GarrettCom DS 880 User Manual

Page 27

Magnum DS880 Dual-Speed Stackable Hubs Installation and User Guide (05/01)

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4.3 Auto-negotiation and speed-sensing

All eight RJ-45 ports independently support auto-negotiation for shared

10BASE-T and 100BASE-TX modes. When the ‘100’ LED is flashing, it means that the

corresponding port is sending out auto-negotiation pluses out that port. When a connection is

made, the other device should respond and both sides should agree to the speed being

advertised. Depending upon the device connected, it will either advertise at 10Mb or 100Mb

speeds. Silence means the port defaults to 10Mb.

When the ‘100’ LED is steady ON, the port has auto-negotiated for 100Mb

operation and is processing packets at 100Mb/s, When it is OFF, it is at 10Mb/s. If a DS880

port is connected to a non-negotiating device, it will default to 10Mb speed. Since Magnum

DS880s are hubs, they always operate in the shared or half-duplex mode on all ports.

4.4 LED’s

PWR

: Illuminates GREEN to indicate AC power is applied to the unit.

BR :

Bridge Module LED-

ON when a bridge module is present in the unit (model DS880-B)

OFF when no bridge module is present ( model DS880-A)

COL

: Two collision LED’s, one for each traffic domain, 10 and 100Mb

Blinks

intermittently

when a collision occurs.

ACT

: Activity (Send or Receive) for each traffic domain, 10 and 100Mb

100

: Speed LED, per port. Flashing when auto-negotiating (No LINK)

Steady ON when the port speed is 100Mbp/s, OFF for 10Mbp/s

: LINK LED, per port. Illuminates GREEN when a working

connection is established between the port and the attached device.

: Activity LED, per port. Flashes GREEN to indicate that the port is

receiving data from the attached device, i.e., there is activity on the
port.

4.5

Up-link Switch

The Magnum DS880s have one up-link slide switch,

used with port 8. This allows repeater-to-repeater connections

without a special cross-over cable. It works the same for 10Mb

or 100Mb connections.

UP-LINK

Set the slide switch to the “=” position for twisted pair cabling from the DS880

port to a user device, or to the “X” position for cross-over or up-link segment connections

from the DS880 port to a repeater or hub. Verify proper switch position by noting the port’s

LINK LED status, which is illuminated when a proper link is made.