Basic Function Principles; Fig. 2 Socket Pin Assignment, 4-Pin M12 - Beckhoff CU2608 Documentation

Product overview
Socket pin assignment, 4-pin M12
Fig. 2: Socket pin assignment, 4-pin M12
2.2

Basic function principles

Store and Forward
The switch operates according to the store-and-forward principle. Frames that are faulty (CRC error), too
short (< 64 bytes) or too long (> 1536 bytes) are generally not passed on.
Address Memory
The switch learns the MAC addresses of the connected devices for each port. Only frames that have these
addresses, broadcast/or multi-cast addresses, or which have unknown addresses are passed on to this port.
Because the switch remembers more than 1000 addresses for each port, it is also suitable for connecting
entire network segments. After approx. 5 minutes (Aging Time) unused addresses are removed from the
memory – if required, they are re-learnt again later.
Throughput
The switch can pass through up to 148800 Ethernet frames per second (Wire Speed).
PoE - Power over Ethernet
The CU20xx, CU22xx and CU26xx switches do not support PoE according to IEEE 802.3; they do not reveal
themselves as PSE (power sourcing equipment) or PD (powered devices). Any PSE connected to the switch
must therefore not apply a voltage.
No provision is made in the standard for passive interconnection or distribution.
Jumbo Frames
Jumbo Frames are oversized Ethernet telegrams with a length of more than 1518 bytes. They are used in
applications that require very high data throughput, for example.
The CU2208 (from hardware version 01) supports Jumbo Frames up to 9720 bytes on all ports. Please note
the following:
• Jumbo Frames only supported by ports with Gbit link
• Jumbo Frames place high demands on internal data transmission. It is therefore necessary to assess
the data throughput that can be achieved through the CU2208 for each individual application. Under
full load no more than 2 ports can be used for Jumbo Frames at the same time.
Jumbo Frames are not subject to standardization. It is therefore necessary to verify that the frames used by
the application are supported by the CU2208.
8 Version: 2.0.0 CU2608