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Fanuc 15m Start Rejected if Spindle ON

namlecnc

Plastic
Joined
Oct 7, 2019
Hello,
I have an issue with fanuc 15M. I have a Henri Line at work that is close to working state.

I can drip feed fine, without spindle on.
When Spindle ON/ M3 , it behaves like I'm holding " feed hold ". display says Tape or MDI * HOLD *
I try hit " Cycle Start " again, it says " Start Rejected "

I have to hit Spindle OFF, then Cycle Start would enable the gcode to move forward .

Hitting Spindle ON triggers that HOLD again.

In a sense, machine won't move with spindle ON, and vice versa.
I have been told that this is a ladder issue, missing FIN signal? I have zero experience with ladder.

Please help me out here, it's so close to working right.
 
Hello,
I have an issue with fanuc 15M. I have a Henri Line at work that is close to working state.

I can drip feed fine, without spindle on.
When Spindle ON/ M3 , it behaves like I'm holding " feed hold ". display says Tape or MDI * HOLD *
I try hit " Cycle Start " again, it says " Start Rejected "

I have to hit Spindle OFF, then Cycle Start would enable the gcode to move forward .

Hitting Spindle ON triggers that HOLD again.

In a sense, machine won't move with spindle ON, and vice versa.
I have been told that this is a ladder issue, missing FIN signal? I have zero experience with ladder.

Please help me out here, it's so close to working right.


Does it do this with a program resident in memory? Or only while DNC?
 
I tried a simple move in MDI such as

( ignore all tool call, and initial code )

M3 S5000; ( this turned the spindle ON and Hold right here , hitting 'cycle start' here results in a message 'start rejected')
G01 Z5. F100.; ( it can only move through this if I turn the Spindle Off and hit cycle start again )
G01 X10. Y10. F200.;

something like that.
 
I'm not real confident in my troubleshooting so hopefully someone else comes along with better information and more knowledge of it.

Looking in a 15MB manual, I've found a couple things worth looking at.

With it running the spindle in program mode, what is the status of:

G227.7
F229.3

There are several other standard signals that I see that might be worth looking at. I found these in Fanuc manual B-62075E/04 Section 4.5 SIGNAL AND SYMBOL CORRESPONDENCE TABLE. If you download that manual, you can have a look through and see what other spindle-related signals to look out for.

Our 15mb machine had G227.7=1 at all times, on or not. F229.3 Was on once machine reached spindle speed and turned off when spindle came to a complete stop.

These may or may not be helpful.

Do you have the manuals to your machine and the ability to view the ladder or at least the PMC signals?
 
Dandrummerman is pointing you in a good direction. Sounds to me that the Speed Arrival signal (Fanuc mnemonic "SAR") is not turning on or being read by the PMC. This is a signal used by the PMC to halt CNC program execution until the spindle reaches 80% of the commanded speed. Once SAR is on then CNC program execution will resume.

It is also possible that the M command Finish signal (MFIN) for the M3 command is not being sent from the PMC to the CNC. This will also cause your problem.

All of this is either implemented within or affected by how the machine builder has written their ladder program in the PMC.
 
Last edited:
I have no exp with ladder. Can you give me some tips of how to edit in there and how to not eff it up?
 
Unless your machine is equipped with a PMC RAM board, you can't eff it up. Teaching how to read and understand the ladder is far deeper than I'm willing to try to do on a forum. There may be some on-line stuff to help a beginner understand the concept of a ladder. Have a look. It does not have to Fanuc specific to get the basics. Only once you start trying to look at your ladder will you need some Fanuc sprcific info.
 








 
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