
5.FUNCTION DESCRIPTIONS FANUC AC SPINDLE MOTOR αi series B-65280EN/05
- 232 -
15i 16i 30i
3160 4160 4160
Speed detection level hysteresis
Unit of data : 1min
-1
(When parameter No. 4006 #2 (SPDUNT)=1, 10 min
-1
)
Valid data range : 0 to 32767
Standard setting value : 0
Specify the hysteresis of the detection level of the speed detection
signal (SDT).
The speed detection signal (SDT) changes from 1 to 0 with the set
speed detection level + hysteresis motor speed, and changes from 0 to
1 with the set speed detection level motor speed. If this data is set to
20 min
-1
or less, the hysteresis is automatically set to 20 min
-1
.
If the speed detection signal (SDT) is used in speed range switching
control, increase the data setting in situations where the switching
circuit is likely to cause chattering close to the motor speed for the
speed detection level.
Set the hysteresis width to a speed change measured during switching
with a margin (about twice the measured speed change).
A rough estimate of the hysteresis width can be obtained from the
following expression (on the assumption that the motor load torque at
switching is 20% of the maximum output torque):
0.2speedrotation Maximum
reached is speedrotation maximum theuntil on timeAccelerati
timeswitching range Speed
][min widthHysteresis
1
××=
−