AZM DC driver, problem tuning

Hello everyone,

I am new on this forum so if this is posted in the wrong section, I'm sorry.

I am in the process of retrofitting my SHARNOA SD900. and I would need your help to get my 7i77 card my AZM drivers to work correctly.
I am currently trying to adjust the pid of my axes with the procedure of tommylight "Servo Wiring and Tuning detailed How To example Mesa 7i77." but I have a strange behavior when setting in motion my motors.My encoders work correctly, I have the pulses going back to the board.

At the moment my encoders are coupled on the axes and the motors are uncoupled and turn in freewheeling.

The strange thing happens when I press the key on the keypad to make the motor turn, the motor turns but doesn't stop and when I press a second time the motor accelerates (it feels like it's behaving like a variable speed drive for a spindle) to turn in the opposite direction I have to press 3 times in the other direction to make it turn in the opposite direction.
I would like to point out that when the drivers are powered up, the motor turns very slowly in one direction and always in the same direction, whether connected to the 7i77 card or not.This behaviour occurs when wiring between the /DRSW and COMM terminal. I haven't touched anything on these terminals for the retrofit.

Is the motor behaviour correct? If not, would you know how I can find normal motor behaviour?

Thanks for this and sorry for my English. If this is a little bit unclear, please tell.
Greg

for information : the drivers are in a rack and i don't have any wiring diagrams for them, i only have the wiring diagram written on the side of the drivers.

I use LinuxCNC 2.8.4

 

Are you doing this testing with LinuxCNC?

Its normal for Analog drives to "creep" slowly when enabled and there is no feedback
(this would not happen in a fully configured system because the drives would not be
enabled until LinuxCNC was running and providing position feedback control)

Thank you PCW for your reply.

Yes, I forgot to mention that I was using linuxcnc/axis to test the motors.
So if I understand correctly, I would have to activate a contactor to ena the power line of the drivers when linuxcnc is ready to suppress the slip when powering up.

the behaviour of the motors during motor tuning is correct because it is waiting for feedback from the encoders?

It looks like grounding /DRSW to COM is what enables the drives,
so that is what LinuxCNC should control:

7I77ENA+ --> /DRSW
7I77ENA- --> COM


What are your PID values?

I just tried to set the PID of my X axis but I have a problem with the value of FF1. In full speed of 10000 mm/ min (on the drivers it is written that the motor runs at 2000 rev/ min and i have a screw of 5 mm) the fault joint.N.f-error appears. The error appears about 3/4 seconds during the move in full speed, learn the Halscope my error does not vary. So I don’t know why the mistake happens. i will be lead or lag the commanded position ?

 

for the PID parameters ii try to follow your PCW method for H bridge drivers.

in small speed 50mm/min
I start with set 2 for the P, then I set the D as high as possible to avoid vibration during the move and avoid that my driver resounds too much.

at full speed
I was setting the FF1 so that the error remains constant during the move so 0.5 the error evolves during the move while 0.01 the error remains constant but I have the error message  joint.N.f-error.

I have a last question, I do not know if you know answer but, is it normal during ENA driver a very high noise appears?

Those are analog velocity mode drives so a bare PWM tuning scheme
is not correct.

Typically for velocity mode drives, you would have 0 D and all important tuning
is done with FF1 and P

If the following error is in the same direction as the velocity, you don't have
enough FF1

Also make sure you have enough headroom (limit the joint velocity to about the
machine velocity at 9V)

Hello, appolgize for the offtopic,(i can't send you a PM).
I have the same DC driver EL.GE AZM with problem (Fault LED is ON). ,could you share the repair or user manual or any useful information for it?
Here is my E-mail This email address is being protected from spambots. You need JavaScript enabled to view it.