Fcs For Configured Connections - Siemens NCM S7 Manual

Programming FCs (Functions) and FBs for S7 Ethernet CPs
5.3

FCs for Configured Connections

Overview
The following functions (FCs) are available for transferring data over configured
connections:
FC
AG_SEND (FC5)
AG_RECV (FC6)
AG_LSEND (FC50)
AG_LRECV (FC60)
1)
Notes on the FCs in FCs for an S7-300 and S7-400
S S7-300:
With older versions of the Ethernet CPs, the data length per job is restricted to
<=240 bytes (applies up to block version V3.0 of AG_SEND / AG_RECV); with
later versions, longer data records (up to 8092 bytes) can be transferred with
FCs AG_LSEND or AG_LRECV.
With the latest versions of the Ethernet CPs, only FCs AG_SEND and
AG_RECV are used; due to a new and more efficient internal protocol, the data
up to 8092 bytes can be transferred.
S S7-400:
With FCs AG_SEND / AG_RECV the data length per job is restricted to <=240
bytes.
Longer data records (up to 8092 bytes) can be transferred with FCs
AG_LSEND or AG_LRECV.
Please check the manual /3/ of the S7-CP you are using for the data areas
supported. You will find an overview of the versions of the FCs/FBs in the
documentation and block history.
Application
The following diagram illustrates the use of the FCs described here for
bi-directional data transfer on one configured connection.
148
1)
Can be used with
S7 – 300 S7 – 400
x x
x x
x
x
Meaning
for sending data
for receiving data
for sending data
for receiving data
SIMATIC NET NCM S7 for Industrial Ethernet
C79000-G8976-C129–06