Dave & Marius,
When this AIS unit is programed, an icon is loaded onto the desktop
. It opens a screen in which the ship's information can be changed, the unit's transmit, receive, and antenna
status can be monitored, sent and received information viewed, and a contact list accessed. Garmin
does not tell you, either in the manual (at least I didn't pick up on it) or during phone
conversations with them, that this icon should not be activated during operations with a laptop chartplotter
. The comment from Marius opened a new line of thought for me, so I monitored the Garmin screen till a ship came within range, then closed the screen and opened OpenCPN. And it worked! So, it looks like the problem is now solved
. For future reference, should any other sorry, computer illiterate like me run into similar problems, I also found that Garmin's wiring
diagram for connecting to a NEMA 0183 device is in error : the manual shows the gray wire as TX A +, while RX A + was identified by Garmin (on the telephone) as being the white wire. In reality, these two are reversed : gray is RX A +, white is TX A +. Maybe it's just a screw up in this particular unit.
At any rate, thank you very much for the assistance and good ideas and comments, all of which resulted in a good resolution. By the way, if you would care to see some photos of the building and sailing of "Rainbow", there is a nice photo
essay on the website of yacht designer
George Buehler, under "Reg's Boat".
Once again, thanks very much for the help. Either of you ever get around So. MD, give me a shout.