Tandem Y Axis - Can't Jog Both at the Same Time

I don't think the polarity on my Z limit switch is inverted because I had to invert the polarity of my Y limit switches, and before I did that, I would get an error at startup. I do not see any error at startup now for any of the limit switches. I'm not sure if I made it clear before, but I am sharing the limit and home switch.

I tried adding a line to my ini file "HOME_IGNORE_LIMITS", but that caused it to run right into the mechanical stop when I attempted to home Z. Are the logic for home and limit switches inverted by default? Meaning, should limits be active low and home switches be active high? It's possible that I need to invert the polarity of my home signal if that is the case.

Both the max-z signal and the z-home-sw are showing false in hal meter at startup before I attempt to home.

I think I found the problem, but I am having a hard time figuring out how to resolve it.

When I jog to the limit switch and observe halmeter, I see that the max-z signal toggles from false to true, but the z-home-sw signal doesn't change. I am not sure how to map both signals to the same pin in the hal file. Can anyone tell me?


I found these lines in the setup home / limit switch signals section:

net z-home-sw  => joint.3.home-sw-in
net z-neg-limit  =>  joint.3.neg-lim-sw-in
net max-z  ==>  joint.3.pos-lim-sw-in

And this entry under external input signals:

# --- MAX-Z ---
net max-z  <=  hm2_7i96s.0.inm.00.input-03

You have not connected a homeswitch signal.
Try

net t z-home-sw <=  hm2_7i96s.0.inm.00.input-03

instead of what you have for max z

Thank you, that helped, I was able to home Z, but now it does not seem to acknowledge the switch as a hard limit. So if I start the machine and do not home first, it will allow me to jog past the switch. Is that just a limitation of shared switches?

Was I supposed to delete this existing line
net max-z <= hm2_7i96s.0.inm.00.input-03

or just add your line below it?

I deleted it and replaced with your line.

Thanks everyone for the help. I got it working by editing the hal file as follows:

# --- MAX-Z ---
net max-z <= hm2_7i96s.0.inm.00.input-03

# ---setup home / limit switch signals---

net max-z => joint.3.home-sw-in
net z-neg-limit => joint.3.neg-lim-sw-in
net max-z => joint.3.pos-lim-sw-in

yes, now add a HOME_OFFSET to move the axis off the home switch so it does not trigger a fault as it comes out of homing. 1mm should do it.