Rockwell Automation 8520-ARM2 9/Series CNC AMP Reference Manual Documentation Set - Manual (Page 205)

Servo Parameters
Chapter 7
7-59
Notes
This parameter must be set independently for each servo.
Important: This parameter should have a value that is greater than that of
the parameter Analog Servo Neg. Voltage.
An example of this parameter would be if a 15 amp drive is combined with
a servo motor rated at 9 amps peak current, the servo card should probably
never exceed 6 volts to get the drive to output 9 amps to the motor. You
would set this parameter to 6 volts. The following equation is not valid
for servo systems that use the CNC to close the velocity loop.
10 V (maximum servo card output) x 9 A (maximum rated motor current)
15 A (Drive output at 10V)
= 6 V (Analog Servo Positive Voltage)
Function
This parameter is only available for analog servo hardware.
Use this parameter to scale the signal sent from the analog servo interface
to the servo amplifier. This signal may range from --10.0000 to +10.0000
volts. The upper portion of this range is set with the parameter Analog
Servo Pos. Voltage. This value must be entered accurately. Use values
attained from drive specifications or testing. This value is used for
calculation of the servo motors continuous rated current which is used later
as a percent of this parameter. Note use the maximum servo acceleration
value if position/velocity loop is chosen as closed by the control (see table
below). If you feel you must limit the analog output voltage to protect
your machine, use the parameter Max Rated Torque.
If the servo loop type is
configured as:
enter the negative voltage that the servo module must
send to the amplifier to:
position loop maintain rapid axis speed in the negative direction
This parameter should be above --10 volts. If --10 volts is
entered, the control is unable to compensate for any
incontinuities that may occur at rapid speed.
position/velocity attain maximum servo acceleration in the negative
direction. Typically this is the voltage that is sent to the
drive to get the drive to output the servo motors maximum
(peak) rated current.
7.2.18
Analog Servo Neg. Voltage