Transition Networks E-TBT-HB-1002 Manuale utente

24 Port 10BaseT Ethernet Hub

Model E-TBT-HB-1002

Users Manual

Manual #7306

Specifications

Warranty: 2 years

Power Supply: Internal Power Supply, Input AC 100 -

250 VAC, 47 - 63 Hz, 40W Max

Environment: 0 - 70˚C, 5% - 90% humidity non-con-

densing, 0 - 10,000 ft. altitude

Dimensions: Free standing (rack mount adapters

included) 19" W x 6.25" D x 3.4" H

Desk top - 17" W x 6.25" D x 3.4" H

Accessories: Rack mounting tabs included for stand-

ard 19" wall racks

Rubber feet for free standing

Safety Approvals: UL Listed

C-UL Approved (Canadian Safety)

Table of Contents

Introduction........................................................................ 1

About 10BaseT (twisted pair) Topology...........................1

24 port Ethernet Hub Options ......................................... 2

Redundancy Feature......................................................... 2

Using Shielded Twisted Pair Wire.....................................3

Hub Views........................................................................... 3

Hub Reset Switch............................................................... 3

LED's................................................................................... 4

Redundancy Switch........................................................... 4

Rules for Configuring Your Network................................ 4

Table 1.....................................................................13

Figure 7...................................................................14

Twisted pair wiring............................................................. 7

Figure 2.................................................................... 9

Optional Slide In Cards..................................................... 9

Figures 4-6.............................................................. 11

Troubleshooting your Installation...................................12

Fuse Information...............................................................15

Approved European Power Cord Set Information...15&16

FCC Statement.................................................................. 17

Canadian Statement......................................................... 17

Technical Support............................................................ 17

Specifications................................................................... 18

Rack Mounting Tabs.........................................................18

FCC Regulations

NOTE: This equipment has been tested and found to com-

ply with the limits for a Class A digital device, pursuant to

Part 15 of the FCC Rules. These limits are designed to pro-

vide reasonable protection against harmful interference

when the equipment is operated in a commercial environ-

ment. This equipment generates, uses, and can radiate

radio frequency energy and if not used in accordance with

the instruction manual, may cause harmful interference to

radio communications. Operation of this equipment in a res-

idential area is likely to cause harmful interference in which

case the user will be required to correct the interference at

his own cost.

Canadian Regulations

NOTE: This digital apparatus does not exceed the Class A

limits for radio noise for digital apparatus set out on the

Radio Interference Regulations of the Canadian Department

of Communications.

Technical Support

For more information about this product or other TRANSI-

TION Networks products, call your local TRANSITION

Networks distributor, or contact us by telephone at (612)

941-7600 or fax (612) 941-2322.

Trademarks

Ethernet is a registered trademark of Xerox Corporation.

TRANSITION Networks, Inc.

24 Port 10BaseT Ethernet Hub

Model E-TBT-HB-1002

Installation Manual

Introduction

The 24 port 10BaseT Ethernet hub, Model E-TBT-HB-1002,

is an Ethernet repeater that provides an economical and

efficient networking system. It is rack mountable and is

designed to meet the IEEE 802.3 10BaseT standards.

Several repeaters can be cascaded together via

thicknet/thinnet coaxial cable, fiber optic cable and/or twist-

ed pair cable to build a large Ethernet network. The 24 port

hub allows simple installation and expansion flexibility for

your future networking requirements.

About 10BaseT (twisted pair) Topology

The IEEE 802.3 10BaseT specification is defined as

Ethernet across twisted pair wire. This new technology for

Ethernet (across twisted pair wire) represents a step forward

in network cabling and management. Since 10BaseT uti-

lizes twisted pair wire, the cost of networking is considerably

less expensive than using coaxial cables. It is also much

easier to install since it uses RJ-45 modular connectors.

Ethernet thick and thin (coax) networks are designed in a

linear “bus” or “daisy chain” topology where 10BaseT (twist-

ed pair) networks are designed in a “star” type topology. In

a “star” topology the hub is located in the center of the con-

figuration, with the individual nodes connected to the hub,

spread out like spokes on a wheel. In a linear or “bus”

topology, if you disconnect a device or accidentally open a

Table 3: Approved European Power Cord Set Information

Alternate Markings

Surface Utilizing

Printed or Embossed black-red-yellow

Harmonization (thread length/mm)

Approval Organization Marking Black Red Yellow

Belgium: Comite Electro- CEBEC-HAR 10 30 10

technique Beige (CEBEC)

Verband Deutscher Elektro- VDE-HAR 30 10 10

techniker (VDE)e, V., Prufstelle

Technique de l'Electricite (UTE) UTE-HAR 30 30 10

Institute del Marchio Qualita IEMMEQU-HAR 10 30 50

British Approvals Service for BASEC-HAR 10 10 30

Electric Cables (BASEC)

N.V. tot Keuring van Electro- KEMA-KEUR-HAR 10 30 30

technische Matarialien (KEMA)

Svenska Elecktriska (SMEKO) SEMKO-HAR 10 10 50

Osterreichnischer Verband fur OVE-HAR 30 10 50

Electrotechnik (OVE)

Danmarks Elektriske (DEMKO) DEMKO-HAR 30 10 30

Materielkontroll

Institute for Industrial (IIRS) IIRS-HAR 30 30 50

Research and Standards

Norges Elektriske (NEMKO) NEMKO-HAR 10 10 70

Materielkontroll

National Standards Authority NSAI-HAR 30 30 50

of Ireland (NSAI)

you would inadvertently disconnect users from your network.

With a “star” topology this cannot happen, each node is iso-

lated from each other, making the network much easier to

control and manage. The 24 twisted pair ports are designed

for 24 or 26 AWG twisted pair cable (meeting IEEE stan-

dards).

About the TRANSITION Networks 24 port Ethernet Hub

The TRANSITION Networks Model E-TBT-HB-1002 hub is a

free standing or rack mountable multiport repeater with 24

modular RJ-45 connections. In addition, an AUI port (DB-15

connector) is provided for another Ethernet interface.

Included are two expansion slots for optional Slide In Cards;

providing coaxial cable, fiber optic and twisted pair Ethernet

connections.

*E-CX-SIC Coaxial cable interface slide in card

*E-FRL-SIC Fiber optic interface slide in card

*E-TBT-SIC Twisted pair interface slide in card

These optional cards allow extended interface capabilities;

providing greater flexibility for your network's present or

future needs.

Redundancy Feature

A special feature of the TRANSITION Networks 24 port hub

is the Redundancy feature that allows dual connections

when cascading hubs. This feature insures that if one line

fails between hubs, another line provides transmission auto-

matically. If both lines fail, a fault light on the front panel

indicates trouble. The Redundancy feature requires the

switch enabled (on side of the hub) and both optional Slide

in Card ports be utilized. Either twisted pair or fiber optic

The following are network topology constraints that apply to

10BaseT as well as mixed media networks containing

10BaseT segments.

1) Repeater sets are required for all segment interconnec-

tion.

2) MAUs that are part of repeater sets count towards the

maximum number of MAUs on a segment.

3) The transmission path permitted between any two DTEs

may consist of up to five segments: four repeater sets

(including optional AUIs), two MAUs and two AUIs.

4) When a network consists of four repeater sets and five

segments, up to three of the segments may be coax and the

remainder must be Link segments. When five segments are

present, each FOIRL Link segment should not exceed 500

meters.

5) When a network path consists of three repeater sets and

four segments, the maximum allowable length of the FOIRL

segments is 1000 meters each as specified.

Fuse Information and Approved European Power Cord

Sets

AC Inlet Fuse Information:

For installing new fuses, open the fuse cover using a small

blade screw driver or similar tool.

Warning:For continued protection against risk of

fire, replace only with the same type of fuse.

Note: For replacement of North American style

fuse, replace with 1/4 x 1 1/4 inch 250 V, 2 Amp,

UL listed fuse.

For European replacement style fuses, replace

with 5 x 20 mm, 250 Volt, 2 Amp fuses.

may be used. Note: Coax slide in card (E-CX-SIC) may

not be used for redundancy connection.

Shielded RJ-45 Connectors/Twisted pair wire

The 24 port hub is provided with shielded RJ-45 Modular

connectors to meet European requirements. To fully utilize

shielding capability, use AMP shielded male modular RJ-45

connectors; tying cable shield to the shielded connector.

You may use shielded or unshielded 24 or 26 AWG twisted

pair wire without loss of transmission distance. The maxi-

mum distance between the hub and a network device is 100

meters (330 feet). The use of flat cable (silver satin) patch

cables are not recommended and may affect the system’s

overall performance.

Power

123 56784

12 13

15 16 17

19 20

21 22

UnitI.D.

10BaseT Hub 1002

1315

2123

1416

2410

Link

RearSlot

Enabled

Fault

Power

123 56784

12 13

15 16 17

19 20

21 22

UnitI.D.

10BaseT Hub 1002

1315

2123

1416

2410

Link

RearSlot

Enabled

Fault

Power

123 56784

12 13

15 16 17

19 20

21 22

UnitI.D.

10BaseT Hub 1002

1315

2123

1416

2410

Link

RearSlot

Enabled

Fault

Power

123 56784

12 13

15 16 17

19 20

21 22

UnitI.D.

10BaseT Hub 1002

1315

2123

1416

2410

Link

RearSlot

Enabled

Fault

Power

123 56784

12 13

15 16 17

19 20

21 22

UnitI.D.

10BaseT Hub 1002

1315

2123

1416

2410

Link

RearSlot

Enabled

Fault

Power

123 56784

12 13

15 16 17

19 20

21 22

UnitI.D.

10BaseT Hub 1002

1315

2123

1416

2410

Link

RearSlot

Enabled

Fault

Power

123 56784

12 13

15 16 17

19 20

21 22

UnitI.D.

10BaseT Hub 1002

1315

2123

1416

2410

Link

RearSlot

Enabled

Fault

Power

123 56784

12 13

15 16 17

19 20

21 22

UnitI.D.

10BaseT Hub 1002

1315

2123

1416

2410

Link

RearSlot

Enabled

Fault

Power

123 56784

12 13

15 16 17

19 20

21 22

UnitI.D.

10BaseT Hub 1002

1315

2123

1416

2410

Link

RearSlot

Enabled

Fault

Power

123 56784

12 13

15 16 17

19 20

21 22

UnitI.D.

10BaseT Hub 1002

1315

2123

1416

2410

Link

RearSlot

Enabled

Fault

Power

123 56784

12 13

15 16 17

19 20

21 22

UnitI.D.

10BaseT Hub 1002

1315

2123

1416

2410

Link

RearSlot

Enabled

Fault

FIG 7: FIVE SEGMENT RULE

Model 1002 Hub Views: Figure 1

2A, 250V

Caution:

For continued protection against

risk of fire, replace only with same type and

rating of fuse. 250V, 2A

SIC SLOT 1 SIC SLOT 2

USE ONLY WITH

250V FUSES

DISCONNECT POWER

BEFORE REPLACING FUSES

AUI

Power

784

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Unit I.D.

10BaseT Hub 1002

1 3579

13 15

17 19

21 23

2468

14 16

18 20

2410

Link

Rear Slot

Enabled

Fault

24 PORT HUB FRONT VIEW

24 PORT HUB REAR VIEW

Reset Hub

Rear Port Configuration:

Normal AUI Operation

Redundancy Enabled

24 PORT HUB SIDE VIEW

Attention:

Couper le courant avant de

replacer le fusible

Hub Reset Switch

The Hub Reset switch is used if the hub locks up or a mal-

function occurs. This switch is located on the side of the

hub.

AUI (DB-15 female D-Sub) Connector

The AUI connector provides another port for connecting to a

network via a transceiver or for cascading hubs. NOTE:

Do not cascade hubs together with an AUI cable! If

attaching a transceiver through an AUI cable, use only IEEE

approved Ethernet AUI cables. Maximum distance for an

AUI cable is 50 meters (150’).

Rules For Configuring Your Network

Follow these rules when configuring your network:

* When connecting multiple hubs together on a backbone,

you can use the AUI port of your hub; utilizing a transceiver

(TN models E-CX-MC02, 03, 04 and 05) to attach to the

backbone. A thicknet or thinnet backbone will allow you to

run longer distances between hubs and provide better noise

immunity because the cable is shielded. In addition, fiber

Table 2

Media Maximum Maximum Minimum Maximum

Segment Number Segment Medium Medium

Type MAUs per Length Propagation Delay per

Segment (meters) Velocity* Segment

(nano/sec)

Coax

10Base5 100 500 0.77 c 2165

10Base2 30 185 0.65 c 950

Link

FOIRL 2 1000 0.66 c 5000

10BaseT 2 100*** 0.59 c 1000

AUI**1 DTE/MAU 50 0.65 c 257

*c = 3 x 10 to the 8th power, expressed in meters/second

**AUI connection is not a segment

*** Maximum segment length depends on the cable characteristics

Hub LED’s

The 24 port Ethernet hub provides Power, Link, Fault and

Rear Slot Enabled LED’s, for monitoring convenience.

Power is indicated after the unit is plugged into any AC out-

let (100-240 VAC, 50-60 Hz) and with the rear power switch

turned on. Link indicates the hub is receiving link pulses

from a 10BaseT compliant device. Fault LED indicates the

redundancy feature has failed and is not functioning. Rear

Slot Enabled indicates which optional slots are active when

the redundancy feature is utilized.

Redundancy Switch

The redundancy switch is also located on the hub’s side and

is used for the redundancy feature utilizing the optional slide

in cards. Both slots must be installed with any combination

of fiber optic or twisted pair slide in cards.

cable. Use only IEEE approved AUI cables. Check

the connections.

* The network interface card is improperly configured.

Refer to users manual; verify proper configuration.

* Another network device is disrupting communica-

tions of the device your are trying to bring on line.

Remove that device and troubleshoot the problem on

that line.

Integrating Ethernet IEEE 802.3 Compatible Hardware

This information provides guidelines for integrating 10BaseT

and non-10BaseT compatible hardware for use with the 24

port Ethernet hub in your network. The following table sum-

marizes the delays for the various network media segments.

optic connection between two hubs can be provided

through fiber optic transceivers (TN model E-FRL-MC01)

connected to the AUI port.

* Do not cascade hubs directly together with an AUI cable.

* When cascading hubs via twisted pair, a cross over cable

is required (see section on cascading hubs).

* Be sure your network configuration does not exceed the

maximum distance and MAU limitations set forth by the

10BaseT standards. Refer to IEEE 802.3 specifications or

check with a professional network installer.

* When connecting your network devices to the hub via

twisted pair cable, the maximum twisted pair length is 100

meters (330 feet) and is equal to one segment. Use a

straight through cable assembly.

* Choose a centrally located area for the hub installation.

Separate Data and Voice transmission lines. Use only a

dedicated cable, per device to prevent crosstalk. Utilize

level 4 cable or better.

* The text of this manual assumes that the reader is familiar

with network systems in general.

Choosing an Installation Location

The installation location you choose must have the following:

* An AC power outlet (100-240 VAC, 50-60 Hz) for the hub’s

power cord connection.

* Suitable rack space to mount the hub for proper ventilation.

Troubleshooting Your Installation

The first step after the wiring has been installed is to con-

nect two devices (such as the file server and a workstation)

to the hub to see if they will communicate with each other.

Use your operating system software to locate each device.

When you have verified that they communicate correctly,

you can continue to connect other network devices to the

hub.

If the two network devices do not communicate, or any addi-

tional device after the initial test, follow the procedures listed

below.

1) Check the LINK indication on the front panel. If not lit,

LINK has not been established.

2) Bypass the building wiring and test directly using test

cables between the hub, workstation and server.

3) Verify that the individual devices are Ethernet compatible

and can communicate with each other.

4) Examples of common internal wiring problems found:

* The internal (building or premise) wiring is not prop-

erly configured (punch down blocks, wall jacks, patch

cables).

* Flat or “silver satin”telephone wire used for patch

and line cords. These may have reverse pinning,

replace and use level 4 grade cable.

* The maximum distance from a hub to network

device cannot exceed 100 meters (330 feet).

5) Examples of common network problems:

* An environment within the requirements for the product as

described on page 18.

* The hub or twisted pair wiring IS NOT located close to any

sources of electrical noise (such as radio transmitters and

broadband amplifiers, motors, high power electrical lines,

unshielded data cables, and fluorescent light fixtures).

* The twisted pair cable does not run in the same conduit

with power lines or other data cables.

* Phone lines should be separated from data cables.

Utilizing Existing Twisted Pair Wiring

You may be able to use the existing twisted pair wiring in

your installation. Determine the following:

* Identify the manufacturer of the twisted pair wire installed

in the building(s). If identifiable, contact the manufacturer

(or distributor/installer) and have them send you the wire

specifications or have them determine if the cable meets the

10BaseT requirements listed on page 7.

* Make sure the cable run is in a star configuration and all of

the cables are run to a central location which is easily

accessible.

* In your central location, look at your punch down blocks

and bridging panels. Make sure the wiring used is not

“Straight or Flat telephone wire”. This must be replaced with

twisted pair wire.

* After you have determined that your cable meets the

requirements for 10BaseT, you may install an RJ-45 jack at

each location for a network device. FIG 6: HUB CASCADING VIA TRANSCEIVERS ON AUI

HUB CASCADING VIA FRONT CONNECTORS

FIG 4: HUB CASCADING VIA FRONT CONNECTORS

FIG 5: HUB CASCADING VIA SLIDE IN CARD

BNC "T" and terminator

required.

Make sure there are no double lines or branches punched

down together. The system may work for a while, but the

non-connected branch will act like an antenna (picking up

unwanted noise) and slow down the network. Eliminate any

branches.

Installing New Twisted Pair Wire

If the existing wire in your building(s) does not meet IEEE

802.3 specifications, you may want to install new wiring. If

you have a noisy (electrical noise) environment, you may

select shielded twisted pair wire. If shielded twisted pair

wire is used, the shield may be connected to chassis ground

through the shielded modular RJ-45 Amp connector (see

page 3).

Wiring Specifications

Twisted Pair Media

The cabling between nodes on the network must be twisted

pair cable. Shielded twisted pair is also available. The

physical characteristics must meet or exceed those set forth

by the IEEE 802.3 10BaseT specifications. Generally, Level

4 wire or better is recommended. The cable must have a

minimum of 2 pairs of twisted 22-26 AWG wire. “Flat or

Straight”wire is not recommended.

-Gauge 22 to 26 AWG

-Attenuation Less than 11.5 dB

between 5 and 10 MHz

-Differential Characteristic 85 to 110 Ω@ 10 MHz

Impedance

-Maximum Distance 100 Meters (330 Feet)*

Cascading Hubs

Ethernet hubs may be cascaded together to support larger

networks. When cascading the 24 port hub to another

Ethernet hub, a crossover cable is required (See page 9 for

pinning instructions). Also, when cascading via the optional

Slide In Card (E-TBT-SIC), or cascading through trans-

ceivers connected to AUI ports, a crossover cable is

required. Note: Do not cascade hubs via AUI ports with an

AUI cable.

FIG 3: SIC CARD INSTALLATION VIEW

Slide in Card Indicator Lights

E-CX-SIC Power indication only

E-FRL-SIC Power and Link indication

E-TBT-SIC Power and Link indication

The Slide In Cards are installed in the rear of the hub and

can only be installed one way. If seated properly, the power

indicator LED will light. When Link has been established,

the Link LED will light on the E-FRL-SIC and E-TBT-SIC

cards. See Figure 3 below:

Fiber optic cable specifications for E-FRL-SIC option

Recommended fiber optic cable:

62.5/125 µm multimode fiber

The following Fiber optic cable can be used:

100/140 µm multimode fiber

85/µm multimode fiber

50/125 µm multimode fiber

Coax cable RG-58 specifications for E-CX-SIC option

Coax type: Coax RG-58 thin-net cable, 50 ohms. Cable

must meet the Ethernet IEEE 802.3 specif-

ication for a thin coax segment.

Coax Segment Distance: Maximum distance of 185

meters (610 feet)

Table 1 illustrates the individual wires that make up a

straight through twisted pair modular cable. Each pair has

designated pin connections on an RJ-45 modular connector.

There are only two active pairs in a 10BaseT network.

10BaseT pinning for straight through cabling (from hub to

network device): Pins 1 and 2 are paired, and pins 3 & 6

are paired. Use only dedicated wire pairs (such as

blue/white, white/blue, or orange/white, white/orange,etc.).

Table 1A

RJ-45 Male RJ-45 Male

1- - - - - - - - - - - - - - - - - - - - - - - - - - -1

2- - - - - - - - - - - - - - - - - - - - - - - - - - - 2

3- - - - - - - - - - - - - - - - - - - - - - - - - - - 3

6- - - - - - - - - - - - - - - - - - - - - - - - - - - 6

Installing Optional Slide In Cards

Optional Slide In Cards provide added capability to your net-

work. These are available in Coax (E-CX-SIC), Fiber optic

(E-FRL-SIC) and Twisted pair (E-TBT-SIC) cabling. (See

cabling specifications on page 7&8.) With the optional Slide

In Cards you can cascade to other hubs or connect to a dif-

ferent backbone media. In addition, the hub redundancy

feature may also be utilized using either Twisted pair or

Fiber optic Slide In Cards (see page 2).

When installing Slide in Cards, note the following: 1) The

Coax Slide in Card (E-CX-SIC), may not be used for the

redundancy feature and requires a coax T (and terminator if

at the end of a segment). 2) The SQE switch must be set to

OFF. 3) Before installing Slide in Cards, disconnect AC

power to the hub.

83 18

FIG 2: RJ -45 PIN CONFIGURATIONS

Crossover Cable for cascading hubs or connecting trans-

ceiver to transceiver. Table 1B

RJ-45 Male RJ-45 Male

1- - - - - - - - - - - - - - - - - - - - - - 3

2- - - - - - - - - - - - - - - - - - - - - - 6

3- - - - - - - - - - - - - - - - - - - - - - 1

6- - - - - - - - - - - - - - - - - - - - - - 2

Indice

Altri manuali Transition Networks Interruttore

Transition Networks

Transition Networks SM8TAT2SA Manuale utente

Transition Networks

Transition Networks SISGM1040-184D-LRT Manuale utente

Transition Networks

Transition Networks SISPM1040-582-LRT Manuale utente

Transition Networks

Transition Networks SISGM1040-284-LRT Manuale utente

Transition Networks

Transition Networks SM24-100SFP-AH Manuale utente

Transition Networks

Transition Networks E-TBT-HB-0400 Manuale utente

Transition Networks

Transition Networks E-MUX-SA05 Manuale utente

Transition Networks

Transition Networks SM12DP2XA Manuale utente

Transition Networks

Transition Networks MIL-S4800 Manuale utente

Transition Networks

Transition Networks E-PSW-TX-02 Manuale utente

Transition Networks

Transition Networks SISTP1040-382B-LRT Manuale utente

Transition Networks

Transition Networks SM24DP4XA Manuale utente

Transition Networks

Transition Networks MIL-S2400S Manuale utente

Transition Networks

Transition Networks 1005 Manuale utente

Transition Networks

Transition Networks SISTM1040-262D-LRT Manuale utente

Transition Networks

Transition Networks SM24T6DPA Manuale utente

Transition Networks

Transition Networks SM24T6DPA Manuale utente

Transition Networks

Transition Networks SISTG1040-242-LRT Manuale utente

Transition Networks

Transition Networks SISPM1040-582-LRT Manuale utente

Transition Networks

Transition Networks SISPM1040-384-LRT-C Manuale utente

Transition Networks

Transition Networks E-TBT-HB-0402 Manuale utente

Transition Networks

Transition Networks SISTM1040-262D-LRT Manuale utente

Transition Networks

Transition Networks SM8TAT2SA-DC Manuale utente

Transition Networks

Transition Networks SM24TBT2DPA Manuale utente

Manuali Interruttore popolari di altre marche

URC

URC Total Control MFS-8 Manuale utente

Azbil

Azbil HPQ-D11 Manuale utente

Sony

Sony DFS-900M Manuale utente

SICK

SICK i17S Manuale utente

F&F

F&F SZR-277 Manuale utente

Shure

Shure UAMS/BK Manuale utente

Dräger

Dräger X-zone Switch Off Manuale utente

Asco

Asco Joucomatic 349 Series Manuale utente

BT Mini Hub Manuale utente

D-Link

D-Link DES-1226G Manuale utente

Johnson Controls

Johnson Controls FS80-C Manuale utente

Alcatel-Lucent

Alcatel-Lucent 7450 ESS-12 Manuale utente

MicroNet

MicroNet SP1200A Manuale utente

Ruijie

Ruijie RG-PF2920 Series Manuale di installazione e funzionamento

Altinex

Altinex DA1914SX Manuale utente

MiLAN

MiLAN MIL-SM2401M Manuale utente

RJM

RJM MASTERMIND PBC/6X Manuale utente

Atlas

Atlas MMK-KVM8 Manuale utente