Lantronix MINI FAST LFH4-M User manual

LFH4-M/LFH8-M
Mini Fast Hubs
Installation Guide

Table of Contents
CHAPTER 1. Introduction
1.1 Product Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Product Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
CHAPTER 2. Using the LFH Hub
2.1 Packing Checklist. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 Planning 100BASE-TX Networks . . . . . . . . . . . . . . . . . . . . . 5
2.3 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.4 Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.5 Connecting LFH Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
CHAPTER 3. LED Indicators
3.1 Power LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.2 Collision LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.3 Link/Activity LEDs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.4 Partition LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.5 System Status LEDs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Limited Warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Declaration of Conformity . . . . . . . . . . . . . . . . . . . . . . . 15
1

CHAPTER 1 Introduction
1.1 Product Introduction
Congratulations on your purchase of the LFH 4-port or 8-port Mini Fast
Ethernet Hub! The LFH4-M and LFH8-M are designed to give you the
ultimate in flexibility, ease-of-use, and reliability.
The LFH4-M and LFH8-M Mini Fast Ethernet Hubs are 100BASE-TX
multiport Class II repeaters for use with networks using Unshielded
Twisted Pair (UTP) category 5 cable or Shielded Twisted Pair (STP)
cable. The LFH hubs are simple to install, and Link/Activity, Partition,
and Collision LEDs provide convenient monitoring of the status of the
hub and of each port. For additional expansion, the hub offers an
Uplink port that makes it easy to cascade the hub to another Fast
Ethernet hub.
The LFH4-M/LFR8-M hubs can be placed on a tabletop or wall-
mounted, and provide the ideal solution for small to medium
100BASE-TX Fast Ethernet networks. The LFH hubs are designed
to comply with the IEEE 802.3u Fast Ethernet standard.
To insure network reliability, the LFH4-M and LFH8-M monitor each
port for signal quality and automatically disconnect stations transmit-
ting noise, reconnecting them when the problem is resolved. Data
packets that exceed the maximum legal length for IEEE802.3 Ethernet
packets are automatically truncated. This prevents a device from
blocking the network by transmitting a continuous data stream or
excessively long packet. The LFH hubs completely retime and restore
full-amplitude waveforms for each retransmitted packet. A full-length
preamble is also generated, insuring packet integrity across the
network.
2

1.2 Features
▼The LFH4-M provides four 100BASE-TX ports and the LFH8-M
provides eight 100BASE-TX ports for Fast Ethernet connectivity
▼The LFH4-M/LFH8-M comply with the IEEE 802.3u Fast Ethernet
standard
▼Supports Category 5 Unshielded Twisted Pair (UTP) or Shielded
Twisted Pair (STP) cable
▼An Uplink port on the front panel enables the LFH4-M/LFH8-M to
be connected to another 100BASE-TX hub using a straight-through
cable
▼Performs preamble regeneration, signal retiming and restoration,
extension of fragmented packets, automatic partitioning, and jabber
truncation
▼Global Power and Collision LEDs and individual Partition and
Link/Activity LEDs indicate system status
▼Comes with external AC/DC power supply (120VAC or 220VAC)
▼FCC Class A, CE, UL, CUL, TUV certifications
▼Five year limited warranty
3

1.3 Product Specifications
Standards IEEE 803.3u 100BASE-TX Ethernet
Network Media 100BASE-TX Unshielded Twisted Pair cabling
(Category 5 UTP)
Max. Lengths 100 meter hub-to-station connection
5 meter hub-to-hub connection
Connectors 8/16 RJ45 connectors, one crossover ÒUplinkÓ port
LED indicators Power, Collision, Partition, Link/Activity
Dimensions 221mm x 111mm x 26mm (L x W x H)
Environment Temperature: Operating: 0¡C to 40¡C
Storage: -20¡C to 70¡C
Humidity Operating: 10 to 80%RH
Storage: 5 to 90%RH
Certifications FCC Class A, CE, UL, CUL, TUV
Warranty 5-year limited
4

5
Chapter 2 Using the LFH Hub
2.1 Packing Checklist
Your LFH package should contain the following:
✓An LFH4-M or LFH8-M Mini Fast Hub
✓Mounting brackets and screws
✓External AC/DC power adapter (120VAC or 220VAC)
✓Installation Guide
If any of these items are missing, contact your dealer immediately.
2.2 Planning 100BASE-TX Networks
100BASE-TX networks need to be planned out slightly differently from
10BASE-T networks, because new hubs and new wiring configurations
are necessary. (10BASE-T hubs are incapable of sending or receiving data
at 100Mbps, so a 100BASE-TX network requires a 100BASE-TX hub.)
100BASE-TX supports a maximum length of 100 meters from a network
station to a hub. The total network diameter (the maximum cable
distance between any two stations on the network) is 205 meters for
100BASE-TX, as opposed to 500 meters for 10Mbps Ethernet. Because
100BASE-TX sends signals ten times faster than 10BASE-T, the collision
window (the time during which the network can detect a collision
between packets) is reduced to one-tenth the duration of the 10BASE-T
collision window, making the maximum network diameter smaller.
In a repeater environment, 100BASE-TX only allows a single layer of
cascaded hubs.
Switching hubs, such as LantronixÕs LSW8FA, may increase the
network diameter for 100BASE-TX networks by buffering data packets.
Each port can be connected to a separate LAN segment, each with a
maximum diameter of 205 meters, thereby increasing the overall
100BASE-TX network diameter.

6
Not only does 100BASE-TX have a different data transmission scheme,
it also has different cabling requirements. As previously noted,
100BASE-TX requires data-grade (Category 5) UTP cable.
Some installations have Category 5 cabling but do not have wall outlets
and wiring closet punch-down blocks that meet Category 5 require-
ments. 100BASE-TX requires that all wiring and accessories meet
EIA/TIA 568B specifications for proper operation. When wiring a
100BASE-TX network, make sure that the entire cable plant meets
specifications.
Figure 2-1 LFH4-M 100BASE-TX Network Example
2.3 Installation
The LFH Mini Fast Ethernet Hubs are easy to install and require no
special training. You should, however, read the following instructions
carefully before proceeding to install your hub. Figures 2-2 and 2-3
show the layout of the front panels.
4321
4 321
PWR
COL
PARTITION
LINK/ACT
PORT NO.
Uplink 4321
4 321
PWR
COL
PARTITION
LINK/ACT
PORT NO.
Uplink
LFH4-M LFH4-M

Figure 2-2 LFH4-M Front Panel
Figure 2-3 LFH8-M Front Panel
The LFH Mini Fast Ethernet Hubs were designed for easy Òplug and
playÓ installation. Before you connect the LFH to other devices, there
are several issues you should keep in mind:
▼When connecting the LFH to a workstation using unshielded
twisted pair cable, you must make sure that the cable length is not
greater than 100 meters
▼When you connect two LFH hubs, you must make sure that the link
between them is not longer than 5 meters
▼Network cable segments can be connected to, or disconnected from
the hub while the power is on. Plugging in or removing network
cables while your hub is operating will not interrupt the operation
of the hub
▼When placing your LFH hub, you need to avoid dusty locations and
electromagnetically noisy areas
7
4321
4 321
PWR
COL
PARTITION
LINK/ACT
PORT NO.
LFH4-M
Uplink
4321
4 321
PWR
COL
PARTITION
LINK/ACT
PORT NO.
LFH4-M
Uplink

2.4 Mounting
Your LFH4-M or LFH8-M hub is delivered with a mounting bracket.
The LFH hub can be mounted to the wall or to the surface of a counter-
top by using the bracket and hanging the LFH hub on the wall using
the keyholes provided on the bottom of the hub.
If mounting the LFH hub is not your preference, you may choose to
place the LFH hub on a table or wiring closet shelf. Use the four self-
adhesive rubber feet, which are provided with the hub for cushioning
purposes. Place them on the four corners of the bottom surface of the
hub.
8

2.5 Connecting the LFH Hub
Use the following procedures to connect 100BASE-TX network devices
to the hub:
NOTE: If the Uplink Port is being utilized on the LFH hub, the adja-
cent Port may not be used. Conversely, if that Port is being utilized, the
Uplink Port may not be connected.
The following table describes the two cable types:
Make sure that the length of the straight-through cable between the
LFH hub and the other device does not exceed 100 meters, including all
patch cables and cross-connect wires.
Make sure that the length of the straight-through cable between two
hubs does not exceed 5 meters.
9
LFH4-M Ports 1-4 Uplink Port
LFH8-M Ports 1-8
PC, Workstation S C
Server S C
Hub, Switch port C S
Hub, Switch uplink port S C
S = Straight Cable C = Crossover cable
Straight cable Crossover cable
Pin 1 TD+ RD+
Pin 2 TD- RD-
Pin 3 RD+ TD+
Pin 6 RD- TD-