Siemens SIMATIC NET System Manual page 17

Fast Ethernet
The Fast Ethernet standard IEEE 802.3u is an expansion of the existing standard (IEEE
802.3). Fast Ethernet is based essentially on the classic Ethernet standard for twisted pair
cables.
Ethernet and Fast Ethernet have the following common features:
● the CSMA access method
● the glass fiber-optic cable used and category 5 twisted pair cables
Fast Ethernet includes the following expansions / modifications:
● Data transmission rate up to 100 Mbps
● Autosensing, automatic detection of the transmission rate
● Autonegotiation, automatic detection of the functionality of the interface of the partner
● Full duplex mode
● Auto polarity exchange, automatic adaptation of the polarity if the wires of a cable pair are
swapped over.
● MDI/MDIX autocrossover, prevents malfunctions if transmit and receive cables are
crossed over.
Gigabit Ethernet
Gigabit Ethernet is an expansion of the Ethernet specifications to increase the data
transmission rate to 1 Gbps or 10 Gbps.
The relevant standards are as follows:
● IEEE 802.3z for transfer via glass fiber
● IEEE 802.3ab for electrical cables.
The increase in the transmission speed is achieved not only by adaptation of the protocol but
also by using category 5e, 6, 6
interference.
Differences compared with PROFINET
PROFINET expands Industrial Ethernet with the following additional properties:
● Transmission mode and real-time response
It can be guaranteed that frames are transferred within a specified time.
● Determinism
The same conditions always lead to the same results and there are no undefined
statuses.
See also
Transmission procedures and real-time response (Page 23)
Fault tolerance and redundancy (Page 44)
Access Methods (Page 45)
Industrial Ethernet
System Manual, 09/2019, C79000-G8976-C242-10
Basics of communication with Industrial Ethernet
and 7 twisted pair cables that are particularly immune to
A
1.2 Industrial Ethernet
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