RL70C not communicating with RC631

[Chuck - Raymarine - Moderator]

Q. I did as you said and disconnected the red lead from the st1-stng converter to the autopilot but left the yellow and silver connected. I also left the yellow,silver and red connected from the 400g to the st6001 control head. However when doing so, I lost all power to the control head.

Only when I put the red lead from the st1-stng converter back onto the 400G did it power the ST6001 control head.


With that configuration, i could get the mfd to turn the autopilot on and off but i had a seatalk fail showing at the control head so had no way of adjusting the parameters of the autopilot.

Is the 400G actually supplying power to the buss or is it just passing it through?

Where should i go from here?

A. The SeaTalk ports of the 400G autopilot course computers are designed to supply power to a SeaTalk bus. As such, a meter would measure +12VDC across its the red and silver SeaTalk terminals of both of its SeaTalk port. As indicated previously, the SeaTalk bus must be disconnected from its power source (this minimally be be the red terminals of the 400G autopilot course computer's SeaTalk ports. SeaTalk autopilot control heads are designed to be powered by the SeaTalk bus. As such, all three leads of SeaTalk cables to connected to the autopilot control head must be connected to the corresponding leads of the SeaTalk bus. When using a SeaTalk to SeaTalkng Converter (s) the SeaTalk bus(ses) will instead be powered by the SeaTalkng backbone via the SeaTalk to SeaTalkng Converters. The power insertion point within the SeaTalkng backbone will be located at the approximate midpoint of the backbone's LEN load. Insufficient power dellivered to the SeaTalk bus(s) or a device having failed SeaTalk communications circuitry will cause the autopilot control head to report SeaTalk failure. If wired as has been indicated within this response, then it is recommended that the voltage to the autopilot control head be measured to verify 12VDC across its red and shield pins. Should this voltage not be observed, then you should verify that the vessel's batteries have been fully charged and that afterwards while still connected to shore power that the system be tested again.

Should the problem persist, then an updated system diagram should be attached to your response.