If you were looking for some advice in the form of "connect red to green" you will not find it here. Instead, you will be given a simple, logical, concise method and the information necessary to make the connection.
STEP 1: IDENTIFY NMEA-0183 STANDARD COLORS AND SIGNALS
The NMEA-0183 standard for wire color identification of signals is:
TALKER A = White
TALKER B = Brown
LISTENER B = Green
LISTENER A = Yellow
Unfortunately, this is seldom followed in actual practice by manufacturers. Information on the NMEA-0183 Interface of various devices will be given using a standard form, as follows:
DEVICE: Device NameSource: [Hyperlink to primary source of the information.]
TALKER A = Wire Color
TALKER B = Wire Color
LISTENER B = Wire Color
LISTENER A = Wire Color
(The reason for the ordering in my list of the A/B signals in the TALKER and LISTENER to be opposite--ABBA instead of ABAB--will be seen in a moment, when I describe the connection arrangement that I have found works very simply and consistently. The hyperlinks to primary reference material are very useful, as those resources usually include additional information that will be helpful in making these connections.)
Browse the listings below (in articles appended in this thread) to locate your particular device. Identify the signals and wire colors for your particular device. Once NMEA signals are identified by their wire color, interconnection of them can be done.
STEP 2: RULE FOR INTERCONNECTION OF NMEA-0183 DEVICES
Interconnection between devices will then always follow these simple rules:
RULE 1: LISTENER connects to the TALKER of the other device with the same A/B notation.
RULE 2: If a LISTENER B has no corresponding TALKER B signal, that LISTENER B connects to ground or the power source common (i.e., negative battery bus in most boats).
RULE 3: If a TALKER B has no corresponding LISTENER B, that TALKER B is insulated and left unconnected.
STEP 3: SIMPLE METHOD OF WIRING FOR INTERCONNECTION
A five-pole terminal strip makes a very simple way to interconnect devices. A terminal strip with compression clamp connections is often used. A typical example is shown below. These can be obtained from many sources at low cost (about $1.20). Finding a terminal block with five terminals may be a problem as the terminal blocks seem to be stocked only in even-number of terminal. A solution is to get a larger one (6-position) and cut off the unused terminals Compare at
On the left side of the terminal strip you connect one device, and on the right side you connect the second device. If you lay out the signals as I show below, you have a very consistent method. IMPORTANT: the middle connector of the five pole terminal strip is always connected to the boat 12-Volt power negative bus by its own dedicated conductor. Here is the layout in ASCII drawing:
NMEA-0183 FIVE POLE TERMINAL STRIP
TALKER A---[O-O]---LISTENER A
TALKER B---[O-O]---LISTENER B
---[O-O]---(connect to power negative)
LISTENER B---[O-O]---TALKER B
LISTENER A---[O-O]---TALKER A
When wiring two NMEA devices to the terminal strip, there is only one possible inconsistency that can occur: if a LISTENER B has no corresponding TALKER B, wire that LISTENER B to the middle terminal or power negative.
If two devices which adhered to the NMEA-0183 standard for wire color and each provided both A and B signals were interfaced with a five-pole terminal strip, the connections would look like this:
SAMPLE TABLE OF CONNECTIONS
NMEA-0183 FIVE POLE CONNECTION
---[O-O]---(connect to power negative)
Note that the order of the colors is the same on each side, just inverted top-to-bottom. Make a similar table for your two devices. This table will be a record of the wiring arrangement. If you follow my design, the table will also aid you in remembering the functions of each wire.
STEP 4: MAKE CONNECTIONS
Using the information on connections from your table and using the five-pole connector method, connect the two devices to the wiring device and interconnect them as your table indicates. At this point you will have finished with the electrical interconnection of the devices.
REVIEW: FOUR STEPS TO MAKE INTERCONNECTION
There are four steps in making a NMEA-0183 wired connection:
--locate the manufacturer's information about signal names and wire colors in the articles below
--apply the three interconnecting rules given above
--develop a table of wire connections for your two specific devices
--connect the signals according to your table of connection using the wiring pattern and rules above
When you have made the electrical interconnections, you have finished the actual wiring portion of the interface. You may have to continue the process by making changes to settings for the data characteristics of the interface ports and by selecting what data will be send across the interface. These topics are covered in other articles. Please see
Guide to NMEA-0183 Interconnections
NMEA-0183 Interface: Signal Data Rate; Data to be Exchanged
The above articles will review the interconnection method, explain addition parameters or settings that need to be configured, and explain how the particular data to be exchange must be configured by the installer.