7i92/7i77 Yaskawa Servo

Haha, just updated the HAL file, back to tuning. Thanks!

Ok so I am not able to move the axis at the max velocity of 666.67 and max acceleration of 900 during an MDI command. When I start pushing over 550 velocity the axis output and ferror shoot to the roof. Ferror never comes close to my max value.....I have tuned per instructions, let me know Peter

Yes. Ferror = 10.0 and min is set at 1. The ferror never goes over .004mm from.readings in HAL scope.

Sorry max ferror .04mm

Sounds exactly like what happens like you are running out of headroom on the drives.
(that is the analog out is set higher but the drives dont respond anymore)
you can verify this by seeing if the analog output voltage goes to ~ 10V when the ferror suddenly increases

How big is the ferror? normally when you run out of headroom the ferror increases till you get a following error
(It is normal to have higher following error at higher speeds) A mechanical problem may cause this as well
since the drive torque decreases with speed

See attached, first is at a velocity of 33,000mm/min, second is at 40,000mm/min. Let me know. Thanks

Dan

Looks like either a drive fault or you have exceeded the maximum encoder count rate.

If you are limited by the encoder count rate you can try turning off the encoder filters
by changing:

hm2_7i92.0.encoder.00.filter 1
hm2_7i92.0.encoder.01.filter 1
hm2_7i92.0.encoder.02.filter 1

to:

hm2_7i92.0.encoder.00.filter 0
hm2_7i92.0.encoder.01.filter 0
hm2_7i92.0.encoder.02.filter 0

In the HAL file

I would not do this unless you are using differential encoder signaling...

Yes they are differential signals.

Thank you! Removing the filtering resolved the issue.

1 down, 2 more to go

I am converting a Denford Novaturn to Yaskawa SGDA 01AS drives. I switched the drives over to torque mode. I wonder if there is a real advantage in Velocity vs Torque mode? I also noticed a small drift in the servos in "velocity mode". In the manuals it states "Speed Reference Offset Manual Adjustment" Do your servos have this adjustment? If yes, it may help to further fine tune them. My controller is base on the Gizmosphere 1 + 7i77 with a special adapter card i designed. It is very compact.
Proof of Concept iBOB2 Gizmosphere 1, CNC Controller, Industrial Servo Amp

Denford NovaTurn Servo retrofit AMD Gizmosphere iBOB2 PCIe x1

Iron-Man

There are advantages and disadvantages to velocity and torque mode control

Velocity mode works well with lower servo thread rates (1 KHz is fine for most applications)
since the local drive velocity feedback will maintain the commanded velocity between updates

For torque mode you probably need at least 2 - 8 KHz for good performance
(since Linuxcnc needs to close the velocity loop in this case)

Torque mode allows simple monitoring of the applied torque so provides
useful system performance information (like what percent of peak available torque you are using)
thats not available with simple velocity mode systems.

Note a velocity mode servo should not drift, this most likely indicates an improperly setup system
(most commonly drives enabled before linuxcnc's position PID loop is running)