You didn't say if you have a newer or older model board. Either are capable and have the connections to hook up limit switches, and as Gerry said the older 3axis board uses J10 & J11. If you look on the xylotex web site under the data sheets, there are schematics for simple series, or parallel home switch setups. You'll need one or three 10k resistors (depending on which way you want to wire them) and a +5v supply to pull the circuit low. You don't have to have a board, you can just put the resistor(s) inline and use some shrink tubing. You can set up for normally open (NO) or normally closed (NC) switches. If all you have is NO switches they will work but with a NC switches and circuit it will also stop things if a limit switch wire breaks, unlike the NO circuit. You have lots of setup options for limit or home switch setup with software like Mach2, but I don't know what you're using... I'd really suggest a breakout board tho... a simple one for about $75-80 from PMDX will not only isolate your computer's parallel port from damage, but will have the resistors built in to pull your switch circuit low as well as a 10amp 120v ac relay built on the board for spindle control. That paticular board also has a watchdog circuit (also called a charge pump circuit) that will stop things should the software runnning on the PC stop working properly. I know Mach2 has a charge pump feature, but any software that will toggle pin 17 on the PC's parallel port will work. Most steppers are capable of doing some serious damage to your machine if something goes wrong. It seems like a fairly inexpensive safety "bridge".
-marc  |