Trying to fit 2 MPG

I converted my m300 Quite a while ago and after a few hiccups got it to work just fine. I use a ess smoothsteper and 2 bobs. I decided to fit 2 MPGs of the internet , simple 4 wire items easy to set up they say. Gave each 5 volts from the bobs and the ground from the same bob put the other 2 wires to inputs . In setting's I set for bob no 2 and input 2 and 3. Nothing at all happens? Changed inputs to proper inputs. Nothing? changed power to a phone charger . Nothing . Any body know what the simple thing is I got wrong. Thanks

Depending on the bob they might need pull-ups what bobs are they?

eBay item number:
122515449243 Sorry I don't know teck specs

eBay item number:
121924104910 this is the bob I have 2 thanks

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Originally Posted by keith wainwright

eBay item number:
121924104910 this is the bob I have 2 thanks

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Well with that bob you will have to supply the bob with 12-24 v as well for the input pins to work

A 5V MPG won't be able to drive the inputs on that BOB directly. The inputs on those BOBs are rated at 12-24V.

If you could find a datasheet for the optos on the board, you'll probably find you could change or even bypass the series resistors on the board, so they'll work on 5V, however it would depend on the current needed to drive the optos, and how much current the MPG can deliver.

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A 5V MPG won't be able to drive the inputs on that BOB directly. The inputs on those BOBs are rated at 12-24V.

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I am sorry but I have to disagree as I have a 5V mpg running on one of those boards

The boards are powered by a 24 volt power source but also have a 5 volt usb input . So clive are yours wired in any way diferent from mine.

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Originally Posted by Clive S

I am sorry but I have to disagree as I have a 5V mpg running on one of those boards

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You could of maybe mentioned that in your previous post :rolleyes:

However, back to basics.
Is the MPG switching the inputs of the BOB (the voltage should switch every two notches of the MPG on each channel)?
Are the inputs shown on the diagnostic screen in Mach?

But does the ESS support MPGs?
I know the original USS had a dedicated MPG input, which they dropped for the ESS. However I've not paid much attention to what Warp9 have or have not added since I last had one several years ago.

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Originally Posted by keith wainwright

The boards are powered by a 24 volt power source but also have a 5 volt usb input . So clive are yours wired in any way diferent from mine.

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So you do have a 24V supply connected to the board? If not, the inputs do NOT work.

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You could of maybe mentioned that in your previous post

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I don't see why as I gave the correct info to do the job.

OK
a) connect 8-12 V to the bob centre two terminals near the blue relay
b) connect 5 V or the USB to the bob
c) connect 5 V to the mpg + & - and A & B to input pins via a 1k resistor pins 10 and 11 (or any of the inputs)

Job done , You will have to set the pins up and high/low in Mach3. I used Linuxcnc
you might have to change the sense of the pins in Mach3 I used Linuxcnc

Edit : If you need to use the bob to drive the VFD (0-10v) you need to power the BOB with at least 12V
but if you don't need that the MPG will work with just 5V connected to the same pins at a) above

Yes 24 volts to both boards . All the other inputs work because the machine works fine . I am going to check diagnostics now

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Originally Posted by keith wainwright

Yes 24 volts to both boards . All the other inputs work because the machine works fine . I am going to check diagnostics now

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How have you wired them? Did you put a current limiting resistor in series ?

Yes I put one end in the bob and the wire to the other tail on both A and B