I prefer to have seperate 5v & 24v but you can do this image below with a single 24v.
If daughter cards are going to be used on the IDC26 expansion headers then I'd use seperate ones.
Search 'Mesa 7i76e' in google images and loads of stuff comes up:
NPN 3 pin inductive switches:
https://www.rainydayprojects.ch/user.../Mesa7i76e.svg
NOTE... looks to be wired to analog in. Should be wired to digital in.
You get the jist though.