Inductive proximity sensor interfacing

[milldrone]

The pulse frequency is about 100-150 ppm, i am using a sensor from some surplus equipment to retrofit a machine in our shop.What I would like to do is replace the limit switches which trigger some pneumatic solenoid valves, with a PLC controlled system to increase the precision of operation. We don't have much money to spend on R&D so I am trying to use what we have on hand

Hi Milldrone,
Actually, I would like to use the prox sensor to count the links on a iron conveyor chain and then use that data to fire the pneumatic solenoid valve after the count reach a predetermined set point.

Thanks

xilog,

My previous post was aimed at narcilla

A 1 watt 20K ohms resistor should work nicely. If a 1 watt is hard to come by two 10 K 1/2 watt in series will work and spread the heat out over a larger area. Keeping Roy's and Okie's suggestions in mind

If you have doubts about how much damage 1 or two watts of heat can do consider this. I use a 15 watt soldering iron to connect Amphenol connectors to cables.

 

[Roy Matson]

I just looked up the Pepperl&Fuchs switch I have used with 120 VAC Modicon input module.
It's leakage current is <= to 1.7 mA just like yours.
I suggest you just hook your switch in series with a spare input and try it. If you find it doesn't turn off add a resistor as Mildrone indicated.
Sensing links on the chain might be tricky, perhaps you could place your switch beside the tail pulley sprocket teeth.