with Fanuc 31i-TB turret pulscoder reference position

Hello guys !
I've got slightly tired Tongtai TB-20 (Fanuc 31i-TB nc) at my new workplace and it needs more knowledge than anyone has here.
Tongtai haven't answered for two weeks and Fanuc just directly refused to help.
Turret is 12 position Tongtai-made with Fanuc B-series servo and pulsecoder.

I don't know the history, but the machine behaves like this:
After switching tool number selector and pressing "manual tool change" button turret unclamps, rotates to selected position and stays in right position unclamped (forever) without any warning/error.
To resolve this situation I have to press Reset and M54 (manufacturer's code to clamp).
But after this I don't have any tool number in the memory of NC.
It works just the same with MDI T-code.

Clamping is hydraulic, solenoid valves and clamp-unclamp sensors are ok (checked with ladder too)
It clamps-unclamps with MDI M-codes without any issues.

I suppose, there's a problem with turret motor's pulscoder which doesn't understand when the turret is in the right position for clamping.
Searched for parameters of this motor for something like 1240, 1850, but found only axis servo and it seems, NC doesn't consider turret position as an axis/coordinate.

So it would be great if you share some thoughts how to set zero/reference position for turret servo.

Best Regards, Alex

provided there are no in-position switches or other position sensors;
I would try as a test opening up the in-position width (maybe double current value) parameter and see if that allows it to complete.
Without seeing the logic used it is very difficult to offer other ideas.
But I do not suspect anything involving the motor or encoder at this point.

No other sensors in this turret, only two inductive sensors of clamping disc and pulsecoder of servo.
Sensors are ok (voltage and logics), NC shows "suitable" errors when something happens with them, for example if I command clamp in wrong position, clamping disc stays in place and sensor mismatches active solenoid.

Also, how can I assign tool number with system variable ? (I mean, without actual tool change, just put the number in NC memory)
These threads are close https://www.cnczone.com/forums/fanuc/123638-mazak.html https://www.cnczone.com/forums/fanuc...variables.html
but I can't open #1033-1035 with method described.
"parameter 9000 bit 1 (NDP). Needs to be set to 1" Doesn't make anything. #102=#1035 gives an error.

I would suspect they are using PMC axis control. The fact that that there is no alarm following an index that doesn't clamp indicates a short coming in the logic.
Getting through the logic can be tough but that is where you need to look.

I'm not sure what you are asking regarding the tool number.
The active tool (cutting position) is most likely stored in a PMC register (D or K) or is based on the position of the servo motor.

As far as the "active tool" the NC typically doesn't use that value. The Offset number associated with the T code is all the NC really cares about unless some probing routine uses the tool number for something.
This is supposing of course that the T code is broken out as Tnnoo where nn is the tool /station number and oo is the geometry/wear value.
The control can be configured where nn is both the tool and geometry value and nn is just the wear value but I dont see this way used often.

i guess you have a beta driver managed by a Power Mate Manager-PMM.
Attachment 471590
Search on the cnc a menue called PMM or Power Mate .
In that menu you will find the position displayed for the encoder in degrees and also the parameters for the motor.
you will see when rotating the turret ,the position will be displayed as:30.000,60.000,90.000,etc until 360.000
look if the turret stops exactly on these values with a small error of 0.3
you can try to make the origin again by putting the turret on the tool no.1 position and make parameter (that you will find it on the PMM menu) 11 bit 0 like the 1815.
after that try to rotate again and see

zavateandu, thanks a lot, problem solved !
There's only one channel and it's for turret servo, in 11 parameter the rightmost bit (#0) was 1 already, but after changing leftmost bit (#7) to 1 it works fine !
When P11 is 0000-0001, coordinate "1" is always 0 after rebooting the machine.
Interestingly, even now tool number doesn't change on display after changing tool with manual switch, only after T-code from MDI or program.

yes indeed you did not have define the absolute encoder
Attachment 471910