01/2007
11.7 Digital and analog I/O devices
11-393
© Siemens AG 2007 All Rights Reserved
SINUMERIK 840Di sl Manual (HBIsl) – 01/2007 Edition
11.7.5 Time–based reaction
After the system variables have been set, e.g. $A_OUT[8] for setting the 8th
digital output of the NCK on a SIMATIC S7 signal module connected via the
PROFIBUS DP, the system variable is transferred from DP master to the signal
module via the PROFIBUS DP during the next position controller cycle.
The signal module will then provide the signal to the appropriate with the output
next output cycle. The PROFIBUS DP cycle and the cycle of the signal mod-
ule are not synchronized during this process.
The transmission cycle described is illustrated in Fig. 11-32, Page 11-393.
The time properties when reading in a digital or analog input are analogously to
the properties described above.
DxDxDx
GCMSG RES MSG
R
R
DP slave:
Signal module
NCK:
Position controller
and interpolator
T
M
T
MAPC
T
DP
RES GC
PROFIBUS DP
communication
2
R
DxDxDx
1
T
DX
3
R R R
R
Pos
.
R
Interpol.
Fig. 11-32 Time response when outputting an output signal with optimized DP cycle
Key to Fig. 11-32:
T
MAPC
Master application cycle: NCK position control cycle
The following always applies for SINUMERIK 840Di sl: T
MAPC
= T
DP
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
11 NCK Commissionin
with HMI Advanced
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