Reply with QuoteI'm not sure, but there may be separate battery for the absolute encoders on the NCU or PSU cover.
There should be small detachable cover on it described as baterry or accu.
Fanuc 16i on Robodrill T14Alpha often throws alarm 300 APC axis need ZRN
Hello, we have this machine which sometimes when turned on will throw this alarm 300 APC - X axis need ZRN.
Meaning it lost reference for X axis, but normally when batteries which hold axes position run out, this alarm would show on all three axes, not just one...
When it does that, you normally reference axes and it's all good, replace batteries and your good to go for next year or two...
This time it's only on X axis, meaning only X axis loses position.
I did swap batteries for new ones (all 4) with quality Duracell batteries and it still does this..
I suppose this happens because of cabling issues (somehow X axis communication cable on motor loses connection), but it doesn's seem to be only logical reason to me, because, if you had cabling issues, wouldn't it throw some kind of other alarms during milling?
Let's say it's cable issue and we start working on the machine, milling... whatever, at some point cable loses connection and then it should throw some kind of servo error (too large) alarm, wouldnt it?
But that doesn't happen.
Only thing what is happening is, like just now, everything is good, you turn the machine off (don't touch anything in it), you power it back on and alarm 300 will be on... Other time, nothing will happen, no alarm, everything is good.
What else besides cable could it be?
And if it's the cable, how to check/confirm it?
I've removed cables from X motor and cleaned them, dried them out, reconnected (good) and still it will happen sometimes, sometimes it won't...
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Re: Fanuc 16i on Robodrill T14Alpha often throws alarm 300 APC axis need ZRN
I'm not sure, but there may be separate battery for the absolute encoders on the NCU or PSU cover.
There should be small detachable cover on it described as baterry or accu.
I agree, the drive could have a ZPR buffer battery behind a small cover. It depends on the type of motor encoder, absolute or incremental.Originally Posted by steryd
If absolute, the motor encoder could be defective. I've changed one or two over the years. But first check the FB cable for connection, damage or coolant ingress.
Re: Fanuc 16i on Robodrill T14Alpha often throws alarm 300 APC axis need ZRN
Is there a way to see in machine diagnostics X axis encoder cable data being sent or not sent, also cable connection pins which work which dont?
I believe there is a problem with X axis encoder motor cable, but I can't test it while it's running, I'd like to see those bits/connections flowing/not flowing.
Re: Fanuc 16i on Robodrill T14Alpha often throws alarm 300 APC axis need ZRN
you will see on diagnostic page around 360 number the feeback from the encoder in pulses and compare with the NC command ,the numbers must match with small puls errors from backlash,pitch etc
Good luck
It might not be the X axis, because X axis is the first axis, it may give only an X axis fault in certain cases.
Check the other axes, because X is the first in the chain.
Re: Fanuc 16i on Robodrill T14Alpha often throws alarm 300 APC axis need ZRN
I still think it is, because I've removed encoder cable from X axis motor, dried out pins on both end and put some PTFE band on the threads, sprayed contact spray on pins and inside connector, dried excess spray and reconnected cable back on, tightened cable a bit more than it was and for now it happened only one time, as before it started to occur every time you turned machine off and back on...
