Rudder sensor only works when AP is engaged

[Muaddib1116]

I'm having some autopilot issues, the rudder position readout on my p70 and my axiom mfd only shows up when Auto is engaged, not in standby. This is a recent development. I did a software update, and now the whole system needs to be recommissioned. When I start the dockside wizard, it doesn't seem to even recognize that there is a rudder sensor, since it goes into the setup prompts for a system without it (rudder limit angle, hard over time, etc.) It doesn't go into the prompts to calibrate the sensor center position and hard over positions. Any ideas on what's going on?


I have an EV400, 2x P70 control panels, and a Lewmar Mamba autopilot drive (which I selected as a type 2 rotary drive in the dockside wizard).

[Muaddib1116]

I tested the rudder sensor resistance values.

Red/Green:
Any Position 5.7-5.8k

Green/Blue:
Starboard Lock - 2.63k
Center - 3.07k
Port Lock -3.6k

Red/Blue:
Starboard Lock - 3.46k
Center - 2.98k
Port - 2.48k

A couple values slightly outside the range, but that seems like maybe it could be error in my multimeter?

[RonaldL]

Sensor seems to be ok
I see the same values at
https://www.svb24.com/en/raymarine-r...ransducer.html

Why the system doesn't recognize, I don't know,sorry

[smac999]

This happens when it’s using a virtual rudder. With no rudder feedback installed.

Measure voltage while turning. The wiper should go from 0-5v. With 2.5v at center.

[Pizzazz]

I would reset the autopilot heads. Your sensor seems OK.

[Muaddib1116]

I did a factory reset from the head unit. Then I powered down the ACU400 and reinstalled the sensor leads, powered it up and the heads showed rudder position in standby. So I ran the dockside wizard, it let me do the sensor lock to lock calibration and finished that up. I need to do the magnetic calibration, planning on doing that tomorrow morning.

After a day out, came back and turned one of the P70s on and the rudder position is not showing up again, unless I put it in Auto.

Hopefully it kept all the data from the dockside wizard setup, and hopefully it will do the calibration tomorrow properly. Maybe it's some issue with the ACU? hopefully since the rudder position shows up when in Auto, the pilot will operate properly?

[s/v Jedi]

This day and age, the rudder angle sensor must have only one connection: nmea2000. Same for the heading sensor. This provides all sensor data to be available even when the AP computer is switched off.

On the same note, the AP computer must have a nmea2000 connection from which it accepts heading and rudder angle data regardless of which manufacturer the sensor is from.

Sorry to see Raymarine is still messing with resistance based sensors.