YASKAWA GA800 Technical Reference page 768

12.3 b: Application
Monitor U6-22 [ZeroServoPulse Move] shows the difference between the position of the motor shaft and the Zero
Servo start position when Zero Servo is enabled. To find the difference, divide the number of pulses shown in U6-22
by 4.
When the position of the motor shaft is in the range of "Zero Servo start position ± b9-02 [Zero Servo Completion
Window]", the drive will activate an MFDO set for Zero Servo Complete [H2-xx = 33].
NOTICE: Do not let the Zero Servo function hold 100% load for long periods of time. When the application must use Zero Servo to
hold 100% load for long periods, operate in less than 50% of the drive rated output current or use a larger capacity drive. If Zero
Servo holds the load for too long in 50% or more of the drive rated output current, it will cause damage to the drive.
Note:
• When you use the Zero Servo function, keep the Run command ON. If the Run command is OFF, the drive will not hold the motor shaft in
position.
• When you turn oFF the Zero-Servo command, the terminal set for Zero Servo Complete will deactivate.
• If A1-02 = 7 [PM Closed Loop Vector] and an external force rotates the motor during Zero Servo, the drive will detect dv4 [Inversion
Prevention Detection]. To prevent dv4 detection, increase b9-01 [Zero Servo Gain] or increase the number of pulses set in F1-19
[Deviation 4 Detection Selection].
■
b9-01: Zero Servo Gain
No.
Name
(Hex.)
b9-01 Zero Servo Gain
(01DA)
If the drive is not responsive, or if there is too much deviation from the Zero Servo start point when you increase the
load, increase this setting. If oscillation or hunting occurs, decrease this setting.
Note:
• Set C5-xx [Automatic Speed Regulator (ASR)] parameters correctly before you adjust the Zero Servo gain.
• When you operate with the Zero Servo command enabled, oscillation and hunting must not occur.
■
b9-02: Zero Servo Completion Window
No.
Name
(Hex.)
b9-02 Zero Servo Completion
Window
(01DB)
When the position of the motor shaft is in the range of "Zero Servo start position ± b9-02", the drive will activate a
MFDO set for Zero Servo Complete [H2-xx = 33].
768
Figure 12.43 Zero Servo Time Chart
V/f CL-V/f OLV CLV AOLV
Sets the responsiveness for the Zero Servo function.
V/f CL-V/f OLV CLV AOLV
Sets the range to trigger an output terminal set for "Zero Servo Complete" during Zero Servo
operation. Be sure to set the deviation from the Zero Servo start position.
Description
OLV/PM AOLV/PM CLV/PM EZOLV OLV/PM
Description
OLV/PM AOLV/PM CLV/PM EZOLV OLV/PM
YASKAWA SIEPC71061737D GA800 Drive Technical Reference
Default
(Range)
5
(0 - 100)
Default
(Range)
10
(0 - 16383)