Hi Rainer, Sorry it has taken me a month to get around to testing. I had some mechanical issues that I needed to sort out before being able to test properly. That being said, in my sim configuration where there was no amplifier feedback the new homing states seemed to work perfectly. Now with the feedback connected, the homing routine will go as far as locating the home switch at search velocity, then slows to latch velocity when the switch goes high. Ultimately, it fails when the final location of the home switch is detected i.e. the switch goes low again, you immediately get a following error. When the homing routine is active I can see in HALShow the joint.0.following_error is 0.0001, well below the very high following error I have set.
The weird thing is when I reset the machine and switch back to homing mode, the amp indicates that homing has been attained but the counter is not reset to exactly zero. I'm guessing that the homing signal from LinuxCNC is dropping out before the amp has a chance to reset the counter to 00000000 as the final position of the home switch is always slightly different. Kind regards, Dan -----Original Message----- From: Rainer Stelzer <[email protected]> Sent: September 21, 2021 12:35 PM To: EMC developers <[email protected]> Subject: [Emc-developers] more convenient homing for machines with limit switches and reference switch. Hi, when discussing the Autohoming issue for computerized servo drives I came to an old point (not related to Autohoming) best summarized by the documentations statement: "If using a separate homing switch, it’s possible to start homing on the wrong side of the home switch, which combined with HOME_IGNORE_LIMITS option will lead to a hard crash." But even if it does not crash and only stops, the operator has to know where to move manually to leave this "wrong side zone". (Have a machine here with 1900mm X travel and ref switches are at X=850mm. Not even at x=950mm what may be guessed by the operator) Because this setup (+/- limit and ref switch) IMHO is quite common on industrial machines, i wonder if someone already came up with a solution. I would go for extending the homing statemachine to reverse search direction when limit switch is hit and go with search velocity until the reference switch is activated. Then continue with "HOME_INITIAL_BACKOFF_START" state. Or is it intentional, to keep things simple ? I noticed that homing questions are very often a topic. cheers Rainer _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
