View Full Version : OSP5000 100-6 Alarm A DIF OVER - ??? help!

SRT Mike
07-26-2007, 10:17 AM
I have an LC-40 with dual turrets. When I try to move the lower turret in the +Z direction, I get alarm that says

"100-6 Alarm A DIF over ZB-Axis 4380"

Anyone know what this means? I'm guessing it's not getting feedback from the encoder or something? It moves fine in -Z (well its on the limit and doesnt error when you push the button to move more in -Z, anyway), as well as working fine in the +X and -X axes... just this one motion that causes a problem.

Anyone got any info they can share or know what the error actually means???


07-31-2007, 08:07 PM
From my experience you have a damaged servodrive board
check your motor leads resistance to ground, must be "infinite"
I mean if you use digital multimeter you must read OL from the leads to ground or chassis.
On the other hand you can swap drives after this test and see if problems persists in the other axis.

SRT Mike
07-31-2007, 08:30 PM
Thanks, I will give it a shot.

The previous owner of the lathe said he thought it was a servo driver board, but I think he was just guessing :) Thanks again!

08-01-2007, 06:30 PM
This means that whilst moving, the actual position and the expected position have gone outside of the allowable range, e,g, servo lag.
If you have LDUTR drives, on the servo page of the check data, you will see an ODIF value. If at jogging at 100% this exceeds 0.050, I might be wrong on the decimal point, but just read the figure displayed, ( it will initially be high on moving due to axis accelerating to speed), then your servo is incorrect.
This should be a + figure jogging +, and -jogging -. Before adjusting ensure the slides are receiving lube oil, or this alarm can be generated due to stiction.
Adjust the gain pot to get below this figure, or as close to it as possible. As you adjust you will see one direction decrease and the other increase, you are basically adjusting a band sideways until the centre point is as near to zero as you can get it.
You can also get this problem on these drives, after a period of use, if the heat sink compound between the transistors and the heat sink is old, hence the more heat generated, the less responsive the transistors get.
I am sure it is the gain pot, accessible through the cutout in the smoked plastic cover.
The easy test is swap the top boards between drives, set up as above, and if the fault moves, then the board is faulty. Ensure any DIPS are set as per the boards you swap.

01-28-2010, 07:26 PM
Stroke Limit alarm, Any body know how to fix it? Thanks Jim 714 6121480 www.tntind.com

01-28-2010, 08:19 PM
Hello, the stroke limit is easy just go to the operators panel and there should be a key switch that will say OT Release on it. Turn this to on. You may get another alarm stating OT Release has been activated, if so then press reset, the alarms should go away. Then you can pulse the axis in the plus direction using the hand wheel to move it, make sure the machine is in manual. When you are off the limit then turn your OT Release switch back to off.

01-28-2010, 08:31 PM
The Diff Over problem may be electrical and this is probably the quickest test but it usualy indicates bindage in the axis somewhere. I wouldnt recommend swapping the top cards of the drives. It is better to keep the drive components together. Swap the whole drive. This will be fine for the purpose of testing. The X axis drive should move the Z fine. You are only trying to determine if the problem moves or not, you are not going to be running the machine. If you dont feel comfortable doing this then you can always remove the belt from the screw and motor to seperate the 2. Then try and move the Z in both directions. If the motor turns in both directions fine then you have something wrong in the screw, bearings, or gibs. If it alarms in the pos direction then it is electrical, I.E. drive or encoder, more likely drive. If you do this procedure you will have to reset your Z zero when you put the belt back on or if you have to replace the encoder.