Using a Servo for a Mill spindle 7i76e

This is on my test bench. 1.8Kw servo in position mode I think connected with step/dir on a 7i76e
I believe the encoder is 2500 p/r

It seems to be running OK ie. commanded speed 1000 and the spindle dro is the same and checked with a rev counter.


But don't see the encoder working. Also the spindle at speed is not working (probably due to the encoder not giving feedback)

I need the encoder feedback for rigid tapping

Does the ini file look correct for the spindle?

Edit: I am wanting to do this on a 7i96 eventually but I don't have that board in stock

tommylight wrote:

There is nothing related to spindle encoder in the hal file.
Open pncconf and choose to modify an existing config, add the encoder as spindle encoder, and do not set a spindle at speed input, that should be generated by the encoder velocity.

Ok spindle is commanded 1000 and it is doing 1000 the spindle dro is zero

I still don't see any encoder life from the show hal config. Any clue to what am I missing?

Hardware?

Is the 7I76E's encoder input jumpered to match the encoder signal type?
( single ended or differential )

Are there valid signal levels at the A and B encoder inputs?

PCW wrote:

Hardware?

Is the 7I76E's encoder input jumpered to match the encoder signal type?
( single ended or differential )

Are there valid signal levels at the A and B encoder inputs?

Yes the 3 jumpers are in the right hand position for dff.

I will check in the morning re the signal levels.

Clive wrote:

PCW wrote:

Hardware?

Is the 7I76E's encoder input jumpered to match the encoder signal type?
( single ended or differential )

Are there valid signal levels at the A and B encoder inputs?

Yes the 3 jumpers are in the right hand position for dff.

I will check in the morning re the signal levels.

Jumpers in RH for diff. Step/Dir on TB-2 20,21,22,23 No field power supplied only 5V on P3 .Nothing else connected to 7i76e

Between TB-3
With Servo speed 100rpm
7-8 17 mV
10-11 17 mV
13-14 3V

With Servo speed zero
7-8 3V
10-11 3V
13-14 3V

tommylight wrote:

Check the encoder-a and encoder-b inputs, turn the spindle by hand slowly and see if the LED's are both going on and off.
The commanded velocity is working properly, but there is no feedback at all as can be seen by encoder.0.velocity that stays at 0, it should also show 1000 if the scaling is correct.

The encoder A and B don't change

Jumpers in RH for diff. Step/Dir on TB-2 20,21,22,23 No field power supplied only 5V on P3 .Nothing else connected to 7i76e

Between TB-3
With Servo speed 100rpm
7-8 17 mV
10-11 17 mV
13-14 3V

With Servo speed zero
7-8 3V
10-11 3V
13-14 3V

Edit : with the encoder disconnected from the mesa card ie measuring the encoder outputs I get about the same results as above.
So I wonder if the servo encoder output is not setup properly?

You should measure ~+3 or ~-3 across the A,B differential pairs
(and never close to 0) if you wiggle the shaft around to see all
quadrature states