Intermittent MOTN-110 Fault

    I have a robot that used to have a linear fine movement to home before it decides which conveyor to place the part on. To save cycle time I changed that movement to CNT 100. This worked fine for some time, but with a new heavier part only (as far as I can tell) we get intermittent MOTN-110 command.
    Cause: Cannot replan joint motion in interpolator for this move.
    Remedy: Use FINE in last L statement.

    What I can not explain to myself is why this only happens intermittently, and only (so it seems) with heavier parts. We’re talking going from 40kg to 50kg. The payload is set to 165 kg btw. Not my doing and I do not want to change parameters I do not fully understand just yet.

    Any explanations and ways around it would be appreciated.

    Maybe the issue is that the payload is maxed out? The robot is overcompensating for a lighter payload.

    I never use linear moves to home, because of singularities and the possibility to move to that position in more than one arm configuration. Typically, joint moves to home are faster as well because they are long air cuts in most cases.

    I'd suggest a joint move if possible, then looking at payload settings.

    Yes. I would assume that if the payload has not been touched, that payload schedules are probably not being called out in your programs.

    Don't forget to add the mass of your tooling.

    Not having the moment's of inertia is not the best, but it's better than the robot thinking that it is swinging around a 165 KG load when it's only ~50 KG.

    We have a whole bunch of R-2000 165F arms. I checked a few and the payloads are all over the place. So are the moments of inertia.
    Some of these robots have been running for years without the need of repair. So, frankly, how important are the payload settings? I read somewhere that if set correctly if makes sure that the robot stays truer to the programmed path, but for me that is not important. How much does it effect longevity?

    You won't get a direct, numerical answer to "how much does it affect longevity", but there's no good reason to intentionally use wrong payload settings (neither way too low nor too high). Actually, with any kind of motion-related errors, payload settings should be one of the first things you check, because wrong payload settings can really cause (often indirectly) multiple different errors.

    Edited once, last by Witty (May 31, 2019 at 7:17 PM).

    I figured it's difficult to answer. Asked my boss, he said on the newer robots you have to be super precise on the older ones (we still have a few rj and a bunch rj2 controllers) its not as important. Does that statement have merit?
    Either way, I will fix the payload at least on the critical robots. One question is inertia. All manipulate the same parts, the EOATs vary slightly but should be less significant for inertia than the large parts we produce. I guess its better to copy slightly wrong inertias values then to leave zeros?

    Quote from IRockWell


    Does that statement have merit?

    Sounds like some folk wisdom to me :uglyhammer2: Even if it's not "as important" (which I'm not sure of), I still see no reason for intentional use of wrong values (good luck explaining that to your boss).

    And yes, slightly wrong values are better than zeros.

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