Fanuc Alarm 401

I am getting an alarm sometimes;-
401 servo alarm X axis VRDY OFF
and
401 servo alarm Z axis VRDY OFF
When they come up, I have to shut up and re start
to clear them.
anybody could hint why these come up?

When does the alarm appear? Start up? Idle? While in cut? Will the axis still move?

when the come up

unpredictable!
ususall when referencing or at power on or startup of the machine.
they will not go away. You have to power off and power on.
Alfonzo, just in case you know, I have changed Parameter 40 on the OT machines bit Zero to 1.
This will change the way programs are displayed. Mine I do a number and the description of the program in parenhesis.
the fanuc 18T control does not have this parameter or better still, have not managed to find it. I am sure that this control can show the programs this way too.
any leads?

One possibility is a bad cable on one of the axis drives,, we had a similar problem with a servo alarm that seemed to happen unpredicably,,the wires actually looked ok but they were broken inside the insulation,, Keep an eye if the alarm happens in one area of travel only, and then move the cables to try and get the same alarm,,

Batteries getting low?

OK - I'm cornfused .... is this on an "0" or "18"?

----

Think Snow Eh!
Ox

The control is an 18T Fanuc.
The cables are in perfect condition. New machine with just a few hundred hours of work.
but it was idle for some years in storage. maybe the batteries-? somebody mentioned?

sputnikprecision said:

Alfonzo, just in case you know, I have changed Parameter 40 on the OT machines bit Zero to 1.
This will change the way programs are displayed. Mine I do a number and the description of the program in parenhesis.
the fanuc 18T control does not have this parameter or better still, have not managed to find it. I am sure that this control can show the programs this way too.
any leads?

Click to expand...

I don't have any machines with 18T, only 18MC.
On those:

3107.0 toggles program number only/ number and name.
3107.4 sorts programs by number/registration.
3107.5 displays G code menu.

Seems to me that you need to buy a number of (GE)Fanuc manuals. I have found that the manuals from GEFanuc cost 25% less than from Fanuc. Of course that's in the USA. May be cheaper for you from a European source.

About the 401 error. Since the machine was stored for a long time, the contacts in the various relays may be slightly oxidized and not allowing current to pass thru normally. I have one machine that regularly gives an error message on start up because of this. Pop the relay lever and the message goes away.

Also, pain in the ass, but disconnect and reconnect every cable connection related to axi control just to make sure there are good connections.

If you can figure out where to look in the ladder display, you can see the location where the circuit is not right. Have a print of the ladder from the MTB?? Sure could help you find problem.

Alphonso, thanks for the tip. On the 18T I changed bit zero to 1 and there it was.
I have heaps of manuals here but the 18T came with some manuals missing.
contacted Gildemeister and asked them what a new machine would be issued with. Sure, I had the Fanuc manuals missing. So they said, I pumped up 500 euros and they sent me about six books from Fanuc. will look this place you siad.
Thanks for the tips...