Originally Posted by CaptMarc
I have a similar issue:
OPencpn with BU 353 GPS: works fine
Standard Hor GX2150 receiving gps signal from Magellan Meridian Marine
: 4800 baud
I switch the GX2150 to 38400 baud to send AIS to Opencpn,via Milltech USB; it works for awhile but then I loose gps signal from Magellan to GX2150 .
The magellan does not have 38400 baud, it has: 1200,4800,9600,19200,57600,115200
it also has NMEA
settings: off, V1.5 APA, V1.5 XTE, V2.1 GSA
I know this is an old gps but works great for 10 years!!
If you read the GX2150 manual carefully, I think that you will see that you are making a couple of mistakes
The GX2150 will not pass-through the GPS signal that it gets from the Magellan. To use the Magallan's GPS signal in OpenCPN, you would need to split the wire and connect it to a separate COM port on your computer at 4800 bps. I suggest that you just keep using the GPS from your BU353.
Also, your statement "switch the GX2150 to 38400 baud to send AIS" is confusing. AIS always goes out from the GX2150 at 38400 bps. I suspect that what you are "switching" is the way GX2150 sends out the DSC
sentences. The GX2150 offers the option of sending both AIS and DSC through the same wire at 38400 bps. However, when you select that option, the GX2150 requires that it receive the GPS at 38400 bps. Since your Magellan can't send at 38400, you cannot select that option. But regardless of whether you could or not, the GX2150 would not send the GPS signal to OpenCPN anyway.
You need to read the GX2150 manual. These things are explained there.
When you say "it works for awhile," you are probably seeing the ownship icon stay red for a minute or so until it times out and turns grey. But the fact is that OpenCPN is not getting a GPS signal from the GX2150 at all. As soon as you disconnect your BU353, the GPS signal stops, even if the ownship stays red for a few seconds.
Looks like I already said this earlier in the thread:
Originally Posted by RhythmDoctor
I am not sure which VHF radios that you are referring to, but the very popular Standard Horizon GX2150 will NOT do this. It will take in GPS from an external source, but it will not repeat it back out again on the AIS wire (or any other wire). So you would need two serial/USB conversions going to the computer running OpenCPN - one for AIS, and a separate one for GPS.
The GX2150 is capable of sending out AIS and DSC
sentences on a single
port at 38400. Perhaps that is what you were thinking of...