Transducer and Power Questions

[Captain Addison]

Good afternoon

We are planning the installation of our new Axiom 9” with Quantum radar, and an i70s system pack. The install is going in a Gozzard 36 sailboat. The existing system is a 1995 Autohelm ST50 Plus suite; we plan to keep only the existing autopilot.

Attached is a rough schematic diagram of our planned equipment.

Transducer questions:
Currently there is a depth transducer that is installed forward of the keel looking straight down, and a speed transducer which is installed in the keel orientated at roughly 90 degrees. We plan to replace the depth transducer with a CPT-110 Down Vision and replace the speed with the Airmar DST800 that came with the i70s system pack.

Will the CPT-110 provide depth information to the system when only wanting to view depth?
Given the 90 degree orientation of the DST800 can we simply not connect depth wires to the ITC5 and reply on the CPT-110 for depth?
Is it that simple, or are we missing something?

Power Questions:
Currently, the entire system seems to be powered by one switch at the DC panel. We wish to be able to power the Auto pilot and the instruments separately. Perhaps even power the Quantum radar separately to save power. As I’ve studied the installation manuals I’ve noted that 12v power is supplied to the Axiom, the ITC5, the Seatalk to Seatalk ng converter, and the Quantum radar. The existing system also had 12v power supplied.

Please help me understand where we should connect 12v power to the new backbone and how power is shared between the components.
Is it feasible to switch the items separately as suggested above?


I haven’t completely got my mind around the Seatalk to Seatalk ng converter just yet, but will save any questions until we get in a little deeper and understand exactly how the existing system is installed.

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Addison,

Q1. Currently there is a depth transducer that is installed forward of the keel looking straight down, and a speed transducer which is installed in the keel orientated at roughly 90 degrees. We plan to replace the depth transducer with a CPT-110 Down Vision and replace the speed with the Airmar DST800 that came with the i70s system pack.

Will the CPT-110 provide depth information to the system when only wanting to view depth?
A1. It's not quite clear what is meant by "only wanting to view depth". However, numerical depth data from the fishfinding product that the CPT-110 has been interfaced may be display within the MFD's Databar, Databoxes, Data application, and via other compatible devices which the Data Master MFD has been interfaced to. Depth may also be view graphically via the MFD's Fishfinder application.

Q2. Given the 90 degree orientation of the DST800 can we simply not connect depth wires to the ITC5 and reply on the CPT-110 for depth?
Is it that simple, or are we missing something?
A2. Your suggestion is valid for the analog DST800 transducers packaged with ST70 System Packs. Depth for the system would then be provided CPT-110.

Q3. Currently, the entire system seems to be powered by one switch at the DC panel. We wish to be able to power the Auto pilot and the instruments separately. Perhaps even power the Quantum radar separately to save power. As I’ve studied the installation manuals I’ve noted that 12v power is supplied to the Axiom, the ITC5, the Seatalk to Seatalk ng converter, and the Quantum radar. The existing system also had 12v power supplied.

Please help me understand where we should connect 12v power to the new backbone and how power is shared between the components.
Is it feasible to switch the items separately as suggested above?
A3. Please click here to view a FAQ addressing this subject. As indicated within the FAQ, it is considered to be a best practice to create separate power circuits for the radar scanner, MFD(s), autopilot, SeaTalkng backbone, VHF radio(s), and fishfinder sounder modules. The SeaTalkng backbone will only supply power to devices which are specifically designed to be powered via a SeaTalkng / NMEA 2000 backbone (ex. instrument displays, autopilot control heads, autopilot CCUs, GPS sensors, etc.). Other products (MFDs, fishfinder sounder modules, radomes, VHF radios, etc.) are designed to be powered via the power cable's supplied with the product.

[Captain Addison]

Thank you, Chuck, this is helpful. The referenced power circuit discussion clears up some confusion.

I'm sure we'll have more questions once we get started, but this was helpful as we continue to plan on installation.

[Chuck - Raymarine - Moderator]

You're welcome.