Light curtain as *start* switch?

I came across this question the other day, and it gave me pause. This fellow has a station set up where the machine automatically starts up when the operator removes his/her hands from the area, as detected by a light curtain. Presumably it stops again when the light curtain is interrupted.

Can you see anything intrinsically wrong with this? I have to admit, it makes me a bit queasy, since I'm used to seeing more explicit start commands (even two-hand controls) required in such instances.

Granted, much may have to do with the particulars of the equipment involved, but are there any generalizable principles involved here?

Ken Crater
Control.com
 
Top