840Di-specific data and functions
18.3 Travel to fixed stop with high-resolution torque reduction
Manual
604
Commissioning Manual, 05/2008, 6FC5397–4CP10–4BA0
18.3
Travel to fixed stop with high-resolution torque reduction
The full description of functions for "Travel to fixed stop" can be found in:
References:
/FB1/ Function Manual, Basic Functions; Section "F1 Travel to Fixed Stop"
18.3.1
Description of functions
As part of the NC function "Travel to fixed stop", you specify the reduction of the drive torque
effective in the drive (terminal torque) via the part program instruction FXST. The torque
reduction value specified via FXST is transferred cyclically to the drive in the PROFIBUS
message frame as "MomRed" process data.
The effective drive torque M
setpoint
is calculated from:
0
VHW
0
PD[
෪0$;,080
'ULYHSDUDPHWHUV>@
0RP5HG
෪
●
M
max
:
Maximum possible drive torque from rated motor torque and parameter P1230 torque
limit value.
●
MomRed:
Control word in cyclic PROFIBUS message frame:
16384
D
= 4000
H
≙ 1, i.e. at MomRed = 16384, the drive moment is reduced by the
amount of the drive parameter.
'
+
'
))))
+
0RP5HG
'ULYHWRUTXH0
VHW
0
PD[
$3
0LQ
$3
0D[
Figure 18-6 Drive torque for the evaluation (drive parameter AP) and torque reduction (MomRed)
(Not true to scale)
The evaluation of the torque reduction must be identical in the drive and in the NC. The
settings range for torque reduction is defined by the limit values (0.005% to 10%) for the NC
machine data:
●
MD37620 $MA_PROFIBUS_TORQUE_RED_RESOL
