10/15
The synchronization of the SPL output data described above ensures that if it is
intended to simultaneously change several SPL output data in the SPL program,
then these are also consistently transferred (in time) in the F net data telegram of
the F_SENDDP. If, in a user application, several SPL output data are interpreted
as a contiguous bit pattern, it must therefore be taken into account that inter-
mediate values can briefly occur.
Example:
Three SPL output data are considered to be contiguous. The value is changed
from 101 to 110 in both SPL programs (NCK--SPL and PLC--SPL).
Values transferred from the F_SENDDP in the F net data telegram:
Output value
Possible intermediate values
Final value
Warning
!
Due to runtime differences in the NCK--SPL and PLC--SPL, it cannot be
guaranteed that these are sent consistently (in time) by F_SENDDP in the F net
data telegram when several SPL output data are simultaneously changed (NCK:
$A_OUTSE, PLC: $A_OUTSEP).
7.4.16
Boundary conditions
For SINUMERIK 840D sl, the following restrictions apply for the safety--related
CPU--CPU communication to couple plants and systems:
S The 2 integer values, defined in the F net data area of the F telegram, are not
used or not evaluated by the F_SENDDP and F_RECVDP realized for
SINUMERIK.
S Axis specific SGE/SGA cannot be directly coupled to F_SENDDP and
F_RECVDP.
S A maximum of 250 ms can be set for the F_DP clock cycle.
S The F net data are automatically coupled to the SPL interface in data block DB
18 by the basic PLC program. It is not possible to couple them in a PLC user
program.
© Siemens AG 2015 All Rights Reserved
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) - - 10.2015 Edition
7.4 Safety- -related CPU- -CPU communication (F_DP communication)
NCK--SPL
AND
101
&
110
&
110
&
Connecting Sensors/Actuators
PLC--SPL
= F net data telegram
101
= 101
101
= 100
110
= 110
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