Mastering at a Non-zero position - R30iA Controller Fanuc

  • Controller Type: Fanuc R30iA

    Good morning, we have to change out our EE cable, but all six joints are at different degrees (see picture). Once we change this cable out, I assume I will have to re-master. What type of Mastering should I do on my robot? I have an image backup and an AoA "all of the above" backup as well. I want to master it so that we don't have to touch up any points.


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  • Fanuc dont have any kind of Mastering EMD Device, so you select the "right" Axis Position by looking with you eye on it. So be sure, you will have to teach points again, unless you dont have a User Frame which you can recreate.

    BTW: The EE Cables have nothing to do with mastering and if you dont got any error message, you can be sure the master data were already wrong before you changed the kables.

  • Are you sure? If I replace the RCC [RM1] cable that goes from robot to controller, then I don't have to re-master? What about the other end that goes all inside the robot to all the motors? If I replace that one, then I will have to remaster and recalibrate, correct?

  • Are you sure? If I replace the RCC [RM1] cable that goes from robot to controller, then I don't have to re-master? What about the other end that goes all inside the robot to all the motors? If I replace that one, then I will have to remaster and recalibrate, correct?If

    If the batteries are good in your robot base, and you do not disconnect any of the pulsecoder cables going to the encoders, you should not need to remaster.

  • The backup batteries are in the base of the robot. You can safely disconnect the robot from the controller. But if you disconect the internal cable that connects pulsecoder to battery then you will need to remaster.

    I would setup a quick master reference first, preferably at 0 position but any place you can mark and get back close to. Then Park the robot at that known location or all 0's and write down all the exact joint angles. When you have it back together see if it needs mastering. As long as it didn't move you can master it to the know location. If you have to move it while disconnected then you can try taking it back to the quick master position and quick master. If all else fails zero master each joint to witness marks.

  • My issue is I am getting a srvo 68 DTERR alarm. We tried new amplifier, new RM1 cable (from robot to controller), and cleaned out the RP1 cable. It will run a program, and then we open the safety fence and let the robot sit there during break. When we come back, it's faulted out with the DTERR alarm; after recycling power, it says "please power off if you want to recover"; estops don't work, and if you try running the main program, it faults out with INTP-222 MCTL-003.

    I've been backing up the image files and All of the above before we change any parts, so if I lose the master, my plan is to just restore the AoA and image files, and I should be good to go right? I won't have to master anything in that case?

  • We had re-greased and replaced the batteries last week. When we started up this week, the servo 68 dterr kept coming up. Restarting wasn't doing anything; next we unplugged the RP1 cable and sprayed contact cleaner; furthermore, we cleaned off the ground cable and rewired that. When we ran it, we ran at 50%, it ran for about 20 seconds, then faulted with DTERR on axis 5 and 6. We cycled power, then ran at 10%, then slowly bumped it up. Now it ran at 80% for about 10 minutes. We will see how it runs on Monday, but I wouldn't have thought DTERR would've been the alarm if we greased it too much or if there was a grounding issue or problem with any of the cables.

    At one point, on the POSN screen, all the degrees on each joint just kept climbing up or down forever, so I had to reboot to clear that out. Not sure what would cause that?

  • Before you do anything wild. Go to the DMR_GROUP variable and write down your master count numbers. This way if you do loose master, load your image file back up and re-enter your master counts. If those numbers change, that's when you have to reteach positions.

    What robot do you have. if its a 200xx check the drive belts. I actually had a pulley come loose and give me all kinds of errors.

  • Doesn't the image file already contain all these parameters? Why do I have to grab these extra #s? I am thinking if I reload the image file at the exact position the robot was in when I first backed up the image file, then all the master counts will be good, no?

  • The image backup will contain the original master counts, but it's a good precaution to take a picture of them in case a wrong button is pushed and they are accidentally overwritten.

    After power up you will probably need to set mastering done variable to true and then verify by jogging to zero marks.

  • Help me to understand this. Lets say hypothetically all 6 axis of my robot are at 0° witness mark and lets say all master counts are at 1000 and I take an image of this.

    Let's say I accidentally move all 6 joints to 5° and I don't have the master count. Am I able to move everything back to 0° using the POSN screen, and then restore my image file without having to change the master count data, or do I need to go back and change these to 1000?

  • In your hypothetical situation you didn't say if you disconnected anything.

    If you have to disassemble a joint or disconnect that joints encoder, then be prepared to zero master that joint to the witness mark. How close you get it determines how much touch up you have to do.

    I personally don't know how much disassembly is required to change out an EE cable. Never had to do that. If you can tell us what you are going to disconnect then we can help you more with what to expect. Fanuc should know.

  • Controller: R30iA

    Robot: M70iC/70

    Right, okay, let's say everything is at 25°, and I have an image and 'all of the above' backup at this location. I then move the robot slightly so all axises are different. Then I unplug the pulse-coder on each motor. When the robot powers on, I should just be able to move everything back to 25° and restore my image and 'all of the above' backup, correct? What does the master count have to do with any of this, if it's already saved in the image / 'all of the above' backup? This way, I don't have to re-master anything since everything is in one of the backup files.

    The EE cable [rm1] cable is going from the back of the robot into the servo amplifier, it's not too difficult to change. There is an RP1 cable as well right next to that.

  • If you are just replacing the external rm1 cable (from back of robot to controller) then you won't lose anything. I thought you were replacing the cable inside the robot arm that goes to the EE connector.

    I don't see why you would disconnect any encoders to do that.

    Unplugging a robot from the controller doesn't cause any loss of memory so no need to restore any backups.

    Unplugging a robot from the controller won't cause loss of encoder counts either.

    If you disconnect an encoder, which I'm not sure why you would, then the robot will lose that encoders position. Once you lose that you cannot send the robot back to a position because it no longer knows where it is. It must the restablish the marker pulse. At that point you must do some sort of mastering such as quick master, single axis master, or zero master.

  • No I don't plan to change out the encoders anymore, I'm speaking hypothetically now. If the pulse-coder cable goes bad, and I have to replace it, then according to what I have read, I need to:

    1st backup the image and AoA files, then

    2nd take a picture of the master count in case the robot moves, correct?

    3rd change the encoder cable out.

    4th restore my image and AoA files, which already has the original master count #s values.

    5th double check master count values

    6th single axis master each axis back to 25° assuming everything was at 25° before unplugging the encoder cables

    Are these the correct steps when trying to replace any encoder cables on the robot?

  • The joint values will change when you power up the robot with the new harness due to the loss of communication with the encoders. You'll have to jog each axis to establish the pulses.

    Now, you can jog them 20* each direction, and then back to whatever value they powered up with, and single axis master to 25*.

    1. You write down Joint values before work begins.

    2. Change harness

    3. Power up and clear pulse coder faults (PCA and a couple reboots)

    4. Write down NEW joint positions

    5. Jog all axis 20* + and - and then put them BACK to new positions

    6. Single axis each joint to the first (original) values.

    Hope that makes sense.

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