YASKAWA A1000 HHP Programming Manual page 45

To activate Zero Servo mode, use a digital input set for H1-oo = 72 and the drive will decelerate when this input is closed.
The drive goes into Zero Servo mode and holds the current position when the motor speed falls below the level set to parameter
b2-01. The drive accelerates when the input assigned to trigger the Zero Servo function is released and the Run command is
still present.
When Zero Servo mode is active, the deviation between the rotor position and the zero position is displayed in monitor U6-22
(monitor value must be divided by 4 to get the deviation in actual encoder pulses).
A digital output programmed for "Zero Servo complete" (H2-oo = 33) is turned on when the rotor position is within the zero
position, plus or minus the Zero Servo completion width set to parameter b9-02.
Note: 1. The Run command must remain on when using the Zero Servo function. Zero Servo will not hold the load in place if the Run command
is switched off.
2. When the Zero Servo command has shut off, the Zero Servo Completion digital output width also shuts off.
3. Avoid using Zero Servo to lock 100% load for long periods, as this can trigger a fault. If such loads need to be held in place for long
periods, either make sure the current is less than 50% of the drive rated current during Zero Servo, or use a larger capacity drive.
4. If the load rotates the motor when using CLV/PM, a dv4 fault may occur. To prevent this increase the Zero Servo gain (b9-01).
n b9-01: Zero Servo Gain
Adjusts the responsiveness of the Zero Servo position loop. Increase the value if the response is too slow and the deviation
from the zero position rises too high when load is applied. Decrease the value if vibrations occur during Zero Servo operation.
Note: Before adjusting the Zero Servo gain, make sure the ASR parameters (C5-oo) are set up properly and vibration or hunting does not occur
when running with a zero speed reference.
No.
b9-01
n b9-02: Zero Servo Completion Width
Sets the output range of the Zero Servo completion signal. Enter the amount of deviation allowable from the desired position
to trigger Zero Servo. An output terminal set for Zero Servo (H2-oo = 33) will be triggered when the motor reaches the
position Zero Servo plus or minus b9-02.
No.
b9-02
YASKAWA ELECTRIC SIEP YEAHHP 01B YASKAWA AC Drive – A1000 HHP Programming Manual
Run command
Zero Servo command
Motor Speed
b2-01
DC Injection Braking
start frequency
Figure 1.27 Zero Servo Operation
Name
Zero Servo Gain
Name
Zero Servo Completion Width
ON
ON
Zero Servo
Operation
1.2 b: Application
OFF
OFF
Setting Range
0 to 100
Setting Range
0 to 16383
Default
5
Default
10
1
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