Rockwell Automation 1784-PM16SE SoftLogix Motion Card Setup and Configuration Manual - Manual (Page 332)

Publication 1784-UM003A-EN-P – June 2003
324 Motion Object Attributes
Position Servo with Torque Servo
Drive
This configuration provides full position servo control using an external
torque loop servo drive. Synchronous input data to the servo loop includes
Position Command, Velocity Offset, and Torque Offset. These values are
updated at the coarse update rate of the associated motion group. The Position
Command value is derived directly from the output of the motion planner,
while the Velocity Offset and Torque Offset values are derived from the
current value of the corresponding attributes. These offset attributes may be
changed programmatically via SSV instructions which, when used in
conjunction with future Function Block programs, provides custom “outer”
control loop capability.
Figure 13.8 Position Servo with Torque Servo Drive
Pos P
Gain
Pos I
Gain
Vel
FF
Gain
d/dt
Error
Accum
-ulator
Position
Error
d/dt
Low
Pass
Filter
Vel P
Gain
Output
Limit
Position
Accum-
ulator
Σ Σ Σ
Position
Command
(Coarse)
Fine
Interpolator
Position
Command
Velocity
Command Velocity
Error
Velocity
Feedback
16-bit
Encoder
Counter
Position
Integrator
Error
Marker
Latch
Torque
Servo
Drive
Ch Z
Marker
Input Marker
Event
Handler
Regist.
Event
Handler
Watch
Event
Handler
Watch
Event
Registration
Event
Homing
Event
Regist.
Latch
Registration
Input
Acc
FF
Gain
d 2 /dt
Σ
Vel I
Gain
Velocity
Integrator
Error
16 Bit
DAC
Position
Feedback
(Coarse)
Position
Feedback
Error
Accum
-ulator
Low
Pass
Filter
Output
Scaling
Friction
Comp.
Output
Offset
&
Servo
Polarity
Servo
Output
Level
Output
Filter
BW
Encoder
Polarity
Velocity
Offset
Watch
Position
Torque
Offset
Σ
AQB
Encoder
Ch A/B
Encoder
Input
Motor
Servo Config = Position
S