VHF and NEMA 0183

[Alaskan Sea-Duction]

So I have 2 Raymarine MFDs (along with a laptop) and 2 iCom VHFs.I wanted to hook up the VHFs to the MFDs so they could "talk" to each other. The purpose is so the VHFs would have position and date, should I need to push the "Little Red Button." It would transmit our position.

So it appears (unless I had Raymarine VHFs, then it is connected to Sea-Talk NEMA 2000) that nothing is standardized on NEMA 0183 or even between the same brand.

So the first thing I had to figure out was what wires (small ones about 20ga) were output +, output negative -. Then you have to figure out Input + and Input -.

None of the wire colors are standardized. Raymarine does use the same colors so long as you stay with Raymarine. iCom on the other hand. I have a M-504 and M-324. None of the wires on these are standardized.

Once you figure this all out it isn't so bad. You take the Output + on the MFD to the Input+ lead on the VHF. Then you connect the Input+ on the MFD to the Output+ VHF. Confused yet?

What they don't tell you is all the rest of the negative leads need to be wired together to ground.

Wouldn't it be nice if all of NEMA 2000 and 0183 were all standardized......

Hopefully by the end of all this it will look like this:

 

[Comodave]

Yes, it would have been great if there was a standardized color code. It is a PITA trying to figure it out. Not to say anything about splicing the tiny wires...

 

[boomerang]

I don't feel splicing those tiny wires & making 0183 talk is all that bad. The hardest part for me is navigating some of the equipment software menus to turn the 183 on!
NMEA 2000 is easier yet but don't fret... NMEA OneNet is coming.

 

[twistedtree]

Actually 0183 is standardized, but as you observed, it does not include wire colors. It's pretty much impossible to standardize colors, because as soon as you have more than one 0183 port on a device, you are screwed.

Where it becomes a pain is that some vendors don't follow the standard, which is their shortcoming, not the standards.

I'm really interested to hear you wired all the "-" connections together. Generally you would NOT do that. The "-" connections for different ports are not the same. It's not like a negative battery terminal. Maybe it was forced by one of the devices cutting corners on the standard?

 

[Larry M]

We have a stand alone Furuno GPS that feeds the VHF radio (s) for DSC. We found it was easier to wire plus we didnt want to put all our eggs in one basket.

 

[Alaskan Sea-Duction]

We have a stand alone Furuno GPS that feeds the VHF radio (s) for DSC. We found it was easier to wire plus we didnt want to put all our eggs in one basket.

Same here. Always have a backup. Sometimes a backup to the backup

 

[Maerin]

I'm really interested to hear you wired all the "-" connections together. Generally you would NOT do that. The "-" connections for different ports are not the same. It's not like a negative battery terminal. Maybe it was forced by one of the devices cutting corners on the standard?

Likely Garmin, where they commonly use a common ground for NMEA. Not sure why they do it, but it can create problems in some of the other manufacturers' gear if the NMEA (-)'s are jumpered. Each manufacturer wants to beat their own drum, often to the frustration of their customers. "See, you should buy all OUR stuff cuz using other manufacturers' stuff with our stuff will give you problems". Y' gotta wonder how much of that's intentional...

 

[High Wire]

One would think that something as important as the GPS interface to a DSC VHF radio would be plug and play compatibility. Not every device, just GPS to DSC. Its no wonder most DSC radios are not hooked up to a GPS.
I applaud Standard Horizon for placing internal GPS into some of their radios. For the extra couple bucks, all new VHFs should have internal GPS chips.

 

[JeremiahM]

I don't feel splicing those tiny wires & making 0183 talk is all that bad. The hardest part for me is navigating some of the equipment software menus to turn the 183 on!
NMEA 2000 is easier yet but don't fret... NMEA OneNet is coming.

Don's splice. Instead use one of these terminal blocks.
https://www.bluesea.com/products/2408/Terminal_Block_20A_-_8_Circuit
Connect wires using ring terminals. If you get the connection wrong, then it's easy to move the connection to another spot on the block.

 

[twistedtree]

Likely Garmin, where they commonly use a common ground for NMEA. Not sure why they do it, but it can create problems in some of the other manufacturers' gear if the NMEA (-)'s are jumpered. Each manufacturer wants to beat their own drum, often to the frustration of their customers. "See, you should buy all OUR stuff cuz using other manufacturers' stuff with our stuff will give you problems". Y' gotta wonder how much of that's intentional...

I check the two VHFs and they have full support for 0183, not a shortcut implementation. The two MFDs are Raymarone and look to be relatively current models, so I expect they support proper 0183 too.

ASD, I'm quite sure those "-" connections should not be tied to ground, and in fact it might damage any connected transmitter.

 

[boathealer]

ASD, I'm quite sure those "-" connections should not be tied to ground, and in fact it might damage any connected transmitter.

I think he said the other '-' connections, meaning unused TX/RX ports (at least that's the way I took it).

Since these are likely differential links and not single-ended, it makes good sense to ground unused I/O.

 

[twistedtree]

I think he said the other '-' connections, meaning unused TX/RX ports (at least that's the way I took it).

Since these are likely differential links and not single-ended, it makes good sense to ground unused I/O.

Interesting. I didn't take it that way, but you might be right.

You definitely don't want to ground either of the Tx signals. Some transmitters can tolerate it, but some manufacturers caution that it will damage the transmitter.

You could argue that biasing the Rx signals would prevent noise. But the whole idea of a differential pair is that the same noise is induced into both signals in the pair, so it can't create the signal differential associated with actual data. I have never seen any 0183 device that suggests or recommends doing anything to unused RX inputs other than leaving them open circuit.

 

[Alaskan Sea-Duction]

Don's splice. Instead use one of these terminal blocks.
https://www.bluesea.com/products/2408/Terminal_Block_20A_-_8_Circuit
Connect wires using ring terminals. If you get the connection wrong, then it's easy to move the connection to another spot on the block.

Good idea but the wires are short and you may still have to splice in a comm wire. I used stranded communication wire

 

[Alaskan Sea-Duction]

I check the two VHFs and they have full support for 0183, not a shortcut implementation. The two MFDs are Raymarone and look to be relatively current models, so I expect they support proper 0183 too.

ASD, I'm quite sure those "-" connections should not be tied to ground, and in fact it might damage any connected transmitter.

I think he said the other '-' connections, meaning unused TX/RX ports (at least that's the way I took it).

Since these are likely differential links and not single-ended, it makes good sense to ground unused I/O.

Interesting. I didn't take it that way, but you might be right.

You definitely don't want to ground either of the Tx signals. Some transmitters can tolerate it, but some manufacturers caution that it will damage the transmitter.

You could argue that biasing the Rx signals would prevent noise. But the whole idea of a differential pair is that the same noise is induced into both signals in the pair, so it can't create the signal differential associated with actual data. I have never seen any 0183 device that suggests or recommends doing anything to unused RX inputs other than leaving them open circuit.

The transmit + and Input + are connected according to the manufacture. But associated with each of the above is a transmit - and Input -. These are tied together to a device ground such as black wire (0183) on my my Raymarine.

 

[twistedtree]

The transmit + and Input + are connected according to the manufacture. But associated with each of the above is a transmit - and Input -. These are tied together to a device ground such as black wire (0183) on my my Raymarine.

The Tx- and Rx- should be connected together just like the Tx+ and Rx+. That part is good. But the TX- and Rx- should not in turn be connected to ground, or anything else for that matter.

Did it not work with the "-" leads ungrounded?

 

[boathealer]

The Tx- and Rx- should be connected together just like the Tx+ and Rx+. That part is good. But the TX- and Rx- should not in turn be connected to ground, or anything else for that matter.

Did it not work with the "-" leads ungrounded?

Might be one or the other pieces of equipment want to operate in single-ended mode.

http://nolandeng.com/downloads/Interfaces.pdf

"NMEA 0183 originally allowed "single-ended" drive, but was later updated to differential drive (RS-422)."

 

[Alaskan Sea-Duction]

The Tx- and Rx- should be connected together just like the Tx+ and Rx+. That part is good. But the TX- and Rx- should not in turn be connected to ground, or anything else for that matter.

Did it not work with the "-" leads ungrounded?

A few years ago when I was connecting my iCom 504 to my Lowrance It wouldn't work unless I had the "negatives" connected together and then connected to the shielding. Per instructions of the iCom tech support. Works great on both VHF units. I am happy that IF I have to push that red botton that it will also send my position.