Fanuc 11M M function problems

Hi there all.
As usual I have a wierd one.Machine is a Komatsu BMT so no North America help available.Machine has 3 controlers on it Fanuc 11M ,Sharp satalite 51 and I think a Mitsubushi tool changer. Any way what I am seeing is when I do any M function comand the hachine just sits there and does nothing not even time out.It fires up and zero returns with no problems just no M codes seem to work.Any one have any ideas as to where to start?LAdder is available thru the Sharp control and it looks as if the M code is loading into the flag but I am not 100% sure of what I'm looking at.Is there a way of testing Fanuc side? (chair)

The M codes are passed over the BMI buss to the PMC, they can be seen by looking in the diagnostic BMI-DO, if the sharp unit is a PLC, maybe the M codes are processed externally, but they have to get there via an output, so you really need the PMC I/O diagrams etc for the Fanuc to begin with. If the M code gets to the Sharp then that is where you should be looking maybe. The CNC expects to get a finish signal back when the M codes have completed, otherwise it will hang there also.
Al.

When the Fanuc outputs an M-code, the PLC (Sharp?) is supposed to perform the function and then signal back to the controller that the M-function has been completed.

For example, when the Fanuc sends an "M03" to the PLC, the PLC starts the spindle. Then, when the spindle is up to speed, the spindle drive sends a signal back to the PLC and then the PLC signals the CNC that the M03 has been completed. The CNC can then resume by executing the next block of the program.

There is a diagnostic area on the 11M that will tell you what the CNC is waiting for. If it's waiting for the "M-function finish", then it's likely that your problem is with the PLC, not with the 11M itself.

Do ALL M-codes hang up the control, or just one or two? What if you wrote a short program with no M, S, or T codes? Would the CNC complete the program OK? The M, S, and T codes are usually processed in the PLC.

I have a kitamura with an 11M also and i also had the same problem, as it turns out you can't have the m6 code and the T#on the same line since it pre-staged the tool and put it back in the same pot... So now I call tools up like this

T1;
M6;
T2;
AND SO ON...

It was a new one one me.
I checked the BMI screen and could see the outputs working.
Checked the Sharp side and could see them inputing but after some searching found a common MF signal was not being issued on all M functions from The fanuc side.Found that the Fanuc output card was bad although the green OK light was on.Apperantly this was a common problem on the 11 controlers.Now the next complaint is why call it a MF signal?I always thought MF = M finished.
Anyway thak you for everyones help. :cheers:

Glad to hear you found it, normally the FIN signal is the responsibility of the PLC to send it back to the CNC side via the BMI-DI when the PLC knows the M codes has completed.
On the 15 (probabally same for 11) it is G5.1 .
I would have thought that if you had an external PLC it would issue it through a Fanuc input?
Al.

Hi Al,
Nearest I can figure is the way the ladder is writen and what the Fanuc does is the output is put over the BMI-DI it also puts out a MF signal.I had checked another 11M control I have and it also does this.Most machine builders do not use this signal in the ladder as it is enough that it is output and will wait for a M fin signal.Not so with this machine,it is writen in the ladder that it must see the MF signal and the M command,PLC will then do and when completed send a
M Fin signal back to the Fanuc unit over the BMI-DI input.
Made things interesting though.
Machine has a third controler on it for tool changer and magazine.Had a 27 second delay in it that was driving me nuts.After going through the parameters for this thig that has no manufacturers name on it for the millonth time I discovered that a blank spot did not mean 0,when I entered write into the parameters up poped 9.9.there were 3 that were to be 0 and all had defalted to 9.9. This totaled 27.27 and that was my delay All set to 0 and delay was gone.Been this way for 2 months and feel good that it is fixed but feel stupid that it took so long.
Thank you all for your help.