Circular connectors with three to eight pins have become known as DIN connectors, named after the German Institute for Standards called "Deutsches Institut für Normung" in German. Created in the 1950s, the connectors have been used in all areas of electronics. To wire a DIN connector you must know the exact application for which you want to use it, know how many wires to use, and know which wires go to which pins. You also need to know how to solder.
Layout a wiring plan to show which wires go to which pins on your DIN connector. The wiring plan depends entirely on your applications.
Remove the outer covering from the DIN connector. Some covers screw onto the body, some have set screws holding them in place and others have a rubber boot that pops off with a tug. Slide the cover over the cable that you will use to wire the connector. Be sure not to reverse the direction, as it will only fit back on one way.
Solder each wire to its appropriate pin inside the DIN connector. Some have solder cups that you heat and fill with solder and then heat again to insert the wire tips. Others have terminals that you must hook the wire around before soldering.
Let the connections cool, then slide the outer cover back over the connector body. Secure it in place by either screwing it on, installing the set screw or popping it back into position.