Garmin 496 data output

[olyolson]

Thinking about upgrading my GPS from the 296 to the 496. My 296 has 2 data outputs, one I use to my Gemini PFD for course info and the other to the autopilot for tracking. I looked at the 496 manual and it only has one data output. Can I split this signal into two so I can provide strong enough GPS data to my PFD and autopilot?

I like the moving map airport diagram on the 496 that my 296 does not have. I have Foreflight on an IPAD Mini so I have access to the moving map but would like the better and faster refresh rates on the 496.

I have my 296 wired to the electrical system for power and have a remote GPS antenna. I realize I will have to change the power/data cord but does the 496 use the same GPS cable and antenna as the 296? I don't plan on using the XM radio features.

Anyone know if the 496 will do what I want?

Thank,
Oly

[g3xpert]

Hello Oly,

Yes, it is typically quite possible to split an NMEA RS-232 output and run it to two devices as you describe.

The GPSMap 296 and 496 can both use the same power/data cable and GPS antenna, so you will not have to replace these.

- Matt

[olyolson]

Matt,

Thanks for the info. Right now I have two separate wires from the 296 power/data cable and run these to the two devices. So with the 496 I would simply "Y" the single 496 output data to 2 wires and run these to the respective devices right? Will they have enough output data for each?

Jet guy John- our resident Garmin support guy thinks otherwise from your response, do you know something different? Thanks for your input and please explain. I can use all the help I can get.


Oly

[g3xpert]

Hello Oly,

Yes, that is correct. You will simply need to connect the single RS-232 output from your GPSMap 496 to the RS-232 inputs of your two devices.

This is digital data, so nothing will be "used up" by splitting the RS-232 connection. (assuming the receiving devices have sufficiently high input impedance, which these very likely do)

- Matt

[krw5927]

What no one has said yet, is that you need to make sure both "receiving" devices are set to receive at the same "baud" rate as the 496 is putting out. Since you only have one output, if its data output rate is, say, 9600 baud (bits/sec) then both receiving devices will need to be set to receive at 9600 baud. This makes sure everything is listening at the same speed the 496 is talking.

You may need to do some research to figure out what setting may be common between all 3 devices.

I and others would be glad to help if you post what kind of autopilot you have. That's the only unknown device right now.

The Gemini PFD receives at 4800 or 9600 baud, and automatically recognizes which one it's getting. The 496 can output 9600 baud on the "Aviation In/NMEA & VHF Out" setting, and does so on the blue wire from the harness. Now if your autopilot can receive at 9600 baud, you're in business just like Matt advised.