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Resetting a magazine servo drive on Nexus 510C


Cast Iron
Dec 3, 2010
Kansas City KS
One of our mills started alarming out this morning, alarm 212 "magazine fault" or something similar. It turns out the battery for one of the two ATC drives was dead so I changed it.

After changing the battery the drive is stuck in an alarm mode, Z1-N1 01 which the book for the drive says is "absolute position detector data lost." The solution is listed as initialize the zero point, but it's pretty vague as how to do that exactly.

The machine will not move at all from commands in the ATC menu, nor does it have a "magazine zero return" option like all the M+ mills I'm used to. It does have a "F1" menu that seems to control tool change components manually (or without PLC checks or something.) If you hold the "magazine forward/reverse" buttons on either of these pages the belt will turn ever so slowly. I've taken the belt around twice both directions to see if it would eventually home but it never does. I've got a few M codes I'd like to try, but MDI mode is largely useless because the alarm resets itself instantly after it is cleared and I've yet to get anything going.

I've also read that there may be a reset or override switch in the cabinet to bring the belt around to tool 1 but my machine doesn't have that switch. I've let both drives discharge completely a few times after I swapped the battery but that doesn't seem to change anything. I even got desperate enough to swap batteries between both drives but the alarm is still there...

For some reason (only because I spent way too much time crawling through menus on the mill and PDF's for servo drives) I think this can only be reset by getting directly at the drive from a PC over a serial connection. There's a round DIP switch (Not sure if that's the correct term.) and the manual says that a certain position on that switch is an initialization setting but that it clears all loaded parameters. I'm almost positive that's a bad idea so I haven't done that yet.

So is it possible that the drive just needs all of it's parameters reloaded? The mill was running fine a few hours this morning till it threw this alarm. I swapped the battery within an hour and had the machine on when I did. It was low though, so I guess some parameters could have been lost.

Does anyone else have any experience with a deal like this? I'd greatly appreciate any insight!!

Contact Mazak tech support on this one. They will want to walk you through the process while you are in front of the machine. It is a rather involved procedure that requires setting PLC bits in the control to release the carousel motor brake then shelling out to Windows to access the Mitsubishi drive software to complete the Home position reset.

If Mazak won't help you send me a PM and I'll check around to see if I have a procedure.
I finally figured it out, I got to poking around in Windows on the machine control and I found the drive software which had everything I needed to reset the drive.

In case anyone else needs to know in the future, it was as easy as dragging the mazatrol window to the side and opening my computer. In the C: drive there is a folder, J2CTBus. In that folder is a program J2CTBus.exe. Run that program then go to "setup axis" in the toolbar. There should be a "select axis" submenu, if your lucky the drives will be labeled as what they are. Pick the bad one and be sure the name changes in the title bar.

After that go to "test operation." A warning should come up saying something like "operation become invalid in test mode..." click OK. After that hit "stop" on the lower right hand of that screen.

Next go to parameter on the toolbar, after that window loads up you should see a button towards the lower left highlighted in red that says "ABS POS. REPAIR." Click that button and wait for it to finish. It should come back saying something about written successfully and restart. I did just that before I had time to write the confirmation dialog down (sorry!)

If it comes back saying something like "cannot write" go back to the test mode window and try again. I believe the test mode window removes the signal from the machine control (thus the "operation invalid in test mode" window) because the parameters can't be written while the drive is in use or something like that.

Of course this is all for a 510C, YMMV!
Here is a pdf file explaining how to do it manually for VTC / VCN machines.


  • VCN_VTC ATC and Magazine Home Set Procedure.pdf
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