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YPSILANTI · 27-12-2015, 07:09

I have a B & G Netwrok auto pilot which is faulty. The auto pilot is activated by hitting the auto button which, if set correctly on comp mode for compass, it should engage the current heading and do its job of steering the vessel. However, she veers sharply to port off course. I have read the entire manual and the set up is correct. The LCD display shows "RUD DRV" WHICH IS RUDDER DRIVE ERROR. THE COMPUTER UNIT HAS ATTEMPTED TO MOVE THE RUDDER BUT THERE WAS NO FEEDBACK FROM THE RRU.' CHECK THE RUDDER DRIVE CABLING, THE DRIVE AND LINKAGES. Ive checked the drive and the system engages properly and the rudder is being activated and the unit motor engages the chain, linkages and the rudder is turned to to port.

Can anyone advise what the fault is likely to be. Im not sure what the " NO FEEDBACK FROM THE RRU" means.

Also, the backlight no longer works. Is it a matter of replacing LED's?

Any advice will be appreciated.
Rgds
Mike

AedanC · 27-12-2015, 07:43

Hi Mike,

I have the same unit and I had to chase down some other problems with it.

Attached to your rudder quadrant you should find a strong connection to the RAM and a much smaller and lighter connection to a small device that measures the rudder angle. This is the RRU, but right now I can't remember what RRU stands for. It's telling you that it's not getting a signal back from it, ie as far as it's concerned it's telling the rudder to move but it's not moving. If you are lucky it's pushrod might just have fallen off the rudder quadrant.

I might have a photo of the arrangement at my rudder showing the RRU, I'll take a look.

Aedan

Edit: Sorry, I've had a look and I don't have any photos. RRU = Rudder Reference Unit.

AedanC · 27-12-2015, 07:50

This might help in case you don't have it...

http://www.bandg.com/Documents/produ...epslanguage=de

Time2Go · 27-12-2015, 10:06

While not exactly like your problem
During the summer of 2014 I was crew on a brand new boat
with all new B&G gear, at random the AP would disengage or turn to port.
The problem was eventually traced to outdated software delivered with the
boat. So I would check for updates and versions loaded.
This was a random problem that I believe in computer speak
was called a "time out" issue
Cheers

tanglewood · 27-12-2015, 17:29

I think RRU is Rudder Reference Unit. Or at least something like that. It's the device that tells the AP where the rudder is pointing....

I'm not familiar with the B&G AP, but if the display has a mode where it shows the rudder position, you can use that to test the RRU. Setup to display rudder, then using the helm manually turn the rudder hard over one side to hard over to the other, and see if the display shows the correct position throughout the range.

Moody46CC · 27-12-2015, 19:56

On my B&G Autopilot, the rudder will disengage and I'll get a "rudder drive error" message in the autopilot screen when I turn the wheel all the way to the stop in one direction or the other--usually when pulling out of my slip. The manual says the sensor on the rudder has lost the input as to where the rudder is. I get a beeping alarm as well. Once the rudder is centered, I recycle the autopilot and it works fine.

colemj · 28-12-2015, 04:44

Have you removed or even disconnected the RRU recently?

Assuming you have the normal linear one that came with the Network systems, these are very finicky and easily lose their calibration if disconnected or removed.

You should be able to tell if this is an issue by looking at the rudder indicator on the display while turning the rudder from one stop to the other - as tanglewood suggested.

The indicator should move and gradiate smoothly from fully one side to fully the other. If it "jumps", or changes side early, then it is either faulty or needs recalibration.

In your pic, is the rudder actually turned hard over? The indicator thinks it is.

Recalibration is easy, but I don't have access to the instructions now. I got them from Myles Electronics, so you can contact them if needed.

Mark

colemj · 28-12-2015, 04:48

Quote:

Originally Posted by Moody46CC

On my B&G Autopilot, the rudder will disengage and I'll get a "rudder drive error" message in the autopilot screen when I turn the wheel all the way to the stop in one direction or the other--usually when pulling out of my slip. The manual says the sensor on the rudder has lost the input as to where the rudder is. I get a beeping alarm as well. Once the rudder is centered, I recycle the autopilot and it works fine.

You need to either recalibrate the AP commisioning to know where your stops are, or move the stops to be within the AP drive range. Or your RRU is installed incorrectly and is bottoming out.

Mark

Dave Lochner · 28-12-2015, 08:07

The manuals for the Network series can still be downloaded on the B & G website.

Downloads

Look for "discontinued models" in the dropdown box.

TheThunderbird · 28-12-2015, 08:45

Same as on Raymarine AP.

It is the Rudder position .sensor

sailormed · 28-12-2015, 08:55

It is possible that the GPS antenna is positioned to close to the GPS antenna of another equipment (AIS or other). In this case the 2 antennas RF waves wreack havoc on one or both of the GPS receivers, resulting in the outcome you describe. Try temporarely moving the autopilot antenna to another location to see if you still get the same error.

Also check the breaker of the drive arm of the autopilot. When I got this error on my Simrad (same) autopilot, it was a blown fuse on the rudder drive arm. The autopilot sends orders to the drive arm, the drive arm does nothing, the autopilot only sees the rudder feedback not moving and indicates rudder feedback error.

Envoyé de mon iPad à l'aide de Cruisers Sailing Forum

**Symphony** · 28-12-2015, 12:30

I've been through this with a Raymarine system. Keep in mind that the Error Message may be in error itself. I have no data except my experience and I think somewhere around 40% of the error messages are not correct, maybe close, but often wrong. Also realize that even if your system was working then stopped working -it could be a single fail point, but it could be the build-up of 2 or 3 fail points.

1) if the AP never holds a course, check the mechanical connection of the RRU (called RPI on Raymarine). you can likely find a graphical indicator of this on the AP head, but take a look at the actual device and how it connects to the rudder as others here have said.

2) if the bad behavior happens often but not every time then try this. a) calibrate the autopilot, easy to do in flat water and enough space. This fixes a lot of wacky problems in any system, and is a good idea as an annual service item. b) if the AP will only turn circles hard to port, then move the wheel back and forth a few times and steer a course to starboard and engage the AP. This would point to issues in the rheostat of your RRU or your drive unit seals.

Still broken? then check the mechanical connections at the course computer, especially the fluxgate compass and RRU. fluxgates are not too expensive, I once solved a system with your problem by swapping in a new fluxgate. There was nothing wrong with the RRU or AP head or linear drive (the error messages were all wrong).

still broken? it would be nice to swap out the course computer to test but these are often hard to borrow. Instead find the manufacturer's R and V values to test outputs of your devices (course computer, fluxgate, RRU, AP head). I would be suspicious of continuity in your wiring harness and voltage since your backlights are also non-functional at the AP head. could be low voltage.

Good luck and let us know - these things are maddening. especially if you're single handing and depend on the autopilot.

colemj · 28-12-2015, 13:55

Quote:

Originally Posted by sailormed

It is possible that the GPS antenna is positioned to close to the GPS antenna of another equipment (AIS or other). In this case the 2 antennas RF waves wreack havoc on one or both of the GPS receivers, resulting in the outcome you describe. Try temporarely moving the autopilot antenna to another location to see if you still get the same error.

Also check the breaker of the drive arm of the autopilot. When I got this error on my Simrad (same) autopilot, it was a blown fuse on the rudder drive arm. The autopilot sends orders to the drive arm, the drive arm does nothing, the autopilot only sees the rudder feedback not moving and indicates rudder feedback error.

Envoyé de mon iPad à l'aide de Cruisers Sailing Forum

An autopilot has no "antennas" whatsoever.

GPS antennas are receive only - there is no transmit function. There won't be any "interference" by having them close together (we have two of them 1" apart). Set your phone on top of another while looking at your position and you will see this.

If the rudder drive fuse was blown, the OP would not experience his unit turning hard to port. It wouldn't turn at all.

Mark