I currently have the commanded spindle velocity, NDI if it is supposed to 
be rpms or what, essentially being fed thru the abs function directly into 
the pid.0.command input.

I am sending the encoder.0.velocity thru the abs function also then into 
pid.0.feedback.  This voltage on the hal meter is noisy but visually 
averages someplace in the 3 to 5 range, which I believe is about 2x the 
real speed it is turning in rps, and is not majorly modifiable by the plus 
and minus buttons on the gui, which issue 1 to 1101 numbers in 100 
increments and that i what I see with the halmeter at the pid.0.command 
input.  The whole range of numbers presented to pid.0.command in can modify 
the spindle speed by perhaps 20%.  Running like this, the spindle speed is 
extremely stiff, responding to an increased load in a small fraction of a 
second.

If and when I wire up a reverse, it will be done with a dpdt relay 
controlled the .rev command from motion module.

But 2 things, one being that in the halscope, the pid.0.output is 
oscillating rail to rail, according to the scope at several hundred volts 
peak to peak, and of course the pwmgen is outputting little trains of 
pulses at the oscillation speed which is something in 100 hz range.

I am getting the impression that the gain of the pid.0.feedback pin is many 
decades higher than the gain of the command pin.

Presently from the hal file:

setp    pid.0.Pgain                     0
setp    pid.0.Igain                     1
setp    pid.0.Dgain                     1
setp    pid.0.maxoutput                 401 # to keep it from running away

Those values are straight from the Closed_Loop_Spindle_Speed page of the 
wiki, and obviously I don't know enough about PID controls to make 
intelligent adjustments.

I sure could use some help in taming this beast.

Thanks everybody.

Cheers, Gene
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
My web page: <http://coyoteden.dyndns-free.com:85/gene>
"For three days after death hair and fingernails continue to grow but
phone calls taper off."
                -- Johnny Carson

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