NPN type sensors would work best with our digital inputs. Our DIN port on the DT9801-DT9806 boards is not terminated and is floating, therefore you must provide both a source and sink.  Choose an NPN type sensor, connect the low side to the isolated ground pin of board. Connect the positive side to both the digital input pin as well as the 5v isolated output pin through a 10k ohm resistor.  *Created: 10/08/03