Siemens S7 4.4.4 ISO Transport with the FETCH/WRITE Mode

Configuring Communication Connections
107
SIMATIC NET NCM S7 for Industrial Ethernet
C79000-G8976-C129–06
4.4.4 ISO Transport with the FETCH/WRITE Mode
Using FETCH PASSIVE / WRITE PASSIVE
If you select one of the FETCH PASSIVE or WRITE PASSIVE modes for the ISO
transport connection, you can access the system areas on a SIMATIC S7 PLC
from a SIMATIC S5 station or other non-S7 station.
Figure 4-11
The connection can then only be used for this mode; sending or receiving with the
FCs AG_SEND/AG_LSEND or AG_RECV/AG_LRECV is then no longer possible.
The connection establishment is passive; in other words, only the partner station
(SIMATIC S5 station or other non-S7 station) can establish the connection. The
setting is made automatically in the “General” tab and cannot be changed.
SFETCH
If you select the FETCH mode, you allow direct read access to system memory
on the SIMATIC S7 PLC. Such access can be, for example, from a SIMATIC
S5 station or other station.
SWRITE
If you select the WRITE mode, you allow direct write access to system memory
on the SIMATIC S7 PLC. Such access can be, for example, from a SIMATIC
S5 station or other station.