User`s manual

4-30 Motion Mate™ DSM314 for Series 90™-30 PLCs User's Manual – January 2001 GFK-1742A
4
off the integrator.
If used,
t
he Integrator Time Constant should be 5 to 10 times greater than
the
Position Loop Time Constant
to prevent instability and oscillation.
Default: 0.
6.11 Velocity Loop Gain
Velocity Loop Gain. Used to set velocity loop gain. This applies to GE
Fanuc Digital Servos only.
This parameter is not used for Analog Servo Mode.
The formula
Load Inertia (J
L
)
Velocity Loop Gain =
Motor Inertia (J
M
)
x 16
can be used to select an initial velocity loop gain value. The allowable value range is 0 to 255. The
value of 0 should be used if the motor shaft is not attached to a load.
Default: 16 (load inertia equals motor inertia).
Computing Data Limit Variables
The data limit values for parameters MaxPosnUu, MaxVelUu, and MaxAccUu, referred to in some
of the tables in this chapter, can be calculated using the following formulas:
Table 4-12. Computing Data Limit Variables
Formulas for Computing Data Limit Variables
Position Limit MaxPosnUu Velocity Limit MaxVelUu Acceleration Limit MaxAccUu
If uu:cts >= 1:1
MaxPosnUu = 536,870,912
Else (uu:cts < 1:1)
MaxPosnUu = 536,870,912 * uu/cts
MaxVelUu = 1,000,000* uu/cts If uu:cts >= 1:1
MaxAccUu = 1,073,741,823
Else (uu:cts < 1:1)
MaxAccUu = 1,073,741,823* uu/cts