Siemens S7-400 Equipment Manual page 36

Requirements for use
3.5 Program blocks
Note
Using current block versions
We recommend that you always use the latest block versions for all module types. You will
find the current blocks to download from the Internet in Siemens Industry Online Support at
the following address:
Link: (https://support.industry.siemens.com/cs/ww/en/ps/15335/dl)
With older module types, this recommendation assumes that you are using the latest
firmware for the particular module type.
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 70) for operation with a high communications load.
36
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).
Equipment Manual, 03/2023, C79000-G8976-C256-07
CP 443-1 Advanced