Siemens NCM S7 Manual page 163

How the Block Works
The following diagram illustrates the normal sequence of data acceptance
triggered by an AG_RECV in the user program.
Each AG_RECV job in the user program is acknowledged by the Ethernet CP with
an entry in the output parameters NDR, ERROR and STATUS.
User program
(CPU cycle)
Accept / evaluate
received data "A"
Accept / evaluate
received data "B"
Legend:
1) Parameter transfer NDR, ERROR, STATUS
The status code is updated at each block call.
SIMATIC NET NCM S7 for Industrial Ethernet
C79000-G8976-C129–06
Programming FCs (Functions) and FBs for S7 Ethernet CPs
Ethernet CP
AG_RECV
1)
0, 1, 8180
AG_RECV
1)
1, 0, 0000
AG_RECV
1)
0, 0, 8180
AG_RECV
1)
1, 0, 0000
AG_RECV
.
.
.
Time
Communications Partner
Transfer
"A"
active on
Ethernet
Transfer
"B"
active on
Ethernet
Transfer
"C"
active on
Ethernet
Time Time
163