Master reference test fails.

    • New

    Hey there

    We're trying to do the master referencing but it fails with error:

    15066, Level at Mastering Reference Switch Unexpectedly low

    We're using SafeOperation 3.6, and the robot is connected to PLC via ProfiNet.

    Here is masref_user.src:

    SafeOperation_36_en talks about a file named VW_USER.INI, but it doesn't exist on our controller, so it's been a bit of cherry-picking from different sources, but we're out of ideas now.

    Can someone explain what were doing wrong?

    Edited once, last by Rebold (July 2, 2025 at 1:24 PM).

  • Go to Best Answer

  • MOM July 2, 2025 at 11:32 AM

    Approved the thread.
    • New

    What ist the controller you are using? KSS or VSS?

    The error "Mastering Reference Switch Unexpectedly" typically indicates that the mastering reference switch was triggered when it shouldn't have been, or the signal was inconsistent during the mastering process. So either check that both signals on the switch are triggered simultaneous or do not hit the reference switch too early, for example already on your way to the check position. Maybe also your mastering position ist not even where you expect it to be. It needs to be entered into the safety configuration.

    • New

    Thank you for your replies!

    The controller is KSS. The position has been set up in safety config.

    I've updated the code, i see i posted the wrong one (we've tried a few things.)

    I assume the last move in MASREFSTARTG1() should be the one engaging the switch?

    • New

    first off, you are using wrong manual. this is KSS manual for SOP3.6 and there is no mention of VW_USER.INI


    so i would follow suggestions to check if:

    mastering reference switch is configured correctly (connected to KRC or to PLC?), if the reference position is taught etc.

    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

    • New
    Quote from Rebold

    I assume the last move in MASREFSTARTG1() should be the one engaging the switch?

    why assume? this is dealing with safety and there is no room for playing around. just follow the manual.

    you need to teach motions in two places:

    MASREFSTARTG1() to take you to the reference switch (from safe position such as home)

    MASREFBACKG1() to return from reference switch to a safe position

    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

    • New
    Quote from panic mode

    why assume? this is dealing with safety and there is no room for playing around. just follow the manual.

    I was unaware that i had the wrong manual. I don't have much experience in the field.

    The robot is still in commisioning in-house. We are not playing around, we are trying to find the correct solution, hence we seek advice here.

    Thanks for your reply, i hope this will fix the issue! :smiling_face:

    • New
    Quote from Rebold

    We're trying to do the master referencing but it fails with error:

    When does it fail? At what point in the program? During the move to MasRef position, or immediately on the start of the MasRef program? How is the KRC receiving the MasRef signals? Is the sensor wired directly to the KRC, or are you using a network safety signal from a Safety PLC?

    The MasRef sensor is a dual-sensor unit, with both sensors always "on" -- that is, the "normally closed" contacts of the sensors are wired to the KRC. And both lights on the sensor should always be on, until a piece of metal trips one (or both) of the sensors.

    The reason for this is so that the KRC can detect if the sensor has lost power or been disconnected, before attempting the MasRef test. If the error trips the moment you begin the program, you need to check for this.

    So the sensor being "unexpectedly low" means that either the signal is not being received by the KRC, or it could mean that the sensor is being tripped before the robot reaches the MasRef position set up in the SafeOp configuration.

    SafeOp depends on both of the MasRef sensors being tripped at the same time (within a few milliseconds), at the moment the robot reaches the MasRef position (plus/minus a very small window of error). That's why the "fork" that you're supposed to attach to the end effector is shaped the way it is -- a fairly small positional error will cause the MasRef check to fail.

    • New

    make sure the reference switch software configuration matches connection.

    also approach of fork to sensor matters (depends on velocity). you want both channels to be triggered at the same time. so avoid approach where forks move like this:

    or this:

    i prefer to do it like this:

    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

    • New

    Some extra information:

    1. We're using these to bolts to trigger the sensor.

    2. We have an external linear vertical Kuka axis, that the robot is mounted on. The reference switch is connected to this controller because, for some reason, the safety fails when it is connected to the robot controller. The mastering test input is set to "at cabinet"

    - I see now, that the error is present already before even attempting the master referencing, i didn't notice this before. I'm beginning to think it has to do with point 2. above.


    Where can i monitor the inputs from the reference switch? I can't find anything about that in the manuals or online.

    Appreciate you help!

    • New
    • Best Answer

    SOLVED!

    The problem was that under safety configuration->hardware options, Customer input had to be set to "Discrete CR5 Micro with JR input"

    (And the switch was connected to main controller)

  • Rebold July 3, 2025 at 11:54 AM

    Selected a post as the best answer.

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