Elcon LT2MSKU-T Operating Instructions Manual

© ELCON Systemtechnik GmbH 2008

LT2MSKU-T

Digital Transmission System

for 2 Mbps signals via copper cable

Operating instructions

Art. no. 101388-1

LT2MSKU-T LT2MSKU-T

Version: 2008/05/23 Version: 2008/05/23

10 Miscellaneous

Please keep this manual always accessible at a safe place!

When putting the device into operation, pay attention to the safety precautions (→ chapter 11).

We reserve the right to apply modifications. This is contributed to the technical progress and
aimed at the permanent improvement of the product.
.

11 Safety precautions

For your own safety, please observe the following hints. Read them carefully before you put
the device into operation.

Precautions against electrostatic discharge

Upon opening and installation of the components of the SHDSL transmission system, atten­tion shall be paid to the safety precautions as stipulated by IEC 61340-5-1.

Safety precautions during thunderstorms

Keep away from manipulations on the SHDSL transmission system and its components
during thunderstorms (Do not disconnect or connect sub-units or cables).

Grounding and potential equalization

During installation, operation and maintenance of the SHDSL transmission system, the
regulations as set out in IEC 60364-5-54 shall be observed.

Warning of dangerous electric voltage

The SHDSL transmission system has got interfaces being under dangerous electric voltage.
Therefore, all works on the system should be performed by personnel who has acquired the
necessary special knowledge.

LT2MSKU-T LT2MSKU-T

Version: 2008/05/23 Version: 2008/05/23

9 Technical data LT2MSKU-T/ continued

T3an interface:

Nominal clock frequency 2048 kbps (depending on T3an)
Sensitivity 0.5 V

S0

... 1.9 VS0, symmetrical (rectangular

or sine-shaped)
Impedance 120 Ω
Safety degree SELV

Power supply:

Operating voltage range -32 V ... -75 V
Current consumption 1 A
Power consumption (without/with FSP2M) 7 W / 30 W
Fuse protection (F700) 1.6 A, T, 250 V (IEC 60127-3/IV)

Remote power supply module 112 V ± 3 V / 59 mA (nominal values)

Contents

1. Short description 2

2. Interfaces 5

3. Block diagram 10

4. Display elements 11

5. Operating elements 12

6. Remote power supply module FSP2M 13

7. Mounting of remote power supply module 14

8. Installation / Mounting of LT2MSKU-T 22

9. Technical data 23

10. Miscellaneous 25

11. Safety precautions 25

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LT2MSKU-T LT2MSKU-T

Version: 2008/05/23 Version: 2008/05/23

1 Short description

The SHDSL transmission system made by ELCON Systemtechnik GmbH allows the bidi­rectional transmission of 2 Mbps signals via copper cable (one-pair or two pairs) between the
exchange side and the subscriber in accordance with the ETSI Technical Specification 101
524 (TS 101 524). Using the SHDSL technology (SHDSL: Symmetrical High bit-rate Digi­tal Subscriber Line), the subscriber can benefit from 2 Mbps services on short call. Com­pared to the HDSL technology, the SHDSL system provides higher range and spectral com­patibility.

The complete system for transmission of 2 Mbps signals using the SHDSL technology con­sists of the sub-units LT2MSKU and NT2MSKU and permits economic exploitation of the
copper cable deployed in the subscriber access area.
The system has been designed for these application scenarios:

- ISDN primary multiplex access (PMXA)

- Structured fixed connections with frame structure as per ITU-T G.704

- Unstructured fixed connections
In addition, the system provides configuration options and allows to execute different moni-

toring functions, e.g. to indicate emergency states or to check quality parameters.
The line terminating unit in desktop version LT2MSKU-T can be used, among others, as

network termination for unstructured fixed connections (leased lines). It matches the V2M
interface, consisting of a twin-wire pair, to the UKS line interface (SHDSL), which has one
or two copper wire pairs. The 2 Mbps signal in compliance with ITU-T G.703 is transpar­ently transmitted in both directions. There is no CRC4 framing in this case. The LT2MSKU-
T ensures a defined network termination, independent from the operating state of the NT2
(subscriber terminal equipment, TE). This allows the network operator to run its transmis­sion network as self-sustaining system, independent from the connected subscriber terminals.

At the UKS interface, a TC-16-PAM line code with line digit rate of 7731/3 kbaud (one-pair
system) or resp. 389

1

/3 kbaud (two-pair system) is used. The transmission is on each path
bidirectional (duplex mode). Independent of the chosen transmission mode, at the UKS
interface the transmission quality is permanently monitored by means of the CRC-6 tech­nique. This makes it possible to monitor in transparent mode the line section between
LT2MSKU and NT2MSKU with respect to signal existence, synchronization loss (SHDSL
frame), CRC-6 error, HDB3 code error and AIS (V2M interface). Processing of the SHDSL
overhead is also effected in all modes of operation.

9 Technical data

UKS SHDSL interface (one-pair system): as per ETSI TS 101 524

Bit rate 2320 kbps ± 32 ppm
Line digit rate 773

1

/3 kbaud
Line code TC-16-PAM
Impedance 135 Ω
Safety degree TNV3

UKS SHDSL interface (two-pair system): as per ETSI TS 101 524

Bit rate 2 × 1168 kbps
Line digit rate 3891/3 kbaud
Line code TC-16-PAM
Impedance 135 Ω
Safety degree TNV3

V2M interface: as per ETS 300 011

Bit rate 2048 kbps
Useful load 31 x 64 kbps (30 x B + D)

or 2048 kbps unstructured
Line code HDB3 (AMI)
Impedance 120 Ω
Pulse shape nominally rectangular
Amplitude at V2Mab 3 V

P0

± 10%
Frame structure ITU-T G.704 or unstructured
Return loss >18 dB (100 kHz...2 MHz), symmetrical
Admissible attenuation of the received signal
at V2Man related to the transmitted signal 6 dB
Safety degree SELV

PC interface:

Layer 1 Interface compliant with EIA-RS232C
Layer 2 Data transfer protocol as per HDLC with

TC57 frame
Layer 3 Network protocol VMP01
Layer 7 User protocol AWP01
Data rate 9600 Baud, 19200 Baud asynchronous
Databits 8
Parity even
Stop bits 1
Safety degree SELV

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LT2MSKU-T LT2MSKU-T

Version: 2008/05/23 Version: 2008/05/23

8 Installation / mounting of LT2SMKU-T

The LT2MSKU-T can be used as wall-mounting or desktop unit.

Do not install the device in the neighbourhood of strong electromagnetic fields (i.e. close to
loudspeakers, TV-sets or the like), since radiation sources and interferences of such kind can
reduce the transmission range. Further, the place of installation should be protected from
direct sun radiation, heat sources and humidity and should also be dust-free, if possible.

If the LT2MSKU-T is used as desktop device, it should be placed on a plain and dry table
surface.

For mounting the device to the wall, use the existing casing pockets (key holes) to fix the
unit with help of the 3 × 35 screws and 6 mm dowels tension-free to a plain and dry wall
surface. Before inserting the dowels, make sure that there are no concealed supply lines in
the wall.

After connection of the signal cables, the device is ready for work.

To put the sub-unit LT2MSKU-T into operation, the supply voltage has to be applied.
This is indicated by the green LED turning ON. The applied supply voltage and successful
initialization promptly start activation of the transmission line if a repeater ZWR or an
NT2MS has been connected. This will take a few seconds and is indicated by the flashing of
LED DSL1 (in two-pair mode also DSL2). Upon initial start-up, the system ramps up in
structured operating mode (default state). Note: The disconnecting switch must be in
position „Operation“! If the default state does not comply with the desired configuration,
the LT2MSKU-T and the NT2MS have to be reconfigured with help of the management
system. The configuration data are stored in the LT resp. NT as non-volatile information.

1 Short description/ continued

The ISDN primary multiplex access uses the CRC-4 method as per ITU-T G.704 and G.706.
This ensures additional protection against faulty synchronization and allows to check the
transmission quality between the S2M interface (E1, G703) and the digital local exchange.

With the unstructured 2 Mbps fixed connection (D2MU, unstructured operating mode
(transparent mode)) the line terminating unit / network terminating unit LT2MSKU-T
transmits the complete 2 Mbps signal, irrespective of the bit sequence, in both directions, i.e.
there is no frame synchronization against the 2 Mbps signal and no CRC4 application. The
received digital signals at the V2M interface (E1) are only checked with regard to existence,
HDB3 code error and AIS (Alarm Indication Signal).

A controlled loop (via Sa6 bits or SHDSL overhead) to be established close to the S2M
interface (E1) of the NT2MS permits in all modes of operation a distinct fault localization,
i.e. to recognize whether the failure belongs to the area of responsibility of the network
operator or, respectively, the subscriber. The LT2MSKU-T allows a loop close to the UKS
port(s). The activation (initiation) of the loop(s) is carried out with help of the MSP (Modu­lar Service PC) with ENMS (ELCON Network Management Software) via the PC interface.

The various settings of the SHDSL can be configured with a PC per SHDSL overhead (EOC
channel) from the LT2MSKU-T. Local configuration of the SHDSL is possible via the PC /
RS232/V.24 interface. This requires a PC with respective ENMS software. Optionally, the
system can be configured as well by the DIL switches which are arranged on the circuit
board of the LT2MSKU -T. This means, configuration is executed for each system indi­vidually.

Note: Once the system has been configured via the EOC channel, the settings of the

DIL switches will have no effect!

For powering a regenerative repeater, an optionally available remote power supply module
(FSP2M) can be used, which can be integrated into the LT2MSKU-T. For this, the device
has to be opened (→ Mounting of remote power supply module).

Further, the LT2MSKU-T can be switched between the operating modes „one pair“ and
„two-pair“. The respective switch can be found inside the device on the motherboard, so the
device has to be opened for switching. Besides, the LT2MSKU-T can be operated not only
in one-system mode, but also in double-system mode, whereby in the latter case the
LT2MSKU-T card contains two fully separate systems, to which two NT2MSKU can be
connected via a twin-wire copper cable.

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