Wiring 24v NPN Proximity Switch to 5v BOB - Why does'nt it work

[MikeyC38]

Thanks for that, Rob - first time I've seen a representation of the switch internal circuit. I find those little extracts of both input and output circuits very useful in getting an understanding of how things go together, and especially when it comes to working out why something doesn't work! Too much detail for some, perhaps...

Now I'll have to draw out the combined circuit of four of those (NC versions) strung in series, so that I can use a single input for combined limit switches, just to reassure myself that it should work - even though I've wired it up on the bench and it does seem to.

Maybe some of us take a more theoretical approach where others just want to know where to stick the black wire

Just in case the OP is still with us and hasn't given up the will to live - this just confirms that your original wiring should be fine if you take out the resistor.

Hi Neale - I'm still here! Just about. But I must be having a brain fade because when I connect the black wire to pin 10, the blue wire to the pin 10 GND, then run a wire back to the -ve 24v supply it buzzes and does'nt work. I checked the GNDS on the ZP5A-INT board (it has a 5v supply from my Leadshine PS408/5 ), all the gnds are connected by doing a continuity check with the BOB unpowered from the -5v pin. I guess I just need to sleep on this and start again tomorrow. I must be missing something in what you guys have said and suffering from a case of "Goldfish brain"

[m_c]

I hope you mean +ve and not -ve.
.
Best to go back to basics, wire up just the power and gnd to the sensor, and use a multimeter to check that the output is switching. Provided that works, connect it to the BOB.