Siemens SINUMERIK 840C - Manual (Page 888)

10.94 12 Functional Descriptions
12.13.10 Error messages from the NC to the PLC
12.13.10 Error messages from the NC to the PLC
Indexing from the PLC is via the command channel. If disturbances occur while this function is
being executed, an error message is sent to the user interface.
The error messages are divided into general and function-specific command channel errors.
12.14 Dynamic feedforward control and setpoint smoothing filter
A P feedforward control (MD 312* and MD 465*) and a D feedforward control (MD 1124*/
MD 2449*) with a symmetrizing element to prevent overshoots (MD 392* and
MD 467*) are implemented in the position controller. In addition, a smoothing filter in the
setpoint path can be activated (MD 1272* with option bit MD 1820*, bit 0/MD 486*) to level out
dynamic differences between interpolating axes. (See figure for structure of feedforward
control). Please note the additional calculation time required for this function.
d
dt d
dt
D feedforward control factor
MD 1124*/MD 2449*
MD 312* or MD 465*
Feedforward control factor
Position
setpoint
d
dt
Position
actual value
-
+
MD 1272*/486*
Setpoint filter MD 392* or 467*
Symmetrizing filter MD 252* or MD 435* ff.
Servo gain factor
Note:
The parameters for the 1st parameter set are shown in the diagram above. A total of 8 pa-
rameter sets are available. Refer to ”Parameter set switchover” function for further details.
© Siemens AG 1992 All Rights Reserved 6FC5197- AA50 12–113
SINUMERIK 840C (IA)