Mesa 7i85 and PNP encoder

Hi,
  I'm trying to use a new slot sensor with the spindles existing sensor ring to provide spindle feedback in to LinuxCNC along side the display on the Mill. I've found a sensor that physically fits the machine and lines up perfectly but the trouble is it is has a PNP output - Is it possible to use this with a 7i85 or do I need to find an NPN version?

Thanks
  Russell

NPN would be easier, but you can use a PNP sensor if its a 5V device
and you add a stiff pull-down resistor (say 270 Ohm) at the 7I85 input

Thanks, I give that a go until the suppliers have the NPN versions back in stock.