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Manual Pulse Generator On Fadal VMC retrofit

Posted: Wed Feb 04, 2015 9:31 pm
by dbensavage
I am installing a ALLIN1DC on A Fadal Mill. I would like to wire the original MPG and switch's to the allinone. The fadal mpg has 4 posts on the back and 2 selector switches. One selector switch for the axis and one for increment of movement. The MPG hand wheel on my machine only has 4 terminals. It does not have the -a and -b terminals. Will his work or would I need to buy a different mpg hand wheel?

Re: Manual Pulse Generator On Fadal VMC retrofit

Posted: Thu Feb 05, 2015 9:32 pm
by dbensavage
Maybe this will help. one is a picture of the 4 terminal mpg on the fadal and the other is a picture of the allinonedc wiring schematic. I guess I am wondering what the difference is between the 4 terminal and 6 terminal mpg's?

Re: Manual Pulse Generator On Fadal VMC retrofit

Posted: Fri Feb 06, 2015 12:54 am
by cncsnw
Your pulse generator has a single-ended TTL output.

The MPU11 and All-in-one DC require a differential line driver input.

You either need to replace the pulse generator with one that has line driver output (recognizable by the complementary channels: A, /A, B, /B) or you need to install a TTL-to-differential signal converter between your pulse generator and the control board.

I believe Centroid sells a small converter board. You can also build your own using any suitable dual (or quad) line driver IC.

Re: Manual Pulse Generator On Fadal VMC retrofit

Posted: Fri Feb 06, 2015 11:15 am
by dbensavage
Thank you for the reply. I'll give centroid a call this afternoon and see what they get for one.