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I have a Bridgeport Series II Interact 2:

igor.chudov.com/projects/Bridgeport-Seri...Interact-2-CNC-Mill/

I am converting it to use with EMC. I already have a PC with EMC installed.

It has FIVE (sic) limit switches: two on X and Z, and one on Y. The limit switch on Y is triggered by overtravel in either direction.

The switches are normally closed.

I use PPMC by Pico systems.

My question is, how should I wire the limit switches to facilitate homing the mill, etc?

Can I just use them as inputs to the PPMC controller and let EMC take care of it?

What is the "canonical way" or treating limit switches?

you talk about limit switch, then talk about them being used as home switch also,
Limits should be limits,
home switch should be for homing only.


its realy down to the integrator on how they are wired in etc.

most machines have the limits wired into the Estop system, which then you need a button to get out of the limit areas if you do run into them, if soft limits do fale etc.

realy there is no real true answer.

rob

EMC does accept limit and homing on the same switch. Take a look in the integrators manual in the homing section of the ini.

John

Thanks BogJohn. Just to make sure, the limit switch can be Normally closed, this is not a problem for EMC?

Typically a safety type of device like a limit switch is wired N/C but EMC has no problem with either configuration. You just have to configure the input as needed.

John

John, thanks a lot, this is great to know.

I apologize for the confusion. My limit switches are normally closed.

I think that I will let EMC handle the limits without them invoking estop, etc.

That way I could home the mill etc.

i

Yes, you only have to tell EMC that home and limit switch is shared on an axis in the ini file and EMC takes care of not thinking it has hit a limit when homing.

John

But it would respect limit switches when working, right?

Let's say I give some stupid milling instruction to the machine, such that it would hit a limit switch. EMC can be configured to stop operation, right?

Thanks

i

When EMC is doing anything other than homing the switch is a limit switch and will stop the machine.

If you configure your soft limits correctly you never hit a limit switch.

John