Siemens Simantic Net NCM for Industrial Ethernet S7 - Manual (Page 76)

SEND/RECEIVE Interface in the User Program
76
SIMATIC NET NCM S7 for Industrial Ethernet
C79000-G8976-C129–06
Calling FCs in the CPU Program
One possible sequence for FCs in conjunction with the organization and program
blocks in the CPU cycle is illustrated in the following diagram.
ЗЗЗЗЗЗЗЗ
ЗЗЗЗЗЗЗЗ
НННННННН
НННННННН
AG_RECV
ННННННННН
ННННННННН
AG_SEND
AG_SEND
Read in the received
data of the
connection
Transfer send data
for the connection
Write PIQ
OB
ЗЗЗЗЗЗЗЗЗ
ЗЗЗЗЗЗЗЗЗ
ЗЗЗЗЗЗЗЗЗ
Legend: Sequence of the CPU cycle
AG_RECV
AG_RECV
Communication
connection
ЗЗЗЗЗЗЗ
ЗЗЗЗЗЗЗ
ЗЗЗЗЗЗЗ
ЗЗЗЗЗЗЗ
ННННННН
ННННННН
ННННННН
ННННННН
ННННННН
AG_SEND
User program
The different shading shows which
connections and FC blocks belong
together.
ЗЗ
ЗЗ
НН
НН
Read PII
Communication
connection
Communication
connection
Figure 3-2 Typical Sequence of Function Calls in the CPU Cycle
The following points are illustrated by the diagram:
S
The user program consisting of any number of blocks (OBs, FBs or FCs –> see
also /6/ accesses several connections (Figure 3-2 illustrates three
connections).