Siemens SIMATIC S7-1500 Manual page 32

Connecting
PROFIBUS interface X4
The table below shows the pin assignment of the PROFIBUS interface. The assignment
corresponds to the standard assignment of an RS485 interface.
Table 4-2 PROFIBUS interface pin assignment
NOTE
Supply of I/O devices
The CPU 1518T‑4 PN/DP does not provide a 24 V DC power supply on the PROFIBUS interface.
I/O devices (for example, PC adapter USB 6ES7972‑0CB20‑0XA0) are only operational on the
interface in conjunction with a plug-in power supply set for external power supply.
The innovated successor product, PC adapter USB A2, receives the required power supply via
the USB port. This means it does not need a 24 V DC supply voltage and can be operated
without a plug-in power supply set for external power supply.
Reference
You can find additional information on the topics of "Wiring the CPU" and "Accessories/spare
parts" in the S7-1500, ET 200MP
(https://support.automation.siemens.com/WW/view/en/59191792) system manual.
Assignment of the MAC addresses
CPU 1518T‑4 PN/DP has three PROFINET interfaces. The first interface is an interface with
2-port switch. The PROFINET interfaces each have a MAC address, and each of the PROFINET
ports has its own MAC address. The CPU 1518T‑4 PN/DP therefore has seven MAC addresses
in total.
The MAC addresses of the PROFINET ports are needed for the LLDP protocol, for example for
the neighborhood discovery function.
The number range of the MAC addresses is sequential. The first and last MAC addresses are
lasered on the rating plate on the right side of each CPU 1518T‑4 PN/DP.
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View
1
2
3
4
5
6
7
8
9
Signal name
- -
- -
RxD/TxD-P Data line B
RTS Request to send
M5V2 Data reference potential (from station)
P5V2 Supply plus (from station)
- -
RxD/TxD-N Data line A
- -
CPU 1518T-4 PN/DP (6ES7518-4TP00-0AB0)
Equipment Manual, 11/2022, A5E50479758-AB
Designation