[pturn]

So if I have a Radar that I want to see waypoints and gps on and a VHF and SSB that I also want gps info on and wind/depth/speedo that I'd like to see dislayed on my PC and the PC that I want to have GPS and all the other stuff and a small Chartplotter that I might like to throw in - is a multiplexer what I'm looking for. I think it is, but it's a little confusing which one. Anybody have any tips? I've looked at the ShipModual but not sure I understand how many intsruments they accept. Would the Shipmodual Multiplex Lite be sufficient?

Any insight appreciated.

Pat

[GPSNavX]

Yes you would want a multiplexer. The Miniplex-lite can accept 3 NMEA inputs (i.e. GPS, AIS, Radar, Instruments) and output up to 4 NMEA listeners (i.e radar, autopilot). The downside of the Miniplex-lite is it needs the Mac always connected for it to work.

If you need to use your system without the Mac connected sometimes than I would recommend the Miniplex-41USB. It's only weakness is that it does not handle the higher speed NMEA data from an AIS receiver.

Both units can be purchased here..

http://wiredboat.com/nmea_multiplexers.htm

[xymotic]

I too am very confused by all of this listener/talker stuff. seems to me just about everything does both!

In my setup, I have the GPS talking to MacENC, and I can repeat it to the autopilot.

Where I get confused is trying to add a DSC VHF. having it listen to the GPS for position seems straightforward enough, but how do I make it talk to the GPS when it gets an emergency call?

Both the VHF and the GPS have 2 ports, however the GPS has one tied up with the garmin sounder module.

I just ordered a shipmodul 41BT, but I'm wondering if I need the 42?

I have uniden UM 525 DSC VHF
A Garmin 192c GPS with a GSD sounder.
Mac ENC w a 4 port keyspan serial adapter
miltec sr161 AIS

I am planning on adding a new autopilot and wind instruments.

[GPSNavX]

An important point is you do not want to create a feedback loop. That is you do not want the output/repeat port of MacENC or GPSNavX to end up coming back to MacENC. This pages helps explains things.

http://www.shipmodul.com/en/multiplexer.html

MacENC is quite flexible in how it works with ports. If all NMEA devices connect to a Multiplexer then one wants to select the NMEA port in the GPS Panel settings drawer and then check "Use GPS Port" in both the Instruments and the AIS/Radar Panel settings drawers.

MacENC can also repeat NMEA to a port. All NMEA data received in the GPS Port will be repeated unless "Autopilot only" is checked. In that case only the NMEA messages for an active waypoint or route will be repeated.

[Jade]

Where I get confused is trying to add a DSC VHF. having it listen to the GPS for position seems straightforward enough, but how do I make it talk to the GPS when it gets an emergency call?

You're right; it is definitely confusing!

I skimmed through the on-line manuals for your GPS and DSC VHF and found the following:

Your DSC VHF sends out two NEMA messages when a distress call is received ($CDDSC and $CDDSE) using NEMA version 3.01. These are sent on the NEMA + (Green) and NEMA - (Orange) wires on the GPS/Alarm cable bundle.

Your GPS can receive DSC emergency info using NEMA version 2.3. This may be problematic so some testing on your part is required. (The Garmin manual does not mention which DSC messages types that it recognizes.) You may connect the DSC VHF directly to the GPS input 1 NEMA + (#4 brown) or input 2 NEMA + (#5 white) and NEMA - (#2 black).

If you choose to route through the ShipModul 41BT then you might consider the following:
- Wire the DSC VHF Green and Orange to an unused NEMA IN port on the multiplexer. (This will allow the VHF to broadcast its DSC messages to all devices connected to the ShipModul.)
- Wire the GPS (#4 brown and #2 black) to the NEMA OUT on the multiplexer. (Up to four devices can be tied together on each NEMA OUT port on the multiplexer.)

I have not tested this setup so I strongly recommend that you check your manuals to verify the wiring and test it well yourself.

LOL

[GPSNavX]

At this time GPSNavX nor MacENC process NMEA DSC messages. Something I could add if there is any demand. I assume in the event of a DSC message a new waypoint where the distressed vessel is could be created? Any feedback as to how the response to each NMEA DSC message should be handled would be very helpful.

[xymotic]

OK, so I recieved the 41BT today, and I got it working to the point the mac ENC and the VHF get position from the GPS. Mac Enc over bluetooth which is mucho cool.

Now, I'm trying to add my Milltech AIS, and and got a little stuck. The 41BT says that the input ports are 4800 baud. But then it also says connection of an AIS @ 38400 is also supported.

But that's it, I put the AIS into NEMA IN port 1 on the multiplexor and get nothing. Do I need to tell the 41 BT to up the baud on a port? Or put it in AIS mode? DO I need to use a specific port on the multiplexer?

[xymotic]

RTFM'd and discovered deep in the 41BT's manual that the AIS needs to be connected to the serial port.

Still can't quite make it work. Is there any reason I wouldn't want to change the SR161 to 4800 baud and plug it in to a regular NEMA port on the multiplexer?

[GPSNavX]

In order to use an AIS receiver with a Shipmodul Miniplex-41/42BT multiplexer, the AIS receiver must be connected to the RS-232 RX and COMM connectors. The rate in MacENC's GPS panel Settings drawer should be 38400. Use the Miniplex tool to set the mode to AIS. Set "Use GPS Port" in the AIS panel Settings drawer. AIS receivers only work at a rate of 38400. Keep in mind you will not see any AIS NMEA (!AIVDM messages) unless there is ship traffic to receive in your reception range.

[rcassano]

[quote="GPSNavX"]At this time GPSNavX nor MacENC process NMEA DSC messages. Something I could add if there is any demand.

I think having the DSC distress signals show up on the chart would be very helpful. Like most mariners, I would not hesitate to alter course to assist a vessel in distress. As a singlehander being able to redirect the autopilot to a new DSC generated waypoint would free me up to work the deck. DSC signals other than distress are not something I would use often.