FTR LYCA 012V is a relay. It has a NO/NC contact. I don't know how you use it as a proximity switch, but in any case, it is not a good idea to use NO as proximity (do you mean limit?) switch. NC is what normally used because NC will react on wire or connection failure, with NO you will not detect that situation. But if you insist on using two NO connected to one input you must connect each pair of two in parallel. If you'd use NC type you'd need to connect them in series.