10771
10
COL:
Two collision LEDs one for each traffic domain, 10 and 100Mbps
Blinks intermittently when a collision occurs
ACT:
Activity (send or receive) for each traffic domain, 10 and 100Mbps
100:
Speed LED, per port. Flashing when auto-negotiating (no LINK)
ON when the port speed is 100Mbps, OFF for 10Mbps
LK:
LINK LED, per port. Illuminates GREEN when a working connection is established
between the port and the attached device.
RX:
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.
3.4 Up-link switch
The hubs have one up-link switch, used with port 8. This allows
repeater-to-repeater connection without a special cross-over cable. It
works the same for 10Mbps or 100Mbps connections.
Set the slide switch to the “=” position for twisted pair cabling from
the port to a user device, or to the “X” position for cross-over or up-
link segment connections from the port to a repeater or hub. Verify
proper switch position by noting the ports LINK LED status, which is
illuminated when a proper link is made.
4.0 Troubleshooting
All Ethernet products are designed to provide reliability and consistent high performance
in all network environments. The installation of a dual-speed hub is a simple procedure
(see installation); operation is easy and is described in section 3.0 Operation.
Should problems develop during installation or operation, this section should help to
locate, identify and correct such problems. Please follow the suggestions listed below prior
to contacting
RS
. However, if you are unsure of any procedure described in this section, or
if the hub is not operating as expected, do not attempt to repair or alter the unit. Contact
the
RS
Technical helpline for assistance.
4.1 Before calling for assistance
1. If difficulty is encountered when installing or operating the hubs refer to section 2.0
Installing and section 3.0, Operation. Check to make sure that the other devices of the net-
work are operating.
2. Check the cables and connectors to ensure that they have been properly connected and
the cables/wires have not been crimped or in some way impaired during installing.
3. Ensure the ac power cord is plugged into a functioning electrical outlet. Make sure that
the ac power cord is properly plugged into the hub. Use the PWR LED to verify the unit
is receiving proper power.
4. If the problem is isolated to a network device other than the dual-speed hub it is rec-
ommended that the problem device be replaced with a known good device. Verify
whether or not the problem is corrected. If not go to step 5 below. if the problem is cor-
rected, the hub and its associated cables are functioning properly.
5. If the problem continues after completing step 4 above, contact the
RS
technical helpline,
on Tel: 01536 402888 or fax: 01536 401588.
10771
3
traffic. The 10Mbps users share the 10Mbps domains bandwidth and the 100Mbps users
share the 100Mbps domains bandwidth. Functionally, the hubs operates as two hubs - one
hub at 10Mbps and one hub at 100Mbps - in one unit.
Any port can connect into either the 10Mbps or the 100Mpbs traffic domain, and can also
change from one traffic domain to the other at any time without affecting the speed of other
ports. The automatic per-port speed-sensing is continuous, allowing the connected
devices to change speed at any time without impairing the operation of the other ports and
connected devices.
As the dual-speed units are stacked, the two shared traffic domains automatically expand
to support all of the ports in the stack. Any combination of 10Mbps and 100Mbps ports, up
to the maximum of 32 ports (4units) in one stack, can be in use at any time.
The DS8-B model includes an internal bridge or switch module which interconnects the
10Mbps and the 100Mbps traffic domains. This enables all users on a DS8-B hub or a
stack, whether 10Mbps or 100Mbps, to talk to each other. The internal switch of the DS8-
B filters and selectively forwards packets between the 10Mbps and the 100Mbps domains,
maintaining peak performance in each domain unaffected by local traffic in the outer
domain. The internal bridge is self-learning, with large address table capacity for up to 8K
node addresses. As networked nodes are added or removed or move from one speed
domain to the other, the hubs internal switch automatically keeps track.
Only one DS8-B unit is needed to support a stack. Additional 8-port units of the DS8-A
hubs can be added to the stack, up to the 4-unit stack maximum. In a stack, the DS8-B unit
can be in any stack position.
DS8-A units can also be used without a DS8-B, whereupon they will function as dual-speed
stackable hubs. This could be desired if there is an external non-sensing switch available
to interconnect the two speed domains, or if only 100Mbps devices are connected and the
10Mbps domain is unused (or vice-versa), or if dual-speed operation with two unconnect-
ed and unco-ordinated domains is needed for the application.
Each hubs has its own internal power supply, and is easily added to an existing 10 or
100Mbps network. the dual-speed hubs are suitable for wiring closet shelf, table-top or
vertical mounting.
The hub chassis houses one main PC board, a bridge module daughter-board in the
model DS8-B, and an internal power supply unit. The front side of the chassis has eight RJ-
45 twisted-pair ports and one cascading(UP-LINK) switch for port 8.
LEDs to indicate operating status are on the front left side. There are power (PWR) and
bridge-inside (BR) indicators for the unit. There are activity (ACT) and collision (COL) indi-
cators for each of the 10Mbps and 100Mbps domains, set into a “square” arrangement, for
visual indication of the operating status of each domain and there are link (LK), receive (RX)
and speed (100) indicators for each port. The unit has a cooling fan on the bottom left cor-
ner which sends warm air out away from the unit to the rear. Stacking cables connect in the
rear.
The AC power cord connector, a universal recessed male IEC type connector is situated
on the rear of the chassis. The internal power supply is auto-ranging for AC power input of
110 to 230Vac. 50 - 60 Hz.
UP LINK
