How to wire MPG on 7i77?

rodw
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02 Jan 2017 21:11 #85120 by rodw

Replied by rodw on topic How to wire MPG on 7i77?

OT-CNC wrote:
I checked with a multi meter and pins 6, 7 and 8 appear to share the same ground on the 7i77. I'd like PCW to confirm that that is indeed correct before I utilize those connections.

If you are not using a separate power supply for the 5V side (I am), there is no need to link the two GND's as you will have tied them together when connecting the power. Not your board but this thread and the very handy attachment will explain.
forum.linuxcnc.org/27-driver-boards/3191...n-sheet?limitstart=0
The only difference seems to be that the 7i77 has an additional connector which throws out some of the connector numbers.

It was a post somewhere from PCW that suggested tying the GNDs together as a solution.

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OT-CNC
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03 Jan 2017 03:49 #85129 by OT-CNC

Replied by OT-CNC on topic How to wire MPG on 7i77?

Hey thanks for that link!

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rodw
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03 Jan 2017 04:11 #85131 by rodw

Replied by rodw on topic How to wire MPG on 7i77?

OT-CNC wrote:
Hey thanks for that link!

No problems

The other thing that did my head in was what sort of switch to get. So I phoned a friend and he suggested a link to one. It did my head in wiring it up. I've done heaps with bitmaps but never with hardware, only wirh software. The switch has 12 positions numbered 1 to 12 and 3 outputs A,B,C. It finally sunk in to build a binary truth table and ignore C as we only need 2 bits:

Then it was simply a matter of mapping the wires to make the 1's above light up.
In my case it was pins 3, 4, 6 and 8, So all I did was tie them together with the yellow wire.

So the yellow wire will be wired to 24 volt and the orange and green wires in the middle will go to the two inputs for the Mux 4 component. All tested and working with a multimeter so I'm off to connect it up!

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rodw
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04 Jan 2017 01:14 #85178 by rodw

Replied by rodw on topic How to wire MPG on 7i77?

I got this sorted now for a single axis (as on a plasma table you only need to jog the X & Y and there are 2 encoder inputs on the 7i76/7i77 boards so I will run 2 MPG wheels.
One variant I did was to OR the MUX inputs to light up the enable signal. So if you have any scale selected other, than 0.0, axis.x.jog-enable = TRUE

Here is what I ended up with. You will probably need need to alter the or statements to suit your config.

# Metric units used
loadrt hm2_eth board_ip="10.10.10.10" config="firmware=hm2/7i76/7i76e.BIT num_encoders=1 num_pwmgens=0 num_stepgens=5  sserial_port_0=2xxxx" 

loadrt or2 count=4
addf or2.3  servo-thread

setp axis.x.jog-vel-mode 0
net x-jog-counter <=  hm2_7i76e.0.7i76.0.0.enc0.count
net x-jog-counter => axis.x.jog-counts
net mux-in1 or2.3.in0 <= hm2_7i76e.0.7i76.0.0.input-22 => mux4.0.sel0
net mux-in2 or2.3.in1 <= hm2_7i76e.0.7i76.0.0.input-21 => mux4.0.sel1
net x-jog-enable <= or2.3.out
net x-jog-enable => axis.x.jog-enable
setp mux4.0.in0 0.0
setp mux4.0.in1 1.0
setp mux4.0.in2 0.1
setp mux4.0.in3 0.01
net x-jog-scale mux4.0.out => axis.x.jog-scale

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