NMEA-0183 Connection Advice

[tandacht]

Q1: what is the wiring to connect make a NMEA-0183 connection between a Simrad NAIS-500 AIS and a Raymarine E80 MFD?

[jimh]

In NMEA-0183 wiring, a TALKER A signal is connected to a LISTENER A input; a TALKER B signal is connected to a LISTENER B input.

To better understand the method, please read the article:

Universal NMEA-0183 Interface
https://continuouswave.com/whaler/refer ... A0183.html

For help identifying the signals in the wire bundles for a specific device, please read my lengthy compendium of modern boat electronic devices at

NMEA-0183 Interface Data Collection
https://continuouswave.com/forum/viewto ... ?f=9&t=816

If your devices are not covered in the collection, consult the owner's manuals for your devices.

Look for the information for your specific devices.

For the RAYMARINE E-series, see:

NMEA-0183 Interface Data Collection
https://continuouswave.com/forum/viewto ... 271#p49271

For manufacturer literature see

https://www.raymarine.com/en-us/download/e-series-classic-manuals

Download the appropriate user guide, which is called
E-Series_Classic_Installation_instructions_87043-3-EN.pdf

Note: you have to select this document from a listing. There is no direct link to it.

Locate the information that identifies which wire colors correspond to which signals. You may need to translate the signal names. See my advice in the article on Universal NMEA-0183 Interface linked above for how to translate signal names.

For the SIMRAD NAIS 500 see:

NMEA-0183 Interface Data Collection
https://continuouswave.com/forum/viewto ... 268#p49268

For the manufacturer's literature see

https://softwaredownloads.navico.com/Si ... -001_w.pdf

For the NMEA-0183 wiring diagram see FIGURE 11 on PAGE 21. Note that in their literature SIMRAD uses the term "Transmit" to mean TALKER, the term "Receive" to mean LISTENER, the mark (+) to mean "A", and the mark (-) to mean "B".

Once you figure out the configurations, be sure to set the TALKER devices to send the desired NMEA-0183 sentences. Be sure to set the port speed on both devices to match each other.

[tandacht]

I believe I have the talker and listener wires correctly wired. What I am unsure of is whether I need to connect the screen from the E80 NMEA 0183 cable to the ground. The NAIS-500 NMEA 0183 cable is connected to the ships ground through the black power wire.

[jimh]

I believe I have the talker and listener wires correctly wired. What I am unsure of is whether I need to connect the screen from the E80 NMEA 0183 cable to the ground. The NAIS-500 NMEA 0183 cable is connected to the ships ground through the black power wire.

Generally in NMEA-0183 using shielded paired cables, the cable screen or shield is only bonded to the device chassis at the TALKER end. At the receiver end, the shield is left floating.

If both TALKER and LISTENER signals are contained under one shielded cable, I would expect the screen or shield is already connected at that device, and I would leave it unconnected at the other device. If there is any problem in that configuration, you can always make a second connection of the shield or screen at the other device to see if that implements any improvement.

So to be more succinct in my answer: at the point where the two cables meet, do NOT connect their screens or shield conductors.

The reason for this to avoid the creation of a "ground loop". For more advice on electrical ground loops see

https://en.wikipedia.org/wiki/Ground_loop_(electricity)

[tandacht]

Thank you for your advice. Right now, the screen is left 'hanging' and unconnected. The reason for my initial inquiry is that I am trying to troubleshoot a problem with the E80 recognizing the AIS input. When the AIS was first installed, the E80 had no problems reading and displaying the AIS data. However, over time the AIS became intermittent on the E80, and now it is not recognized. In looking at the nmea buffer, we are seeing odd sentence structure ($AINAK AND $AIVER) in addition to the normal AIS sentence structure (!AIVDO). I have ordered a rs232 to usb cable to see if the problem is coming from the AIS. Do you have any thoughts on this?

[jimh]

…we are seeing odd sentence structure ($AINAK AND $AIVER) in addition to the normal AIS sentence structure (!AIVDO)….Do you have any thoughts on this?

I am not familiar with the two NMEA-0183 sentences you mention.

I found this information:

A "$AIVER" NMEA sentence in the context of AIS (Automatic Identification System) indicates a "Receiver Status" message, providing information about the current state of the AIS receiver itself, like its operating mode, data quality, and potential problems it might be experiencing.

My inference: the AIS receiver is trying to tell you it cannot hear any signals.

Regarding a NMEA-0183 sentence in the form $AINAK, I cannot find any information. Perhaps the “N” refers to Navigation aids. Perhaps the “AK” refers to an acknowledgement.

[tandacht]

Thank you all for your fantastic assistance. This information will be extremely useful in troubleshooting our problems. I will let you know what we eventually find out. Again, you have been extremely helpful.

[jimh]

Part of the confusion in this particular situation may be due to the device connected via NMEA-0183 to the AIS receiver being a recreational grade chart plotter.

The AIS receiver may be sending perfectly valid NMEA-0183 data messages (albeit perhaps not very common messages), but the connected chart plotter has no ability in its design to correctly INTERPRET these messages and thus cannot DISPLAY the content of the message to the operator of the chart plotter.

Exactly HOW a chart plotter may process or handle any information it receives by a NMEA-0183 data connection sent by an AIS receiver is not subject to any regulatory obligation to comply with an established standard, nor is WHAT the chart plotter might do with the information with regard to displaying the information to the operator once it has decoded the information from its encoded form in the data transmission.

[tandacht]

Good to know. Thank you again.