
FANUC AC SPINDLE MOTOR a series
2. FUNCTION EXPLANATION
B–65160E/02
150
When the speed detection signal (SDTA) is used for speed range
switching control, set a greater value if the switching circuitry causes
chattering near the speed detection level.
Measure the speed variation at switching, then set a value obtained by
adding a margin (about twice the measured value) to the measured value
as a hysteresis.
The hysteresis can be calculated by using the formula below as a guideline
(assuming that the motor load torque at the time of switching is 20% of
the maximum output torque).
Hysteresis [min
–1
] +
speed range switching time
acceleration time until maximum speed is reached
maximum speed 0.2
(1) Gear/clutch signals (CTH1A, CTH2A)
For switching of the velocity loop gain, position gain, and gear ratio data
between the high–speed and low–speed characteristics in speed range
switching control, the gear/clutch signals (input signals), CTH1A and
CTH2A, are used.
Usually, the gear/clutch signals are used to select the spindle parameters
(velocity loop gain, position gain, and gear ratio) for a selected
gear/clutch.
For speed range switching control, set CTH1A and CTH2 together with
the winding selection.
CTH1A CTH2A
Gear/clutch selection
state
Winding selection state
0 0 HIGH GEAR (HIGH)
Windings for high–speed
power characteristics
0 1
MEDIUM HIGH GEAR
(HIGH)
–––
1 0
MEDIUM LOW GEAR
(LOW)
–––
1 1 LOW GEAR (LOW)
Windings for low–speed
power characteristics
(2) Relationships between the gear/clutch signals and spindle parameters
(a) When the windings for high–speed power characteristics are
selected (CTH1A = 0, CTH2A = 0)
16i/1601515i
Velocity loop proportional gain on normal operation (HIGH gear)
6540 3040 3040 4040
6680 3180
1st–
2nd–
Velocity loop proportional gain on orientation (HIGH gear)
6542 3042 3042 4042
6682 3182
1st–
2nd–
Velocity loop proportional gain on servo mode (HIGH gear)
6544 3044 3044 4044
6684 3184
1st–
2nd–
Velocity loop proportional gain in Cs contouring control (HIGH gear)
6546 3046 3046 4046
6686 3186
1st–
2nd–
Velocity loop integral gain on normal operation (HIGH gear)
6548 3048 3048 4048
6688 3188
1st–
2nd–
2.7.5
Parameter Switching
Between High–speed
Range and Low–speed
Range