ST1 vs STng for SPX-5 and p70R

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Dylancs,

Q1. Is this unnecessarily complicating the wiring?
A1. Maximum performance of devices having a SeaTalkng communications interface will occur when those devices have been interfaced to the system via SeaTalkng. As SeaTalk has been replaced by SeaTalkng communications, the SeaTalkng backbone which you will be creating will better position your system for any future devices having a SeaTalkng / NMEA 2000 communications interface which may be interfaced to the system. Doing so will also facilitate being able to more readily update software within the products having a SeaTalkng communications interface.

Q2. Is there actually anything to be gained by putting the p70R and the SPX-5 course computer on the STng network vs the ST1 network?
A2. As SeaTalk only supports communications of heading data a 1Hz, interfacing the autopilot to the SeaTalk backbone installed of the SeaTalk bus will permit the MFD to receive 10Hz heading data from the autopilot via the SeaTalkng backbone ... improving the performance of all heading dependent functions of the system.

Q3. Would the simplest solution to getting GPS position to the Ray218 VHF be to use a blue backbone cable from the current ST1-STng converter to a VHF-NMEA 0183 converter kit (basically just a second ST1-STng converter with adapter cable)?
A3. I favor this solution as it also open the door to adding an external GPS sensor (ex. Raystar 150 GPS, etc.) to the system, making if possible to switch off power to the MFD, while still being able to supply GPS data to the Ray218 VHF radio.