Combined limit/home switch config...

[jvanick]

I am trying to get a combined limit/home switch configuration working, however when I 'home' the axis, it ends up tripping the limit switch as well...

is there something special I need to do to get it to jog back of the switch after it homes the axis?

I looked on the documentation wiki, and couldn't find anything relating to this probably very common issue, so I assume it's an easy fix that's just beyond me.

Thanks!
-J

[DonnieET]

I think your looking for "HOME_IGNORE_LIMITS" in your INI file set it to yes

Donnie

[jvanick]

I set that to yes... but I'm still getting the limit/joint following error...

-J

[Big John T]

You might have the direction or something like that wrong. Try posting this in one of the EMC community contact methods as most EMC folks don't hang out on the Zone. For the fastest help hop on the #emc channel on this page http://www.linuxcnc.org/content/view/4/8/lang,en/

John

[Bubba]

I cannot respond directly to EMC, but when I set it up in Turbocnc, I CANNOT setup the limits! If I set homeaslimits, then they will act as limits or home as appropriate.

The first time I set mine up, I also setup limits and had the results that you are having.

[acondit]

I set that to yes... but I'm still getting the limit/joint following error...

-J

I use combined home and limit switches, one switch at each end of travel.

OK, one question. Is it just one switch for home and limit at that end of the travel?

Here is what I did in my ".hal" file.

# create a signal for the limit switches
net both-home-x <= parport.0.pin-11-in
net both-home-y <= parport.0.pin-12-in
net both-home-z <= parport.0.pin-13-in
net both-home-x => axis.0.neg-lim-sw-in axis.0.pos-lim-sw-in axis.0.home-sw-in
net both-home-y => axis.1.neg-lim-sw-in axis.1.pos-lim-sw-in axis.1.home-sw-in
net both-home-z => axis.2.neg-lim-sw-in axis.2.pos-lim-sw-in axis.2.home-sw-in

And here are the settings for the X-axis in my ".ini" file.

HOME_OFFSET = -0.1
HOME_SEARCH_VEL = -1.500
HOME_LATCH_VEL = 0.250
HOME_USE_INDEX = NO
HOME_IGNORE_LIMITS = YES
HOME_SEQUENCE = 1

I am homing at the zero end of travel, using 60ipm travel velocity and I move 0.1" off of the switch to set axis zero.

Alan

[DonnieET]

I set that to yes... but I'm still getting the limit/joint following error...

-J

Is your system a stepper or servo? If a servo then your scaling is off or the the tuning is to far off. If a stepper then contact the mailing list at emc-users@lists.sourceforge.net.

[jvanick]

it is a stepper system, but I have to say that I feel like a total moron.

I had a typo in my HOME_IGNORE_LIMITS line.. doh.

anyways, it's working perfectly now.

thanks for the help guys!
-J