Screen Page "Position" (Pi) - Beckhoff AX2000 Setup Manual

BECKHOFF
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Screen page "Position" (PI)

Cycle time of the position controller: 250 µs
Subscreens
Position Data
Homing
Gearing
Ff Factor
ASCII: GPFFV
Determines the feed-forward factor for the position controller. Feed-forward is used to ease the task of the
position controller. A better setting for the Ff-factor means a better utilization of the dynamic range of the
position controller. The most favorable setting (usually about 1.0) depends on factors external to the drive, such
as friction, dynamic resistance, and stiffness.
KV
ASCII: GP
Determines the proportional gain for the position controller.
Normalization: speed in m/s at 1 mm position deviation.
Tn
ASCII: GPTN
Determines the integral-action time (integration time constant) for the position controller.
Tn = 0 ms switches off the I-component.
max.Following Error
ASCII: PEMAX
The following error is the maximum difference (+/- window) between the position setpoint and the actual position
that is permitted during processing. If the value leaves this window, then the position controller generates an
error message and brakes the drive, using the emergency ramp.
KP
ASCII: GPV
Determines the proportional gain for the speed section of the controller. Increase the value up to the level where
the motor starts to oscillate, and then back it off until the oscillations have clearly stopped. Typical values are
the same as for the KP of the speed controller.
Normalization: as for the KP of the speed controller
PID-T2 Displays the value from the screen page "Speed"
Feedback Displays the value from the screen page "Speed"
Mode / Position Feedback
ASCII: EXTPOS
Mode
Determines the type of position control loop (P/PI). With a P position control this screen page appears in a
different layout.
Position feedback
Determines the feedback source for the internal position controller. For most applications, the position infor-
mation for commutation and for position control are derived from the same source. This source is determined on
the "FEEDBACK" screen page, and can be either a resolver or an Endat/Hiperface encoder. In certain situa-
tions it may be advisable to derive the position information for commutation from a different source to that for
the position control. In such a case the feedback parameter will continue to be the source for commutation, and
the source for the position control will be given by gearing mode.
Standard feedback
- Feedback type is set by feedback
- It is not possible to read in an encoder via X1 or X5
Read external (ROD/SSI) for fieldbus
- Feedback type is set by feedback, external encoder is set by gearing mode
External (ROD/SSI) for position control
- Not possible in this mode
Setup Software
07/03
Opens the screen page "Position Data"
Opens the screen page "Homing"
Opens the screen page "Gearing"
Default: 1
Default: 0,15
Default: 10 ms
Default: 262144
Default: 7
Default: 0
Screen page "Position" (PI)
valid for OPMODES 4,5,8
valid for OPMODES 4,5,8
valid for OPMODES 4,5,8
valid for OPMODES 4,5,8
valid for OPMODES 4,5,8
valid for all OPMODES
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