Time Behavior - Siemens SINUMERIK 840Di Manual

06.03
10.6.5

Time behavior

NC:
Position controller
R
and interpolator
PROFIBUS DP
MSG
communication
DP slave:
Signal module
Fig. 10-34 Time behavior when outputting an output signal with optimized DP cycle
 Siemens AG, 2003. All rights reserved
SINUMERIK 840Di Manual (HBI) – 06.03 Edition
After the system variables have been set, e.g. $A_OUT[8] for setting the 8th
digital output of the NC on a SIMATIC-S7 signal module connected on PROFI-
BUS DP, the system variable is transferred from DP master to the signal module
along 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. 10-34, page 10-383.
The time properties when reading in a digital or analog input are analogously to
the properties described above.
1
T
M
R
Pos . Interpol.
RES GC
Dx Dx Dx
R R
Explanations regarding Fig. 10-34:
T Master application cycle: NC position controller cycle
MAPC
With SINUMERIK 840Di, the following applies in all cases: T
T DP cycle time: DP cycle time
DP
T Data exchange time: Total of transfer times of all
DX
DP slaves
T Master time: Shift of starting time of the NC
M
position control
GC Global Control: Broadcast message frame for cyclic
synchronization of the isosynchronism between DP master
and DP slaves
10 NC Start-Up with HMI Advanced
10.6 Digital and analog I/O devices
T
MAPC
T
T
DX
DP
2
MSG RES GC
Dx Dx
R R R
Dx
3
R
= T
MAPC
10-383
DP