IAI America PCON-CA - Manual (Page 152)

Chapter 3 Operation
POWER CON
PCON-CA/CFA
144
„ Examples of electronic gear calculations:
To set the unit travel distance to 0.01 (1/100) mm for an actuator a ball screw lead of 3mm,
equipped with an encoder of 800pulses/rev.
The electronic gear numerator (CNUM) is calculated as 8, while the electronic gear
denominator (CDEN) is calculated as 3. Based on these settings, the travel distance per
command pulse train input pulse becomes 0.01mm.
Caution:
Ɣ The fraction has to be completely reduced so both the electric gear numerator
(CNUM) and electric gear denominator (CDEN) can be 4096 or less and make them
to be integral numbers. (Do not stop reducing the fraction on the way.)
Ɣ CNUM and CDEN on the line axis have to satisfy the following relative formulas.
Ɣ Use rotary actuators of multi-rotation specification within the range where the
following formula is satisfied. Moreover, the maximum rotation angle is r9999 deg
(maximum software stroke limit).
Maximum rotation angle : Set the usage conditions (MAX. -9999 to 9999deg)
Unit Travel Distance : Travel distance per command pulse
Ɣ Do not set the minimum movement unit out of the encoder resolution ability. If this
setting is conducted, the actuator would not start moving until enough command
pulse is stored in the encoder resolution error.
Ɣ Pay attention not to exceed the specification limit when setting the velocity,
acceleration and deceleration.
=No. of Encoder Pluses [pulse/rev]
Ball Screw Lead Length [mm/rev]
u Unit Travel Distance [deg/pulse]
=
800
3
u
1
100
=
8
3
Electronic Gear
Numerator (CNUM)
Electronic Gear
Denominator (CDEN)
2 31 t
Stroke Length [mm]
Ball Screw Lead Length [mm/rev]
u No. of Encoder Pluses [pulse] u CNUM
2 31 t
Stroke Length [mm]
Ball Screw Lead Length [mm/rev]
u No. of Encoder Pluses [pulse] u CDEM
Encoder resolution for linear axis [mm/pulse] =
Ball Screw Lead Length [mm/rev]
No. of Encoder Pluses [pulse/rev]
Encoder resolution for rotational axis [deg/pulse] =
360=deg/rev? u Rotary Axis Reduction Ratio
No. of Encoder Pluses [pulse/rev]
r 2 31 t
Maximum rotation angle [deg]
Unit Travel Distance [deg/pulse]