New Machine Build- limit switches -proximity sensor vs optical

[circlecn]

Hi, I am installing limit switches on an IH mill. I thought I would address this question to a broader audience in this forum.
I hope it is appropriate.

Which switch will give the most accuracy -- proximity sensor or optical. I have a Proximity sensor, 12 mm diameter, 10-30 VDC, 3-wire, NPN from Automation Direct in mind. Or a homemade optical setup (fully enclosed). I have used these proximity switches with Mach3 with success but in an application that doesn't require the precision I would like to get with my cnc conversion of the IH mill.

Thanks for any help -- opinions

Kent

[Al_The_Man]

If the inductive or optical device does not have any shaping circuitry for e.g. a Schmidt trigger circuitry, the output will be a gradually increasing slope, decreasing slowly as the device is passed.
So if using discrete slot sensor or similar, this can be the result.
Most all-in-one Hall effect devices, and some optical devices have a squaring circuit in them.
Obviously the signal conditioning type will give you more consistent results.
It is something to be aware of.
Al.