PROFIBUS DP Communication
8.1 General information
Manual
232
Commissioning Manual, 05/2008, 6FC5397–4CP10–4BA0
8.1.4
Description of a DP cycle
Actual values
At time T
I
the current actual position values are read from all isochronous DP slave drives. In
the next DP cycle, the actual values are transferred to the DP master in the time T
DX
.
Position controller
The NC position controller is started at the time T
M,
with T
M
> T
DX,
and computes the new
speed setpoint for each axis on the basis of the position setpoint and the transferred actual
position value.
Setpoints
At the start of the next DP cycle, the speed setpoints are transferred from the DP master to
the DP slaves (drives) in the time T
DX
.
At time T
O
, the speed setpoints are taken as new specified values for all drive controllers.
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position controller
Figure 8-2
Example: Optimized DP cycle with 3 DP 611U slaves
