Siemens Sinumerik 840DiE sl - Page 302

01/2007
11.3 System data
11-302
© Siemens AG 2007 All Rights Reserved
SINUMERIK 840Di sl Manual (HBIsl) – 01/2007 Edition
DxDxDx
GCMSG RES MSG
DP slaves:
Drives
NCK:
Position controller
T
M
T
DP
RES GC
PROFIBUS DP
Communication
DxDxDx
T
DX
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
T
Pos
RRR
Fig. 11-2 Position control cycle offset compared to PROFIBUS DP cycle
Key to Fig. 11-2:
T
Pos
CPU time required by position controller
T
DP
DP cycle time: DP cycle time
T
DX
Data exchange time: Sum of transfer times of all
DP slaves
T
M
Master time: Offset of the start time for NCK
position control
GC Global control: Broadcast message for cyclic
synchronization of the equidistance between DP master
and DP slaves
R CPU time
Dx Exchange of user data between DP master and DP slaves
MSG Acyclic services (e.g. DP/V1, pass token)
RES Reserve: ”active break” until the equidistant cycle has elapsed
The interpolator cycle may be chosen freely as a whole multiple of the position
control cycle.
S MD10070: $MN_IPO_SYSCLOCK_TIME_RATIO (factor for interpolator
cycle)
The processor power of the PCU must be shared between the NCK and Win-
dows XP. The parameterized CPU time share of the NCK is the maximum value
that the NCK will only use in the worst case. If the NCK requires less CPU time
in cyclical operation, it will cede it dynamically to Windows XP.
Interpolation cycle
NCK CPU time
share
11 NCK Commissionin
g
with HMI Advanced