Siemens Simantic S7-1500 Manual page 30

Wiring
PROFINET interface X1 with 2-port switch (X1 P1 R and X1 P2 R)
The assignment corresponds to the Ethernet standard for an RJ45 plug.
● 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 3-2
PROFINET interface X2 with 1 port (X2 P1)
The assignment corresponds to the Ethernet standard for an RJ45 plug.
Autocrossing is always active on X2. This means the RJ45 socket is allocated either as data
terminal equipment (MDI) or a switch (MDI-X).
30
PROFINET
CPU 1517T-3 PN/DP (6ES7517-3TP00-0AB0)
Manual, 12/2017, A5E36285525-AB