num parameter manual - Documentation CN

P6
Word N1
Spindles
This word defines the cycle axis position anticipation time constant. It is used to cancel the axis servo-control error
rapidly and approximately.
Its value is 10 3 x Σp/V. Σp is in micrometres and V is in micrometres per smp, i.e. 10 3 x T/smp where T = servo-loop
time constant and smp = sample period.
In practice, the equation for the time constant is:
Word N2
P40 P41 P46 P47 P48 P49 P42 P43 P44 P45 P62 P63
Cycle axis position anticipation time constant = 10 6 x Value P56/Value P50
This word defines the spindle zero crossing anticipation time constant. It is used to define the advance of the axis with
respect to the spindle zero crossing in order to gradually accelerate the axis.
The value is expressed as a number of samples. It is obtained by the equation:
Spindle zero crossing anticipation time constant = (Max speed/γ) x 10 6 /Value P50
where:
- Max speed = maximum authorised tapping speed in mm/s
- γ = acceleration authorised on the axis in mm/s 2 .
The faster the accelerations allowed on the cycle axis, the lower the value programmed in this constant.
! CAUTION
The values entered are constant for all the axes of a group. It is also necessary to set the
same gain for these axes (KVAR set in P21).
Adjusting and checking the values set in parameters P62 and P63
To make the checks, write a part programme including a rigid tapping cycle.
The spindle servo-drive acceleration ramp affects operation of the cycle. The steepest ramp possible should be
chosen.
Below, the adjustments are made for one axis group (parameter P63, words 0, 1 and 2) and spindle 1 (parameter P62,
words 0 and 1).
Setting P63
- Set word 0 to 0,
- Enter the theoretical values calculated by the above equations in words 1 and 2.
Setting P62
- Word 0: keep the default value of 10,
- Word 1: set the value supplied by the servo-drive manufacturer or keep the default value of 100.
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