Friday, February 12, 2016

More Mucking Around with Nav/Comm

Michelle & I spent the past week or so battling cold & flu bugs, so we didn't get a whole lot done on our Ghost Rider punch list.  But I did make some progress on a couple of nav/comm mysteries.

Mysterious AP Nav Error
The first was investigating why, on our last sortie (up to St. Pete), our autopilot Nav (route-following) function had suddenly stopped working.  After tracing potential physical wiring issues, as well as pursuing software configurations, it finally occurred to me that none of that likely would have changed -- the only difference on that last trip was that the various routes we were following had been imported from my laptop's backup copy of Nobeltec Odyssey. Or so I thought.

(Edited here 2-25-16.) After testing several more times, it appears the issue is one of sequencing -- e.g., if the ship's computer was turned on prior to everything else (Furuno Navnets, Simrad AP, etc.) then apparently the various inputs (COM ports) were not being recognized or initialized.
An RD-30 "4-Up" Display

The second was trying to understand what data was available to the (admittedly ancient) Furuno's RD-30 digital display & how to configure / display that properly.  Reading Furuno (old NavNet 2 era) manuals is like practicing bleeding -- it's fairly painful & they are definitely not the drop-dead simple stuff you get with Garmin equipment.  That said, these old Furuno units are nearly bullet-proof commercial grade devices, and once you figure them out, they just work.

Another RD-30 Example
Anyway, after painful reads of the RD-30 and Airmar manuals and decoding NMEA sentences -- oddly aided by a couple of cold fronts that generated consistent 20-30K winds from the NW that you couldn't misinterpret -- we were able to dial in seemingly correct wind & temperature readings from the Airmar antenna, along with a handful of other nav metrics from the Furuno Navnets & the ships's Nobeltec computer.  (And yes, that depth display -- under the keel -- is accurate.)

Sometimes even these minor victories feel majorly good.