Hooking up a Pushbutton SLC 500

I'm want to hook up a push button to activate one of my inputs on my SLC L20 Fixed controller. The diagrams that are shown in the instalation manual show a 3 wire field device. Dos any body know where I can find some schematics on how to wire a switch into my controller. it's DC sink input. I was also wodering if I can use the 24 volts provided by the controller or do I use a separate power supply?

Thanks for any help.

It is just a switch, so run your +24 to one terminal, and connect the other terminal to the input point. Connect the 24v common to the DC Common for that point on the input card to complete the circuit.

Using the SLC power supply for field devices is not normally recommended, but folks still do it frequently without problem. The input point is going to draw very little power, but don't go running a bunch of output devices with it, or you may have problems.

Thanks for the help, got it. I wasn't connecting my common's.