Proximity Sensors / Mach3 not showing

[dudz]

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 ?

[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

[m_c]

fedupwiththecontinualchanges.

[dudz]

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

[dudz]

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

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.

[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" ?

[cropwell]

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.

[Jonathan]

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" ?

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.

[m_c]

allmyworthwhilepostsaregoing

[dudz]

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

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 ?