RS DS80 Manual

Issued 03/1999 V10830
331-6803
Table of Contents
1.0 Introduction ______________________________________2
1.1 Inspecting the Package and Product ________________________2
1.2 Product Description ______________________________________2
1.2.1 DS80 chassis __________________________________________2
1.2.2 10/100 Speed Auto-sensing________________________________2
1.3 Bridge logic between the 10Mb and 100Mb Domains____________2
1.4 Up-link Port for Cascading ________________________________2
1.5 Features and Benefits ____________________________________2
1.6 Applications ____________________________________________3
2.0 Installation ________________________________________3
2.1 Locating DS80 Dual-Speed Hubs __________________________3
2.1.1 Table top or Shelf Mounting________________________________3
2.1.2 Wall (or Vertical Surface) Mounting __________________________3
2.2 Connecting Ethernet Media ________________________________3
2.2.1 Connecting Twisted Pair (RJ-45, CAT 3, CAT 5)________________3
2.2.2 100Mb Collision Domain Limits, Cable Distances, PDV Calculations3
2.2.3 Connecting to NICs which support Auto-Negotiation ____________4
2.3 Powering the DS80 ______________________________________4
2.4 Cooling the DS80________________________________________4
3.0 Operation______________________________________________4
3.1 Dual-Speed Functionality__________________________________4
3.2 Auto-negotiation and speed-sensing ________________________5
3.3 LEDs__________________________________________________5
3.4 Up-link Port ____________________________________________5
4.0 Troubleshooting __________________________________5
4.1 Before Calling for Assistance ______________________________5
5.0 Technical Specifications ____________________________5
RS Stock No.
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RS DS80 Dual Speed Hub
Instruction Leaflet
3
2
14
Two cascaded DS80 hubs
A. 100m Cat. 5 cables to user devices
B. 100m Cat. 5 cables to user devices
C. Cat. 5 cable for cascading
DS80 adds a new 100Mbps
domain to existing 10Mbps
network
A. Server
B. Users
C. Print Server
D. Router
E. 10Mb Hub
DS80 connects combinations of
10Mbps and 100Mbps network
devices
A. Server
B. Users
C. Print Server
D. Router
Multiple cascaded 100Mb Magnum DS80 hubs
All user devices connected via Cat. 5 twisted pair cable of up
to 75m length
A. 2 metre Cat. 5 cable for cascading

2
1.0 Introduction
1.1 Inspecting the Package and Product
Inspect the contents of this package for any signs of damage and
ensure that the items listed below are included.
This package should contain:
1 Magnum DS80 Dual-Speed Hub unit
1 External Power Supply
1 Set of metal clips and screws for secure shelf or wall-mounting
1 Installation and User Guide
1.2 Product Description
DS80 Dual-Speed hubs have eight RJ-45 ports, each 10/100Mbps
auto-sensing. Each port can independently identify (via IEEE 802.3u
auto-sensing) and accept either 100Mbps or 10Mbps Ethernet signals,
adapting to match the best speed of the connected device. There are
two internal traffic domains in DS80 hubs, one for the 100Mbps traffic
and one for the 10Mbps traffic. The 100Mbps users share the 100Mbps
domain’s bandwidth and the 10Mbps users share the 10Mbps domain’s
bandwidth.
The DS80 includes an internal bridge or switch I.C. (Integrated Circuit)
which interconnects the 10Mbps and the 100Mpbs traffic domains. This
enables all users on a DS80 hub, whether 100Mbps or 10Mbps, to talk
to each other. The internal switch of the DS80 filters and selectively
forwards packets between the 10Mbps and the 100Mbps domains,
maintaining peak performance in each domain unaffected by local
traffic in the other domain.
The internal bridge is self-learning, with large address table capacity for
up to 1.8K node addresses.As networked nodes are added or removed
or moved from one speed domain to the other, the DS80’s internal
switch automatically keeps track.
Any DS80 port can connect into either the 100 or the 10Mbps 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.
1.2.1 DS80 Chassis
The DS80 chassis houses one main PC board with a bridge IC on
board, and an external power supply unit. The front side of the chassis
has eight RJ-45 twisted-pair ports and one cascading (Up-link or
Crossover) Port, on the right. LEDs to indicate operating status are on
the left front side. There are power (PWR) and collision (COL)
indicators for the unit. There are Link andActivity (LINK/ACT) indicators
for each of the 10Mbps and 100Mbps domains, set into an aligned
arrangement, for visual indication of the operating status of each port.
The unit has a small quiet cooling fan inside in the centre which sends
warm air out, through the 1/4” plenum space, away from the unit to the
rear.
The DC power plug connector or “jack” is in the right rear of the
chassis.
1.2.2 10/100 Speed Auto-sensing
All eight RJ-45 twisted pair ports support auto-sensing for speed,
independent of the other ports. Speed-sensing is performed by the
DS80’s electronics in accordance with the standards of the IEEE
802.3u auto-negotiation standard. If the connected device or node
indicates that it is capable of 100Mbps speed, then operation on that
port will be at 100Mbps. If the connected device does not positively
indicate that it is capable of 100Mbps speed, then the operation on that
DS80 port will be at 10Mbps. Of course, the hubs’ auto-negotiation
technique is only for 10/100 speed, and does not provide for for any full-
duplex operation.
The per-port 10/100Mbps Link/Activity LEDs on the front panel indicate
the result of auto-sensed speed detection, and the resulting
connectivity to either a 10Mbps or 100Mbps device. The 100Mbps LED
will illuminate (GREEN) when 100Mbps signals are detected; it will be
steady ON if no traffic and blinking ON when the port transmits and
receives data packets. Similarly, the 10 Mbps port will be on when a
10Mbps signal (or no reply to auto-negotiation) is detected, and will
blink if the linked port is transmitting and receiving packets.
1.3 Bridge logic between the 10Mbps and 100Mbps Domains
DS80’s contain a bridge chip (Integrated Circuit) to interconnect the two
traffic domains, filtering and selectively forwarding packets to allow only
necessary packets to cross between the domains. This enables all of
the users and nodes connected into either domain, whether 100Mbps
or 10Mbps, to communicate to each other, and it keeps local traffic on
one domain from consuming any of the bandwidth of the other domain.
The bridge operates in the store-and-forward mode, which filters out
bad packets and maintains optimum performance in both domains.
Packet forwarding delay is only 5µs (plus packet time), much less than
traditional store-and-forward bridge products, enabling DS80’s to
maintain high network performance. The bridge has 1.8K node address
capacity, suitable for use in medium-sized networks. Addresses are
self-learning so that filtering/forwarding of 10Mbps and of 100Mbps
packets is maintained correctly even when users move their
connection, or change speed, or power down.
1.4 Up-link Port for Cascading
The unit has an up-link Port located on the right-front side of the hub. It
enables the port’s cable to cascade to another shared hub or switching
hub port. Like all DS80 ports, this is a dual-speed port which will sense
the speed of the connected device. The up-link operates the same,
whether it is connected to either 100Mbps or 10Mbps devices.
When the up-link port is used to cascade two DS80 hubs, the auto-
sensing feature of the DS80 will cause the connecting link to operate at
100Mbps speed.
1.5 Features and Benefits
Supports 10 or 100Mbps network connections on each of eight
RJ-45 ports
DS80 Dual-Speed 10/100 hubs combine two logical hubs -- one at
10Mbps and one at 100Mbps -- in one physical box supporting two
traffic domains. Each port can operate at either 10 or 100Mbps,
independently of the other ports.
Auto-sensing for speed, 10 or 100Mb on each port
All ports support 10/100 auto-negotiation for speed, operating
separately on each port. Any mix of 10Mbps and 100Mbps users can
be connected to the ports. Speed-sensing is continuous, occurring at
LINK enable. Individual ports can change to 100Mbps or 10Mbps
speed at any time, adapting to any changes in the connected device’s
speed. Speed-sensing complies with IEEE 802.3u, providing
interoperability with other products.
An internal switch connects the 10 and 100Mb domains
The DS80 has an internal switch for filtering/forwarding traffic between
the 10 and 100Mbps domains, allowing all connected devices to
communicate to each other. High performance switching provides full
bandwidth in each domain, unaffected by local traffic on the other
domain.
Installation is “Plug and Play”, operation is transparent to
software
The DS80 operates as a hardware switch, only forwarding those
packets from each domain that are needed on the other domain.
Internal address tables are self-learning, enabling users to change port
connections or 10/100 domains without affecting operations. The
switch in the DS80 will not affect any standard software applications or
SNMP network management platforms.
Small enclosure enables use in offices and labs
The compact packaging of DS80’s allows them to be installed in offices
and labs, or virtually any location within reach of a standard AC wall
outlet. They come in a durable metal enclosure for table-top or wall-
mounting. They have an external AC to 5VDC power supply.
Fan cooled operation for high reliability
A small (6mm) quiet fan inside of the DS80 keeps the 100Mb
electronics cool for longer life without failure, and for operation in very
warm ambient temperatures.
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1.6 Applications
Example 1: A DS80 Personal Hub serves a small office with mixed
speed requirements. Some users operate at 100Mbps, and some users
and utility devices (such as print servers) run at 10Mbps. All share the
same hub, and communicate to each other via the bridge chip inside.
Any node can change speed at any time without affecting network
operation or impacting other users. (see fig 1.)
Example 2: Where there are existing 10Mbps hubs and users, they
can easily be cascaded into any port of the DS80. This allows simple
plug-and-play addition of 100Mbps ports to an existing 10Mbps network
without having to change it. Nodes that are capable of 100Mbps speed
can be moved to any DS80 dual-speed port, and will automatically
operate at the higher speed. The dual-speed ports on the DS80 can be
used for adding 100Mbps users or for accommodating existing high
performance users. The 100Mbps traffic does not use the bandwidth of
the 10Mbps domain, so overall performance of the network is
improved. (see fig 2.)
2.0 Installation
This chapter provides instructions for installing DS80 hubs.
2.1 Locating DS80 Dual-Speed Hubs
The location of a DS80 Dual-Speed Personal Hub is dependent on the
physical layout of the network. Typically the hub is placed where
combinations of the 10Mbps and 100Mbps network devices need to be
connected to communicate with each other. The sleek and compact
size of the unit allows it to be conveniently placed in an office or lab
area, and it can also be either shelf of wall-mounted. Metal wall-
mounting clips are included.
Locate an AC receptacle that is within six feet (2m) of the intended
DS80 site. The rugged metal case of the DS80 will normally protect it
from accidental damage in a lab or workplace setting. Maintain an open
view of the front to visually monitor the status LEDs. Place the unit in
an open area so that fan-driven cooling air can enter each side of the
unit and exit in the rear.
2.1.1 Table-Top or Shelf Mounting
The DS80 Dual-Speed Personal Hub can be easily mounted on a table-
top or any suitable horizontal surface, and has four rubber feet to
provide stability without scratching finished surfaces.
2.1.2 Wall (or Vertical Surface) Mounting
Each DS80 Personal Hub is shipped with two metal mounting brackets
(and screws) to allow the unit to be mounted in nearly any desired
orientation or position. The brackets are attached to the metal hub case
using one of the metal screws for each bracket and attaching to the
DS80 through the round hole of the bracket. A user-supplied screw
attaches the bracket to the mounting surface. It is recommended that
the brackets be attached to two opposite corners of the unit. When
properly attached, the brackets will extend slightly below the base of
the unit to allow clearance for the rubber feet.
2.2 Connecting Ethernet Media
The DS80 Dual-Speed Personal Hub can be connected to the following
two media types: 100BASE-TX and 10BASE-T. CAT 5 cables should be
used when making 100BASE-TX connections. When the ports are
used as 10BASE-T ports, CAT 3 may be used. In either case, the
maximum distance for unshielded twisted pair cabling is 100m (328ft).
Media IEEE Standard Connector
Twisted Pair (CAT 3) 10BASE-T RJ-45
Twisted Pair (CAT 5) 100BASE-TX RJ-45
Note: It is recommended that high quality CAT. 5 cables (which work
for both 10Mbps and 100Mbps) be used whenever possible in
order to provide flexibility in a mixed-speed network, since dual-
speed ports are auto-sensing for either 10 and 100Mbps.
Note that the speed auto-sensing function does not sense the
cable type.
2.2.1 Connecting Twisted Pair (RJ-45, CAT 3 or CAT 5, Unshielded
or shielded)
The following procedure describes how to connect a 10BASE-T or
100BASE-TX twisted pair segment to the RJ-45 port. The procedure is
the same for both unshielded and shielded twisted pair cables.
1. Using standard twisted pair media, insert either end of the cable with
an RJ-45 plug into the RJ-45 connector of the port. Note that, even
though the connector is shielded, either unshielded or shielded
cables and wiring may be used.
2. Connect the other end of the cable to the corresponding device.
3. Use the LINK LED to ensure proper connectivity by noting that the
LED will be illuminated when the unit is powered and proper
connection is established. If not, ensure that the cable is connected
properly and that the device on the other end is powered and is not
defective.
4. For Uplink Port, if the LINK LED is not illuminated, exchange the RJ-
45 wiring plug with uplink port which has a cross-over or up-link
connector for linking to another hub.
2.2.2. 100Mbps Collision Domain Limits, Cable Distances and PDV
Calculations
The 100Mbps Collision Domain Diameter is the length of the longest
path between any two devices in a single collision domain. A Collision
domain is defined as a cluster of network devices which are connected
by means of a repeater or repeaters such that no bridging or switching
devices are present between any two devices in the cluster. In order to
install an IEEE 802.3u complaint Fast Ethernet network, the collision
domain . . regardless of the actual network topology . . must be less
than 512 BT (Bit Times). Bit Times are related to media types as shown
in Table 1
Table 1. Worst case round-trip delay for Fast Ethernet media*
*Worst case delays taken from IEEE Std 802.3u-1995, actual delays may be less for
a particular cable.
Each Fast Ethernet device component also has an associated BT delay
which depends on the physical signaling system employed. Table 2.
shows each Fast Ethernet device component and the associated BT
delay. A “DTE” is an end node, such as a user station. Note that there
is only one DTE pair associated with any device-to-device path.
Table 2. Worst case round-trip delay for Fast Ethernet device
components*
*
Worst case delays taken from IEEE Std 802.3u-1995.
To determine whether a prospective 100Mb network topology adheres
to the collision domain diameter specification, the following formula
should be applied to the worst case path through the network. The
worst case path is the path between the two Fast Ethernet devices
(DTEs) which have the longest round-trip time.
Component Round-trip delay in Bit Times
(BT)
2 TX DTEs 100
2 FX DTEs 100
1 FX and 1 TX DTE 100
1 T4 and 1 TX or FX DTE 127
Class I Repeater 140
Class II Repeater with any 92**
combination of TX and ** Note, the delay is only 80 Bit Times
FX ports for the DS80, front-port-to-front-port.
Media Type Round-trip delay in
Bit Time per Metre (BT/m)
Fibre Optic 1.000
Shielded TP cable 1.112
Category 5 Cable 1.112
Category 3, 4 Cable 1.140
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PDV = (sum of cabling delays) + (sum of repeater delays) +
(DTE pair delay) + (safety margin)
PDV is the Path Value of the worst case path. For the network to
adhere to the IEEE standard, this value must be less than 512 BT.
The safety margin is specified in BT and may be a value between 0
and 5. This margin can be used to accommodate unexpected delays
such as extra long patch cable. A safety margin of about 2 to 4 BT is
recommended.
A typical example of a PDV calculation is shown below, and is
illustrated in Figure 3. Here, an integrator wishes to cascade the
100Mb collision domains of two DS80 Hubs (each having a PDV of
80 BT) for use with standard 100 meter Category 5 user cable
segments (i.e. from computer to hub), and needs to know how long
the inter-repeater Category 5 cable segment, used to cascade the
hubs, can be. The variable “X” represents the unknown maximum
cascade cable delay.
PDV = X+((111+111)+(80+80)+(100)+4) BT < 512 BT
512 > (X+486) BT
X < (512 - 486) BT, X < 28 BT
Twisted Pair cable length, TL < (28 BT) / (1.112 m/BT)
TL < 25 metres
=> 25m maximum total length for Category 5 inter-repeater
segment
Where 111 is the BT delay for 100m of Category 5 cable (1.112 BT/m),
80 is the BT delay for each DS80, 100 is the BT delay for the TX DTE
pair, and a safety margin of 4 was used.
The resulting value tells us that a Category 5 cable with a length of up
to 25 meters may be used to cascade the DS80s. Note that this inter-
repeater cable length may be increased by shortening the lengths of
the 100m hub-to-user cable segments.
It is also possible to cascade a group of up to eight DS80s (serving up
to 56 users with up to 75m twisted pair cables to each 100Mb user) by
using short inter-repeater cable segments. The following is an example
of how to calculate the maximum allowable cascade cable segment
length. An illustration of this example is shown in Figure 4, where the
hub-to-user cable lengths are up to 75 meters for Cat 5 twisted pair in
this situation. The variable ”X”, the maximum hub-to-hub cable delay, is
calculated as follows.
PDV = X+((100)+(80+80+80)+(83+83)+2) BT < 512 BT
512 > (X+508) BT, X < 4 BT
Twisted Pair user cable length, TL < (4 BT) / (1.112 m/BT)
TL < 3.6 metres for two hub-to-hub cascading cables, i.e.,
3.6/2m each
=> 2 metres (6ft.) length max. for each of the cascade
segments
In the above example, 83 is the BT delay for 75m of Category 5 cable
(1.112 BT/m), 80 is the Bit Time delay for each of the DS80 front ports,
100 is the BT delay for the DTE pair in the user stations, and 2 BT is
the safety margin applied.
Note that the cascading of multiple DS80 Dual-Speed hubs is a
capability beyond what industry standards normally permit, and is
different from what competitive 100Mb Class II hub products normally
allow. This additional cascading level and cable length is due to the
relatively shorter bit time (80 BT actually measured, port-to-port) delay
of the 100Mb domain of the DS80 vs. the industry standard delay of 92
BT for Classe II repeaters. The installation flexibility and network
growth potential is accordingly better with DS80s than with hubs that
merely meet the standard.
Table 3 shows maximum cable lengths for common network
configurations using industry standard Class II repeater PDV’s.
Calculations such as above should be performed using measured PDV
data supplied by the equipment manufacturer in important installations.
Table 3 Maximum segment lengths for common network
configurations
The configuration of the 100Mb domains of DS80 Dual-Speed hubs
using PDV limits does not affect the configuration of the 10Mb domains,
or vice-versa.
2.2.3 Connections to NICs which support Auto-Negotiation
The DS80 Dual-Speed Hub will function properly with NICs (Network
Interface Cards) which support Auto-Negotiation. The DS80 will
establish link with any NIC which can send and receive the Fast Link
Pulse (FLP) coding for the 100BASE-TX signaling system. When
connecting a NIC to the DS80, it may be necessary to reload the NIC
drivers on the user device if the NIC has been communicating with a
protocol other than 100BASE-TX (such as 10BASE-T.) When 100Mb
operation is agreed and in use, the 100Mb LINK/ACT LED is
illuminated, steady ON if no traffic or blinking when there is traffic.
2.3 Powering the DS80
The DS80 Personal Hub is provided with an external power supply, and
has a jack for the DC power cord in the rear. A lightweight DC power
cord for 5V, 3Amps is supplied with each unit. The small DC power cord
from the power supply plugs into the matching rear power jack of the
DS80. When the power is applied, the green PWR LED will illuminate.
2.4 Cooling the DS80
The DS80 is a fan-cooled unit for reduced component temperature
during operation, and longer lifetime with better reliability for the unit
accordingly. The DS80 is designed with a tiny and very quiet fan
situated in the centre of the unit that moves air in from the side vents,
across the electronic components, up into a 1/4”H plenum chamber,
and exhausts out the back. The unit is rated at 40°C (104°F) ambient.
When in operation, place the unit in an open area so that unobstructed
cooling air can enter each side of the unit and exit in the rear.
3.0 Operation
This chapter describes the function and operation of the DS80 hubs.
3.1.1 Dual-Speed Functionality
The DS80 handles the two different traffic domains separately. The
DS80 provides switched (bridged) connectivity between the Ethernet
(10Mbps) and Fast Ethernet (100Mbps) domains. It joins the two
network domains for unified operation, and filters/forwards packets in
both directions to maximize bandwidth utilization and performance.
DS80’s are hardware plug-and-play devices. There is no software set-
up to be done at installation or for maintenance. The functions of the
DS80’s are described in this manual.
Each time a packet is received on one domain of the bridge chip, the
decision is taken to either filter or forward the packet. Errored packets
are always filtered. For good packets, the filter and forward decisions
are made based on the destination address contained in each packet.
If the destination address is on the same domain from which the packet
originated, then it is filtered and not forwarded to the other domain. If
the destination address is not found to be a match in the address table
for the originating domain, then it is forwarded to the other domain. If it
is a new node address coming in which the switch did not previously
know about, it “learns” the new address and puts it in the correct port
address table.
Number Repeater Max. User Max. Iner- Notes
of Hubs Hop Count Segment Repeater
Lengths (m) (Cascade) Length
(m)
1 1 100.0 n.a. All ports TX
2 2 100.0 5.0 All ports TX
2 2 92.0 20.0 All ports TX
3+ 3 75.0 2.0 DS80, TX ports
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3.1.2 Address Learning (Address Table Maintenance)
The DS80 bridge chip is a state machine design which has a total
address table capacity of 1.8K addresses. With a large address table,
a DS80 can serve the needs of a medium-sized to large network. When
a new node-address packet comes into a port for the first time, then the
new source address is “learned” at the same time that the packet is
forwarded. After learning, subsequent packets from the same node
address are routinely processed. The address tables are flushed
periodically to update the network status and to purge any inactive
stations from the tables of both domains.
3.1.3 Throughput Increase
By selectively forwarding packets from each domain to the other
domain based on its switching (bridging) logic, the DS80 increases the
available bandwidth for the users on both sides of the network. It keeps
the local traffic on each side contained, preventing unnecessary
packets and bad packets from traveling to the other domain and using
up bandwidth needlessly over there. This results in more available
network bandwidth on both sides and a throughput increase for all
users on both domains.
3.1.4 Software Transparency
The DS80 Personal Hub’s need no software set-up and are transparent
to system and application software, including network management
software.
3.2 Auto-negotiation and speed-sensing
All eight RJ-45 ports independently support auto-negotiation for shared
10BASE-T and 100BASE-TX modes. Operation is according to the
IEEE 802.3u standard.
When an RJ-45 cable connection is made and each time when a LINK
is enabled, auto-negotiation takes place. The DS80 advertises it’s
capability for 10 or 100Mbps speed, and the device at the other end of
the cable should similarly advertise / respond and both sides will agree
to the speed being used. Depending upon the device connected, this
will result in agreement to operate at either 10Mbps or 100Mbps speed.
When the ‘10 M LINK/ACT’ LED is ON, either steady or blinking, the
port has auto-negotiated for 10Mbps operation. (If a DS80 port is
connected to a non-negotiating device, it will default to 10Mbps speed
and half-duplex mode, per the IEEE 802.3 standard). Similarly, when
the ‘100M LINK/ACT’ LED is lit, it means 100Mbps operation. Since
DS80’s are hubs, they always operate in the shared or half-duplex
mode on all ports.
3.3 LED’s
PWR: Illuminates GREEN, to indicate hub is receiving power.
COL: Collision LED, flashes ON when a collision occurs, otherwise, in
normal case it will be OFF.
10 M LINK/ACT: Steady ON for 10Mbps LINK with no traffic, Blinking
indicates 10Mbps packet activity.
100 M LINK/ACT: Steady ON for 100Mpbs LINK with no traffic, Blinking
indicates 100Mbps packet activity.
3.4 Up-link Port
DS80’s have one up-link port, for cross over, on the front of the hub.
The up-link (or cross-over) on the port allows its RJ-45 cable to connect
for cascading to another hub or switch port. This allows repeater-to-
repeater connections without a special cross-over cable. This port
works the same as regular ports for 10Mbps or 100Mbps auto-sensing
connections.
Cascaded connections may be operated at either 10 or 100Mbps
speed. The DS80 even supports cascaded connections of both
10Mbps and 100Mbps at the same time. . . on different ports. When
attaching a 10Mbps hub, the Ethernet configuration rules (hop count
limits, etc.) for 10Mbps domains are in effect. When the cascaded
connection is operated at 100Mbps speed, the Fast Ethernet
configuration rules (PDV limits, etc.) are in effect. Two DS80s cascaded
will auto-negotiate to operate the connection at 100Mbps.
4.0 Troubleshooting
The DS80 is designed to provide reliability and consistently high
performance in all network environments. The installation of a DS80
Dual-Speed Hub is a simple procedure (see Section 2.0, 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 your supplier. However,
if you are unsure of any procedure described in this section, or if the
DS80 hub is not operating as expected, do not attempt to repair or alter
the unit, contact the RS Technical Helpline.
4.1 Before Calling for Assistance
1. If difficulty is encountered when installing or operating the DS80
refer back to section 2.0, Installation and Section 3.0, Operation.
Check to make sure that the various other components of the
network are operable.
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 installation. (About 90% of network
downtime can be attributed to wiring and connector problems.)
3. Be certain that the AC power cord is plugged into a functioning
electrical outlet. Make sure that the AC power cord is properly
plugged into the DS80 unit. 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 DS80,
it is recommended 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 corrected, the DS80 and
its associated cables are functioning properly.
5. If the problem continues after completing Step 4 above, contact the
RS Technical Helpline Tel: [phone]
Fax: [phone]
5.0 Specifications
Technical Specifications
100 or 10Mbps per port, auto-sensing for speed. DS80 Personal Hubs
support two traffic domains, one at 100Mbps and one at 10Mbps, have
eight RJ-45 ports, and an up-link port for cascading to another hub.
Performance
When a port is operating at 100Mbps:
Data Rate: 100Mbps
PDV (Path Delay Value): 80BT, exceeds Class II
When a port is operating at 10Mbps:
Data Rate: 10Mbps
Partitioning: Enforced after 63 consecutive collisions
Auto-reconnect: Occurs after one packet of error-free reception
Network Standards
100Mb: Ethernet IEEE 802.3u, 100BASE-TX
10Mb: Ethernet IEEE 802.3, 10BASE-T
Auto-sensing for speed: IEEE 802.3u
Packet-Processing Between Domains (internal 10/100 switch or
bridge)
Filtering and Forwarding Rate from 100Mbps ports: 148,800 pps max.
Filtering and Forwarding Rate from 10Mbps ports: 14,880 pps max.
Processing type: Store and Forward
Auto-learning : 1.8K address table, shared for both traffic domains
Packet buffers: 256KB, dynamically shared on both domains
Latency (not including packet time): 100 to 10Mbps: 5µs
10 to 100Mbps: 5µs
CPU Type: State Machine
Maximum Ethernet Segment (or Domain) Lengths
10BASE-T (Unshielded twisted pair) - 100m (328ft)
100BASE-TX (CAT 5 UTP) - 100m (328ft)
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Operating Environment
Ambient Temperature: ______________32°F to 104°F (0°C to 40°C)
Storage Temperature: ____________-5°F to 160°F (-20°C to 70°C)
Ambient Relative Humidity: ________10% to 95% (non-condensing)
Power Supply (External)
Input: ________________________________200-250 Vac at 50Hz
Output: ____________________________________5VDC, 3Amps
Polarity: ______________________Centre positive, shell negative
Power Consumption: ______________8 watts typical, 10watts max.
Network Cable Connectors - for the eight RJ-45 shielded female ports
per hub
100Mbps: ____________________________Category 5 UTP/STP
10Mbps: ______________________________Category 3, 4, 5 UTP
(Note: speed-sensing does not sense cable type)
Up-Link
Up-link port for connecting to a central hub or another cascaded hub.
The up-link port is auto-sensing for speed, and the auto-negotiating up-
link port works the same at 10Mbps or 100Mbps.
Packaging
Enclosure: High strength metal. Metal mounting brackets included.
Suitable for wiring closet shelf, wall or desktop mounting.
Dimensions: ______________________219mm x 1001mm x 26mm.
Weight: ____________________________________________810g
Cooling method: __________________Fan cooled, internal @ 5cfm
LED Indicators
PWR: ________________________Steady On when power applied
COL: ____________________Collision LEDs, one each for 100Mb
and 10Mb speed domains
ACT:________________________Common packet activity indicator,
one for each traffic domain
LINK/ACT (10Mbps): Steady On when speed is 10Mbps, with no
traffic, blinking indicates 10Mpbs activity
LINK/ACT (100Mbps): Steady On when speed is 100Mbps, with no
traffic, blinking indicates 100Mbps activity
Agency Approvals
UL Listed (UL 1950), cUL, CE
Emissions: ______________________meets FCC Part 15, Class A
RS Components shall not be liable for any liability or loss of any nature (howsoever
caused and whether or not due to RS Components’ negligence) which may result
from the use of any information provided in RS technical literature.
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