16.3 Travel to fixed stop with high-resolution torque reduction (SW 2.2 and higher)
The NC reads the resolution set in the parameters on the drive via parameter P0881 using acyclic
communication and transforms the read value into the format of the above mentioned machine
If the detected drive-end resolution is not equal to the resolution currently set in the parameters in
the NC machine data, the value determined by the drive is transferred to the NC machine data. The
resulting NC-end rescaling of the torque reduction for this machine axis is indicated in the following
If the value of parameter P0881 converted into NC format lies outside the admissible limit values,
the value set in the NC machine data is retained. An alarm is then not issued.
Parameterizing the DP slave 611U
The value 1638.40 is entered in parameter P0881.
The parameters are set with the start-up tool SimoCom U: menu command Start-up > Additional
Parameters > Expert List > Number > 881
The parameter is immediately effective.
SimoCom U 12A drive
File Edit Start-up Operation Diagnostics Tools Help
Online to drive 12A => data are modified directly in the drive!
Evaluation of torque/power reduction PRO
Fig. 16-5 Set parameter P0881
Siemens AG, 2003. All rights reserved
SINUMERIK 840Di Manual (HBI) – 06.03 Edition
To simplify the start-up of torque reduction, as standard the NC tried to perform
an automatic matching procedure. The adjustment is carried out in the following
– SINUMERIK 840Di boot
– "Incoming station" of the DP slave 611U.
Alarm 26024 "Axis axis identifier machine data $MA_PROFI-
BUS_TORQUE_RED_RESOL value adapted".
You can disable automatic adjustment via:
MD 13070: DRIVE_FUNCTION_MASK[n], bit 15 = 0
If one of the requirements listed above for automatically adjusting the torque
reduction resolution is not met, it is possible to set the parameters manually to
achieve consistence if the torque reduction resolution was parameterized in the
mappable range (0.01% to 10%).
The following conditions apply:
– Machine axis X1 corresponds to drive 12A
– The torque reduction resolution is to be 0.1%.
Control of clock-synchronized PROFIBUS
16 840Di Specific Data and Functions