Rockwell Automation 1391ES AC Servo Controller - Manual (Page 38)

Inputs, Outputs and Adjustments
Chapter 5
5-36
Torque Block/Velocity Loop Operation (S2-5)
Switch S2-5 is used to disable the velocity error amplifier to configure the
controller for torque block operation. In torque block mode the controller
acts as a current amplifier producing current (torque) proportional to the
command present at terminals 15 and 16 of TB2. Note that the Command
Scale and Velocity Loop Gain potentiometers (R132 & R144) have no
effect in the torque block mode. Scaling for torque block is
±
3V
Command=100% of the S1 Current Setting (i.e. motor rated current). Place
switch S2-5 to the “ON” position for torque block operation and “OFF” for
velocity loop operation.
Velocity Loop Compensation (S2-6)
This switch is used to compensate the velocity loop for applications with
higher load inertia. Position the switch to “ON” for high inertia
compensation. High inertia compensation will generally improve
performance on systems with load inertias greater than three times motor
rotor inertia, although the user may wish to evaluate the impact of this
compensation at slightly lower inertias.
Error Amp Gain (S2-7, 8)
1326AD motors require less gain on the velocity loop. Switches S2-7 and 8
reduce the gain by a fixed percentage. If both switches are “OFF,” there is
no gain reduction. If either switch is ON, the gain will be reduced by 33%.
If further gain reduction is required, both switches should be placed to
“ON,” which provides a 50% reduction.
Tachometer Filter (S2-9, 10)
If the motor/tach is operating in a mechanically noisy system, additional
tach filtering may be necessary. These switches offer four levels of
filtering. Filter bandwidth can be decreased from 430 Hz. to 165 Hz. using
the switch settings described in Table 5.D.
Staircase Filtering (S2-11, 12)
These switches provide additional filtering to minimize “staircasing” of the
DAC output from the position loop controller. Three levels of velocity
command filtering are available as shown in Table 5.D.
A Quad B Encoder Output Switch - S3
S3 selects the line count that will be output from the A Quad B Board.
ATTENTION: Incorrect setting of S3 can cause erratic and/or
improper machine motion which may result in personal injury
or equipment damage. Assure that switch S3 has been properly
set as shown in Figure 5.3.
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