Connecting Sain Smart Mechanical End Stops to Ramps 1.4?

I have Sainsmart Mechanical End Stops, and I'm building a Prusa i3 Rework.

I've recently gotten the x-axis to move, but it needs to stop when it gets to the end and it does not do that; I end up having to pull the plug.

From what I understand, there are two ways to wire ends stops in general, but you have to change the settings in the firmware to make it work right.

There are 3 connectors on the board:

• S (signal)
• - (ground)
• + (VCC)

My Sainsmart Mechanical End Stops have 4 connectors!!!

According to their website, left to right with the white connector facing you, they are as follows:

• S
• Normally Closed (NC)
• Normally Open (NO)
• VCC

Now it seems to me that if I take those connections and connect them as follows it should work...(ramps on the left, sainsmart end stop on the right):

• S (signal) -> S
• - (ground) -> Normally Open (NO)
• + (VCC) -> VCC
• nothing -> Normally Closed (NC)

...but! Screwing this up by either using the wrong firmware of selecting the wrong wire frys your board, so I thought I'd ask here about the correct way to connect them.

Edited 1 time(s). Last edit at 07/07/2016 12:00PM by leeand00.

I wired my endstop as

S = Yellow
GND = EMPTY
GND = Black
VCC = Red

And used this image to connect wires on the RAMPS:


NOTE: This image shows position for X/Y/Z MIN end stops.
MAX position is one step to the right.

EDIT:
BTW, if you bend that end stop connector up a bit. You will see they are probably marked on the circuit board. The connector just covers it.

Edited 1 time(s). Last edit at 07/07/2016 12:15PM by Veesta.