Speed through water and water temp not showing

[Anonymous]

I have an airmar PT 850 speed/temp sensor that I hooked up to my Navnet vx2 in port 4. I run the sensor through an airmar NMEA 0183 converter. I wired the red to red, black to black, blue to green and white to yellow and it goes into port 4. I made sure the port 4 settings have DPT and MTW "on", but I still get no reading on the machine?

Do I need an independent power source for the NMEA converter or is the power pulled from the machine (red wire?)

Any suggestions?

 

[Anonymous]

Update to this, I have the sensor hooked up but it does not display speed through water and the temperature is about 35 degrees off. It was 85 degrees this weekend and the temp sensor shows up as 46 degrees. Is this potentially an internal setting in the machine? I was doing the install and testing while the boat is out of the water, so will the water temp register better when it's in the water?

Do I need to adjust the NMEA version to 1.5, baud rate, etc?

 

[Johnny Electron]

PT 850 ?? Are you talking about the ST850?
What is the part number of the converter you are using?

Normally you don't turn on any NMEA sentences in the NavNet port output. It would be receiving data from the sensor not providing it. Typical setup is NMEA version 2.0 at 4800 baud.

 

[Anonymous]

You are correct - ST850.

The setting is NMEA 2.0 at 4800 baud.

Are there any other types of settings that could be causing this or anything else I can do? I can't imagine it's simply the machine because I have 2 units side by side and I tried hooking it up to each one and both units have the same reading. It's a navionics unit, software is 4.01, 6 if that helps.

 

[Johnny Electron]

You still didn't provide any information about the converter you are using.

If it is the Airmar (analog to NMEA 0183) converter (Furuno part number AIR-044-103) then it can NOT be connected directly to data port 4. The wiring of that converter is designed for the wiring pin out of data port 1. Although data 1 and data 4 are using the same type of 7 pin connection, they are wired differently. To use this converter on data 4, it would require a "Y" cable (AIR-033-407) to correct the wiring and keep items like your external buzzer port still available. But if truly, the ST850 (NMEA 2000 or analog models) is being used, then it would need to be the analog model and not NMEA 2000.

Can you please provide the information on the converter you are using and how you have it wired into data 4?

 

[Anonymous]

My apologies, I am using an airmar analog-NMEA converter for speed/temp. It's an airmar product, not Furuno. The sensor was a ST650, the analog version, not the NMEA 2000. When I ordered the replacement, they sent me another analog version, but I believe it was with the housing in the ST850 that has an upgraded housing.

Here is a link to the installation guide for the NMEA converter, can't find the link to the actual part #
http://www.airmartechnology.com/uploads ... 444-01.pdf

Instead of plugging it directly into the machine, the original install used an old furuno data cord, then spliced that into the output of the converter. I did the same with my new converter, but this might explain where the problem lies. If I get the "Y" cable, do I then simply slice that into the NMEA converter and hook it up to port 4?

I have to use data 4 because data port 1 is already taken with I think my gps input.

Lastly, I recently repowered with new Mercury Verados and a new vesselview 4 system from mercury that needs NMEA 2000 and so I need to run data out of my Navnet, into a converter to NMEA 2000, and into the Mercury vesselview so that it reads my speed over ground from my GPS (to calculate MPG, efficiency, etc). Can you advise on what port it should come out of, and what cords/converters are required?

Many thanks for your help so far, it's very much appreciated after several hours of frustration and sweat trying to figure this all out.

 

[Johnny Electron]

I will leave the wiring information on your connection from the Airmar speed/temp sensor into the Airmar converter to the Airmar/Gemeco tech guys.

(phone 843-210-7000 - http://www.airmartechnology.com) because I don't have all the specifics.

Using the link you provided from the Airmar Analog to NMEA 0183 data converter; Here is how it should be wired from the converter to the Furuno.

Converter -------- Furuno Vx2 data 4 NMEA data cable (7 pin - 000-154-028)

WHITE (+) out -------- YELLOW (+) input
BLUE (-) out -----------GREEN (-) input

The Airmar document you provided isn't clear if the 12V dc on that same wiring is an output or an input. I suggest you talk to Airmar to see if you should connect this to your boat power or not. It should not be connected to the Furuno.

Once everything is properly wired; you should setup the NavNet to display NMEA STW/TEMP. (MENU - SYSTEM CONFIG -NAV OPTION - NAV SOURCE SETINGS - then set speed and depth source to NMEA)

Concerning where to draw you NMEA data out for your NMEA 0183 to 2000 converter; it depends on which port you are not currently using.
There is NMEA RS422 0183 output on data 1 and data 2. (the 10.4" data 3 is input only for heading and data 4 output is in RS232 format designed for a PC)

 

[Anonymous]

Well, I am still stumped. I followed these instructions and still get the same result. The wire I am using from port 4 to the NMEA converter has blue to green and white to yellow. I still get no reading at all for the speed through water, and my temp says 47.6 degrees (I'm in Florida...it's more like 80 degrees).

I've replaced the sensor and the NMEA converter, the software is updated, at least pretty close to the most recent version, etc. so I don't know what else it could be, is there any change that the 7 pin cable has the wrong setup some how, i.e. I need to hook white to green or some other random combo?

 

[Johnny Electron]

Sorry for the slow response. Peak season and a million other excuses has kept me away.

Did you speak to Airmar about the wiring of the converter? This appears not to be the correct converter for the job. See below on what I was told about this unit.

The converter box you speak of is p/n 33-555-01. It was specifically designed to work with our CS4500. It will work with an ST850, but the Hz/knot is different. The Hz/knot for a CS4500 is 5.5 Hz and the Hz/knot for an ST850 is 4.0 Hz. So the speed conversion using an ST850 with this converter will not be as precise as it should be as a result.

 

[Anonymous]

I did not speak with airmar, other than the guide I was given for installation. I still have no reading on STW and the temp is showing 46 degrees when the water temp is more like 80. The only piece I haven't replaced in this chain is the cord running into the back of the machine from the bus bar I used to connect from the transducer.

I've given up though, this problem has beaten me. I would love to have these two readings, but I've lost too much time worrying about them so I just threw in the towel. It shouldn't be this difficult for something as simple as speed and water temp.