[TG] [TG11] P70s autopilot won’t complete linearisation

[benzy]

I have the following setup:
- p70s control head
- ACU 200
- EV-1 core
- Type 1 mechanical drive
- Rudder transducer

Installed the system less than a year ago while the boat was in Europe and it worked well.

Have since shipped the boat back to Australia. Now the compass refuses to compete the linearisation process. I have tried resetting the compass, performing the dockside wizard. Neither of these have worked.

(Side note: upon firing up the autopilot for the first time in Aus, my rudder transducer was now backwards. Easily fixed by reversing it in the settings, but very odd all the same!)

Any ideas?
Thanks

[Tom - Raymarine - Moderator]

Hello benzy, sorry for the delay replying.

In what way is it refusing to complete the linearisation process? Are you getting an error message, and if so, what is the text of the message?

You shouldn't need to relinearise unless something's changed around the EV heading sensor, but if you do want to do so, there are some pre-requisites for this to progress:

• Compass Lock must be turned off (Menu > Setup > Autopilot calibration > Commissioning > Compass Lock)
• vessel speed must be between 3 and 15 knots (and the pilot must know this from incoming speed or GPS speed-over-groud data, or in the absence of either must have a Cruise Speed calibration value in this range)
• compass magnetic and yaw-rate sensor data must match (if they don't, the pilot assumes a stray magnetic influence)
• vessel must be turning, whilst all of the above conditions are true.
  

If the compass linearisation progress bar on the pilot Standby screen isn't progressing, it's probably one of the above conditions not being met at the time. If the linearisation fails, the cause is almost certainly a large magnetic influence on the EV, so check for current-carrying cabling or magnetic objects that may have shifted into place in transit (or wiring changes in converting the boat to comply with Australian AC power regs.)

Re. the reversed rudder direction, that sounds like the pilot lost calibration data at some stage. That happens after some pilot software updates, or occassionally if pilot power supply dips/is turned off at an inopportune moment when the pilot's trying to write to memory, resulting in an incomplete/corrupted write. For this reason, we often advise people to physically invert the rudder data by swapping the red and green rudder reference wires at the ACU rather than doing so in software.

Regards,
Tom