Here I connected 2 input pins on the controller to a jack on the rear panel. In most cases these will be used to connect to homing switches on the CNC.
Attach Wires to Jack
Cut a wire (black) about 15" long and remove 1/2" of the insulation and tin with solder.
Solder the black wire to pins 1-5 as shown.
Cut a wire (red) about 15" long and remove about 1/4" of the insulation from the wire and tin with solder. Solder this wire to pins 6-8 as shown. This will be input 1.
Cut a wire (yellow) about 15" long and remove about 1/8" of the insulation and tin with solder. Solder this wire to the remaining pin (9). This will be input 2.
Add a tie wrap the wires as shown.
Attach DB9 Jack to Rear Panel
Note that you will need special mounting hardware for this task. These consist of two #4 standoffs and nut for each jack.
It may be helpful to first hold the jack in place with a #4 machine screw and nut while you attach the first #4 standoff.
A kit of 4 connectors, standoffs, and nuts can be found here:
Connect Jack Wires to Controller
Attach the ground wire (black) to the grounding terminal block as shown.
Attach the input 1 (red) to the input pin on the controller associated with your homing switches x,y, and z.
Attach the input 2 (yellow) to the input on the controller associated with homing switch A.
Note that homing switch A may not be used. If so this input can be used for other purposes.
Wire Homing switches to Plug
You have a couple ways of wiring your XYZ switches to the DB9 male jack.
You can connect them all together and bring only a single set of wires as shown here.
Since the first three terminals on the DB9 are connected together, you can also bring them in and connect them individually.
If you need a second input for a fourth axis, connect them to the connector as shown with the yellow arrows.
Add a housing and connect to your jack as shown.