Rockwell Automation 8520-ARM2 9/Series CNC AMP Reference Manual Documentation Set - Manual (Page 216)

Servo Parameters
Chapter 7
7-70
Notes
This parameter must be set independently for each servo.
Function
This is also a scaling parameter used to create a portion of the acceleration
command for a particular servomotor.
In the control, Velocity Proportional Gain is multiplied by the velocity
error. Velocity Integral Gain is multiplied by the summation of velocity
error. These two products are added to form the acceleration command.
(Velocity error is the difference between the velocity command and the
actual velocity as derived from the feedback device.)
Generally, if set too high, the servo is underdampened and oscillation
results. If set too low, the servo is overdampened and requires too much
transition time between servo speeds.
For rapid positioning, with the Positioning Acc/Dec Mode as exponential,
these parameters may affect underdampening/overdampening so that the
Programmed Delay Constant will have to be adjusted to achieve proper
machine performance.
(Init. Gain Pos. Loop)(3277) < (Vel. Proportional Gain) < (Init. Gain Pos. Loop)(10923)
Important: On digital systems, if you use a standard motor, a value for
this parameter is entered automatically by the control when AMP is
downloaded or when the control is powered-up. When parameter
Standard Motor Table Values is set to Yes, then the control ignores the
value entered for this parameter and uses values as shown in Table 7.B and
Table 7.C.
Important: Once you have powered up your system and confirmed wiring,
fine tuning of the servo gains is almost always required once the servo shaft is
coupled to a load. Using online AMP to adjust the velocity/position loop
gains will automatically reset the Standard Motor Table Values parameter
to “No” at the control. Once you finish tuning your servos we recommend
uploading the AMP from the control to store the new gain values.
Important: The velocity integral gain can be adjusted online using online
AMP capabilities of the control. Once this is adjusted, online AMP sets
the Standard Motor Table Values parameter to “No”.
7.3.7
Velocity Proportional Gain