Use port #1 (or ports 2 thru 24) for straight-through twisted pair cabling from
the 4K24 switched port to a user device, or the “1X” port for cross-over or up-link
segment connections from the first 4K24 port to a repeater or hub or switch. Verify
proper port connection by noting the port’s LINK/ACT status, which is illuminated
when a proper link is made, and is blinking when there is activity.
Note: Port # 1 and Port # 1X, both RJ45 ports, are logically one port. Only one of
these ports, either # 1 or # 1X, may be used at any one time
.
4.4
Auto-negotiation for RJ-45 (copper) ports
The 4K24 Switch’s RJ-45 copper ports are N-way auto-negotiation. There are 4
different speed and F/H modes selection depending on what the other device supports.
These are: (1) 100Mb full-duplex, (2) 100Mb half-duplex, (3) 10 Mb full-duplex and (4)
10 Mb half-duplex.
The auto-negotiation logic will attempt to operate in descending order and will
normally arrive at the highest order mode that both devices can support at that
time. (Since auto-negotiation is potentially an externally-controlled process, the original
“highest order mode” result can change at any time depending on network changes that
may occur). If the device at the other end is not an auto-negotiating device, the 4K24-
Switch’s RJ-45 ports will try to detect its idle signal to determine 10 or 100 speed, and
will default to half-duplex at that speed per the IEEE standard.
General information -
Auto-negotiation per-port for 802.3u-compliant switches occurs when:
the devices at both ends of the cable are capable of operation at either 10 Mb
or 100Mb speed and/or in full- or half-duplex mode, and can send/receive
auto-negotiation pulses, and . . .
-- when the second of the two connected devices is powered up*, i.e., when
LINK is established for a port, or
-- when LINK is re-established on a port after being lost temporarily.
•
NOTE
–
some NIC cards only auto-negotiate when the computer system that
they are in is powered up. These are exceptions to the “negotiate at LINK –
enabled” rule above, but may be occasionally encountered.
When operating in 100Mb half-duplex mode, cable distances and hop-counts may
be limited within that collision domain. The Path Delay Value (PDV) bit-times must
account for all devices and cable lengths within that domain. For RFL 3000 4K-Series
switched ports operating at 100Mb half-duplex, the bit time delay is 50BT.
