Proximity Sensors / Mach3 not showing

I have wired in 2X Proximity sensors on the X axis on my cnc. Ebay Item 32113180610
I am using a USB BOB (Ebay Item number 26116368592)

The normal micro switches I have on Y and Z axis work fine, but I want to use Proximity switches for X, as they will get splashed with liquids.

I have used the BOB DC +5V supply to power the P switches (as it states on the specs 5-24V). I have tested the output of both the switches which is again 5V DC. Plus the LED on the switches light up when metal is passed over the sensor part *all good so far*. But the BOB does not light up its input LED's, Nor does Mach3 diagnostics recognise that there is anything connected to these pins (14 / 15). I have tryed swapping to other input pins, and all the ports and pins settings in Mach3 are correct.

Any Ideas ?

I use prox sensors on my system. I used 24vdc and ran the output to a relay. I then wired the contact in the relay to the BOB. The transistor in the prox sensor never really is going to operate the input pins directly reliably. Thanks. Mike

fedupwiththecontinualchanges.

When I test across the connections on the bob it shows 0V

CNC Controller Mill Router Home & Limit switch Proximity Sensor Panic Button | eBay

http://www.ebay.co.uk/itm/CNC-3-axis...item3a805b211b

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Originally Posted by msanderson

I use prox sensors on my system. I used 24vdc and ran the output to a relay. I then wired the contact in the relay to the BOB. The transistor in the prox sensor never really is going to operate the input pins directly reliably. Thanks. Mike

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I use a 48V DC supply for my Drivers/Motors. I hope I have not got to start adding more PSU's or relays. The reason I chose these Sensors is because it shows them wired to the PC +5V supply and directly into the input pins on the BOB.

Contacted the Ebay Member with the sensors. Replyed that I can go direct to the parallel port without the BOB. I guess I just change the "Port" setting in Mach3 "ports and pins" ?

Attachment 9048

This is just as unlikely to work as the problem could be switching reliability at the 5v end of the operating supply voltage range. The BoB I use is voltage switchable would not run the sensors at 5v and so the inductive switches now operate at 12v. I would never advise going directly in to a printer port, unless you have a ready supply of spare computers.

Cheers,

Rob - A man of great girth.

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Originally Posted by dudz

Contacted the Ebay Member with the sensors. Replyed that I can go direct to the parallel port without the BOB. I guess I just change the "Port" setting in Mach3 "ports and pins" ?

Attachment 9048

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It doesn't say in the listing (Edit: Just spotted the datasheet in the eBay listing, which does say open-collector), but the inductive sensors are probably an open collector output, in which case you need a pull-up resistor from the signal to +5V. Use something like 4.7k, exact value isn't critical.

You're much less likely to have problems with noise if you use a breakout board and run the sensors at a higher voltage. Connecting to the parallel port directly can work, just make sure you connect it up correctly on the first go otherwise the port could be damaged.

allmyworthwhilepostsaregoing

Quote:

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Originally Posted by Jonathan

in which case you need a pull-up resistor from the signal to +5V. Use something like 4.7k, exact value isn't

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Ok, So it "may" work if I add the pull up resistor while still using the +5v power and the USB BOB?
Other than that I would need to use 43V (my PSU is set at) and use a resistor to lower the power into the Sensor ?