What type of cable for B&G NMEA 0183?

[Streetcar]

Hi, I need to get 10m of extension cable for an older NMEA 0183 B&G jumbo display unit. It just needs to be raw cable without end fittings. How do I specify the cable? The existing cable has 6 cores (only 4 used) and a shield, but I can't tell whether any of these are twisted in pairs, or there is any other internal arrangement. Can I use an off-the-shelf network cable that has the same apparent configuration? Any help very much appreciated...

[Reefmagnet]

Originally Posted by Streetcar

Hi, I need to get 10m of extension cable for an older NMEA 0183 B&G jumbo display unit. It just needs to be raw cable without end fittings. How do I specify the cable? The existing cable has 6 cores (only 4 used) and a shield, but I can't tell whether any of these are twisted in pairs, or there is any other internal arrangement. Can I use an off-the-shelf network cable that has the same apparent configuration? Any help very much appreciated...

I'll take a punt and say twisted pair will work fine. The additional pair may have been used for the power supply bus. Ideally you should be using using shielded cable, but ethernet cabling is cheap enough to experiment with if that is all you can get...

[Streetcar]

OK, think I've found the answer to this if anyone is interested. Not straightforward to get there so I'll share.
NMEA 0183 signal is apparently very tolerant of wiring spec. Screened cable is preferable (but apparently not essential). Wire gage of 0.22mm sq (AWG 24) is sufficient for most runs. So the most important criteria for cabling is marine environment resilience. I have sourced a length (not a drum!) of 4 core cable with braided screen - all tinned - from boatbits.com in UK.

[sailormed]

NMEA 0183 version 2.0 (the last version, the other was 1.5) is in fact send over a RS422 connexion. I think the RS422 norm is more widely known then NMEA0183 for ordering cable online or in a shop. Just my 2 cts 😊

[Squanderbucks]

There is no such thing as a 0183 cable. Individual wires for each function desired to either send or receive data.
Use 22 to 16 gauge multi strand wire. Not computer network twisted pair stuff. It is typically single strand copper wire and difficult to fit with proper wire End crimps.

If possible use wire color that is similar to what comes out of the plug at the back of the machine just to help keep the wires identified. Makes future tracing much easier.

[ramblinrod]

You can use 1 x shielded twisted pair for simplex or 2 x shielded twisted pair duplex. If the device had 2 ports, each at different baud for different purpose, you may only need one.