Proximity Wiring Problem

[Bruce]

Hi All

My first post but i have been lurking for awhile.

Firstly i would like to thank Audioandy for his help with my safety circuit and TonyD for his wiring schematic and pics.

I am nearly finished with my first build and today i was able to get my motors to turn.

I have a problem with my npn no proximity switches (LJ12A3-4-Z/BX) or it could just be me.

( 1/5Pcs Inductive Proximity Sensor Detection Switch NPN DC 6-36V LJ12A3-4-Z/BX UK | eBay (http://www.ebay.co.uk/itm/1-5Pcs-Inductive-Proximity-Sensor-Detection-Switch-NPN-DC-6-36V-LJ12A3-4-Z-BX-UK-/390603350619?pt=UK_BOI_Electrical_Components_Suppl ies_ET&var=&hash=item5af1c6225b) )

If i connect one directly to the PMDX126 it does what it's supposed to in mach3.
If i parallel two as the PMDX manual shows it trips in mach3

11263

Am i missing something in the mach settings or do i need different sensors?

Any help or suggestions would be appreciated.

Thanks
Bruce

[JAZZCNC]

Have you checked the second switch works correctly.? IE NO . . . . I've recently had some of those that have been marked wrong and some that where faulty.

If you have one working then it won't be a wrong setting has your obviously seeing the signal on the input. It really can only be a faulty switch or you have wired it wrong.

[Bruce]

Thanks for your reply Jazz

I thought i might have cross wired the sensors that are in position on the machine, so i used two spare sensors and tried a direct connection to the board with the same results.
I will get some new sensors from a reputable supplier.

[JAZZCNC]

Thanks for your reply Jazz

I thought i might have cross wired the sensors that are in position on the machine, so i used two spare sensors and tried a direct connection to the board with the same results.
I will get some new sensors from a reputable supplier.

Did you try the spare ones individual.? Or both wired parallel.

Have you got a spare power source and say a relay or lamp so you can test them off the machine before fitting.

[Bruce]

No, i connected one spare then both, not individually.
Thanks i will do that tomorrow.

[JAZZCNC]

No, i connected one spare then both, not individually.
Thanks i will do that tomorrow.

First confirm both switches work. Then it's just down to wiring and because Mach's seeing the switch when individual that confirms the PMDX is working and you have the correct settings.
If both switches work then it can only really be down to how you have them wired.

[EddyCurrent]

I think you tried some which were mounted and some that were just lying on the bench.
If mounted than some don't like being flush with the surrounding metal, they need to protrude a bit. Are you sure one of them is not being activated.

[Bruce]

Thanks for the feedback guys.
This is now slightly beyond my electronics diagnostic skills :-). Today i laid them on wood, connected them directly to the board individually and they worked as they should in mach.
If i join two together brown/brown blue/blue black/black and connect to the board it trips in mach?
I will order a different brand this evening and see how i get on.