Siemens SINUMERIK 840D sl Function Manual page 193

Special MD settings
In some cases, it may be necessary to be able to adapt the delay (see examples below).
This machine data was introduced for this purpose:
MD10065 $MN_POSCTRL_DESVAL_DELAY
It allows you to adapt the setpoint delay in the position controller for the entire NCU. You can
use positive and negative values. The set values (time in seconds, max. +/- 0.1sec) are
added to the automatically calculated values. See under "Information" below.
Setting notes
The required position setpoint delay depends on the controller structure used (DSC (dynamic
stiffness control), feedforward control); this delay is taken into account when switching to the
respective controller (e.g. FFWON (travel with feedforward control ON)). The automatic setting
function obtains the maximum value for the position control cycles of the individual NCUs
and delays the times on all the NCUs, thus providing compensation at constant speed for the
different cycle times on all types of controller structures. In this manner, an additional delay
can even be active on the axis with the slowest position control cycle.
The controller structure with
● the highest compensation requirement is operation of torque feedforward control or with
● the least compensation requirement is DSC or if feedforward control is deactivated.
Information
The setpoint delay for the three controller structures
● Without feedforward control (index 0)
● Speed feedforward control (index 1)
● Torque feedforward control (index 2)
is displayed in read-only machine data:
MD32990 $MA_POSCTRL_DESVAL_DELAY_INFO
Negative values in machine data:
MD10065 $MN_POSCTRL_DESVAL_DELAY
reduce the values for all three controller structures; positive values increase them.
Extended Functions
Function Manual, 03/2009, 6FC5397-1BP10-4BA0
Several Operator Panels on Several NCUs, Distributed Systems (B3)
speed feedforward control and activated ramp encoder in the drive,
NCU link with different interpolation cycles
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