IRB 2400 axis fault

  • following the restart of our IRB2400 M2000/S4C, many thanks Iowan... on trying to synchronize all axis i receive a error message.

    Error 39217
    Drive unit unable to supply ordered current, due to low DC-voltage or broken motor connections. Drive unit joint: irb_5.
    Measured DC-bus voltage: 374.00 (v).


    all axis other than 5 move OK. when 5 is moved it travels a short distance then stops with the above message. Is the fault likely to be the wiring to the motor failing? a defective axis drive motor? or software cabinet related? are there any tests i could perform to localize/identify the issue and how do you access the wiring in the robot arm?
    Any help would be much appreciated.
    Cheers Steve.

  • Swapping drive units between the two robots would be a relatively quick/easy test. Next, check the cables in the elbow area - the next likely spot would be where the base rotates - not an easy place to access. You might move the robot to a different position (either driving or releasing brake - CAREFULLY) then try axis 5 again. If a wire is breaking, you might find a sweet spot where motor will run. Another test would be to ring out (ohmmeter) the cable from motor to connector on robot base - powered down, of course. Depending on how the cables are routed, you could swap cables that run from controller to robot.


    If you're REALLY lucky (doesn't usually happen for me), reseating the connectors might be enough.

    Edited once, last by Iowan ().

  • Is it possible to swap cable drive connectors i.e. connector block 5 to drive motor 4 and vise versa? they look identical are the pin positions the same or would the control unit throw a wobbler? Just to rule out the cables?
    presently when axis 5 is tried sometimes the joint moves rapidly a few degrees with an over speed warning, other times it moves a small amount with the previous error message, have tried after moving the joint manually but still the same.


    are the drive motors a difficult swap and still available as i'm leaning toward this as being the problem.


    last thing how stiff should the joint be when brake removed as it didn't move over freely.
    Cheers. Steve.

  • I would probably try swapping motor and resolver leads... but it will probably lose rev counters on those axes.
    There is some interaction between axes 5 and 6 when you release the brakes, so they might feel a little stiffer than others.
    I don't remember if the connecting rods for axes 5 and 6 made replacing the motor(s) trickier, or not.

  • Once again many thanks Iowan...
    Are there any guides to drive motor removal or do i just feel my way through it?
    what leads do you mean by resolver, how are they marked?
    cheers. Steve.

  • Just want to add:
    Do not remove or try to adjust the resolver. When the motor is built, the resolver is installed to give an expected commutation value of 1.5708. A motor with a resolver that has been moved from its original position can give the same faults.


    Per Iowan, did you try a different servo amp yet? Axis 5 is in the servo amp in the A2 (second from the right) position.
    Also better to just swap the axis 5 motor (MP5) and resolver (FB5) connectors with either axis 4 or axis 6. Only replace the motor if the problem stays with the motor. Motor and resolver connectors are the same on all 3 upper arm motors.

  • Hi Fellas... Thanks for the info.
    presently i have just changed over the MP drive blocks leaving the resolver as is. i.e. plugging drive motor 5 into 4s cable and vise versa.
    this resulted in the error code moving from drive motor 5 to 4 leading me to believe that there is a fault in the cable.
    i am gonna try and do a continuity test on the cable between the robot base and the believed faulty drive motor block should this be straight forward or is there any wire linking?
    Can you suggest any other tests before i look at getting the cable out, which doesn't look easy...
    Cheers Steve.

  • To properly test, you must swap both the MP and FB connectors as a set.
    MP4 <> MP5 and FB4 <> FB5.
    When the motor is commanded to turn, the controller must see that it is moving (resolver) as it is commanded.
    It may not change the outcome but I would do it just to make sure.


    Before attempting to change the internal cable, I would verifiy it was bad.
    Have you ruled out the servo amp & robot-to-controller cable & connections?

  • Hi Fellas.
    Swapped drive connector blocks and resolver connector for motors 5 & 6. axis 5 performed normally and 6 error'd out. Thankfully the drive motors seem ok. My natural thought is the robot power/signal umbilical cord as this is subject to constant flexing. this looks quite an involved removal, for a start i assume the pins need removed from the plastic blocks at the drive motor end as they won't go through the casing, is there a special tool for this?
    but before i go for it is there anything within the cabinet that could generate the fault, i have checked all cable connections


    as an aside...when jogging individual axis 4,5,6 i'm getting slight movement from multiple axis. i.e. rotating 4 generates minor movement in 5 is this normal?


    to add insult to injury the battery low error message has just arrived.
    Cheers. Steve

  • I must assume you don't have a spare amplifier to try, since you never mention trying a different one.
    Search the part # for the cable set, 3HAC9330-1 Upper Arm for example, and look at the pictures. The connection boxes on the back of the motor are part of the cable harness, you do not have to remove any pins from connectors.
    You should make sure you find out if it's in the robot and not the robot-to-controller cable or the MP1 connector at the base of the robot.
    Replacing the cable set without knowing if it's the problem seems expensive to me. At least try to find out if it's the upper or lower set.

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