Adding Airmar 220WX... what of the existing stuff?

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wkearney99

Guru
Joined
Feb 17, 2018
Messages
2,164
Location
USA
Vessel Name
Solstice
Vessel Make
Grand Banks 47 Eastbay FB
I've got an Eastbay 47 with four Furuno MFD12 displays (upper and lower helm stations). We're not the first owners of the boat so I don't have any rationale for what/why past stuff was installed. Overall most of it seems to be working reasonably well.

I'm looking to add an Airmar 220WX sensor for wind/weather data.

Right now there's already a Furuno PG-700 and an Airmar H2183 installed. Along with a GP-320B (gps).

In the process of doing this I'll have the chance to clean things up a bit, where it would be useful.

The PG-700 is mounted in the starboard berth, the H2183 is mounted high on the mast. I get that the PG-700 needs to be far from any other metal (like the two big C-12 engines).

I've never looked into it fully, but there have been situations in the past where the boat's orientation didn't match what was being shown on the chartplotters. As in, physically pointed one direction, while the plotter shows something else. Likewise some rare occasions underway where it'd show the boat moving in one direction, but the hull pointed in another. Not just a degree or two, that I could understand based on wind or current conditions. This was more like a good 30 deg. off angle.

In looking at the docs for all these it doesn't appear there's enough overlap to eliminate anything if I add the 220WX. Am I correct here?

What I haven't yet determined is whether the MFD12's will accept GPS from something other than their own GP-320 unit. If so I could potentially replace that with the 220WX.

Or not? Would the 220WX provide 'as effective' a source as the GP-320B?
 
Regarding the PG-700 performance, those types of devices are used to show the direction the bow is pointing versus the heading the boat is traveling along. A way to think of this is to imagine the boat running on autopilot from point A to B. The pilot keeps the boat on the line (as best it can) by adjusting the compass heading to offset winds, currents, waves, and other things that are pushing it off course. In an extreme condition, the boat can be pointing maybe 30 degrees off the course it's making. This pointing of the bow is what the PG-700 displays. To verify the PG-700, it's reading should roughly match your helm compass.

Ted
 
While I'm not familiar with the MFD12s, most modern units allow for more than one input device whether it be a GPS or depth transducer. Generally you go into a device menu to specify which one you want the MFD to use.

Ted
 
I think there are a couple things you could do, or ways you could approach this.


- The PG700, mounted low down, will give the best heading measurement, so I would use that as the primary heading source. Then use the H2183 and 220WX as secondary and tertiary, in any order.


- The heading variation is likely due to interference with the PG 700. Things way smaller than your Cat can cause problems, as can changes in electrical operation onboard. We had a boat that would veer off at odd times and we finally realized that it correlated with running the microwave. The high current DC cables were close enough to the heading sensor to be affected by the magnetic field when there was a high current. The mast mounted heading sensors (H2183 and 220WX) will be away from such influences which might suggest they should be used as primary heading source, but they will flop around more as the boat moves, so are worse in that respect. My first choice would be to get the PG700 working well. If nothing else, I'd rather sometimes have a crappy heading vs always have a crappy heading.


- For GPS, I would use the GP320 as primary, and the 220WX as secondary.


- If you want to save a few bucks, the 110WX has the same weather capabilities as the 220, but no GPS and no heading.


- As best I can recall, in the MFD12 you can select which data source to use for each function (GPS, heading, etc), but I don't think you can explicitly set a secondary and tertiary. If the primary fails, the MFD12 might pick whatever else is out there, or you may need to reconfigure to select the secondary device. I just don't remember, and it's way beyond how most people use the equipment.



Good luck with the refit..
 
Yes, in the old boat the Raymarine flux gate was very picky about things being near it. Made storing things a challenge sometimes. Same thing with the PG-700. Someone decided right next to it would be a place to mount a metal canister fire extinguisher. So, yeah, moving that improved heading accuracy.

I believe you're correct re how the MFD12 selects sources. It also tends to be a somewhat onerous process for some of them as the only way to change them is to re-run the entire setup for a display. That's "just how things were" on that generation of hardware. It's working well enough presently, and I don't hate it $20k+ to replace it.

Past implementations of stuff on this boat had sensors coming into several different MFDs, and the data gets bridged over Ethernet between them. Trouble is NN3D doesn't bridge anything it doesn't know about, and there's no way to add new sentences. Nor can multiple MFD12 displays be on the same NMEA2k network.

Any network or cabling changes are now being made with an eye toward eventual upgrades. That's meant re-arranging the NMEA2k bus to run through the entire boat instead of just point-to-point into separate MFD12s. That's coming along, but it's not without challenges. What with the DST-200 being in the engine room, the PG-700 being forward, the lower helm, the flybridge and then the mast. There's a few double-runs to/from some things in order to keep the continuous bus that NMEA2k requires. Seems ok thus far. But the mast is going to be the next challenge as there's not an NMEA2k run to it. There will be soon enough, along with wired Ethernet (wifi is a whole other project).

So it looks like I'm going to be keeping both the GP-320B and the H2183 up there, and that'll mean adding another mount point for the weather unit.
 
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