Forward Feed Control For Command- And Plc Axes - Siemens SINUMERIK 840D sl Function Manual

K3: Compensation
5.5 Dynamic feedforward control (following error compensation)
Activation (MD32900)
The dynamic response adaptation is only active if the following machine data is set:
MD32900 $MA_DYN_MATCH_ENABLE= 1
Reference
Function Manual, Basic Functions; Velocities, Setpoint-Actual Value Systems, Closed-Loop
Control (G2), Chapter: "Optimizing the closed-loop control"
5.5.5

Forward feed control for command- and PLC axes

Function
For command and PLC axes, it must be prevented that the feedforward control is
activated/deactivated at higher velocities as follows:
MD32630 $MA_FFW_ACTIVATION_MODE = 2
With this setting, the FFWON/FFWOF operation only becomes active below the stationary
velocity (MD36060 $MA_STANDSTILL_VELO_TOL) configured for this particular axis.
If the switchover instruction coincides with an axis motion, the required switchover is
executed only in the next stoppage condition of the axis. This avoids the following error
being suddenly established/reduced.
NOTICE
A stoppage velocity set to a very high value can lead to the changeover of the feedforward
control in the movement. Controls can be activated depending on the existing following
error.
Commissioning
We recommend the following procedure when checking the feedforward control for
command and PLC axes:
1. Check the stoppage velocity in MD36060.
2. Check the existing following error of the axis in stoppage condition.
3. Setting the changeover condition and activating it:
4. Traverse axis in the part program using the POSA operation.
5. Execute FFWON during the axis motion.
406
MD32630 = 2
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
Extended Functions