
6. INTERPOLATION FUNCTION
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(With the above setting, the reference counter capacity is 36000.)
Parameter No. 1820 = 2 (CMR)
Parameter No. 1821 = 36000 (reference counter capacity)
Parameter No. 2084 = 36 (DMR numerator)
Parameter No. 2085 = 1000 (DMR denominator)
For the other servo parameters, specify typical values.
D Parameter setting for polygonal turning
The least command increment, detection unit, the angle to rotate
through per rotation for the polygon axis are as follows:
Least command increment =
L CMR
Q DMR
Detection unit =
DMR
least command increment
=
L
Q DMR
Angle to rotate through per tool axis rotation
=
360
least command increment
where
L: Tool axis rotation angle per motor rotation (degrees),
(360 speed increment ratio)
When the servo motor is connected directly to the rotation tool, for
example, L = 360. When the tool speed is doubled, L = 720.
Q: Number of pulses per pulse coder rotation
(For a serial pulse coder, Q = 1000000.)
The least command increment specified here is specific to the polygon
axis. It is determined regardless of what is specified in parameter No.
1004 (ISA/ISC). However, both ISA and ISC must be set to 0 for IS–B
setting.
If the servo motor is connected directly to the rotation tool:
Least command increment =
1000000
36
360 1
1000
= 0.01 (degrees)
Detection unit = 0.01 (degrees)
Angle to rotate through per tool axis rotation =
360
0.01
= 36000
(degrees)
The upper limit to the tool rotation axis speed is:
Maximum servo motor speed speed increment ratio
Therefore, if the maximum servo motor speed is 2000 min
–1
, and the
servo motor is directly connected to the servo motor:
Upper limit to the tool rotation axis speed = 2000 1 = 2000 (min
–1
)
This means the parameters must be set as follows:
No. 7620 = 36000 (angle to rotate through per tool axis rotation)
No. 7621 = 2000 (upper limit to tool rotation axis speed)
D Feedrate parameter setting
Because the least command increment is 0.01 degrees, the input unit
for the feedrate is 10 degrees/min.
To obtain a rapid traverse speed of 2000 min
–1
, for example, specify
as follows: