== Spindle Control{Spindle Control}[[cha:Spindle-Control]]

=== 0-10v Spindle Speed{0-10v Spindle Speed}

If your spindle is controlled by a VFD with a 0 to 10 volt signal
and your using a DAC card like the m5i20 to output the control
signal.

First you need to figure the scale of spindle speed to control
signal. For this example the spindle top speed of 5000 RPM is equal
to 10 volts. :math:`$10/5000=0.002$` so our scale factor is 0.002

We have to add a scale component to the hal file to scale the
motion.spindle-speed-out to the 0 to 10 needed by the VFD if your
DAC card does not do scaling.

    loadrt scale count=1 
    addf scale.0 servo-thread 
    setp scale.0.gain 0.002 
    net spindle-speed-scale motion.spindle-speed-out => scale.0.in 
    net spindle-speed-DAC scale.0.out => <your DAC pin name>


=== PWM Spindle Speed{PWM Spindle Speed}

If your spindle can be controlled by a PWM signal, use the pwmgen
component to create the signal:

    loadrt pwmgen output\_type=0  
    addf pwmgen.update servo-thread 
    addf pwmgen.make-pulses base-thread 
    net spindle-speed-cmd motion.spindle-speed-out => pwmgen.0.value 
    net spindle-on motion.spindle-on => pwmgen.0.enable 
    net spindle-pwm pwmgen.0.pwm => parport.0.pin-09-out 
    # Set the spindle's top speed in RPM  
    setp pwmgen.0.scale 1800


This assumes that the spindle controller's response to PWM is
simple: 0% PWM gives 0RPM, 10% PWM gives 180 RPM, etc. If there is
a minimum PWM required to get the spindle to turn, follow the
example in the nist-lathe sample configuration to use a scale
component.

=== Spindle Enable{Spindle Enable}

If you need a spindle enable signal link your output pin to
motion.spindle-on. To link these pins to a parallel port pin put
something like the following in your .hal file making sure you pick
the pin that is connected to your control device.

    net spindle-enable motion.spindle-on => parport.0.pin-14-out


=== Spindle Direction{Spindle Direction}

If you have direction control of your spindle the hal pins
motion.spindle-forward and motion.spindle-reverse are controlled by
M3 and M4. Spindle speed Snmust be set to a positive non zero
value for M3/4 to turn on spindle motion.

To link these pins to a parallel port pin put something like the
following in your .hal file making sure you pick the pin that is
connected to your control device.

    net spindle-fwd motion.spindle-forward => parport.0.pin-16-out 
    net spindle-rev motion.spindle-reverse => parport.0.pin-17-out


=== Spindle Soft Start

If you need to ramp your spindle speed command and your control
does not have that feature it can be done in HAL. Basically you
need to hijack the output of motion.spindle-speed-out and run it
through a limit2 component with the scale set so it will ramp the
rpm from motion.spindle-speed-out to your device that receives the
rpm. The second part is to let EMC know when the spindle is at
speed so motion can begin.

In the 0-10 volt example the line net spindle-speed-scale
motion.spindle-speed-out => scale.0.inis changed as shown in the
following example.

    # load real time a limit2 and a near with names so it is easier to follow 
    loadrt limit2 names=spindle-ramp 
    loadrt near names=spindle-at-speed

    # add the functions to a thread 
    addf spindle-ramp servo-thread 
    addf spindle-at-speed servo-thread

    # set the parameter for max velocity 
    setp spindle-ramp.maxv 60

    # hijack the spindle speed out and send it to spindle ramp in 
    net spindle-cmd <= motion.spindle-speed-out => spindle-ramp.in

    # the output of spindle ramp is sent to the scale in 
    net spindle-ramped <= spindle-ramp.out => scale.0.in

    # to know when to start the motion we send the near component  
    # (named spindle-at-speed) to the spindle commanded speed from 
    # the signal spindle-cmd and the actual spindle speed 
    # provided your spindle can accelerate at the maxv setting. 
    net spindle-cmd => spindle-at-speed.in1 
    net spindle-ramped => spindle-at-speed.in2

    # the output from spindle-at-speed is sent to motion.spindle-at-speed 
    # and when this is true motion will start 
    net spindle-ready <= spindle-at-speed.out => motion.spindle-at-speed


== Spindle Feedback{Spindle Feedback}[[cha:Spindle-Feedback]]

=== Spindle Synchronized Motion{Spindle Synchronized Motion}[[sec:Spindle-Synchronized-Motion]]

Spindle feedback is needed by EMC to perform any spindle
coordinated motions like threading and constant surface speed. The
StepConf Wizard can perform the connections for you if you select
Encoder Phase A and Encoder Index as inputs.

Hardware assumptions:


 - An encoder is connected to the spindle and puts out 100 pulses
   per revolution on phase A

 - The encoder A phase is connected to the parallel port pin 10

 - The encoder index pulse is connected to the parallel port pin
   11


Basic Steps to add the components and configure them:

    loadrt encoder num\_chan=1 
    addf encoder.update-counters base-thread 
    addf encoder.capture-position servo-thread 
    setp encoder.0.position-scale 100  
    net spindle-position encoder.0.position => motion.spindle-revs 
    net spindle-velocity encoder.0.velocity => motion.spindle-speed-in 
    net spindle-index-enable encoder.0.index-enable <=> motion.spindle-index-enable 
    net spindle-phase-a encoder.0.phase-A 
    net spindle-phase-b encoder.0.phase-B 
    net spindle-index encoder.0.phase-Z 
    net spindle-phase-a <= parport.0.pin-10-in 
    net spindle-index <= parport.0.pin-11-in


=== Spindle At Speed{Spindle At Speed}[[sec:Spindle-At-Speed]]

To enable EMC to wait for the spindle to be at speed before
executing a series of moves you need to set motion.spindle-at-speed
to true when the spindle is at the commanded speed. To do this you
need spindle feedback from an encoder. Since the feedback and the
commanded speed are not usually **exactly** the same you need to
use the nearcomponent to say that the two numbers are close
enough. The connections needed are from the spindle velocity
command signal to near.n.in1 and from the spindle velocity from the
encoder to near.n.in2. Then the near.n.out is connected to
motion.spindle-at-speed. The near.n.scale needs to be set to say
how close the two numbers must be before turning on the output.
Depending on your setup you may need to adjust the scale to work
with your hardware. The following is typical of the additions
needed to your hal file to enable Spindle At Speed. If you already
have near in your hal file then increase the count and adjust code
to suit. Check to make sure the signal names are the same in your
hal file.

    loadrt near

    addf near.0 servo-thread

    net spindle-cmd near.0.in1

    net spindle-velocity near.0.in2

    net spindle-at-speed motion.spindle-at-speed <= near.0.out

    setp near.0.scale 1.01