[CA] [CA11] EV-200 Hunting

[kev_rm]

I have a p70/ev-200, which is replacing an older unit that was working fine.

The new unit constantly hunts when on course and I have been unable to find *any* calibration settings other than the heads "cruise/leisure/racing" setting. The steering gear and ram is all fine, again, prior unit working perfectly.

Please advise,

Thanks.

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum kev_rm,

It is normal for an autopilot which is operating in Track mode to have a degree of S-ing, as when operating in Track mode, the autopilot is simply attempting to maintain the vessel within a corridor surrounding the course line. This differ from steering to a locked heading, as would be the case when commands the autopilot into Auto mode. The relative width of the corridor surrounding the course line is determined by the Response Level setting ... of which Performance will yield the narrowest relative corridor.

Should significant S-ing be observed when steering to a locked heading (i.e. Auto mode), then it may indicate an issue with the software within the autopilot's components or with the speed source being used by the autopilot. Accordingly, it would be recommended that:

- that the software level within each of the autopilot's components (EV-1, p70RS/p70S/p70/p70R) be listed (MENU->SET-UP->DIAGNOSTICS->ABOUT SYSTEM) and if any have been found to not have been updated with the latest available Raymarine product software updates.

- that a Pilot Factory Reset (HOME->SET-UP->AUTOPILOT CALIBRATION->COMMISSIONING->PILOT FACTORY RESET) be commanded

- that the Dockside Wizard (HOME->SET-UP->AUTOPILOT CALIBRATION->COMMISSIONING->DOCKSIDE WIZARD) be executed again

- that the vessel be taken for a cruise to determine the maximum sensed deviation ... this value should be no more than nine degrees ... if not, then the area of the EV-1 CCU should be inspected for objects capable of producing a magnetic field and/or the EV-1 CCU should be moved to a more suitable location. The latter will require that a Compass Restart (HOME->SET-UP->AUTOPILOT CALIBRATION->COMMISSIONING->RESTART COMPASS) be commanded and that the aforementioned cruise be executed again.

- That the Speed (Speed Through Water (STW)) and Speed Over Ground (SOG) data items be displayed. If the Speed data item is found to differ by more than 10% from SOG in the absence of leeway, then it would be recommended that STW be calibrated via either the instrument or fishfinder feature through which STW is being introduced t the system. Alternatively, the autopilot's Speed Input (HOME->SET-UP->AUTOPILOT CALIBRATION->VESSEL SETTINGS->SPEED INPUT) may be changed to SOG.

Should the problem persist when the items specified above have been addressed, then please respond with:
- the magnitude of the XTE data item when observing the hunting / S-ing;
- indicate whether hunting / S-ing is also observed when steering to locked heading (Auto mode)
- indicate the value for GPS HDOP reported within the GPS status dialog when observing the hunting / S-ing
- indicate the values reported for the Speed and SOG data items when observing the hunting / S-ing.