[TG] [TG11] Integrating legacy Seatalk devices

[Tom - Raymarine - Moderator]

If you measure resistance with your multimeter between the red terminals on the two Seatalk connectors on your T400G, you'll find that they're connected (<<1 ohm), meaning that if you connect 12V on one (via STNG), that should also power up the ST6001 connected to the other. If it doesn't then you have a fault somewhere - excess current being drawn or an open-circuit inside the 400G for example.

When you measured 12V being output from the 400G, was that loaded (ST6001 connected) or unloaded? If the latter, what do you see when the ST6001 (only) is connected?
Seeing a particular voltage does not mean that you can draw sufficient current to power a device - if you had a cracked solder joint or some corrosion somewhere for example then you might see 12V under no load but 1 or 2V when a small load was applied.

To reiterate, you should only ever have a single point of power in a combined ST1, STNG network. If you're considering multiple power supplies then you have another problem that you should solve rather than attempt to work around.

Regards,
Tom