Soft Limits

Moderators: TomKerekes, dynomotion

Post Reply
Chevvron
Posts: 38
Joined: Mon Apr 22, 2019 9:26 pm

Soft Limits

Post by Chevvron » Tue Feb 17, 2026 8:55 pm

Tom,

Operational testing of the 8 axis machine continues.
Discussions on Friday for the next two machines.

I have noticed that the software limits change during the machine operation.
I am now convinced this happens after a program exit and then a program start but no homing.
The Kogna has not been rebooted so the axis positions are still true.
After closing , opening, and homing i randomly get software limit activation when the axes are clearly in valid positions.
At this point a reboot of the Kogna seems to be the answer.
I am thinking that the Adjust Software Limits code has variables that are not being cleared on program exit and re-intialised on program start ?

Sometimes on program exit I find a message box left open on the desktop.
What is the best way to ensure they are cleared on program exit ?

Regards,
Tim

User avatar
TomKerekes
Posts: 2901
Joined: Mon Dec 04, 2017 1:49 am

Re: Soft Limits

Post by TomKerekes » Tue Feb 17, 2026 9:48 pm

Hi Tim,
i randomly get software limit activation
What do you mean by this? A Console Message? Popup Message? When you Jog?

AdjustSoftlimits.c triggers a Feed Hold while Jogging.

You might use KMotion and upload the Axis to view the parameters and check if Soft Limits are correct.

It isn't clear regarding homing. In one case "but no homing" and also "After homing" Please clarify.
Regards,

Tom Kerekes
Dynomotion, Inc.

Chevvron
Posts: 38
Joined: Mon Apr 22, 2019 9:26 pm

Re: Soft Limits

Post by Chevvron » Tue Feb 17, 2026 11:22 pm

Tom,

On power up, initialisation and homing all axes obey the software limits without a problem both in jogging, mdi and g code run.
In jogging a feed hold happens when physically the axis is at the end of software iimit travel.
An mdi move which would move the axis outside of the software limits displays a pop up message.
All as expected.

If KMotion CNC is exited back to the desktop when the axis are maybe in mid travel for example then when KMCNC is subsequently restarted that is when the software limits behave differently.

The axis do not need re-homing as the Kogna has not been reset and physically the axis are in the correct position.

However if the axis jogged towards the +ve limit for example instead of it stopping at +6mm which is what the software limit is set to in the homing program it stops at +25mm on probably the hardware limt.

Whilst writing the above it occurs to me that as I have not done the homing / homing c program which is where the software limits are set then they are not the valid values.

Maybe I need to add setting the software limits code as part of the initialisation or program start c program ?

I might have just answered my own question.

Regards,
Tim

Post Reply