Etl Training2

ABB Power System Communications

Power Line Carrier ETL Family Training Program

Power Line CarrierCommunication

ETL



ETL; NSD50; NSK5 TRAINING PROGRAM

1. PLC OVERVIEW

2. PLCC OVERVIEW

3 ETL OVERVIEW

4 ETL BLOCK DIGARM &PROGRAMMING

5 TESTING FACILITIES

6 ETL TESTING



PLC OVERVIEW



DIFFERENT OPTIONS FOR POWER UTILITY COMMUNICATIONS

• MICROWAVE

• UHF/VHF SYSTEMS

• RADIO LINK

• FIBRE OPTIC

• TELEPHONE CABLE

• POWER LINE CARRIER COMMUNICATION (PLCC)

Atmospheric conditions, High Capital Cost

Atmospheric conditions, high capital cost,high maintenance

Congested frequency band

High cost for low trafficMechanically weaker,High theft chances

PLC OVERVIEW



ADVANTAGES OF POWER LINE CARRIER COMMUNICATION

• COMPACT

• RELIABLE

• COST EFFECTIVE FROM DISTANCE POINT OF VIEW

• ENTIRELY WITHIN POWER UTILITY’S CONTROL

• IMMUNITY FROM ATMOSPHERIC CHANGES

PLC OVERVIEW



PLCC OVERVIEW



Phase to Ground System

PLCC OVERVIEW



Phase to Phase System

CC blocks high voltage 50Hz power

entering into the PLCC terminal

BT & LMU matches the

PLCC terminal impedance to

the line impedance

Earth Coil, LA are for protections for leakage /surges and earth switch

for maintenance

purpose

Line trap blocks PLCC signal entering into

switch yard equipment

PLCC OVERVIEW



USER INTERFACES

MODEMPOWER AMPLIFIER

LINE INTER-FACES

POWER SUPPLY

FREQUENCY GENERATION UNIT

CONTROL UNIT

PLCC OVERVIEW



FEATURES REQUIRED FOR POWER SYSTEM COMMUNICATIONS:

• ROBUSTNESS AGAINST ALL KINDS OF INTERFERENCE

• DIRECT INTERFACING TO POWER SYSTEM SERVICES e.g PROTECTION , TELECONTROL

• HIGH FLEXIBILITY OF NETWORK CONFIGURATION

• INETERFERENCE OFFERED TO OTHER EQUIPMENTS

• IEC HAS SPECIFIC STANDARD (IEC 495) FOR PLCC TERMINAL

PLCC OVERVIEW



ETL OVERVIRW



ETLETL

LTLT

C CFAX

FAX

PR PC MS PAX FAX

M DC

PR PC RTU FAX

M

C = Coupling DeviceDC = Dispatcher's consoleFAX = Facsimile equipmentLT = Line trapM = Modem

MS = Master stationRTU = Remote terminal unitPAX = Private automatic exchangePR = Protection relayPC = Computer

ETL OVERVIEW



P7L

BP

7LA

NSD 50

NSD 50

NSK 5

ETL OVERVIEW



ETL FAMILY

PLCC TERMINAL : ETL-4X FOR 1 TO 4 CHANNELS TOTAL POWER 40WETL-8X FOR 1 TO 4 CAHNNELS TOTAL POWER 80W

PROTECTION : NSD-50 FOR 2/4 CODED/UNCODED COMMANDS SIGNALLING CAN BE USED IN ETL RACK ONLY EQUIPMENT

MODEM : NSK-5 FULLY PROGRAMMABLE RS232 MODEMWITH MAX 2400 BAUD RATE. CAN BE ACCOMO--DATED IN ETL RACK OR STAND ALONE USEPOSSIBLE

ETL OVERVIEW



MODULAR EQUIPMENT ARCHITECTURE

• SINGLE / DOUBLE / TRIPLE AND FOUR CHANNELS OPERATION

• DOUBLE / TRIPLE AND FOUR CHANNELS BY ADDING TIERS

• DIFFERENT TRANSMIT POWERS AVAILABLE SELECTABLE ACCORDING TO NOISE LEVEL IN POWER LINES - 40 W / 80 W

• THE MODULES ARE FUNCTIONALLY ORGANISED

ETL OVERVIEW



FEATURES• INTEGRATED TELEPROTECTION EQUIPMENT TYPE NSD-50 (OPTION)

INTEGRATED FSK MODEM TYPE NSK-5 (OPTION)

MEETS OR EXCEEDS IEC495/IEC663/IS9482/IS10706

MEETS OR EXCEEDS LATEST IEC ON EMC/EMI COMPLIANCE

FULFILLS ISO9001 QUALITY SYSTEM

ETL OVERVIEW



Standard Versions

P7LB

P7LA

P7LB

P7LA

P7LB

P7LB

P7LA

P7LB

P7LA

P7LB

P7LA

P7LA

ETL 41 Single Channel 40 Watt

ETL 42 Double Channel 40 Watt ETL 82 Double Channel 80 Watt

ETL 81 Single Channel 80 Watt

9 A

SA

Un

its1

5 A

SA

Un

its

19

AS

A U

nits

13

AS

A U

nits

ETL OVERVIEW



P7LB

P7LA

P7LB

P7LA

ETL 84 Four Channel 80 Watt

31

AS

A U

nits

P7LB

P7LB

P7LB

P7LA

P7LB

ETL 44 Four Channel 40 Watt

27

AS

A U

nits

P7LB

P7LB

Versions for 3 or 4 channel operation

ETL OVERVIEW



ADDITIONAL VARIANTS:

AF SECTION: 5 SLOTS RESERVED A COMBINATION OF FOLLOWING IS POSSIBLE

§One 2/4 Pax Interface/4w Pax Interface/ Remote Subscriber Interface;each having programmable cutoff filter from 1800HZ to 3400HZ in any one of the 5 slots

§1 to 5 Telecontrol Interfaces each with 3 isolated I/P & O/P in any of the 5 slots; each inteface with (optional) programmble transit filter for fre. from 360 hz to 3720 hz (steps of 60hz) for 1 I/P or any combination of O/P

§Protection Signalling equipment (NSD50) with 2 or 4 commands (fixed slots 1st or 1st &2nd)

§1 to 5 Modems with RS232 Interface (NSK-5)in any of the 5 slots

ETL OVERVIEW



ADDITIONAL VARIANTS:

PILOT: SELECTABLE FROM 3780 HZ / 2160HZ /2640HZ / 3360HZ / 3600HZ

RF PROGRAMABILITY: EASY TO TUNE THE SET IN EITHER 40 TO 100KHZ OR 100 TO 500KHZ IN A RASTER OF 4KHZ

RF TERMINATION: 75OHM, 125OHM

ETL OVERVIEW


Power Line Carrier ETL Family Training ProgramETL OVERVIEW


FREQUENCY CARDP4LG/P4LI

CONTROL CARDP4LAPOWER SUPPLY

B5LAB4LA

POWER AMPLIFIER &LINE

INTERFACESP1LA

E5LA/E5LBP3LA/P3LB

MODEMP4LB,P4LC,P4LD,P4LE

P4LF

USER (AF)INTERFACESO4LA, O4LBO4LC, O4LD

--------------------NSD50,(G4AA,G4AC)NSK5(G4AE/G4AF)

POWER AMPLIFIER & LINE INTERFACESP1LA: POWER AMPLIFIER

E5LA:100KHZ TO 500KHZ TX FILTERE5LB: 40KHZ TO 100KHZ TX FILTERP3LA: RF HYBRID

POWER SUPPLY

B5LA: 48 VOLT STABILISER

B4LA:48 VOLT DC DC CONVERTOR

ETL: PLCC TERMINAL INTERFACESO4LA: TELECONTROL INTERFACEO4LB: 4WIRE PAX INTERFACEO4LC:2/4 WIRE PAX INTERFACEO4LD: 2WIRE PAX-SUBSCRIBER INTERFACE

NSK5: ETL OPTIONAL IN RACK MODEMG4AE/F: PROGRAMMABLE MODEM

NSD50: ETL IN RACK OPTIONALPROTECTION SIGNALLING EQP.G4AA: DSP INTERFACEG4AC/D: COMMAND INTERFACE

MODEM SECTION

P4LB: AF MULTIPLEXOR + AF TO IF1 AND BACKP4LC:IF CONVERTOR IF1 TO IF2 AND BACKP4LF: TX RF CONVERTOR IF2 TO RFP4LD: RX RF CONVERTOR RF TO IF2P4LE: RX RF CONVERTOR SECOND CHANNEL

FREQUENCY SYNTHESIZER CARD

P4LG: FOR 1ST AND 3RD CHANNELP4LI: FOR 2ND AND 4 RTH CHANNEL

Power Line Carrier ETL Family Training ProgramPower Line Carrier ETL Family Training ProgramETL OVERVIEW



Speech 2.0 kHz

Speech 2.2 kHz

Speech 2.4 kHz

Speech 2.6 kHz

Speech 2.8 kHz

Speech 3.0 kHz

Speech 3.2 kHz

Speech 3.4 kHz

0.3 3.6 4.0

0.3 3.6 4.0

0.3 3.6 4.0

2400 Bd

1200 Bd

600 Bd

300 Bd

200 Bd100 Bd

50 Bd

Spe

ed

Center frequency120 Hz steps

2.0

Programmable2 wire / 4 wirespeech bandwidth

plus

NSD 504-command teleprotection

plus

NSK 5programmable FSK data transmission

kHz

kHz

kHz

ETL OVERVIEW



AF Bus layout



ET

L

O4LDO4LD

E&M E&M

442 2

O4LDO4LD

E&M E&M

442 2

PAX

O4LBO4LB

E&M E&M

44 4

PAX

E&M

4

PAX

E&M

ET

L

ET

L

ET

L

ET

L

ET

L

ETL OVERVIEW



2 SLIDES FOR FREQUENCY MODULATION SCHEME

ETL OVERVIEW


Power Line Carrier ETL Family Training ProgramETL OVERVIEW

DETECTOR(2ND DEMODULA-TOR)

IF STAGEMIXER(DEMODULA-TOR)

RF STAGE

AF SECTION OSCILATOR

COAXIAL INPUT

SUPERHET RECEIVER

fo

fsfo-fs

fo

fo+fs

fi

IMAGE FREQUENCY ( fs+2fi )REJECTIONADJACENT CHANNEL REJECTION (SELCTIVITY)

LET’S TAKE SIGNAL FREQUENCY = fs = 300KHZ TWO RECEIVERS WITH TWO DIFFERENT IF FREQUENCY

IF = fi = 16KHZTHE MIXER MAY HAVE AT ITS INPUT FOLLOWING FREQUENCIES:fs = 300 KHZ, fsa = 304 KHZ AND fs+2fi =300 +2x16=332KHZThe oscillator freq. For 300KHZ will be 300+16=316KHZ.Hence the O/P of mixer will havefor I/P O/P will contain

300 16 (316-300)304 12 (316-304)332 16 (332-316)

Since it is easy to make a r a filter tuned to 16 KHZ which rejects 12KHZ; adjacent channel rejection is easy. But 332KHZ may present at input and further RF stage O/P may have component of this causing poor image frequency rejection.

IF = fi = 624KHZTHE MIXER MAY HAVE AT ITS INPUT FOLLOWING FREQUENCIES:fs = 300 KHZ, fsa = 304 KHZ AND fs+2fi =300 +2x624=1548KHZThe oscillator freq. For 300KHZ will be 300+624=924KHZ.Hence the O/P of mixer will havefor I/P O/P will contain

300 624(924-300)304 620(924-304)332 624 (1548-924)

Since it is difficult to make a filter tuned to 624 KHZ which rejects 620KHZ completely; adjacent channel rejection is difficult. But 1548KHZ (of significant strength ) presence at input is ruled out Good image frequency Good image frequency rejection. rejection.

To have advantages of both low IF and high IF ETL uses multiple stages of modulation.

The use of multiple stages makes the RF programming easily possible.



Channel 3 & 4Channel 2

Pilot AlarmSuper-vision

DEDE

MOMOSA

AF-Bus

MainPowerSupply

PA

H

dB

+12V-12V+ 5V

SPDND

Channel 3 & 4Channel 2

AF Interfaces Basic equipment Power amplifier

NSD50

NSK 5

Tele-contr.

Tel.

Option

Teleprot.

VFT-mod

MO ConverterDE ConverterSA Summ.Amplifier

AF-ChannelsND Non-disconnectableD DisconnectableSP Speech

PA Power amplifierH RF-HybridMO

DE

B4LA

B5LA

P1LA

E5LA

P3LAP4LG

P4LC P4LD

P4LF

P4LA

P4LB

ETL OVERVIEW


Power Line Carrier ETL Family Training ProgramPower Line Carrier ETL Family Training Program

Absolute power level L [dBm]

The absolute power level L defines by how many dB a signal strength Px is greater or less thanthe reference power P0 = 1 mW:

PxL = 10 log ------ [dBm]

1 mW

Absolute voltage level Lu [dBu]

The absolute voltage level Lu defines by how many dB a signal voltage Ux is greater or less thanthe reference voltage U0 = 775 mV:

UxLu = 20 log ------- [dBu]

775 mV

Basic terms

ETL OVERVIEW



Basic termsConversion to another system impedance

If the voltage level is measured at a correctly terminated point of the system and referred to600 Ohm, the value of Lu is the same as the power level L. The value must be converted asfollows for other impedances Z:

600 OhmLu [dBu] = L [dBm] - 10 log --------

Z [Ohm]

Example: The power level at the 75 Ohm RF O/P of a PLC equipment is given as 40 dBm. What isthe voltage level Lu?

600 OhmLu = 40 dBm - 10 log -------- = 31 dBu

75 Ohm

Modern power measuring instruments permit the reference impedance to be set and the levelreferred to 600 Ohm can be directly read from them.

ETL OVERVIEW



Basic terms

Relative level Lrel [dBr]

The relative level Lrel is used, in order to define the performance of a communications systemregardless of channel loading.

The dBr value defines the magnitude of the difference in level with respect to the (virtual)reference point (0dBr).

Previously the two-wire I/P was taken as the reference point in telephony systems, which corre-sponds to the I/P of the AF hybrid in a PLC system. As with the dBm value, the relative systemlevel (dBr) is equivalent to a power level.

Absolute signal level Lo [dBmo]

In order to compare signal in relation to acommon base level they are defined in relation toasystem ref. Point with a relative level of 0dBr.

ETL OVERVIEW



AF signals Signal levels Absolutevoltage levels atthe test sockets TXAF(-10 dBr)

dBm0 Weighting dBu

Speech test tone 800 Hz 0 1.0 -10Internal test tone 1000 Hz

Speech with safety margin +3 1.41 -7

VFT channels and modems50 Bd -14 0.2 -24100 Bd -11 0.28 -21200 Bd -8 0.4 -18600 Bd -3 0.71 -131200 Bd, V.23 0 1 -101200 Bd + speech -3 0.71 -132400 Bd 0 1.0 -10

Max. permissible load with +10.8 3.48 +0.8speech plus superimposedchannels

Pilot tone -6 0.5 -16

Power allocation to speech and VFT channels

ETL OVERVIEW


Power Line Carrier ETL Family Training ProgramETL BLOCK DIGARM & PROGRAMMING

WHY THE PILOT IS STRONGER IN ETL?

MULTI PURPOSE PILOT

• AGC FUNCTION • SIGNALLING

• GUARD SIGNAL FOR TELEPROTECTION • SYNCHRONISATION

• AS TELEPHONY SIGNALLING CHANNEL

• REF. FOR SIGNAL QUALITY CHECK

• REMOTE LOOP CHECK



ETL BLOCK DIAGRAM AND

PROGRAMMING

Instructions to be followed

In the next slide shown the ETL setup has modules with information icons or . To see information about that particular module click the icon present on the module When the information reaches at the end there will be a back arrow icon . Click on the icon and you will be back again at the ETL set up. In case you want to skip over to next section; click on the forward icon .



B5LA Power Supply48 VDC

E5LA/B Tx-FilterP3LB

RF-Hybrid

Channel shelfbasic equipm.

User interface Power shelf Option

P7L

AP

ower

she

lf

Channel 1

ETL 41 Single Channel Equipment 40 Watt with speech (4wire)+ 1 data modem NSK5 and 2 teleprotection commands

Module layout, example

NSD 50

B4L

A D

C-c

onve

rter

O4L

C 4

-wire

PA

Xin

trf.

P4L

B A

F-c

onve

rter

P4L

C I

F-c

onve

rter

P4L

D R

x-co

nver

ter

P4L

F T

x--R

F-c

onv

.

P7L

BC

hann

el s

helf

9R 4R 6R 6R 6R 6R7R 8R 8R 6R4R 4R 10R

G4A

A D

SP

-Mod

ul

G4A

C I

nte

rfa

ce

G4A

E M

ode

m N

SK

5

Pow

er a

mpl

.40

W

P4L

A P

ilot+

Sup

ervn

P

4LG

Car

rier

syn

th.

O4L

AT

elc

ont

rol i

nte

rf.

ETL BLOCK DIGARM & PROGRAMMING


Function Level/Level range Remarks

4-wire PAX interface O4LB

4-wire I/P 600 Ohm -3.5 dBr standard-20 up to +10 dBr adjustable in steps of 0.25 dB

4-wire O/P 600 Ohm -3.5 dBr standard-20 up to +10 dBr adjustable in steps of 0.25 dB

M-SIGNALLING "MARK" 0 V external contact closed "SPACE" -12.5 V external contact open

E-SIGNALLING "MARK" opto-coupler on O4LB "ON" "SPACE" "OFF"

SPEECH CONTROL"ON” 0 V external contact closedcompandor off

"OFF" -12.5 V external contact opencompandor on

PAX BLOCKING potentially-free contact on O4LB"ON" closed"OFF" open



O4LB 4 WIRE PAX INTERFACE

FOR CONNECTING 4 WIRE SPEECH SIGNALS AND ASSOCIATED SIGNALLING (E, M, SPEECH CONTROL ETC)TO EXCHANGE. ALSO HAS OPTIONAL HANDSET FACILITY

TX SPEECH PATH: A6-C6---INPUT TRANSFORMER --- INPUT AMPLIFIER WITH ADJ.GAIN S1----HIGH PASS FILTEROF 300HZ-- (COMPRESSOR)---LIMITER---PROGRAMMABLE(1800-3600HZ) FILTER--C13 AF BUS

RX SPEECH PATH: FROM AF BUS A20--PROGRAMMABLE (1800-3600HZ) FILTER--(EXPANDER)--OUTPUT AMPLIFIER WITH GAIN ADJ S3 O/P AMPLIFIER--A8-C8

HANDSET SIGNALS: IN THE TX PATH ENTRY BEFORE HIGH PASS FILTER; IN THE RX PATH BEFORE S3 THROUGH AMPLIFIER

SLOW MUTE: BLOCKS RX WHEN SIGNAL QUALITY LOW

RX SPEECH OFF- WHEN NSD 50 TRIPPING PRESENT

SYNT- CLOCK REQD FOR PROGRAMMABLE FILTER

M SIGNAL (TX) PATH: A26-C26--OPTO-- BUFFER--FILTER-- C31 M WIRE

E SIGNAL (RX) PATH: A31-- BUFFER--FILTER- OPTO--A30-C30. BUSY LED LITS FOR HIGH E/M

SPEECH CONTROL : A24-C24-- OPTO TO MAKE COMPANDER ON /OFF FOR LOCAL/TRANSIT




O4LB: 4 WIRE PAX INTERFACE PROGRAMMING:

I/P (TX) LEVEL: SWITCH S1 (DEFAULT -3.5dBr)O/P (RX) LEVEL: SWITCH S3 (DEFAULT -3.5 dBr)

LOW PASS FILTER: FROM 1800HZ TO 3400HZ THROUGH JUMPERS GH,GG,GE,GF,GD

COMPANDER: CF PERMANENTLY OUT OFF CIRCUIT; CX EXTERNALLY CONTROLLED,CO PERMANENTLY IN CIRCUIT ( WHEN CONTACTS CLOSED BECOMES OUT OFF CIRCUIT”)

PILOT SWITCHING: NORMAL FREQUENCY TC (TX); RC (RX) INVERTED MARK SPACE TD (TX); RD (RX)

O4LC: 2/4 WIRE PAX INTERFACE




2/4-wire PAX interface O4LC2-wire I/P 600 Ohm 0 dBr standard

-16 to +6 dBr adjustable in steps of 0.25 dB

2-wire O/P 600 Ohm -7 dBr standard-16 to +6 dBr adjustable in steps of 0.25 dB

4-wire I/P 600 Ohm -3.5 dBr standard-20 to +10 dBr adjustable in steps of 0.25 dB

4-wire O/P 600 Ohm -3.5 dBr standard-20 to +10 dBr adjustable in steps of 0.25 dB

M-SIGNALLING "MARK" 0 V external contact closed"SPACE" -12.5 V external contact open

E-SIGNALLING "MARK" opto-coupler on O4LC "ON""SPACE" "OFF"

HYBRID "ON" 0 V external contact closed, hybrid in"OFF" -12.5 V external contact open hybrid out

SPEECH CONTROL "ON" 0 V external contact closed, 4-wire levelcompandor off

"OFF" -12.5 V external contact open, 2-wire levelcompandor on

PAX BLOCKING potentially-free contact on O4LC"ON" closed"OFF" open




O4LC: 2/4 WIRE PAX INTERFACE DETAILS & PROGRAMMING

FOR CONNECTING 4 WIRE SPEECH SIGNALS AND ASSOCIATED SIGNALLING (E, M, SPEECH CONTROL ETC)TO EXCHANGE. ALSO HAS OPTIONAL HANDSET FACILITY

O4LC IS SIMILAR TO O4LB EXCEPT THAT IT HAS ADDITIONAL SWITCHABLE HYBRID WITH ADDITIONAL GAIN ADJUSTMENT S2 &S4 FOR 2WIRE TRANS /RECEIVE ALIGNMENT.

2 WIRE SIGNALS COMING OVER A2-C2 ARE CONNECTED TO HYBRID VIA INPUT TRANSFORMER. THE HYBRID IS CONNECTED TO TX RX PATHS BY MEANS OF SWITCHES OPERATED BY HYBRID CONTROL.

THE SPEECH CONTROL SELECTS 4 WIRE PATHS WHEN MADE HIGH; APART FROM OPTIONALLY SWITCHING THE COMPANDER.

JUMPER PROGRAMMING: SIMILAR TO O4LB

ADDITIONAL JUMPER PROGRAMMING:

2 OR 2/4 WIRE MODE TA; JUST 4 WIRE MODE TB

FOR O4LD




O4LD REMOTE SUBSCRIBER INTERFACE

FOR CONNECTING 2 WIRE COONECTIONS TO EXCHANGE/ SUBSCRIBER. ALSO HAS OPTIONAL HANDSET FACILITY

THE PRINT FACILITATES TWO MODES OF OPERATION : PAX TO SUBSCRIBER AND HOTLINE(POINT TO POINT

IN THE FIRST MODE THE PAX SIDE O4LD DETECTS RING RHYTHM FROM THE PAX AND SEND IT TO REMOTE SUBSCRIBER THROUGH M SIGNAL WHICH ARRIVES AS E AT THE OTHER END. THE SUBSCRIBER SIDE O4LD AT THIS END DETECTS IT AND SIMILAR RING RHYTHM IS SUPERIMPOSED ON THE RINGING FREQUENCY AND FED TO THE SUBSCRIBER.; WHEN RECEIVER LIFTS THE PHONE IT DETECTS THE LOOP CONDITION AND PASS ON THE INFORMATION OVER M CHANNEL TO THE OTHER END. HERE THE PAX SIDE O4LD RECEIVES IT OVER E WIRE AND OFFERS LOOP CONDITION TO THE PAX. PAX STOPS APPLYING RINGING VOLTAGE AND THE SPEECH PATH IS MADE THROUGH. WHEN SUBSCRIBER DIALS THE DIALLING PULSES ARE CONVEYED TO THE PAX SIDE VIA THE M-E CHANNEL AND IT OFFERS CLOSED LOOPS TO PAX ACCORDINGLY.

IN HOT LINE CONNECTION BOTH SIDES O4LD ARE SIMILAR. WHEN A SUBSCRIBER LIFTS ITS HANDSET, LOCAL O4LD DETECTS CLOSED LOOP AND THE OPPOSITE END OVER M WIRE THE CLOSED LOOP CONDITION IS INFORMED. AT OPPOSITE END RINGING VOLTAGE IS APPLIED TO THE SUBSCRIBER PHONE TILL THE HANDSET IS LIFTED. DURING THIS TIME THE CALLING PARTY GETS 400HZ RING BACK TONE. WHEN BOTH PHONES ARE OFFHOOK COMMUNICATION IS ESTABLISHED.




O4LD REMOTE SUBSCRIBER INTERFACE

THE PRINT HAS ALL THE REQUIRED OTHER UNITS LIKE FILTER; COMANDER ETC.

THE HYBRID DIVIDES THE SIGNALS IN TO TX AND RX PATHS.

PROGRAMMING

MODE: REMOTE SUBSCRIBER/ POINT TO POINT INTERFACE S1, S2, S3

PAX INTERFACE P1, P2,P3

SWITCH S7: FOR RING SEQUENCE/ RING FREQUENCY

2 WIRE INPUT (TX) LEVEL : S5

2 WIRE OUTPUT (RX) LEVEL: S6

LOW PASS FILTER: S8

COMPANDER: CF PERMANENTLY OUT; CO: PERMANENTLY IN

SIGNALLING: TC; RC NORMAL FREQUECY, TD, RD INVERTED MARK SPACE




O4LA: TELECONTROL INTERFACE :

I/P’s Impedance Setting rangeRemarksINPUT 1, 2, 3 600 Ohm -20 to +10 dBr Steps of 0.25 dB

All I/P's can be programmed to be disconnectable or

non-disconnectable.

I/P 2 can be programmedas transit filter I/Por as broadband I/P

O/P'sOUTPUT 1, 2, 3 600 Ohm -20 to +10 dBr Steps of 0.25 dB

All O/P's can be programmed as transit filter O/Por as broadband O/P




O4LA: TELECONTROL INTERFACE :

3 DC ISOLATED INPUTS (TX) AS WELL AS 3 ISOLATED OUTPUTS (RX)

THE INPUT TX SIGNALS’ LEVELS CAN BE ADJUSTED BY USING SWITCHES S1,S2,S3 (WITH STEPS OF 0.25dB)AND THEN CAN BE CONNECTED TO TX ND OR TX-D BUS.

THE OUTPUT RX SIGNALS CAN BE TAKEN FROM THE BROADBAND RX SIGNAL OF 3.85K OR OPTIONAL 3.6KHZ FILTERED SIGNAL FROM P4LB. THE LEVELS CAN BE ADJUSTED WITH S4, S5, S6.

OPTIONAL TRANSIT FILTER E1LA: THIS OPTIONAL FILTER CAN BE FITTED IN EITHER 2ND TX-INPUT CHANNEL OR ANY COMBINATION OF RX-OUTPUT CHANNEL. THE START AND STOP FREQUENCIES CAN BE ADJUSTED WITHIN BAND OF 360HZ TO 3720HZ IN STEPS OF 60 HZ.




O4LA: TELECONTROL INTERFACE :PROGRAMMING (JUMPER)

DISCONNECTABLE BUS: I/P1-TB, I/P2-TD,I/P3-TF;NONDISCONNECTABLE BUS: I/P1-TA, I/P2-TC,I/P3-TE;

I/P2 : DIRECT TG; THROUGH(OPTIONAL) E1LA:TH,TI (RI,RC,RF,RK OPEN)

SIGNALS 3.85K 3.6K TRANSIT E1LA (TH,TI OPEN)O/P1 RA RB RC,RIO/P2 RD RE RF,RIO/P3 RG RH RK,RI E1LA SETTINGS: HIGH PASS FRE. SWITCHES CD ON E1LA: 300+CD*60

LOW PASS FRE. SWITCHES AB ON E1LA: 360+AB*60STANDARD 10 OPTIONS SELECTABLE BY SETTING D FROM 0 TO 9 WITHABC =990

O/P3 MUTING: FAST(THROUGH NSD50):RL SLOW(WHEN RX QUALITY POOR): RM




P4LB: AF CONVERTOR :TX SECTIONALL AF INPUTS ARE MIXED AND MODULTED WITH 16 KHZ. THE PRODUCT IS FILTERED (<20KHZ) AND PASSED ON TO P4LC.

AF INPUTS TO P4LA: TX D;TX-ND FROM O4LA; TX SPEECH FROM O4LB/C/D;TX-AF(FROM NSD50);TX TEST TONE;TX PILOT(FROM P4LA)AUX AF INPUTFROM EXT.:TRANSIT AF OR EXT.TELEPROTECTION

BOOST LOGIC:TX SPEECH OFF(NSD50): CUTS SPEECH;AUX AF(IF TRANSIT);TEST TONEPILOT SWITCH(NSD50): CUTS PILOTBOOST(NSD50): CUTS TX-D , TRANSIT AUX AF;TEST TONE) BOOSTS TX-AF; SETS 0dB GAIN

FOR EXTERNAL PROTECTIONAUX BOOST(FROM EXT.TELEPROTECTION): CUTS TX-D; TX-SPEECH; TEST TONE; SETS

POWER BOOSTING FOR EXTERNAL TELEPROTECTION




P4LB: AF CONVERTOR :RX SECTION IF SIGNAL IS EQUALIZED AND DEMODULTED WITH 16 KHZ. THE PRODUCT IS FILTERED (<20KHZ) AND PASSED ON TO AF BUSES.

PATH:

EQUILIZER: OPTIONALLY SWITCHED ON OTHERWISE BYPASSEDLIMITER: LIMITS THE AMPLITUDE20KHZLOW PASS FILTER: REMOVES HIGHER FREQ. ELEMENTSDEMODULATOR AND FILTER: DEMODULATES WIH 16KHZ AND FILTERS OUT SIGNAL LESS THAN 3.85KHZ.GAIN ADJUSTMENT: ADJUSTS LEVEL OF AF SIGNALOPTIONAL 3.6KHZ FILTER: SEPARATES OUT PILOT FOR TELECONTROL CARD O4LA OR AUX AF OUT.E CHANNEL FOR AUX INPUT: E WIRE SIGNAL IS FORWARDED TO AUX . CHL FROM E WIRE.




P4LB: AF CONVERTOR :TX SECTION PROGRAMMING

AUX INPUT LEVEL: R65+R66INPUT TRANSITAUX AFCHANNEL: TFINPUT EXTERNAL PROTECTION:TEAUX EXT. TELPROTECTION BOOST: DC ISOLATED-TA,TC; NOT ISOLATED-TB,TD

POSSIBLE BOOST LEVELS: 0dB, 5dB, 7dB, 9dB;THOUGH SWITCH S1-- (S1-1,2,3,4-NSD50) &(S1-5,6,7,8 FOR EXTERNAL TELEPROTECTION)

RX SECTION PROGRAMMINGAUX AF O/PLEVEL -10dBr RI OPEN; -3.5dBr RI INOUTPUT TRANSITAUX AF CHANNEL: REOUTPUT EXTERNAL PROTECTION: RFEQULISATION: THROUGH SWITCHES S2, S3 AND JUMPERS RA,RB,RC,RD.




P4LC: IF CONVERTOR :TX SECTION

THE INPUT COMING FROM P4LB IS FIRST FILTERED FOR 16.3KHZ TO 19.85KHZ; PASSED ON TO MIXER WHICH MIXES WITH 2ND IF( 640KHZ FOR 1/3 CHL AND 636 KHZ FOR 2/4 CHL). THE O/P (624-620KHZ FOR 1/3 CHL &620-61KHZ FOR 2/4 CHL) IS FILTERED BY LOW PASS FREQUENCY AND BALANCED O/P IS PASSED TO NEXT SECTION.

THE FRE. 640KHZ/160KHZ REQD FOR 1/3 CHL IS DERIVED FROM 7.68MHZ SIGNAL FROM P4LG. THE FRE. 636KHZ/156KHZ REQD FOR 2/4 CHL IS DERIVED FROM 1272KHZ /312KHZ SIGNAL FROM P4LI.SELCTION OF IF2 IS CONTROLLED BY V9LK CHANNEL LINK OF 2/4TH CHANNEL.

RX SECTIONTHE SIGNAL FROM P4LD(P4LE) IS IN THE RANGE 144-140KHZ(140-136KHZ) . THEY ARE FIRST DEMODULTED WITH 160KHZ(156KHZ); FILTERD IN THE BAND 16.3KHZ TO 19.85KHZ AND THEN PASSED ON TO AGC AMPLIFIER. THIS FILTER OFFERS MAIN SELECTIVITY OF RECEIVER.THE AGC VOLTAGES VARIES IN ACCORDNCE WITH RECEIVER SIGNAL STRENGTH AND PROVIDED BY P4LA. THIS IS FOLLOWED BY ANOTHER AMPLIFIER WHOSE GAIN CAN BE INCREASED BY 10dB BY SELECTING RX LOW DISTORTION ON BACKPLANE




P4LF: TX RF CONVERTOR :

THE INPUTS COMING FROM P4LC OF FIRST(624-620KHZ) AND SECOND(620-616KHZ) CHANNELS ARE FIRST SUMMED IN A SUMMATION AMPLIFIER ;FILTERED FOR RANGE 616-624KHZ AND GAIN ADJUSTED.LATER THEY ARE MODULATED WITH TXFC AND FILTERD OUT BY A LOWPASS FILTER OF 500KHZ. THE TXFC IS fTXCHANNEL + 624KHZ FOR 1&2 CHANNELSAND FOR 3&4 TH CHANNELS IT IS fTXCHANNEL + 632KHZ . THE FILTERED OUTPUT IS FED TO GAIN ADJUSTMENT UNIT WHOSE SETTING IS DONE WITH SWITCH S1. THE SETTING IOF S1 IS DONE DEPENDING UPON INPUT LOADING. AN ADDITIONAL TRIMMER IS ALSO PROVIDED FOR ALLOWINGCHANGES DUE TO HYBRID /TRANSMIT FILTER.THE TXFC IS SET IN THE P4LG.THE P4LF RECEIVES 2TXFC FROM P4LG. IT IS FILTERD AND PASSED TO P4LA FOR EVALUTION AND ALSO TO HYBRID THROUGH SWITCH. WHEN THE LOCAL LOOP MODULE P3LK IS INSERTED IN PLACE OF P3LA/B IT IS EVALUATED IN P4LA AND THE SWICH IS CLOSED SO THAT P3LK RECEIVES THE TRANSMITTER FREQUENCY.




P4LF: TX RF CONVERTOR :SETTTING TX LEVEL FOR ETL41/42POWER T [dBm]: test tone level at the RF O/P across the dummy load.

T(RF) [dBu]: test tone level at the test sockets RF LINE on P3LB. 0 dBu corresponds to 10 W

S(W1): sum of the voltage weighting of all the channel 1 signalsincluding the pilot

S(W2): sum of the voltage weighting of all the channel 2 signalsincluding the pilot

S(W) = S(W1) + S(W2)

Permissible allocation to the channels for one and two-channel operationETL41: 2.4 < S(W) µ 3.5ETL42: 3.0 < S(W) µ 7.0

S: setting on P4LF




P4LF: TX RF CONVERTOR :SETTTING TX LEVEL FOR ETL41/421) Sum of the channel 1 voltage weightings: S(W1)

S(W1) = [n0*1.41 + n1*0.2 + n2*0.28 + n3*0.4 + n4*0.71 + n5*1.0(0.71) + n6*1.0 + 0.5]

where: n0 = 1, for speech, otherwise n = 0;n1=No. of 50 Baud data channels;n2=No. of 100 Baud data channels;n3=No. of 200 Baud data channels;n4 =No. of 600 Baud data channels;n5=No. of 1200 Baud data channels,1200 Bd V.23: weighting 1.0; 1200 Bd above speech channel: weighting 0.71n6 = 1, for a 2400 Bd data channel, otherwise 0

Channel 2:The calculation of S(W2) is the same as for S(W1), but with the channel 2 signal allocation.

2) Setting on P4LF: SS = S(W) - 0.5

3) Transmitter test tone level at the RF O/P: POWER T = LPEP - 20*log S(W) (dBm)where: LPEP(dBm): transmitter power available +45 dBm with 40 W equipmentNote: The RF test tone level POWER T applies to channel 1 and channel 2.

4) Test tone level at the test sockets on P3LB: T(RF)

T(RF) = POWER T - 40 dB [dBu]




P4LF: TX RF CONVERTOR :SETTTING TX LEVEL FOR ETL41/42

Sum of channel 1 voltage weightings: S(W1)

Setting on P4LF: S

Transmitter test tone level at the RF O/P: POWER T

Test tone level at the test sockets on P3LB: T(RF)

Example ETL 41

Allocation: speech + 600 Bd

Sum of channel 1 voltage weightings: S(W1)S(W) = S(W1) = [1.41 + 0.71 + 0.5] = 2.62

which is rounded to S(W) = 2.6

Setting on P4LF: SS = S(W) - 0.5

S = 2.6 - 0.5 = 2.1

POWER T = 45 dBm - 20*log [2.6] = 36.7 dBm

T(RF) = 36.7 dBm - 40 dB = -3.3 dBu




P4LF: TX RF CONVERTOR :SETTTING TX LEVEL FOR ETL41/42

Sum of channel 1 voltage weightings: S(W1)

Setting on P4LF: S

Transmitter test tone level at the RF O/P: POWER T

Test tone level at the test sockets on P3LB: T(RF)

Example ETL 41

Allocation: NSK 5 2400 Bd

S(W) = S(W1) = 1 + 0.5 = 1.5Since the available setting range is 2.4 < S(W) < 3.5, S(W) = 2.4 has to be chosen.

S = 2.4 - 0.5 = 1.9

Power T = 45 dBm - 20 log 2.4 = 37.4 dBm

T(RF) = 37.4 dBm - 40 dB = -2.6 dBu




P1LA: TX POWER AMPLIFIER

SIGNAL FROM CHL1 & 2 COMES OVER TXRF12; SIGNAL FROM CHL3 & 4 COMES OVER TXRF34;PATH: I/P TRANSFORMER--AGC AMPLIFIER--PREAMPLIFIER--DRIVER--PUSHPULL AMPLIFIER--- OUTPUT TRANSFORMER.

INPUT & OUTOUT TRANSFORMERS: ISOLATES THE POWER AMPLIFIERS DC SUPPLY 9TAKEN FROM B5LA)FROM OTHER PARTS OF THE EQUIPMENTS.AGC AMPLIFIER: SENSES THE EMITER CURRENTS OF THE POWER TRANSISTORS ADJUSTS GAINPREAMPLIFIER: COMBINED CURRENT AND SUPPLY VOLTAGE BASED REGULATION TO MINIMUM DISTORTION DRIVER CIRCUIT: LOW SOURSE IMPEDANCEPUSH PULL AMPLIFIER: MAIN GAINSUPERVISION: MONITORS CURRENT AS WELL AS SUPPLY VOLTAGE; TRIMER FOR SETTING THRESHOLD FOR TX LEVEL ALARM; THE STATUS OF ALRM CHECKED BY P4LA.




TRNSMIT FILTER E5LA/B

FUNCTIONS:REMOVES SPURIOUS EMISSIONS OF POWER AMPLIFIER COMING OVER LINEHIGH IMPEDANCE FOR OTHER FREQUENCIES PARALLELING OF EQUIPMENTSPROTECTION TO POWER AMPILFIER FROM LINE SURGES/SPIKES ETC.

PASSES VIA HYBRID; AND REURNED AGAIN TO HYBRID.

CAN BE TUNED AT SITE ; CENTER FERQ. CANBE ADJUSTED BY FOUR SETS OF CAP.C11---C28. FINE TUNING BY COIL L1, L2.

E5LA FOR 100-500KHZ RANGEE5LB FOR 24-500KHZ RANGE




HYBRID P3LB; P3LA

DECOUPLES TX AND RX SECTIONTRANS HYBRID ATTENUATION MUST FOR ADJUCENT TX -RX CHANNELS

IMPEDANCE MATCHING: FOR 75 OHM JUMPERS 75OHM,CMFOR 125 OHM JUMPER 125 OHM

FOR 16KHZ BANDWIDTH ON P3LB: T3;T4 AND REMOVE TA,TB.

JUMPERS RA;RP & LA…LO;CA..CO FOR TRANSHYBRID ATTENUATION

RECEIVER RX LEVEL ADJ FOR AGC SETTING.




P4LD/P4LE RX RF CONVERTOR

CONVERTS RX TO BAND OF 144-140 (& 144-136 FOR P4LE)

PATH: 1. FILTER TUNABLE(FIRST LEVEL OF SELECTION) MAIN PURPOSE SUPPRESSION OF LOCAL TX FREQ.2. DEMODULATION TO 624-620KHZ(624-616KHZ FOR P4LE) WITH RXFC(DERIVED FROM 2RXFCFROM P4LG)3. FILTER FOR THE ABOVE BAND4. DEMODULATION WITH 480 KHZ (DERIVED FROM 7.68M OF P4LG) TO 144-140 KHZ(144-136KHZ)5. FILTER FOR ABOVE BAND

RXFC FORWARDED TO HYBRID.




P4LG: FREQUENCY SYNTHESISER

QUARTZ CRYSTAL BASED VCXO GENERATES 7.68MHZ AND 16KHZ .

VCXO CAN BE PROGRAMMED AS SLAVE/ MASTER BY JUMPERS SA,SB OR MA,MB. IN SLAVE MODE THE ERROR VOLTAGE GENERATED BY P4LA AFTER COMAPERING 16KHZ LOCAL AND THE RECEIVED; IS USED TO CORRECT THE FERQUENCY DIFFERENCE. THIS VOLTAGE IS CALLED RX SYNC VOLTAGE.. THE RANGE FOR THIS IS 6.0+/-2.0V

PLL TX USES 16KHZ AND GENERATES TXFC AS WELL AS 2TXFC FREQ. IT CALSO GENERATES 16 KHZ AND COMPARES WITH 16KHZ OF VCXO AND CORRECTS ITS FREQUENCY. THE ERROR VOLTAGE IS CALLED TX VCO AND SHOULD BE WITHIN RANGE OF 1.6 TO 2.0V

PLL RX USES 16KHZ AND GENERATES RXFC AS WELL AS 2TXFC FREQ. IT CALSO GENERATES 16 KHZ AND COMPARES WITH 16KHZ OF VCXO AND CORRECTS ITS FREQUENCY.THE ERROR VOLTAGE IS CALLED RX VCO AND SHOULD BE WITHIN RANGE OF 1.6 TO 2.0V

THE TXFC AND RXFC ARE SELECTED BY USING PROPER JUMPERS AND WHILE DOING PROPER JUMPER CONDITION SHOULD BE OBSERVED FOR ELECTROSTATIC DISCHARGE.




B4LA; B5LA

B5LA 48V STABILISER

CONTAINS FILTER AND PROTECTION CIRCUIT AT ITS INPUT TO PROTECT FROM INRUSH CURRENT. THE FILTERED OUTPUT IS PROVIDED AS AUX SUPPLY TO POWER AMPLIFIER P1LA.F2 IS FOR OVERLOAD PROTECTION

B4LA DC DC CONEVERTOR

IT CONVERTS THE 48 IN COMING FROM B5LA TO REQD SUPPLY VOLTAGES OF 12, -12, AND 5V.




• P4LA PILOT AND SUPERVISION CARD

• GENERATES PILOT AND MODULATES WITH M SIGNAL; CHECKS HEALTHY NESS OF TX PILOT (CONVEYS THE SAME TO NSD-50)

• GENERATES TEST TONE (1000HZ)• TEST GENERATOR 800HZ/3000HZ; 0dBm/-3.5dBm• DEMODULATES RX PILOT AND GENERATES E SIGNAL FOR TELEPHONY INTERFACES.• CHECKS THE RX LEVEL STRENGTH AND SIGNAL TO NOISE RATIO FOR RECEIVER.• RX LEVEL BUFFER IS INDICATED BY 2 DIGIT DISPLAY• FACILITATES REMOTE LOOP FUNCTION• DISPLAYS ERROR CODES FOR DIFFERENT ALARMS WHEN TEST TONE CALL BUTTON

PRESSED OVER 2DIGIT DISPLAY.• POWER SUPPLY/ TX/RX ALARMS BY LED INDICATION• SYNCHRONISES RECEIVER IN CASE OF SLAVE STATION.


Power Line Carrier ETL Family Training ProgramETL TESTING FACILITIES

ETL TESTING FACILITIES



• Local Loop Test

– Dummy load

– Frequency conversion RF-TX / RF-RX

• Remote Loop Facilities

– Fully remote controlled

– Received signal of any AF-frequency is transmitted back at fixed amplitude, allowing channel frequency response measurements and equalization from one location

• Test signal generator 800 Hz and 3000 Hz

• Display of AGC voltage and error codes



yfx fy

IF/RF

RF/IF AF

AF

TrackingFilter

PLC

fx fy fx fy

Opposite station

Rem

ote

Loo

p cl

ose

d

f input = foutput

ULoc

ULoc

fx f

UOpp

fx fy

UOpp

UOpp

IF/RF

RF/IF

AF

AF

Local station

dB

G

AmplitudeEqualization

(tracking filter)



ETL TESTING


Power Line Carrier ETL Family Training ProgramETL TESTING

TEST METHOD : SILENT FEATURES (NOT A SUBSTITUTE FOR TEST PROCEDURE ACTUAL SUPPLYED WITH TUNING INSTRUCTIONS)

1. BEFORE SWITCH ON; CHECK THE PROGRAMMING IS DONE AS PER THE REQUIREMENT IN CONSULTATIONS WITH TUNING INSTRUCTION. ENSURE THAT THE ETL IS TERMIANETD ON A PROPER LOAD (ACTUAL LINE/DUMMY LOAD OF 75OHM/P3LK THE LOOP CARD)2. CHECK THE INPUT POWER SUPPLY AND FIRM EARTH CONNECTION.3. AFTER SWITCH ON CHECK THE POWER SUPPLY VOLTAGES /ALARMS ON B5LA;B4LA;P4LA.4. CHECK THE FREQUENCIES AND VCO/AFC VOLTAGES ON P4LG.5. VERIFY THAT THE TEST TONE LEVEL AND PILOT LEVEL GENERATED IN P4LA IS CORRECT.6. ALIGN THE TRANSMITTER USING TEST TONE. CHECK THE LEVEL AT COAXIAL.* THE P4LF SWITCH S SETTINGS SHOULD BE CHECKED WHETHER IT IS AS PER CALCULATIONS.7. IN RECEVER SIDE FIRST PROPER INPUT LEVEL AT COAXIAL.8. ADJUST THE AGC (P4LA-2DIGIT DISPLAY) TO 26.9.EITHER ENABLE THE REMOTE LOOP FUNCTION / ASK SOMEBODY TOPRESS CALL BUTTON AT OPPOSITE END TO MEASURE RX LEVEL AT P4LB.10. CARRY OUT THE TELEPHONY/ TELCONTROL INTERFACE TX /RX TESTING.11. FOR FAULT IDENTIFICATION PRESS THE CALL BUTTON; CHECK ERROR CODE ON P4LB DISPLAY; FOR MEANING REFER INSTRUCTIONS MANUAL.

Documents

Etl Training2