor cable.
- No existing network: install a small backbone with a fused 12 V power connection, two terminators and separate spurs for the display and adapter.
On SeaTalkng, blue connections form the backbone and white connections serve individual devices. Choose the DeviceNet adaptor's male or female connector to match the mating socket. "NMEA 2000 adaptor" alone does not specify enough to buy the right cable.
Fit one 120-ohm terminator at each physical end of the backbone. Keep ordinary device spurs within the usual 6 m maximum. Do not join two separately terminated backbones.
Switch off the plotter and network supplies before changing wiring. Isolate any additional sender or gauge supply before working at the tank.
Match the tank sender
The adapter needs the correct sender characteristics to produce useful readings. Common resistive senders include European units with a range of 0 to 180 ohms and American units with a range of 240 to 33 ohms. Their resistance changes in opposite directions as the tank fills.