Siemens SIMATIC S7-1500 Manual page 44

PROFINET interface X1 with 2-port switch (X1 P1 R and X1 P2 R)
The assignment corresponds to the Ethernet standard for a RJ45 connector.
• When autonegotiation is deactivated, the RJ45 socket is allocated as a switch (MDI-X).
• When autonegotiation is activated, autocrossing is in effect and the RJ45 socket is
allocated either as data terminal equipment (MDI) or a switch (MDI-X).
Figure 3-1
PROFINET interface X2 and X3 with 1 port (X2 P1, X3 P1)
The assignment corresponds to the Ethernet standard for a RJ45 connector.
Autocrossing is always active on X2 and X3. This means the RJ45 socket is allocated either as
data terminal equipment (MDI) or a switch (MDI-X).
Figure 3-2
CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)
Equipment Manual, 07/2021, A5E40882737-AB
Interface assignment X1
Interfaces X2 and X3
Connecting up
43