Connecting Ethernet Ports - ICP DAS USA MSM-508 User Manual

Industrial Ethernet Layer 2 Managed Switch User Manual

Connecting Ethernet Ports

Managed Switch includes all RJ-45 ports with automatic MDI/MDI-X crossover, and
automatic 10/100Mbps data rate sensing for 10Base-T or 100Base-TX connections.
Automatic MDI/MDI-X crossover allows you to connect to other switches, hubs, or
workstations, without regard to using straight-through or crossover cabling. The following
figures depict the schematic diagram of straight-through and crossover cabling. Note that
crossover cables simply cross-connect the transmit lines at each end to the receive lines
at the opposite end.
Straight-through Cabling Schematic
Note that Ethernet cables use pins 1, 2, 3, and 6 of an 8-pin RJ45 connector. The signals
of these pins are converted by the automatic MDI-X function, as shown in the table below:
Connect one side of an Ethernet cable into any switch port and connect the other side to
your attached device. The green LNK LED will light up when the cable is correctly
connected. Always make sure that the cables between the switches and attached devices
(e.g. switch, hub, or workstation) are less than 100 meters (328 feet).
Two switches are now up-linked together. If we change the up-link port manually at this
time, the MAC address table will change as well. After the MAC address table changes,
then the data can be transmitted between these two switches. This period of time is
called the MAC address table aging time. The switch's default aging time is 5 minutes,
which means that if you manually change the up-link port, you will need to wait up to 5
minutes before the data can be sent. If the aging time is too short, the MAC address table
will constantly refresh, resulting in excess consumption of switch computing resources.
For this reason, a longer aging time is recommended.
Crossover Cabling Schematic
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