NAVpilot-711C – Does it offer ±10 V analog rudder control like the NAVpilot-1000?

[wandreis]

Hi Furuno team,


Could you please confirm whether the NAVpilot-711C (FAP-7011C control head + FAP-7002 processor) supports an analog rudder control output of −10 V to +10 V, similar to what is documented for the NAVpilot-1000? I attached a screenshot from the NAVpilot-1000 specs showing “Rudder control (analog): 0–5 V (min), −10 to +10 V (max) (5 mA max).”


My application

• Workboat with hydraulic steering.
• The vessel’s proportional control is achieved by feeding a −10 V…+10 V command into a third-party PWM valve driver, which then modulates the hydraulic solenoid valves proportionally (greater helm amplitude = faster flow; smaller amplitude = slower flow).

What I can’t find in the 711C docs

• On the 711C I only see the SOL-A / SOL-B / COMMON connections to drive solenoids directly. If these are simple ON/OFF outputs, they would bypass my external PWM driver and could introduce “jerks” in the hydraulics rather than proportional control.

Questions

1. Does the NAVpilot-711C provide a dedicated analog rudder command output (±10 V) comparable to the NAVpilot-1000? If yes, which terminals and what menu settings enable it?
2. If the 711C does not natively output ±10 V, is there an official Furuno interface module (or recommended method) to convert the 711C’s steering command to ±10 V (or 4–20 mA) for a proportional valve controller? Part numbers would be greatly appreciated.
3. When using SOL-A / SOL-B, are these strictly ON/OFF drivers, or can the 711C modulate them proportionally (e.g., PWM/ramping) to act like a proportional command? If modulation is available, which parameters control the behavior (gain, rate, soft-start, etc.)?
4. Do you have any application notes for integrating the NAVpilot-711C with proportional hydraulic systems that rely on an external PWM driver?

Thanks in advance for any guidance. The goal is to keep the existing proportional architecture and feed it with the autopilot’s command signal instead of switching to bang-bang valve actuation.

Walter Andreis

(screenshot from NAVpilot-1000 spec page, and the actual PWM controller that I'm using is attached)

 

[Johnny Electron]

No, the NP711c can NOT support analog. The older 711c is designed around the smaller boat market. The new Navpilot 1000 doesn't support reversable pumps like the NP711C and NP300 do. Different products, different options.

 

[wandreis]

No, the NP711c can NOT support analog. The older 711c is designed around the smaller boat market. The new Navpilot 1000 doesn't support reversable pumps like the NP711C and NP300 do. Different products, different options.

Thank you Johnny for the quick reply.
So can you confirm if the 711C work principle for SOLENOIDS is based on ON/OFF signals?

 

[jp498]

Solenoids are on/off. Think electric door locks in a car.
The valve block that holds the solenoids generally has a flow adjustment if it's letting too much or too little fluid through. The solenoid boats I work on take several seconds to move the rudder all the way to one side; it'd be like rotating the wheel/helm a certain speed to turn fully in one direction over the same time interval. It's not a hydraulic snap like assisted car steering... The fluid takes time to operate the ram and probably opposing force on the rudder from not being straight tempers the action a bit too. Things probably happen a little more quickly to keep the boat on course with minor corrections, but I can not hear the solenoids working over the engine and water noise.

 

[wandreis]

Since the entire electro-hydraulic system on my vessel is already installed — including the NAVpilot-711C — I believe the best alternative now is to reprogram the PLC of the rudder control system to accept two digital inputs (SOL-A and SOL-B). These will be used to command the proportional valve that currently controls the steering actuator, based on the duration each input remains "active".


The idea is to progressively increase the output to the proportional valve according to the time either SOL-A or SOL-B is energized, effectively emulating analog proportional control. This makes the automation process a bit more complex than initially expected, but I believe it will work reliably within this architecture.


Thank you all for the support.