On Sun, 26 Aug 2007 03:48:21 GMT, Anthony
wrote:

"Joe AutoDrill" wrote in
newsuLzi.4849$oh1.562@trnddc04:



Something like that... The drill I provided has a dry contact proof
of return switch so I'm looking for something I can put in series with
that so that BOTH (or actually ALL since there are more than one
clamping locations) have to be made for the circuit to be completed
and thus the signal received at the PLC to proceed.

I actually think the clamps are destaco, but I can check monday. We just
use standard balluff or festo PNP flat pack cylinder prox switches. I
would suggest you supply 24V to the sensor off of the plc power supply,
then tie the signal output to an ice cube relay (or a phoenix contact
solid state relay) which would actually pass the current along the series
to the PLC, since the current may be too much for the sensor in a series
application. These things are only good for a few mA. Reliable as whiz
tho when properly used. The only bad thing about a magnetic sensitive
prox is the range of sensing is not 'precise' per se`. You can shade it
to one side or the other of the magnet stop position, this will make it
more accurate. This is the most common type of clamping sensor we use, by
far. Probably in the neighborhood of a couple of thousand of these
sensors in use at our plant.

Sounds good to me.

Gunner