Siemens SIMATIC NET S7-400 Manual page 31

Using program blocks for the SEND/RECEIVE interface
For data transfer on the SEND/RECEIVE interface, there are program blocks for short and
long blocks of data.
For fast data transmission up to a data length of 1452 bytes, the SPEED SEND/RECEIVE
program blocks AG_SSEND (FC53) and AG_SRECV (FC63) are supported.
Functionality
Transfer of data fields <= 240 bytes
Transfer of blocks of data > 240 bytes to <= 8192 bytes
Accelerated transfer of blocks of data <= 1452 bytes
The length depends on the protocol
*)
Note
Multicomputing mode
Note that in multicomputing mode, communication using SPEEDSEND/RECV is possible
only via the CP assigned to the CPU.
Note
Operation with a high communication load
Note the recommendations in section Recommendation for use with a high communications
load (Page 47) for operation with a high communications load.
CP 443-1 (EX30)
Manual, 03/2019, C79000-G8976-C255-05
Requirement
You require the program blocks AG_SEND (FC5) and
•
AG_RECV (FC6) or alternatively the program blocks
AG_LSEND (FC50) and AG_ LRECV (FC60).
*)
You require the program blocks AG_LSEND (FC50) and
•
AG_LRECV (FC60).
You require the program blocks AG_SSEND (FC53) and
•
AG_SRECV (FC63).
Requirements for use
3.4 Programming
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