Technical data

Start-up OBs for SIMATIC S5 PLCs
You must call the SYNCHRON handling block for the interface number of
the CP 5430 TF/CP 5431 FMS in the start-up OB.
Transmitting and receiving data with acknowledgment (service: SDA)
Sequence of the transmission
☞
SEND and RECEIVE job numbers must match the
programmed job numbers (link editor of the COM 5430
TF/COM 5431 FMS).
If the link was not programmed with the link editor of COM
5430 TF/COM 5431 FMS, the job (triggering the SEND HDB) is
blocked by the firmware of the CP (ANZW 0F0A
H
)!
Request to layer 2
(Evaluation of the status word))
The data preceded by an
8-byte header are sent
with the SEND HDB
The receiver is informed
that data have been
received
The sender is informed that
an acknowledgment has
arrived from the receiving CP
The receiver fetches the
received data with the RECEIVE
HDB from the CP.
The first 8 bytes contain
management information (header)
Indication
Confirmation
The sender fetches the
confirmation consisting of an
8-byte header from the CP.
To do this it uses the
RECEIVE HDB
(Evaluation of the status word)
SENDER
RECEIVER
1
2
4
5
3
(Evaluation of the status word))
(Evaluation of the status word))
B8976060/02 Free Layer 2 Communication
8 - 19 Volume 1