4
1. Functional description
The 10/100BASE-T(X) ports of an OCTOPUS
5TX-EEC represent a terminal connection
for the connected LAN segment. You can
connect single devices or complete network
segments.
1.1 FRAME SWITCHING FUNCTIONS
Store and Forward
All data received by the OCTOPUS 5TX-EEC
from the system bus or at the ports are sto-
red and checked for validity. Invalid and
defective frames (> 1.522 byte or CRC error)
as well as fragments (< 64 byte) are discar-
ded. The OCTOPUS 5TX-EEC forwards the
valid frames.
Multi address capability
An OCTOPUS 5TX-EEC learns all source
addresses per port. Only packets with
– unknown addresses
– addresses learnt at this port
– a multi/broadcast address
in the destination address field are sent to
this port.
An OCTOPUS 5TX-EEC learns up to 1,000
addresses. This becomes necessary if more
than one terminal device is connected to
one or more ports. In this way several inde-
pendent subnetworks can be connected to
an OCTOPUS 5TX-EEC.
Learnt addresses
An OCTOPUS 5TX-EEC monitors the age of
the learned addresses. The OCTOPUS 5TX-
EEC deletes address entries from the
address table which exceed a certain age
(300 seconds).
Note:
Restarting deletes the learned
address entries.
Tagging
(IEEE 802.1Q)
The IEEE 802.1 Q standard designates the
VLAN tag to be included in a MAC data
frame for the VLAN and prioritizing func-
tions. The VLAN tag consists of 4 bytes (2
bytes tag protocol identifier TPID, 2 bytes
tag control information TCI). It is inserted
between the source address field and the
type field. Data packets with VLAN tag are
transmitted unchanged by the OCTOPUS
5TX-EEC.
Quality of Service, IP-based (QoS)
Note:
Exclusively the device with the order
number 942 052-001 offers this function.
The device assigns IP packets according to
a DSCP value to different traffic classes.
This function is hard-coded.
DSCP means DiffServ-Codepoint. This is a
field in the IP header which markes the indi-
vidual IP packets according to traffic clas-
ses.
The device supports 2 traffic classes:
It assigns packets with DSCP values ranging
from 0 to 23 to the traffic class 0 (low priori-
ty) and packets with values ranging from 24
to 63 to traffic class 1 (high priority).
The device transmits the packets according
to the Strict Priority rule:
First, the device transmits all high priority-
packets. When there are no high priority
packets left, the device starts transmitting
the packets with low priority.
1.2 SPECIFIC FUNCTIONS OF THE
TP/TX INTERFACE
Link control
The OCTOPUS 5TX-EEC monitors the
connected TP line segments for short-circuit
or interrupt using regular link test pulses in
accordance with IEEE standard 802.3
10BASE-T/ 100BASETX. The OCTOPUS 5TX-
EEC does not transmit any data to a TP seg-
ment from which it does not receive a link
test pulse.
Note:
A non-occupied interface is assessed
as a line interrupt. The TP line to terminal
equipment which is switched off is likewise
assessed as a line interrupt as the de-
energised bus coupler cannot transmit link
test pulses.
Auto polarity exchange
If the receive line pair is incorrectly connec-
ted (RD+ and RD- switched) polarity is auto-
matically reversed.
Autonegotiation
Autonegotiation is a procedure in which the
switch automatically selects the operating
mode of its 10/100 RJ-45 ports. When a
connection is set up for the first time, the
switch detects the speed (10 or 100 Mbit/s)
and the transmission mode of the connec-
ted network (half duplex or full duplex).
Autocrossing
The OCTOPUS 5TX-EEC detects the trans-
mit and receive pairs (MDI, MDI-X). The
OCTOPUS 5TX-EEC automatically configu-
res its port for the correct transmit and
receive pins. Consequently it does not mat-
ter whether you connect devices using a
cross-over or straight cable.
1.3 FURTHER FUNCTIONS
AND FEATURES
Reset
The OCTOPUS 5TX-EEC will be reset by the
following action:
– input voltages fall below a threshold
After a reset the following action is carried
through:
– initialization
1.4 DISPLAY ELEMENTS
Equipment status
These LEDs provide information about
statuses which affect the function of the
entire OCTOPUS 5TX-EEC.
P – Power
– lit green:
– supply voltage present
Port Status
These LEDs display port-related
information.
DA/STAT 1 to 5 – Data, Link status
– not lit:
– no valid link
– lit green:
– valid link
– flashes green: – receiving data
1.5 INTERFACES
10/100 Mbit/s connection (TP port)
M12 socket (4-pin)
Five 10/100 Mbit/s ports (4-pin shielded M12
socket with D coding) allow the connection
of data terminal equipment or independent
network segments conforming to the IEEE
802.3 100BASE-TX / 10BASE-T standard.
These ports support auto negotiation and
the auto polarity function.
The shielding of the twisted pair wires
which can be connected must be grounded
on the plug housing of the M12 connector.
– Pin configuration
of the M12 socket:
– pin 1: TD+ Transmit Data +
– pin 2: RD+ Receive Data +
– pin 3: TD- Transmit Data -
– pin 4: RD- Receive Data -
– housing:
shield
Fig. 3: Pin configuration of an TP/TX
interface (M12 socket)
Power supply connector
M12 connector (5-pin)
The power for the OCTOPUS 5TX-EEC is
supplied via a 5-pin M12 connector (A
coding). Typically, the supply voltage is
+24 V DC. It is electrically isolated from the
function
ground.
– Pin assignment
of the M12 connector:
– pin 1:
input v
– pin 2:
not assigned
– pin 3:
input voltage -
– pin 4:
not assigned
– pin 5:
function ground
Fig. 4: Pin assignment of the M12 connector
(power supply connector)
z
Warning!
The devices are designed for opera-
tion with a safety extra-low voltage.
Thus, they may only be connected
to the supply voltage connections
with PELV circuits or alternatively
SELV circuits with the voltage
restrictions in accordance with
IEC/EN 60950-1.
"
!
#
Fig. 2: Overview display elements and inter-
faces of the OCTOPUS 5TX-EEC
OCTOPUS 5TX
DA/STAT
DA/STAT
DA/STAT
DA/STAT
P
DA/STAT
Five 4-pi
n
M12 sockets
(twisted pair ports 1 to 5)
5-pi
n
M12 co
nn
ector
(power supply
co
nn
ector)
LED display
Power
LED display eleme
n
ts
per port
