Interfacing Garmin 441s to onboard instruments

[prroots]

We're in the process of interfacing our newly purchased Garmin 441s chartplotter to a Standard Horizon gx2150 and existing (10 year old) Raymarine SeaTalk network. The interface between gx2150 and 441s works well with VHF receiving position data and 441s receiving AIS data on 441s port 1 high speed. I've connected port 2 at standard speed of 441s to the SeaTalk network. The network receives position data, but so far have been unable to read SeaTalk data (eg, depth, water temp, rudder position) back into 441s. I called Garmin, but they weren't very helpful. Any ideas what the problem might be?
Pete

[Faster]

Sounds like your Garmin is set for NMEA data since position and AIS is getting across.. I think you need to be connected to the Raymarine's NMEA port too.. as far as I know NMEA and RM Seatalk are not the same protocol - and it seems to me that the RM NMEA port might be 'receive only' - ie picking up a heading or a track from a GPS.

But not an expert, and we'll have several here that are so I'm sure you'll get the dope from them.

[hellosailor]

Pete, last time I checked Raymarine/Raytheon Seatalk was a propritary network and you'll need a translator ("interface") box to connect it to anything that doesn't have a "Ray..."something nameplate on it. (Not inexpensive.)

Or, is that "interface" you mention already a Seatalk/NMEA interface, and you just need configuring it?

Garmin can be a bit, ah, frigid at times. A lot of their equipment speaks "Garmin/Garmin" by default and it has to be switched into "NMEA" mode, or a specific NMEA mode, to communicate with other gear. You may find there's one menu to allow NMEA communications, and a separate one to allow uploads/downloads of tracks and data. Or, that you have to manually match the NMEA baud rate to 4800 and the parameters to 4800,N,8,1 or another combination to match what the interface box is set to put out.

Odds are that if you look at every menu (sigh) on both boxes, and take some notes on the settings, that there's a simple mismatch in the NMEA options or settings.

[prroots]

Thanks for the replies. The ST60 Multi unit includes a NMEA 0183 input and output. The input is working fine since navigation data output by the 441s is displayed. The output is not received at the 441s for some reasons. Since the input is working there is no problem with compatibility of protocol. I have reviewed the sentences supported by the Raymarine system and they are compatible with the 441s. The interesting thing is that the 441s has a NMEA output setup menu, but no NMEA input setup menu?
Pete

[prroots]

If I don't solve this problem soon, my backup plan is to purchase a USB to serial adapter and try reading data from the NMEA 0183 output port of the Raymarine ST60 Multi unit into my laptop navigation program, OpenCPN. The laptop is currently receiving AIS data from port 2 of the gx2150 via a USB to serial adapter. This will provide an indication as to whether the Raymarine or 441s is the problem.
Pete

[r.furborough]

It might be that the talker driver in the ST60 is blown, if you have a sensitive multimeter see if you have a DC voltage that varies on the output, you are looking for 0 to 5 volts.

[prroots]

Originally Posted by r.furborough

It might be that the talker driver in the ST60 is blown, if you have a sensitive multimeter see if you have a DC voltage that varies on the output, you are looking for 0 to 5 volts.

Thanks, I'll check it out
Pete