RS232 to NMEA

[lumphammer]

I am looking at adding a new gps antenna for the dsc radio and ais, this outputs nmea data over a RS232 port. To connect to my equipment is it as simple as connection :-

RS232 Grnd pin 5 to NMEA Common
RS232 Tx pin 3 to NMEA data in?

 

[maby]

In most cases, this will work. Strictly speaking, NMEA0183 runs over RS422 which is the balanced version of RS232 and gives better immunity to interference over long cable runs. On those occasions that I have tried connecting the two together, I've got away with it, but there is a possibility that you may get transmission errors and need a converter. They are not expensive - here's an example for a fiver off ebay:


http://www.ebay.co.uk/itm/Serial-Ad...Components_InterfaceCards&hash=item4aba172e41

 

[AngusMcDoon]

From the NMEA standard...

The NMEA-0180 and 0182 standards say that the talker output be RS-232...and a diode to prevent the output voltage from rising above +5.7 V.

NMEA-0183 accepts this, but recommends that the talker output comply with EIA-422...

So a NMEA compliant device should accept RS-232.

 

[nigelmercier]

The NMEA-0180 and 0182 standards say that the talker output be RS-232...and a diode to prevent the output voltage from rising above +5.7 V...

That's interesting, I thought it was 12V. I'm pretty sure my Raymarine SeaTalk to NMEA converter outputs 12V, as I had to put an attenuator in it to feed my Standard Horizon CP180.

 

[AngusMcDoon]

That's interesting, I thought it was 12V. I'm pretty sure my Raymarine SeaTalk to NMEA converter outputs 12V, as I had to put an attenuator in it to feed my Standard Horizon CP180.

It's a non standard standard. They are the best.

 

[tokoloshe]

Have a look at the Actisense web site. I have bought kit from them.

 

[Phoenix of Hamble]

It's a non standard standard. They are the best.

and the reason Raymarine frustrates me.... they are far too keen to do their own thing and make interfacing to other manufacturers difficult and expensive.

But I agree.... they are good!