Siemens SIMOVERT MASTERDRIVES Manual page 740

Technology Option F01
9.4.33 Generation of the position setpoint [836]
9.4.34 Catch-up function [837]
Uncoupling an axis
Halting an axis at a
defined position
9-92
Before the position setpoint is output, the signals from synchronization
and displacement (offset) angle adjustment (V_displacement, [841])
and of catch-up [837] are switched in. As an alternative, the position
setpoint can be supplied from an external source via U886 (activated
via U885). The resulting speed setpoint is integrated up to the slave
position setpoint in the "ACL integrator" with limitation in the case of a
rotary axis to the slave axis cycle length parameterizable via MD11.
The corresponding corrective actions are also initiated for the position
actual value via KK301 and B303/B304.
A speed precontrol value is available at KK312. It can be switched in
downstream of the position controller to reduce the dynamic tracking
error.
The catch-up function enables a drive to be coupled up to and
uncoupled from a synchronization system. The uncoupled drive can be
operated autonomously at local speed and can be halted at an accurate
position.
Using the "Uncouple/Stop" = 1 command it is possible to decouple an
axis from a synchronization system. The axis then reduces its speed
via a ramp to the "catch-up setpoint speed", which can be preset via
U626.01 in the unit [10 LU/min] or via U626.02 as a percentage. The
deceleration of the deceleration ramp can be set in U628.1, and the
rounding of the same in U627.1. It is possible here to directly influence
the internal ramp or rounding via the "Mode" command, with and
without internal ramp, via any setpoint source without applying the
internal rounding.
The "Enable positioning" command can be used to stop the axis at a
setpoint position that can be parameterized in U626.03. However, the
drive initially travels at "catch-up setpoint speed" until the halt position
can be approached with the ramp, which is parameterizable in U628.3
without having to change the sense of rotation. When the factory setting
value -1 is selected, the ramp of index 1 is applied.
If the "Enable positioning" command is canceled, the axis can be made
to exit the halt position again and to accelerate up to "catch-up setpoint
speed" by setting the acceleration in U628.4 (see the broken-line
acceleration curve in [837]). In this instance as well, a factory setting
value of -1 causes the ramp of index 2 to be applied.
Furthermore, the "Trigger positioning" command can be used to start
the position controller and perform a new positioning operation.
The shutdown position is then approached either in "relative mode"
within one revolution (axis cycle compensated) or in "absolute mode"
via several axis cycles.
6SE7087-6QX70 (Version AG)
Compendium Motion Control
05.2006
Siemens AG
SIMOVERT MASTERDRIVES