1550nm TRANSMITTER

1550 nm EXTERNAL MODULATION

CATV OPTIC TRANSMITTER

USER MANUAL

Quality Cable and Electronics • 1780 N.W. 15th Avenue Suite 400 • Pompano Beach, FL 33069

Tel: (954) 978-8845 • Fax: (954) 978-8831 • www.qualtiycable.com • Email: [email protected]

DECLARATION

Our Company describes the manual of 1550nm external modulation transmitter 2X3 dBm roundly precisely & in latest edition. But we apprizes clients prudently that our company reserves the authority to adjust the relevant content in the file. We will not take the responsibility for the result from the mistake of recommended material, printing & tabling.

This manual states the shape, function, installation, network application and all the acceptable standard options of 1550nm

External modulation CATV optic transmitter 2X3dBm. Includes following items: y SYSTEM INSTALLATION y SYSTEM OPERATION y SYSTEM DEBUGGING y NETWORK DESIGN y OPERATION PRINCIPLE y FAULT DISPOSAL FLOW y RETURN FOR REPAIR

1

CONTENT

Ⅰ. Product summary………………………………………………………………………………………4

1.1 Product summarize …………………………………………………………………………………

4

1.2 Product specialty……………………………………………………………………………………

4

1.3

Technique index ……………………………………………………………………………………4

Ⅱ. Installation …………………………………………………………………………………………5

2.1 Goods receipt checking …………………………………………………………………………

5

2.2 Installation notice ……………………………………………………………………………

5

2.2.1 Safety factor ………………………………………………………………………………

5

2.2.2 Static sensitivity specialty …………………………………………………………………

6

2.3 Installation preparation ……………………………………………………………………………

6

2.3.1 Environment condition ………………………………………………………………………

6

2.3.2 Power supply condition………………………………………………………………………

6

2.4 Equipment setting …………………………………………………………………………………

7

2.5 Electric connection …………………………………………………………………………………

7

2.6 RF connection ……………………………………………………………………………………

7

2.7 Optic connection ……………………………………………………………………………………

7

Ⅲ. Operation ……………………………………………………………………………………………8

3.1

Front panel control & indicator ……………………………………………………………………8

3.2 Rear panel connection ……………………………………………………………………………

9

3.3 Boot-strap Sequence………………………………………………………………………………

9

3.4 Startup main menu ………………………………………………………………………………

10

2

3.5 Startup sub menu ……………………………………………………………………………

10

Ⅳ. （OMI）adjusting …………………………………………………………………………………10

4.1 Request for RF signal……………………………………………………………………………

10

4.2 Request for RF signal……………………………………………………………………………

10

4.3 AGC status …………………………………………………………………………………

11

4.3.1 AGC status setup ……………………………………………………………………

11

4.3.2 AGC status adjusting …………………………………………………………………

11

4.4 MGC status …………………………………………………………………………………

11

4.4.1 MGC status setup ……………………………………………………………………

11

4.4.2 MGC status adjusting ……………………………………………………………………

12

Ⅴ. Network design ………………………………………………………………………………………12

5.1 SBS critical value ‘s choice ……………………………………………………………………

12

5.1.1The longest optic fiber distance of system transmission ……………………………

12

5.1.2 Fiber input optic power……………………………………………………………………

12

5.2 Correct connection between TX & EDFA ……………………………………………………

13

5.3 Incorrect connection between TX & EDFA ……………………………………………………

13

5.4 SBS adjustment process ………………………………………………………………………

14

Ⅵ. Equipment working principle ……………………………………………………………………14

Ⅶ. Fault disposal ……………………………………………………………………………………… 15

7.1 Warning status …………………………………………………………………………………

16

7.2 Alarm status ……………………………………………………………………………………

17

7.3 Fault precaution ………………………………………………………………………………

17

3

7.4 Deflection restoration ……………………………………………………………………………

17

7.5 Sensitivity degree to 980 nm laser ………………………………………………………………

17

Ⅷ. Guaranteed repair range for product ……………………………………………………………18

8.1 Guaranteed repair rule ………………………………………………………………………

18

8.2 Instruction for special product guarantee & repair ………………………………………………

18

8.3 Compensation range ……………………………………………………………………………

18

Ⅰ. PRODUCT SUMMARY

1.1 Product summarize

1550nm External Modulation CATV transmitter 2X3dBm adopts low noise, narrow bandwidth, and continuous wave laser as its light source. It uses high linearity LiNbO3 external modulator to modulate signal. It eliminates the Chirp Effect of 1550nm direct modulation laser. Due to adopting owned system optimized control technology & using top grade key parts, the machine’s technique performance index achieves the standard of same advanced products in the world totally.

1.2 Product specialty

1. High index

：Original system optimized control technology, offers excellent CNR, CTB, CSO & SBS index.

2. Flexibility

：Original SBS critical value 13, 16, 18 adjustable at spot, it can fit for different network.

3. Reliability

：Inside double power supplies, switch automatically. Machine case temperature control automatically.

4. High quality

：Intuitionistic Optic Modulation Intensity（OMI）display.

4

1.3 Technical index

Optic feature

RF feature

Link feature

Wavelength range

Line width

Side mode suppression ratio

Equivalent noise intensity

Output power

Return loss

Optical fiber connector

Work bandwidth

Input level

Flatness

Return loss

Input impedance

RF port

Transmit channel

CNR1

CNR2

CTB

CSO

SBS restrain

Network interface port

Power supply

Power Consume

General feature

Work temp.

Storage temp.

Operating relative humidity

Size

(dB)

(dBm)

(V)

(W)

(dB)

(dB)

(dB)

(nm)

(MHz)

(dB)

(dB/Hz)

(dBm)

(dB)

(MHz)

(dBmV)

(dB)

(dB)

(Ω)

(℃)

(℃)

(%)

(")

1555±5 ITU-TG.692 Standard wavelength

≤

1 FWHM(△λ)

≥ 45

≤ -160

2×3

≥

50

SMSR

RIN (20~1000MHz)

Optional 2×5, 2×6, 2×9, 2×10

47-862

18~28 AGC

≤±

0.75 45~862MHz

>16 45~750MHz

75

F-Female

PAL-D/60CH NTSC/80CH

≥ 53

≥

52

≤

-65

≤ -65

13, 16, 18

RJ45, RS232

Back to back

65Km optical fiber, 0dBm receive

Adjustable

Support I.E. & SNMP

≤ 50

-5~65

Single power works

Machine temp. control automatically

-40~85

5~95

19×14.5×1.75 (W)x(D)x(H)

Ⅱ. INSTALLATION

In installation equipment, please execute as following process. Every detail of installation will be described in this chapter. This chapter includes main contents as below. y Checking the possible loss or damage of the equipment in transportation. y Prepare the executive setting environment y Setting 1550nm optic transmitter

5

y Electric connection y RF signal connection y Optic connection y Network connection ports

2.1 Checking goods in receiving

Carefully open the packing to check the machine & parts. Please check the packing material of small parts also. Checking the objects as below items. y 1550nm optic transmitter y User operation manual y Test datum of leaving factory y Alternating power supply plug wire

If any item lost or damaged, please inform us immediately.

2.2 Installation notice

2.2.1 Safety factor

When install & use the products, please accord with all the relative safe measure of management & operation. If disobey below stated safety measure & special steps in the manual, it will damage the safe grade in product design, production & expected purpose. Our company will not take any responsibility for the result from user disobeying safety measure. Please notice the content with the below sign ; if ignore it, will bring damage to equipment & parts possibly.

WARNING

Don’t operate it before you understanding & realizing all the conditions exactly!

2.2.2 Static sensitivity spatiality

Please obey static protection process and operate it.

Operating according to design request totally, the semi-conductor optic transmitter & receiver have high reliability performance. But, the static result from careless operating will damage the semi-conductor transmitter possibly.

Static can pass through the rear panel connector or front panel test ports into the semi-conductor transmitter. When opening or operating the transmitter, please accord with Static Protection

Procedure, including using grounding metal wrist belt, grounding worktop & grounding conductor.

If place the optic transmitter on the ground, the static charge will mostly decreased.

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2.3 Installation preparation

2.3.1 Environment conditions

According to the design request, 1550nm optic transmitter can work under 0

℃～50℃（32℉～122℉） temperature range. We recommend 25

℃（77℉）environment temperature.

Humidity not bigger than 95 %

（under non-coagulation condition）. If necessary, the equipment should keep the suitable temperature & humidity in the restrained scope. We recommend to operating in the environment without dust.

2.3.2 Power supply condition

Equipment powered by AC or steady voltage DC. In both of AC & DC, AC is the chief power supply.

Request of power supply:

AC input

94-245 VAC

，50-60 Hz

DC input

Power consumption

36-60 VDC

，floating

Maximum 50 W

The DC power supply of the equipment must be the SELV supply stipulated as CAN/CSA

C22.2 No.950-95 standard.

2.4 Equipment setting

1550nm optic transmitter adopts 1U high

，Standard 19″casing. We suggest to keeping 1.75-inch

(about 4.5cm) space on the top & bottom of the machine, to ensure the ventilation & heat dispersion.

2.5 Electric connection

(1) The machine should have good grounding, grounding resistance

＜4 Ω . According to the international standard, 220V plug in adopts tri-wire rule, the middle wire is the grounding wire.

(2) The machine adopts high performance, high reliability, steady voltage switch power supply, it has isobaric ally overflow protection. It can work in 110~254 VAC electric network. The micro processor are monitoring the output DC voltage. If the Fuse is melted broken, it shows the machine’s inner parts has occurred problems.

WARNING

7

Before connecting circuit, please use big spec (#20AWG and more) electric wire to connect the grounding screw on the bottom and the grounding frame. When use DC input power supply, the equipment chassis must be grounding.

2.6 RF connection

Connect the RF cable & the connector on TX rear panel. RF connector is F type plug. The equipment uses Britain System. The resistance is 75

Ω

.

2.7 Optic connection

Considering for protection & safety, all the fiber optic connector need protect cover in transportation.

Don’t take away the protect cover before setting.

In order to ensure the insertion loss & return loss, the end-face of fiber optic connector is polished extremely. Please don’t dirt the pollute the connector. Even very micro dust will also affect the transmission quality. When off the fiber optic connector, please put on the protection cover.

To keep the cleaning of fiber optic connector in connection or re-connecting is very important.

Without proper maintain job, fiber optic transmission system will not realize the function very perfectly.

The system function will be decreased as below forms y Analog signal transmitting quality turns bad y Digital signal wrong data rate will increase y Optic power will be decreased. y Optic receiver’s receipt optic power cannot reach the best range. y Dusty fiber optic connector will pollute other connected optic parts.

Recommended RIFOCS Co., Ltd ’s 945/946 fiber optic cleaning system to clean the connectors. For the covered optic fiber connector, please discharge the rear panel then pull out the inner optic jumper and clean it.

WARNING

Cleaning all the fiber optic connectors before setting.

Connect the output fiber optic jumper into the proper input connector socket of EDFA. The connector type is FC/APC, E-2000, pigtail or SC/APC optional.

8

Ⅲ. OPERATION

3.1 Front panel control & indicator

1. Laser key switch Laser source On/Off switch

（Press to ON）

2. Status indicator LCD

①LASER Laser

②RF

RF status

3. VFD display Double line VFD display each parameter & warning

4. Choose button

△, ▽ Up/down/choice

5. Status Choose main menu and set up working status & parameter

6. OMI modulation coefficient indicator Indicate present OMI index

No RF input, 20 lamps all not turn on

2 pcs green lamps on (in 20 pcs lamps) indicates OMI suitable

（as original status of leaving factory）

7. AGC status indicator This lamp on, it is in AGC status

8. MGC status indicator This lamp on, it is in MGC status.

9. OMI adjusting This function for user application

--

In AGC status, OMI value adjustable slightly In MGC status, OMI value adjustable

① Key switch

Accord with IEC safety standard

；

Protect radiation to the user’s bare skin..

③

Display

⑤

Layered menu,

Select

controlled by front buttons. Monitor &

Select one item from the menu to observe and adjust it. control the selected parameter.

Modulation

Depth

Indicator

⑩

RF

For inspect of input signal

9

②

Lighting diode status

1.Laser status lamp

2.RF input status lamp

3.Casing temp. status

4.Power supply status

3.2 Rear panel connection

④

Up/Down button

Guide user for checks the menu and adjusts the parameter.

⑨ OMI adjust slightly

⑧ MGC status indicator

⑦ AGC indicator status

Power supply input module consists of

“On/Off”switch , adopts 3-pin IEC AC plug-in.

Notice: Before turn on the power supply in rear panel, please confirm the key switch of front

panel is on the ‘Off’ position. Rear panel image:

FAN

3.3 Boot-strap sequence

A

、 Plug in 220V city power supply

B

、 Turn on power switch in the rear panel

Front panel display “ KEY OFF”

Laser Status lamp Red

RS232

RF Status lamp Red

10

FAN powers

FAN Status lamp Green

POWER Status lamp Green

C

、 Press laser start-up key switch

Front panel shows “KEY ON

……”，Laser status lamp turns green from red, machine enters self-checking, after checking it enters working status, display “ Welcome to……

。”

3.4 Start-up main menu

Press Status button will display below main menu in sequence.

A

、 model

B

、 Optic Menu

Optic status menu

C

、 OMI Level Menu

Optic modulation intensity menu

D

、

E

、

F

、 Modulation Menu

External modulator status menu

G

、 Stem Menu

System parameter menu

3.5 Start-up submenu

Press

△、▽ button will display submenu.

When screen displays submenu, press “ Status” will not work any longer.

Ⅳ. OPTIC MODULATION INTENSITY（OMI）ADJUSTING

4.1 Request to RF signal

Input gain

： AGC status 78dBμV～88dBμV

MGC status 75dB

μV～85dBμV

Bandwidth

： 45～862MHz

Flatness degree

： ±0.75dB（45～862MHz）

11

Resistance

： 75Ω

4.2 Description of OMI

A

、 When the machine leaves factory，the default OMI is set on AGC status.

B

、 The machine has Build-in software, after switching off, it will keep the earlier OMI status and

OMI set.

C

、 The OMI is setup on the best status when leaving factory, “Modulation Depth” modulation coefficient status indicator will be on NOM position , ( two green lamps turning on), referring to the Modulation Depth when under full channels loading, TX to RX, system CNR

≥53Db.

D

、 The position of Modulation Depth modulation coefficient status indicator lamp is determined by the needed Modulation Depth, if it is in NOM position has nothing to do with any default of the whole unit.

E

、 Increasing OMI value, CNR will be up，but CTB、CSO value will be down. On the contrary, decreasing OMI value, CNR be down, CTB

、CSO value will be up.

F

、 If not necessary, please don’t adjust OMI value.

4.3 AGC status

4.3.1 Set AGC status

A

、Press Status button, display OMI Level Menu main menu

B

、Press △、Vbutton, check current OMI status

If display RF Mode=AGC, then the unit is under AGC status

If display RF Mode=MGC, then the unit is under MGC status

C

、Press Status button, display RF MODEL=

D

、Press △ button to confirm, RF Mode=AGC

AGC set is completed

4.3.2 OMI adjustment under AGC status

Press Status button, display OMI Level Menu main menu

12

Press

△、Vbutton, display OMI ADJ= ±×.××

Press Status button, display OMI ADJ=.

Press

△、Vbutton, 0.3 dB step length, choose the proper value, such as OMI ADJ= +3.5dB。

Press Status Button, and confirm the OMI value.

4.4 MGC status

4.4.1 Set MGC status

A

、Press Status button, display OMI Level Menu main menu

B

、Press △、Vbutton, display RF Mode=AGC sub-menu

C

、Press Status button, display RF MODEL=

D

、Press △ button to confirm, RF Mode=manual

MGC set is completed

4.4.2 MGC status adjustment

Confirm RF Mode=MGC

Use slim “—“ type screwdriver into OMI adjusting hole, adjusting OMI, make Modulation Depth

（ modulation coefficient indication ）to NOM position, namely two green lamps turning on, this time, RF status will turn from red into green.

The adjusted result should let CNR, CTB, CSO accord with system index.

Ⅴ. NETWORK DESIGN

1550nm system can use EDFA to extend transmission distance, when signal is operated in 1550nm, the fiber should be considered of some factors, such as Chromatic Dispersion, SBS, SPM ( Self

Phase Modulation ) and other non-linearity effect of optic fiber. The network we designed for you has supplied some simple rules of using the transmitter.

5.1 The choice of SBS critical value

5.1.1 The longest optic fiber distance in system transmission

If you want to transmit more than 100km, you need to select 13dBm SBS restrain status. Why you need to do this is because of SPM & optic fiber Chromatic Dispersion. If bandwidth-extending status is not changed, when fiber length is longer, CSO performance will be worse. If you want to choose

13

longer distance transmission, you need to select smaller line bandwidth. 13dBm is much smaller,

16dBm is much bigger, and 18dBm is the biggest. The following table shows the recommended fiber length in which SBS restraint status.

Optic Fiber Length

＜60Km

SBS Restrain Condition

13dBm, 16dBm, 18dBm

13dBm, 16dBm

＜70Km

13dBm

＜120Km

＞120Km

13dBm

（CSO performance will be some different from the specification possibly

）

5.1.2

The biggest optic fiber Input power is restricted by SBS restraint status. If your power is bigger than the stipulated limit, it will occur some bad result. The low frequency band will have 1/f noise, low channel’s CNR will not be good, HUM will also be worse than in normal status. The attached table shows the limit value of SBS restraint power.

SBS restraint power

18dBm

Limit of optic fiber input power

Max.18.4dBm

16dBm Max.16.4dBm

13dBm Max.13.4dBm

The general CATV operator will use high power EDFA (such as 22dBm and higher one), and use optic splitter to arrange the power transmitting in the optic fiber & cable. It is no problem to do this, because the optic fiber patch cord is short. But it is necessary to notice that SBS restraint setup rest with the worse situation, for example, the longest distance & the biggest fiber input power in the optic cable.

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5.2 The correct link for transmitter & EDFA

Transmitter rated at 65 Km,

16dBm SBS restraint

Transmitter rated at 65 Km,

16dBm SBS restraint

16dBm

EDFA

19dBm

EDFA

16dBm

16dBm

65Km

65Km

65Km

Transmitter rated at 65 Km,

13dBm SBS restraint

13dBm

EDFA

40Km

5.3 Incorrect link for transmitter & EDFA

EDFA LAUNCH POWER

ABOVE SBS LIMIT

Transmitter rated at 100 Km,

13dBm SBS restraint

16dBm

EDFA

13dBm

EDFA

65Km

60Km

Receive

Receiver

Receiver

Receiver

Receiver

65Km

EDFA LAUNCH POWER

ABOVE SBS LIMIT

19dBm

Receiver

Transmitter rated at 65 Km,

16dBm SBS restraint

22dBm

EDFA

19dBm

Receiver

65Km

FIBER DISTANCE

ABOVE MAXIMUM

TRANSMITTER RATING

Transmitter rated at 65 Km,

16dBm SBS restraint

13dBm

EDFA

40Km

13dBm

EDFA

60Km

Receiver

15

5.4 SBS adjustment process

1550nm External modulation transmitter 2X3dBm offers special technology. It can let user adjust the

SBS critical value at the spot. The default SBS restraint value is 16.5dBm when leaving factory. The user can adjust it by himself. The adjustment process according to the real requirement of system:

A

：Use STATUS button, select “SBS Menu” main menu；

B

：Use △▽ button, select “ SBS=16.5” submenu ；

C

：Press STATUS button, enter to opening “SBS” select software；

D

：Use △▽ button，select the SBS critical value what you need；

E：Press STATUS button again for confirmation.

Ⅵ. EQUIPMENT OPERATION PRINCIPLE

1550 nm optic transmitter principle frame as picture 18 stated. Input RF signal is verified at AGC circuit unit and affect on optic modulator to modulate the CW light, which is output from 1550nm laser module. The small part output light is checked partly, then feedback to modulator circuit to control the modulation gain & modulation distortion gain.

Picture 18. 1550 nm optic transmitter operation principle frame

16

The non-linearity of optic modulator is inherent. If there is no compensation, the distortion & intercrossing modulation of modulator will let the signal cannot be applied. Generally, the inherent distortion can be modified by adding DC deflected voltage on modulator crystal. For one more modification, you can monitor the inter-modulation result of two low gain test signals, then adjust the

DC deflected voltage of modulator to decrease the distortion into the smallest value. These process is in continuous execution under the closed loop control of system control microprocessor . It is clear to user.

Microprocessor monitors the deflected gain for eliminating the distortion, and sending relative warning. If any gain is close to the margin of control system, or the control system can not sustain the deflection on the necessary gain, it will sending out warning.

The laser is placed on the Thermo-Electric Cooler (TEC) directly. Temperature control circuit drives

TEC working to control the working temperature of the laser , and prevent the performance decreasing or damage result from overheated laser. The microprocessor monitors the temperature of laser & controls the TEC current. If TEC current exceeds the pre-established standard range or is close to the margin of control ability, the system will send out warning.

Setup the temperature warning can let the TX sustain the longest running time under the common aging speed of the laser. And repair or replace the laser when it is necessary before the parts can not be repaired.

Ⅶ. FAULT DISPOSAL

1550nm optic transmitter can monitor system operation and offer brief note of warning. It can correct the majority status deflection of the equipment, such as : system parameter floating, equipment tolerance, laser aging, RF gain changing, temperature changing. The TX will go on working when it is sending out warning. The facility is self-detected continually and relative system parameter will recover into normal range, then the warning will disappear. Some serious warning can be eliminated by restart the power supply of the equipment. If some relative parameter recover to normal range, the warning will disappear automatically.

The majority warnings will be sent out when the correction ability is close to or exceed the permitted range. At most of these situation, user can not modify these status. Status modification needs special equipment & available facility. The modification only could be processed in the factory.

7.1 Warning status

When TX is on warning status, the status LED will turn red and the brief note of status will be displayed on the screen. The warning will not stop the TX running, it only shows the relative parameter exceeding to normal scope slightly. If the warning is stopped, it shows the relative parameter is returned into permitted scope. The screen & diode will return into their normal status and no need to interfere by user. But to be emphasized is that the problem of warning can not be ignored.

It is possible of some serious system fault potentially.

TX work status Status display LED color Explanation

17

Predicts the deflected circuit fault or laser aging. The TX needs repair. Present laser deflection is low

Warning: Lsr Bias Low

Present laser deflection is high

Laser temp. is high

Warning: Lsr Bias Hi

Warning: Laser Temp Hi

Red

Red Predicts the deflected circuit fault or laser aging. The TX needs repair.

Laser output power is Warning: Lsr Pwr Lock locked

Laser temp. is locked Warning: Lsr Temp Lock

Red

Red

Red

AGC circuit is not Warning: AGC Not Locked locked

Fan fault Warning: Fan Failure

Modulator drive gain is Warning: OMI Low low

Modulator drive gain is Warning: OMI Hi high

Red

Red

Red

Red

Laser temperature is floated from 25

℃. Check the room temperature, whether it is still in requested range. Continue monitoring.

Laser output power is floated from correct value. But the circuit is locked. Please continue monitoring.

Laser temp. control loop fault. Check the room temperature, whether it is still in requested range. Continue monitoring.

Optic TX environment temp. was floated from 25

℃. Monitoring it till warning disappears.

TX environment temp. Warning: Itemp(12) Lo is low

TX environment temp. Warning: Itemp(12) Hi is high

Modulator deflected Warning: Modulator Bias

Modulator deflection Warning: Mod. Drift Hi floating

TX inner temp. is high Warning: Itemp(L)

(1)

TX inner temp. is high Warning: Code #13c

(2)

TX interface board Warning: Amb temp low temp. is low

TX interface board Warning: Amb temp high temp. is high

RF input gain is low Warning: RF Input Low

RF input gain is high Warning: RF Input Hi

Red

Red

Red

Red

Red

Red

Red

Red

Red

Red

Optic TX environment temp. was floated from 25

℃. Monitoring it till warning disappears.

Modulator deflection point is close to maximum. Continue monitoring. Deflection maybe need reset.

Modulator deflection point is close to maximum. Continue monitoring. Deflection maybe need reset.

TX inner environment temp. is close to limitation. Check the surrounding temperature and continue monitoring.

TX inner environment temp. is close to limitation. Check the surrounding temperature and continue monitoring.

TX inner panel temp. is close to limitation. Check the surrounding temperature and continue monitoring.

TX inner panel temp. is close to limitation. Check the surrounding temperature and continue monitoring.

RF input gain is close to minimum value of AGC. Check the input gain & route. Continue monitoring.

RF input gain is close to maximum value of AGC. Check the input gain & route.

Continue monitoring.

RF input gain is close to margin. Adjust the input gain to eliminate the warning. If the warning is still existed. The TX needs repair.

TX rear fan parts is faulty. TX needs repair.

The RF drive power entering modulator is low. CNR performance can be improved by increasing OMI.

The RF drive power entering modulator is high. Distortion performance can be improved by decreasing OMI.

Picture16. Warning information

7.2 Alarm status

When the TX send out warning, it is stopped working generally. The alarm is because of some relative parameter exceeding its safety working scope or some situation causes damage to the laser.

Some alarm could be eliminated by restart the power supply or reset the key switch. For some alarm

18

couldn’t be eliminated by user, please contact our company immediately.

7.3 Fault prevention

User can notice below information to prevent some potential problems.

1.Please place the transmitter under environment temperature 0

℃~50℃, other conditions accords with requested running range. We suggest to place the TX in low dust environment.

2. Ensure the rear panel fan & front panel sockets in ventilation , let the rear panel fans running.

3. Check the power supply whether works in stipulated standard scope. And check all the joints are correct.

4. Check the changing of RF gain , control it in the permitted range.

5. Keep the optic fiber connector clean & joint properly. Prevent output optic power decreasing result from optic leakage.

7.4 Deflection restoration

Due to parameter floating result from modulator long time working, it causes the modulator deflected voltage warning. Usually, it can be solved through resetting its deflection, namely turn the key switch into “ OFF”, then turn it into “ ON”. Restoration process needn’t further input operation, but it will spend around 45 minutes to make the control loop return to stable status. In this term, the CSO will be a little bad, the output signal will come down and floating will be smaller. Deflection restoration should be worked when it is not on line or the situation of signal quality decreasing is accepted. The floating process is very slowly, therefore, it needs enough repair time to eliminate the warning.

If the warning still can not be eliminated, please contact us promptly.

7.5 The sensitivity to 980nm laser

When connecting 1550nm EM transmitter & EDFA, please specially notice the influence of the reflect light to the optic transmitter , which is coming from 980nm Pump Laser of EDFA. 980nm Pump Laser can reflect to the optic output port of the transmitter. The extra optic power enters the input port of transmitter will affect the deflection point of CSO loop. And it will make the loop unstable under the extreme situation. In this situation, the CSO fault will be displayed on any monitor warning joints & front screen.

In order to prevent this situation, please use the EDFA with optic isolator. Similarly, the TX output light also exists reflection or un-matching to the optic connector. Generally, the reflect light of entering optic

TX output port can not exceed –25dBm. It is better if the reflect will be weaker.

Ⅷ. GUARANTEED REPAIR RANGE FOR PRODUCT

Our quality guaranty system includes equipment test & inspection to operation process. It ensures the reliability of product quality.

Before product leaving factory, we have adopted any possible measures to keep each index of the electrics, optics & mechanism achieving the standard. We request all the user to inspect the checking

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& assembling; the test person must operate the machine according to the stipulated prevent measure , when they are operating & testing those optic static sensitive parts.

8.1 Guaranty rule

We offer one year guaranty to the material & technique of our products. And respond for repair the product free charge in one year.

When use the product, please obey with all the regulation in the manual. Don’t change it freely. In the guaranty term, any user can not open the machine & change the inner circuit. If the product quality has not reached the request & needs repair, please return the products to our company. Our company will process it according to the rules.

In guaranty term, user has authority to decide either repair or replace the faulty product. But above stipulation is invalid to changing belonging or the faults result from incorrect using, storage, transportation & assembling and other accidents.

8.2 Special product guaranty & repair guide

All the products are produced according to high quality standard and ensure escaping faults on technical , material and out frame. If user wants to repair or replace faulty products, please put forward it in 30days after receipt or in quality guaranty term.

If you need replace the products, which is not matching the quality standard, please accord with below principle. a. Please send back the products after receiving the Callback Bill from us. Please attach the model number, serial number & causes when you apply for withdrawing the product. b. Before repair, we will inform user about the test result and repair charges ( under some problem of incorrect application and not suitable for guaranty.) When we receiving the confirmation from the user, then we go to repair the machine.

c. The product after repair has the same quality guaranty term. It has guaranty treatment

90 days after receiving the goods.

8.3 Compensation range

If the products meet below problem, we will compensate for the customer. We disobey the order , contact and other stipulation on the contract; Damage because of design , sales, transportation, safety check, assembling, inspection & operating according to the manual. The compensated amount can not exceed the damaged product ‘ price or the amount in the contract.

We have not promised for some protocol for product, parts & A-S service except the guaranty in the document. We have no responsibility for the behavior as below & the damage result from incorrect assembling, parts or application.

User discharges or puts IC, inner connect wire, and does coupling or connecting on the fiber. These behaviors will damage the facility or affect the output. For above reason causing performance worse in equipment or fiber optic output signal, our company has no responsibility.

The average invalid time, average fault interval & other reliability data in our test report & datum are

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only used as reference for design. It doesn’t mean that other samples or products have to be the same effect. These datum could be one gist for management and project design, but in real application, it needn’t achieve the same effect. These datum are as one standard of ideal design & perfect parts. The making process will not affect the reliability.

We can repair our products, which are exceeding guaranty term. The user needs to pay the material charge.

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