Installation manual
CNC 8035
5.
CONCEPTS
feedback system
(SOFT M: V15.3X)
(S
OFT T: V16.3X)
·200·
Example 2:
Resolution in "mm" with sinusoidal signal encoder
We would like to obtain a 2µm resolution by using a 250-line sinusoidal encoder mounted on 5 mm-
pitch ballscrew.
We must calculate the multiplying factor "SINMAGNI" to be applied by the CNC to the pulses
provided by the encoder in order to obtain the desired resolution.
SINMAGNI = ballscrew pitch / (Nr pulses x Resolution)
SINMAGNI = 5000 µm / (250 x 2 µm) = 10
Therefore:
Although the CNC accepts a maximum squarewave frequency of 250 kHz, when using Fagor
sinusoidal rotary encoders, the output frequency is limited to 200 kHz; thus, the maximum possible
feedrate (F) will be:
Max. feedrate = (200.000 pulses/sec. / 250 pulses/turn) x 0.2 inch/turn
Max. feedrate = 4.000 mm/s = 240 m/min.
Example 3:
Resolution in "mm" with squarewave linear encoder
Since the CNC applies a x4 multiplying factor to squarewave signals, we must select a linear encoder
whose grading pitch is 4 times the desired resolution.
FAGOR linear encoders use a grading pitch of either 20 µm or 100 µm. Therefore, the resolution
that can be obtained with them are: 5 µm (20/4) or 25 µm (100/4).
Therefore:
The CNC's maximum squarewave feedback input frequency is 400 kHz which means that the
maximum feedrate obtainable with a 20 µm pitch linear encoder is:
Max. Feed = 20 µm/pulse x 400.000 pulses/sec.
Max. feedrate = 8000 mm/s = 480 m/min.
When using Fagor linear encoders, the maximum feedrate is limited by their own characteristics to
60 m/min.
Example 4:
Resolution in "mm" with sinusoidal signal linear encoder
We have a sinusoidal linear encoder with a 20 µm pitch and we would like to obtain 1 µm resolution.
We must calculate the multiplying factor "SINMAGNI" to be applied by the CNC to the pulses
provided by the linear encoder in order to obtain the desired resolution.
SINMAGNI = linear encoder pitch / resolution = 20 µm / 1 µm = 20
Therefore:
The CNC's maximum sinusoidal feedback input frequency is 250 kHz which means that the
maximum feedrate for this axis will be:
Max. Feed = 20 µm/pulse x 250.000 pulses/sec.
Max. feedrate = 5.000 mm/s = 300 m/min.
When using Fagor linear encoders, the maximum feedrate is limited by their own characteristics to
60 m/min.
INCHES = 0 PITCH=5.0000 NPULSES = 250 SINMAGNI=10
INCHES = 0 PITCH=0.0200
PITCH=0.1000
NPULSES = 0 SINMAGNI=0
INCHES = 0 PITCH=0.0200 NPULSES = 0 SINMAGNI=20
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