Power Over Ethernet (Poe) - Siemens SIMATIC NET System Manual

SNMP v3
Compared with the previous versions SNMP v1 and SNMP v2c, SNMP v3 introduces a
comprehensive security concept.
SNMP v3 supports
● Fully encrypted user authentication
● Encryption of the entire data traffic
● Access control of the MIB objects at the user/group level
Note
To further improve security, separate the administration network from the remaining
network as a separate unit if this is possible.
DynDNS
Dynamic Domain Name Servers (DynDNS) allow applications to be reached on the Internet
using a host name, for example myHost.org. Even if these applications do not have a fixed
IP address and the host name is not registered. If, for example, you register a SCALANCE
device for a DynDNS service, you can reach the device from the external network using a
host name, for example SCALANCE.dyndns.org.
1.3.5

Power over Ethernet (PoE)

Power supply via Ethernet cables
In the IEEE 802.3af/at standard, the option of supplying devices with direct current was
standardized. To achieve this, either the wire pairs of the network cable not used for data
transfer are used or the supply voltage is modulated onto the data lines (phantom power).
The supply voltage and the load specified in the 802.3af standard differs from the 802.3at
standard. The standards are abbreviated as PoE or PoE+.
The following voltages or power are available:
Table 1- 3 PoE parameters
Characteristic
Power available on PDs - powered devices
Maximum power output of the power sourc-
ing equipment (PSE)
Voltage range on the power sourcing
equipment (PSE)
Voltage range on the end device (PD)
Maximum current flow
Maximum cable resistance
Industrial Ethernet
System Manual, 09/2019, C79000-G8976-C242-10
Basics of communication with Industrial Ethernet
802.3af (also 802.3at type 1 or PoE)
12.95 W
15.40 W
44.0-57.0 V
37.0-57.0 V
350 mA
20 Ω (category 3)
1.3 Technologies of Industrial Ethernet
802.3at Type 2 (also PoE+)
25.50 W
34.20 W
50.0-57.0 V
42.5–57.0 V
600 mA per node
12.5 Ω (category 5)
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