How to jog when beyond soft limits

I have absolute encoders and thus don’t home. Though through other posts it does not seem that is well supported.

I thought this would be a quick answer. Does Linux cnc not have the ability to jog to get back within soft limits? I would expect the that can’t jog more into the limit but you should be able to jog out of the limit. Is this supported?

tommylight wrote:

Much better to post more info about your machine and how the homing is set up, and uploading config files usually helps a lot.

So you are saying that Linux CNC supports jogging back into soft limits? 

config attached

Yes, LinuxCNC supports backing off of the limits, be it hard or soft, it has a button for that in the GUI, but :
-you never mention any info about the machine, like it uses EtherCAT
-i have no experience with EtherCAT, so no idea if normal LinuxCNC stuff applies to it
-you keep asking for help, but still fail to provide info, this is frankly agonizing
-you posted twice in the wrong sections, there is EtherCAT section on this forum, but this is not important as we do not mind moving topics around, and i did this once, now i have to do this again as you did not provide the info on the first post, nor the second nor....
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In general, limits should never be crossed if everything is set up properly, and that is easy to achieve, but this is EtherCAT, so i am moving this there, much more experienced users there so should figure where the issues is.
I would venture a guess at setting some small HOME_OFFSET in the ini file, like a mm or two, so even when you disable motors they could not reach limits. Maybe this is all you need...

Now that you confirm this feature is supported and should work. Which would have been good to know in the first response. I can dig deeper, I assume this is exposed in the hal, correct? Is there a special condition or hal pin for jog while within soft limits? While, there is tons of ductiontation, it is hard to find it when you don't know what you are looking for. If I had to guess, the issue is that it's not a direct EtherCAT issue (has it just a HAL component), but rather a dependency on the configuration from a configuration wizard.

I do agree a machine should never be beyond the limits, but if the logic is just a straight greater than or less than than I think there could be an edge case that needs better logic. Maybe this has already been addressed. I have 23-bit encoders, so that is > 8.3 million per rev. So even with the translation to machine units there is a very very small "error" factor. Meaning the "actual" location will fluctuate (bad word choice) with no movement by this very small amount. This can make the axis and/or joint appear its beyond a soft-limit. For instance, when I zero the DRO will remain "zero" but the "-" will flash on and off. Again, maybe all this has been addressed.

Additionally, I have found incorrect and inaccurate details regarding the setup of absolute encoders and how LCNC handles them in both document and forum searches. I am more than willing to contribute back, but "guidance" would be more helpful.

Lastly, tommylight  Thanks for all your efforts as a moderator; it's a thankless task.

kubes wrote:

Additionally, I have found incorrect and inaccurate details regarding the setup of absolute encoders and how LCNC handles them in both document and forum searches.

Yeah search is fuzzy on the forum and utterly useless on google lately.
And this is a rare topic, so not much to go on, but more and more users have similar setups with absolute encoders and homing to index and EtherCAT, mainly due to inrush of cheap china drives with haphazard user manuals leaving users to pretty much figure stuff by trial and error.
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I did a retrofit with absolute encoders, used the "immediate homing" feature in LinuxCNC as it was simpler for them and more in line with their type of "one off" work.
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Did you test adding a bit of HOME_OFFSET? Usually negative values, not always.