8680-1-e Bedienungsanleitung NT2MSKU-T ... - Elcon Systemtechnik

© ELCON Systemtechnik GmbH 2004 

NT2MSKU-T 

Digital Transmission System 

for 2 Mbps signals via copper cable 

Operating instruction 

Art.-Nr. 101328

11 Safety precautions 

For your own safety, the following hints shall be observed. Please read them carefully, before 

you put the device into operation. 

Precautions against electrostatic discharge 

Upon opening and installation of components of the SHDSL transmission system, attention 

shall be paid to the safety precautions as stipulated by DIN 100 015. 

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 DIN VDE 0800, part 2, shall be observed. 

Warning of dangerous electric voltage 

The SHDSL transmission system has interfaces being under dangerous electric voltage. 

Therefore, all works on the system should be performed by personnel who has the required 

special knowledge. 

NT2MSKU-T NT2MSKU-T 

Contents 

1. Short description of NT2MSKU-T 2 

2. Interfaces at NT2MSKU-T 5 

3. Block diagram 9 

4. Display elements 10 

5. Operating elements 11 

6. Remote power-supply module FSP2M 12 

7. Mounting of remote power-supply module 13 

8. Mounting / Installation of NT2MSKU-T 21 

9. Technical data of NT2MSKU-T 22 

10. Remarks 23 

11. Safety precautions 24 

Version: 2004/04/19 Version: 2004/04/19 

24 1

1 Short description of NT2MSKU-T 

The complete system for transmission of 2 Mbps signals using SHDSL technology (SHDSL: 

Symmetrical High bit-rate Digital Subscriber Line) consists of the subcriber-end NT2MSKU 

and the exchange-end LT2MSKU and permits economical use of the copper cable in the 

subscriber connection sector. 

The system supports different applications: 

- ISDN primary multiplex connections (PMXA) 

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

- Unstructured fixed connections 

Further, the system offers various configuration options and additional functions, such as 

monitoring of alarm states and quality assessment. 

With the ISDN primary multiplex access, the NT2MSKU-T matches the two twin-wire S2M 

subscriber interface to the two-wire UKS interface, thus ensuring the defined network termination, 

from network operator´s point of view. 

In addition to this, the NT2MSKU-T can be used as termination for structured and unstructured 

fixed connections (leased lines) according to 1 TR 805. 

With structured fixed connections, a framed 2 Mbps signal as per ITU-T G.703 with a frame 

structure acc. to ITU-T G.704 is being transmitted, whereas unstructured fixed connections 

support the transmission of an unframed 2 Mbps signal (transparent mode). 

Regardless of the operating mode, the TU 12-connection is being permanently monitored 

through the evaluation of the VC 12-container. The application of this specific method allows 

an end-to-end monitoring, irrespective of the contents of the 2 Mbps signal. 

At UKS interface, a TC-16-PAM line code with line digit rate of 773 1 / 3 kBaud is used. The 

transmission is bidirectional (duplex mode). Independent of the chosen transmission mode, 

at the UKS interface the transmission quality is permanently monitored using the CRC-6 

method. This makes it possible to transparently monitor the line section between LT2MSKU 

and NT2MSKU with respect to signal existence, synchronization loss (SHDSL frame) and 

CRC-6 errors. Processing of the SHDSL Overhead is also effected in all operating modes. 


10 Remarks 

Keep this Operating Manual available! 

Before putting the device into operation, please make yourself familiar with the safety precautions 

(→ Chapter 11). 

We reserve the right to apply technical modifications aimed to further improvement of the 

product performance. 


2 23

9 Technical data of NT2MSKU-T 

UKS interface as per ETSI TS 101 524: 

Bit rate 2320 kbps ± 32 ppm 

Line digit rate 1160 kBaud 

Line code 2B1Q 

Impedance 135 Ω 

S2M interface as per ETS 300 011: 

Bit rate 2048 kbps 

Line code HDB3 (AMI) 


Pulse shape nominally rectangular 

Amplitude at S2Mab 3 VS0 ± 10% 

Permissible attenuation of the received signal 

at S2Man related to the transmitted signal 6 dB 

T3ab interface: 

Nominal clock frequency 2048 kbps (depends on T3an) 


Amplitude as per G.703: 2.9 V ± 30% 

Power supply: 

Operating voltage range 20 V ... 75 V 

Power consumption (without/with FSP2M) 5 W / 14 W 

Remote power-supply module 112 V ± 3 V / 59 mA 


1 Short description of NT2MSKU-T/ continuation 

The ISDN primary multiplex access uses the CRC-4 method as per 1 TR 218 (ITU-T G.704 

and G.706) and due to this offers additional safety against erroneous synchronization, plus 

monitoring of the transmission quality between S2M interface and the digital local exchange 

DIVO (ET). 

For structured fixed connections, the CRC-4 method is applied to ensure an end-to-end 

monitoring (NT2MSKU ↔ NT2MSKU). 

2 Mbps digital signals as per ITU-T G.703 with frame structure acc. to ITU-T G.704 are 

transmitted via S2M interface. 

This means that in the structured operating modes (PMXA and structured fixed connections) 

the NT2MSKU features bidirectional information transmission from 31 user channels with 

64 kbps each, independent of the respective bit sequence. 

In unstructured operating mode (transparent mode) the NT2MSKU-T transmits the complete 

2 Mbps signal, irrespective of bit sequence, in both directions, i.e. there is no frame 

synchronization against the 2 Mbps signal and no CRC4 application. The incoming signals 

at the S2M interface are only monitored with regard to existence, HDB3 code errors and 

AIS. 

A controlled loop (via Sa6 bits or SHDSL overhead) to be established close to the S2M 

interface permits in all operating modes a distinct fault localization within the areas of responsibility 

of the network operator or the subscriber. 

In structured operating mode it is possible, via T3an interface of subrack BGTLT2MS (clock 

input) to synchronize the 2 Mbps signal on the S2Mab port of the network terminal 

NT2MSKU-T with help of the network timing signal. For this, the network timing is transmitted 

with the SHDSL clocking and recovered in the NT2MSKU-T. 

The various NT2MSKU-T settings can be configured per SHDSL overhead (EOC channel) 

via management interface using a PC. 

The supply voltage for the NT2MSKU-T is generated by a power supply unit. 

For powering a regenerative repeater, an optionally available remote power-supply module 

(FSP2M) can be used. This module shall be installed into the NT2MSKU-T as separate subunit. 

For this, the device needs to be opened (→ Mounting of remote power-supply module). 

Thanks to its special design, the casing is stackable and allows screwless mounting. For 

wallmounting, the device can be installed in a way that the display elements point to the top, 

with interfaces at the bottom. When placing the cramp feet, they have to be turned. 


22 3

1 Short description of NT2MSKU-T/ continuation 

View of the casing with its elements 

LED display 

Legend film 

Upper casing part 

Casing bottom part 

Cramp foot for opening the casing 

Fig 1: View of the casing 


8 Mounting/Installation of NT2MSKU-T 

The NT2MSKU-T can be used as wallmounted or desktop device. 

Do not install the device in the vicinity of high electromagnetic fields (e.g. near loudspeakers, 

television sets etc.), since such sources of radiation and interference may affect the range 

of transmission. The mounting site should not be exposed to direct sun radiation and heat 

sources, but shall be kept dry and, if possible, dust-free. 

When using the device as desktop unit, the installation surface should be plain and dry. 

For mounting the device to the wall, the predetermined casing cut-outs (keyholes) shall be 

used, through which the device shall be mounted tension-free by screws 3 × 35 and dowels 6 

mm. Upon placing the dowels, attention shall be paid to wirings which may be concealed. 

The device is ready for operation after the signal cables are connected. 

For putting the NT2MSKU-T into operation, supply voltage must be provided. This is 

indicated by the green LED going on. Promptly upon provision of the supply voltage the 

NT2MSKU-T starts initialization which takes some seconds. This condition is signalled by 

flashing of LED UKS. 


4 21

7 Mounting of remote power-supply module / continuation 

- Press upper part against bottom part (4 × audible clicking-in) 

- Now place the cramp feet (paying attention to the cut-outs for wallmounting) 

Fig. 19: Placing the upper casing part 


2 Interfaces at NT2MSKU-T 

All interfaces of the NT2MSKU-T are placed on the rear side of the device. 

UB-power 

supply 

T3ab 

FPE 

UKS (RJ45) 

UKS (Wago 

Cage-Clamp) 

S2M (RJ45) 

S2Man / S2Mab 

Switch Operation / Service 

Figure 2: Rear side showing the interfaces 


20 5

2 Interfaces at the NT2MSKU-T/ continuation 

The various interfaces have below functions and assignment: 

UKS interface (RJ 45) 

The UKS interface is responsible for matching to the SHDSL interface. Basically, the interface 

wiring consists of an SHDSL transceiver with accompanying line interface and overvoltage 

protection. From physical point of view, the interface is an RJ 45 jack or, alternatively, 

a Wago Cage-Clamp connector. The interfaces have below functions and assignment: 

Fig. 3: UKS interface 

UKS interface (Wago Cage-Clamp connector) 

1 2 3 4 5 6 

Fig. 4: Wago Cage-Clamp interface 

1 UKSa 

2 UKSb 

3 not used 

4 not used 

5 not used 

6 to 8 not used 

1 FPE 

2 not used 

3 not used 

4 UKSa 

5 UKSb 

6 FPE 

Safety precautions: If the UKS interface is linked through the Western jack (RJ45 

socket, fig. 3), make sure the 6-pole multiple socket connector is 

plugged onto the Wago Cage-Clamp connector of the UKS interface 

(see fig. 4) and screwed on, since in case of linking the UKS 

port via the Western jack (RJ45 socket) there is danger of touching 

the contacts of the UKS-Wago Cage-Clamp connector. 



- Place upper part (keeping it inclined) on the film and then set it onto the casing 

bottom part 

Fig. 18: Closing the casing 


6 19


9. Mount the device as follows: 

- Insert legend film into the casing´s bottom part 

- Make sure that LED domes are duly seated 

Fig. 17: Inserting the front panel 


2 Interfaces at NT2MSKU-T/ continuation 

S2M interface 

The S2M interface represents the subscriber port according to normative 1 TR 237. In the 

main, the S2M interface wiring comprises components for overvoltage protection on the 

input and output, a transceiver and a framer. From physical point of view, the interface is an 

RJ 45 jack. For measuring and test purposes, the operating mode "Measurement" can be 

chosen by a switch on the back. 

T3ab interface for clock-pulse output 

Fig. 5: S2M interface 

1 S2Mab/a 

2 S2Mab/b 

3 not used 

4 S2Man/a 

5 S2Man/b 


The symmetric interface is galvanically separated from the circuitry. Under the condition of 

faultless operation, the interface allows to extract the timing signal recovered from the received 

signal UKSan. The clock pulse consists of a 2,048 kHz signal with a clock-pulse ratio 

of 1:1. 

Fig. 6: Interface T3ab 

1 T3ab/a 

2 T3ab/b 



18 7

2 Interfaces at NT2MSKU-T/ continuation 

UB Power supply interface 

This interface has been designed in compliance with regulation 1 TR216. The interface is 

short-circuit-proof, so that polarity reversal would not cause damage to the device. Thanks to 

the Wago Cage-Clamp connector, unintentional change of polarity is actually impossible. 

The supply voltage range goes from -20 V to -75 V. 

FPE may also be screwed on the earthing screw. 

Fig. 7: UB interface 

1 +UB 

2 FPE 

3 -UB 

If for local power supply of the NT2MSKU-T the used power pack differs from the specified 

one (e.g. older two-pole units lacking of FPE- / earth conductor), the NT2MSKU-T needs 

additional grounding. Duly earthing shall be effected through one of the following two options 

(→ Fig. 8): 

1. Earthing connection to the central contact of the Wago Cage-Clamp connector at 

the UB power supply interface (rear side of the device) 

2. Earthing connection to the earthing screw FPE (on the device´s rear side) 

1 2 

Fig. 8: Rear side of the device - Additional earthing connection 



Fig. 16: Mounting of the FSP module 

- Fix the module by means of two screws (contained in bag with accessories). 


8 17


8. The remote power-supply module shall be mounted according to below figures: 

Fig. 15: Module FSP as separate sub-unit 


3 Block diagram 

E1 

Framer 

& 

E1 Transceiver 

Bild 9: Block diagram NT2MSKU-T 


16 9 

UB 

S2M 

G.703 

Power pack 

DC/DC 

EMC 

Controller & 

Peripheral 

1 ... 8 

SHDSL 

Framer 

SHDSL 

Transceiver 

Line 

interface 

EMC 

UKS

4 Display elements 

On the NT2MSKU-T front panel, there are 5 light-emitting diodes (LED) that indicate the 

various operating modes. Their meaning is given in the table below: 

Meaning EIN S2M E1 UKS FSP 

Normal mode (without FSP or FSP 

switched off) 

ON OFF OFF OFF OFF 

Normal mode (with activated FSP) ON OFF OFF OFF ON 

Error in remote supply unit ** 

(for operation with FSP) 

1 Hz 

S2M Urgent alarm at S2Man 

(LOS/BER3/LOF) 

ON 

AIS at S2Man (in unstructuured mode) 4 Hz 

SHDSL Urgent alarm at UKSan 

(LOS/LOF SHDSL) 

OFF ON 

LOF/BER-3 at UKSan (PDH) ON OFF 

AIS at UKSan (PDH) 4 Hz OFF 

tuAIS at UKSan (SDH) 4 Hz 4 Hz 

tuLOP (Loss of Pointer) (SDH) 4 Hz 4 Hz 

SHDSL startup* OFF 1 Hz 

Explanation of symbols: 

* flashes until SHDSL is established 

** e.g. overvoltage, overcurrent, unbalance or line interruption 

ON LED shines permanently 

OFF LED does not shine 

1 Hz LED flashes at 1 Hz 

4 Hz LED flashes at 4 Hz 

Table 1: Meaning of LED displays 



7. Remove cover plate. 

Fig. 14: Circuit board of NT2MSKU-T 


10 15


3. Insert a screw-sriver (size 4-5) into those holes of the casing that are not 

marked with the crossed-out screw-driver symbol and slightly tilt it outside 

(2×) 

4. The casing snaps open on one side. 

5. Relocate the device with upper part now showing to the top. 

6. Unlocking procedure as described in point 3. 

Fig. 13: Unlocking the casing 


5 Operating elements 

A switch on the rear side of the NT2MSKU-T allows switching between normal mode and 

test mode. If the switch is set on Operation, the S2M interface signals can be checked by 

high-impedance activation of a respective measuring instrument. When the switch is set on 

Measurement, the signal path is separated so that external test signals can be fed in. 

Pin assignment of test socket / splitting jack S2M 

Device side Client side 

14 11 


Switch 

Device side Client side 

Switch 

Fig. 10: Test- / Splitting jack S2M (on device rear side) 

Operation 

Measurement

6 Remote power-supply module FSP2M 

The remote power-supply module is optionally available and can be used for powering of an 

NT-side regenerative repeater. 

The module is designed as plug-in unit and is being mounted to the main unit of the 

NT2MSKU-T by means of DIN connectors (cf. chapter "Mounting of remote power-supply 

module). Two screws are needed for fixing the FSP2M. 

Power supply voltages 

provided by the basic 

module 

Energy 

buffer 

Fig. 11: Block diagram of FSP module 


Regulator 

Regulator 

Remote 

power 

supply 

channel 1 

Remote 

power 

supply 

channel 1 

Main 

processor 

7 Mounting of remote power-supply module 

The optional remote power-supply module is mounted to the basis unit by means of DIN 

connectors. This operation requires opening of the device. For this, proceed as follows: 

1. Put the NT2MSKU-T upside down. 

2. Remove cramp feet. 

Fig.12: Removing the cramp feet 


12 13

8680-1-e Bedienungsanleitung NT2MSKU-T ... - Elcon Systemtechnik

Create successful ePaper yourself

Delete template?

Save as template?