Siemens Simantic Net NCM for Industrial Ethernet S7 - Manual (Page 149)

Programming FCs (Functions) and FBs for S7 Ethernet CPs
149
SIMATIC NET NCM S7 for Industrial Ethernet
C79000-G8976-C129–06
Connection
Ethernet CP CPU
STEP 7
user
program
receive
send
User data areas
AG_RECV
AG_SEND
CPU
STEP 7
user program
User data areas
AG_RECV
AG_SEND
Ethernet CP
send
receive
Note
Unless specifically stated otherwise, the information on this and the following
pages refers to AG_SEND / AG_LSEND or AG_RECV / AG_LRECV.
Specifying the Data Area on the CPU
When you call an FC, you transfer the address and length of the data area in the
CPU. Remember, that the maximum length of the data area depends on the block
type and block version being used.
S AG_SEND and AG_RECV
Up to version V3.0 of these blocks, a maximum of 240 bytes could be sent or
received. The current block versions allow a data area of up to 8192 bytes for
an S7-300. With an S7-400, the FCs AG_LSEND / AG_LRECV must still be
used for larger data areas.
S AG_LSEND / AG_LRECV
Using the CPs of the S7-400 and with earlier versions of the S7-300, larger
data areas can only be transferred with the FCs AG_LSEND or AG_LRECV.
Please check the length of the data area in the product information.
The following table shows the limit values of the various connection types.