data index. All other data sets of an SPL connection are not evaluated with reference to
connection names.
This MD is not incorporated in the checksum calculation; i.e. it can also be changed without
aligning the checksum.
MD13334 $MN_SAFE_SDP_LADDR: I/O start address
When generating the configuration in SIMATIC STEP7 HW Config, for each SPL connection
a start address must be defined for the I/O area, which is used for the F_SENDDP to exchange
data with the associated F_RECVDP. The start address must be the same for the input and
output data areas.
The user must enter the I/O start address of the SPL connection, defined in the configuration,
in MD $MN_SAFE_SDP_LADDR[0...m].
Rules to define the start addresses and address areas of an SPL connection:
● The start address must be identical in the input
● Slot length: Input data area = 6 bytes, output data area = 12 bytes
● Consistency of the slot in the input
length"
The check is made on the PLC side within the scope of the cyclic F_DP communication by
evaluating the SFC14/SFC15 return values. For an error, Alarm 27354 "F_DP: %1
communication, connection %2 signals SFC%3 error %4" is displayed.
Parameterization of the F-net data transfer
The transfer of the SPL outputs in the F-net data is parameterized using the following NCK
machine data:
● $MN_SAFE_SDP_ASSIGN[0...m]
● $MN_SAFE_SDP_FILTER[0...m]
Figure 8-27
Safety Integrated
Function Manual, 12/2017, 6FC5397-4BP40-6BA1
8.4 Safety-related CPU-CPU communication (F_DP communication)
F-net data transfer F_SENDDP
Connecting sensors and actuators
and output data areas
and output data areas in both cases over the "complete
225