Comcast LT1550-E Instruction Manual
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Comcast LT1550-E Instruction Manual

Comcast LT1550-E Instruction Manual

External modulate optical transmitter
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LT1550-E
External modulate optical transmitter
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Summary of Contents for Comcast LT1550-E

  • Page 1 LT1550-E External modulate optical transmitter www.comcast-sa.com...

  • Page 2: Table Of Contents

    LT1550-E Contenido Safety Instruction ..........................3 1. Overview ............................5 1.1 About This Manual ........................5 1.2 Product Description ........................5 6.2 Troubleshooting........................7 1.3 Product Applications ........................8 2. Technique Parameters ........................9 2.1 Optical Parameters ........................9 2.2 Model Test Indicators ......................10 2.3 Test Condition ........................11 2.4 Technical Data Sheet ......................11...

  • Page 3: Safety Instruction

    LT1550-E 3.4.6 MGC Mode ........................22 3.4.7 Frequency Adjust ITU in DWDM ..................23 3.4.8 SBS Suppression Adjustment ...................23 4. Installing Optical Transmitter .......................24 4.1 Receiving and Inspecting ......................24 4.2 Precautions..........................24 4.3 Mounting ..........................26 4.3.1 Mounting in the Rack ......................26 4.3.2 Connecting the RF Cables ....................26 4.3.3 Connecting the Optical Fiber Cables ................26...
  • Page 4 LT1550-E www.comcast-sa.com...

  • Page 5: Overview

    • Chapter 2 describes the complete technical specifications of LT1550-E. • Chapter 3 describes the front/rear panel interfaces and menu system. • Chapter 4 tells you how to install LT1550-E series external modulated optical transmitter. • Chapter 5 tells you the communication setting of LT1550-E.
  • Page 6 LT1550-E Working principle LT1550-E series transmitter has 7 function modules: RF control, DFB laser, optical modulator, SBS control, CSO control, communication/display control and power supply. Automatic gain control circuit (AGC) or manual gain control circuit (MGC) amplifies the RF signal. AGC or MGC control makes the optical modulator maintain a suitable input level.

  • Page 7: Troubleshooting

    Causing optical power fluctuation, generates large noise, and seriously deteriorates the system carrier to noise ratio (CNR). To improve the SBS threshold, LT1550-E series optical transmitter adopts SBS control technology which is independent researched and developed by ourselves.

  • Page 8: Product Applications

    LT1550-E 1.3 Product Applications • High-performance long-distance transmission • High-power distribution network • Redundancy loop architecture • FTTx network • RFOG application • DWDM network www.comcast-sa.com...

  • Page 9: Technique Parameters

    LT1550-E 2. Technique Parameters 2.1 Optical Parameters Item Unit Value 1545～1560 (or specified by the Optical Wavelength user) Side-mode Suppression >30 ratio Relative Intensity Noise dB/Hz <-160 Wavelength Adjustment +/-50GHz Range Optical Power 2*7, 2*8, 2*9, 2*10 +13～+19 (Continuously SBS Threshold Value...

  • Page 10: Model Test Indicators

    LT1550-E 2.2 Model Test Indicators Test Model Channel Plan CENELEC42 PAL D59 PAL D84 PAL D Channel Number 42/0/0 59/0/0 84/0/0 30/0/48 TV/FM/QAM64 Bandwidth Noise CNR Tx/Rx 55.5 54.0 52.5 54.5 CNR Link 1 55.0 53.5 52.0 54.0 CNR Link 2 53.0...

  • Page 11: Test Condition

    LT1550-E 2.3 Test Condition First Second Second First stage paragrap paragrap stage EDFA fiber fiber (dBm) EDFA length length Tx/Rx 0dBm 13.5 Link 1 35km 0dBm 13.5 Link 2 16dBm 65km 0dBm Link 3 13dBm 50km 13dBm 50km 0dBm 13.5 Rx with 8 pA/ÖHz input noise current density;...
  • Page 12 LT1550-E AGC control range +3～-3 adjustable 0~15 range Optical connector SC/APC, FC/APC Operating °C -5～45 temperature Storage °C -30～+70 temperature 90～265VAC Power Source Specification 36～72VDC Consumption ≤60 Dimension 483(L) × 455(W) × 44(H) Total Weight www.comcast-sa.com...

  • Page 13: Panel Interface And Menu System Description

    LT1550-E 3. Panel Interface and Menu System Description 3.1 Front Panel RF modulation degree Power indicator AGC indicator indicator Laser indicator ESC key UP key DOWN key Enter key RF input port (or Optical output -20dB RF input test on the rear panel,...

  • Page 14: Indicator Description

    LT1550-E 3.1.1 Indicator Description One power supply LED yellow Power indicator Two power supplies LED green AGC mode LED green AGC indicator MGC mode LED off Normal LED green modulation degree indicator Abnormal LED flash red Bias current, cooling current...

  • Page 15: Rear Panel

    LT1550-E 3.2 Rear Panel 1 Ground stud 2 Power module 3 Fan RF input port (or on the 5 RS232 interface 6 LAN interface front panel, optional) Optical output Optical output interface A (or on the interface B (or on the...

  • Page 16: Power Module

    LT1550-E 3.3.2 48V Power Module + Positive terminal Negative 1 Mounting screws block terminal block 3.4 Menu Operation 3.4.1 Main Menu www.comcast-sa.com...

  • Page 17: Display Menu

    LT1550-E Displayed parameters Comments Boot display 1.Disp Parameters Menu one: Display parameters 2.Set Parameters Menu two: Set parameters 3.Alarm Status Menu three: Alarm status 3.4.2 Display Menu www.comcast-sa.com...
  • Page 18 LT1550-E Displayed Displayed parameter Comments Comments parameters Laser +24V monitor Output optical power +24V Read: Output voltage +12V monitor Laser Bias Laser current +12V Read: voltage -12V monitor RF CSO CSO monitor voltage -12V Read: voltage Laser Cooling current Laser status LASER：...

  • Page 19: Set Menu

    LT1550-E 3.4.3 Set Menu www.comcast-sa.com...
  • Page 20 LT1550-E Displayed Comments Remarks parameters Set RF MODE MGC and AGC two modes Set RF control mode selectable Adjustable range 0~15dB with MGC mode adjusted Set AGC Set MGC value Adjustable range -3~+3dB with AGC mode Set SBS Suppression Set SBS value Range 13~19dBm, 0.5dB stepping...

  • Page 21: Alarm Menu

    LT1550-E 3.4.4 Alarm Menu The displayed alarm content Comment HIGH（LOW RF IN Status The RF input signal is high (low) ） HIGH（LOW Laser Bais The laser bias current is high (low) ） Laser TEC HIGH The laser cooling current is high OutPutPower HIGH（LOW...

  • Page 22: Agc Mode

    LT1550-E 3.4.5 AGC Mode This mode is the recommended mode and also the standard operation. The optical transmitter will automatically adjust to the optimal gain while the input level is in the working range (see the technical data sheet). And the specified OMI (rms) modulation index will be automatic gain control.

  • Page 23: Frequency Adjust Itu In Dwdm

    LT1550-E 3.4.7 Frequency Adjust ITU in DWDM To help DWDM applications, LT1550-E can adjust optical wavelength. The adjustable range is ±100GHz, 50GHz stepping. The button on the front panel or the Ethernet interface will complete the adjustment. λ=c/f, c is the speed of light. It is the constant value.

  • Page 24: Installing Optical Transmitter

    CAUTION: To protect yourself from potential injury and to protect the equipment from further damage, do not perform any operational tests if the equipment appears to be damaged. 4.2 Precautions Heed the following precautions when working with the LT1550-E. Read installation instructions before connecting the system to the power source.
  • Page 25 LT1550-E Mit Wechselstrom betriebenes Modell: Der Warnung Netzstecker muss jederzeit leicht zugänglich sein. www.comcast-sa.com...

  • Page 26: Mounting

    Mounting in the standard 19 inch equipment rack: 1. Place the equipment in the rack. 2. Use four screws fixed the mounting lug on the LT1550-E front panel to the rack. 3. Reliably ground the equipment. The ground terminal is on the rear panel.
  • Page 27 LT1550-E NOTE: Any contamination of optical connector can significantly degrade optical link performance. This degradation will most likely manifest itself as poor signal-to-noise (SNR) performance. 4. Note to butt the nick of the connectors and align them accordingly. www.comcast-sa.com...

  • Page 28: Connecting The Ethernet Cable

    LT1550-E 4.3.4 Connecting the Ethernet Cable You can connect the LT1550-E to your TCP/IP network in order to monitor and control the transmitter remotely. After you complete the installation procedures described in this chapter, you can use a network management system (NMS) to monitor and control the LT1550-E.
  • Page 29 LT1550-E The DC-powered LT1550-E has two -48 VDC input connectors that require input voltage from -36 to -72 VDC. The DC input connectors are located on the rear panel. Turn on the power source. It takes about 60 seconds for all systems to operate.

  • Page 30: Communication Setup

    LT1550-E 5. Communication Setup 5.1 RS232 Communication Interface Description Adopt DB9 standard connector, the pin definitions as follow: 1: No Connect 2: TX 3: RX 4: No Connect 5: GND 6: No Connect 7: No Connect 8: No Connect 9: No Connect The serial communication uses the standard NRZ form, 1 starts bit, 8 data bits, 1 stop bit and the baud rate is 38400.
  • Page 31 LT1550-E www.comcast-sa.com...
  • Page 32 LT1550-E Then you input your connection name, such as “SNMP38400”，and choose the serial port to connect with your equipment. As follows: Press the “OK” button shows the configuration page of serial port. As follows: Change the serial port configuration to 38400-baud rate, 8 data bits, no parity bit, 1 stop bit, no data flow control, press the “OK”...
  • Page 33 LT1550-E You can click “file→save” menu to save this configuration of Hyper Terminal for later using. www.comcast-sa.com...

  • Page 34: Operating Parameters Configuration

    LT1550-E 5.3 Operating Parameters Configuration Under the condition of power off, use the serial port lines to connect the RS232 port with the computer port. Open the Windows Hyper Terminal which you have set up. Then turn on the power, you will see the page as follows. Enter the password to enter the configuration interface.
  • Page 35 LT1550-E You can input your command in this page, and then configure the operating parameter of the application program. www.comcast-sa.com...
  • Page 36 LT1550-E System supports the following commands: List internal commands of the system; help Configure the Ethernet operating parameters; ethcfg Configure the aim host IP address of the SNMP Trap; settrap Configure the SNMP group name; community List system default parameters or user updated parameters;...
  • Page 37 LT1550-E www.comcast-sa.com...
  • Page 38 LT1550-E ethcfg This command configures the Ethernet parameters, including IP address, subnet mask and gateway. You can refer to the help information for its using. settrap This command shows or modifies the aim host IP address list of the SNMP Trap, IP address of 0.0.0.0 and 255.255.255.255 don’t exist.

  • Page 39: Remote Monitoring: Snmp

    LT1550-E 5.4 Remote Monitoring: SNMP LAN communication interface Adopt RJ45 standard connector, the pin definitions as follow: 1: TX+ 2: TX- 3: RX+ 4: No Connect 5: No Connect 6: RX- 7: No Connect 8: No Connect A: Green indicator flashing means that the LAN port is sending data.

  • Page 40: Web Network Management

    LT1550-E Simple Network Management Protocol (SNMP) is an application layer protocol. It makes the management information between network devices exchange easier. It is part of the TCP / IP protocol group. SNMP enables the end-users to manage network performance, find and solve network problems, and arrange for future network upgrades.
  • Page 41 LT1550-E There are 3 sub-interfaces: About1550 interface: Mainly described the basic information of the equipment. Disp Paraments interface: Mainly described the display menu of the equipment. Set Paraments interface: Change the device parameters in this interface. www.comcast-sa.com...
  • Page 42 LT1550-E Click Set Paraments to enter Set Paraments interface as follows: The Item and Items columns list the parameters that can be changed, the Current column lists the present parameter values, the New column can select or type the new parameter values, and the Update column can update the parameters.
  • Page 43 LT1550-E www.comcast-sa.com...

  • Page 44: Maintenance And Troubleshooting

    In addition, if you suspect that the optical connector of LT1550-E may have been exposed to contamination (by a dirty fiber cable connector, for example), you should properly clean the LT1550-E optical connector before connecting the optical fiber.
  • Page 45 LT1550-E thickness. 2. Use a drop of high-grade isopropyl alcohol to wet part of the paper. 3. Lay the connector on the lens cleaning paper with the tip touching the paper. 4. In one continuous motion, pull the connector from the wet part of the paper to the dry part.

  • Page 46: Troubleshooting

    LT1550-E 6.2 Troubleshooting Should a problem occur, see if the symptoms are listed in Table 6-1. Table 6-1: Troubleshooting Solutions Alarm menu Indicator status Fault phenomenon Solution content Plug in the left (right) left (right) power cord. If that does...
  • Page 47 LT1550-E If that does not solve the problem, contact Customer Service. Disconnect connection, wait Initialization nonlinearity seconds before failed indexes are poor reconnecting signal. Contact Customer Laser Bias HIGH The laser is off Service. Verify that the unit is operating...

  • Page 48: Disclaimer

    LT1550-E problem, contact Customer Service. Check fiber connector. The optical output Follow connector power lower cleaning procedure (see None None than the nominal Section 6.1). value If that does not correct problem, contact Customer Service. 6.3 Disclaimer We reserve the right to change any products described herein at any time, and without prior notice.

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