• Topic ID: id_15840261
  • Version: 1.10
  • Date: Jan 17, 2020 10:44:29 AM

Fiber Optic Devices Installation and Replacement

Prerequisites

Table 1 Personnel requirements
Required persons Preliminary requirements Procedure Finalization
1 - As required -
Table 2 Consumables
Item Quantity Effectivity Part number Manufacturer
Fluke Optics Cleaning Kit 1 -

5478006

 -
Table 3 Safety
  • warning
  • Potential Personal injury!
  • Retinal Burn. Invisible laser radiation may be emitted from disconnected fibers or connectors.
  • Avoid staring into beams or viewing directly with any optical instruments.Reminders:
    • Always turn off laser sources before you inspect fiber connections.
    • Always keep a protective cap on unplugged fiber ferrules.
  • notice
  • Potential component damage
  • Electrostatic discharge (ESD) can cause permanent damage to electronic components.
  • Observe the following ESD precautions:
    • Work on a static-free mat.
    • Wear a static strap to ensure that any accumulated electrostatic charge is discharged from your body to the ground.
    • Create a common ground for the equipment being worked on by connecting the static-free mat, static strap, and peripheral units to that piece of equipment.
Notice Image
  • notice
  • Potential component damage
  • The SFP optical transceiver is very sensitive to electrostatic discharge (ESD), dust, and body oil. When working with the SFP optical transceiver:
    • Always use ESD protection when handling the SFP optical transceiver to prevent early failure.
    • Never touch the SFP optical transceiver without being properly grounded.
    • Never touch the end face of the optical connectors.
    • Never re-use lens tissue or cleaning swabs.
    • Always keep a protective cap on unplugged fiber connections.
    • Always inspect the connection before cleaning.
    • The SFP must be shipped in antistatic packaging. Discard any SFP shipped or stored without proper ESD protection.
    • Some SFPs are shipped in insulated envelopes which can produce excessive contaminates. Do not open these containers in the area where you will be working with the SFP. Remove the antistatic bag containing the SFP and move to a clean area to work.
Notice Image
  • caution
  • Possible Component Damage!
  • The fiber optic cable can easily be damaged by improper handling. Bending, twisting, kinking, or squeezing the cable may cause internal breaks along the fiber, resulting in poor performance or instability.
  • When working with fiber optic cable:
    • Avoid bending the fiber optic cable, or allowing the cable to hang, causing a macrobend in the cable.
    • Do not allow the end of the fiber optic cable to make contact with any surface, including direct contact with fingers. The optical coating on the lens is easily chipped and scratched.
    • Never run fiber optic cable without the protective caps in place.
    • Avoid pulling on the cable end, because this can damage the fiber optic.

Overview

Fiber optic cables can easily be damaged if they are improperly handled during installation or during the replacement of connectors. Proper cleaning is required because microscopic contamination in the fiber connection will cause intermittent signals, due to degraded signal power, resulting in failure of the component or failure of the whole system.

This procedure describes the types of fiber optic devices used in MR and how to properly handle and clean both the fiber optic cable ends and the ferrules on the connectors.

Two types of connectors are used:

  • ST bayonet connectors used for the 80 MHz clock

    Figure 1. ST Bayonet Connector

    Item Description
    1 Bayonet connector assembly
    2 Alignment pin
    3 Protective caps for ferrules
  • LC connectors used with SFP fiber optic transceiver

    Figure 2. LC Connector

    Item Description
    1 LC connectors
    2 Black clip
    3 Protective caps for ferrules

The LC connector is used with the SFP (small form-factor pluggable) optical transceiver. The SFP is a compact fiber optic transceiver used by multiple subsystems in an MR system for the transmission of data. These devices can transmit high rates of data without the concern of noise being induced in the fiber optic cables which join these devices.

The SFP is very sensitive to electrostatic discharge. When handling any of these devices, use proper ESD procedures to prevent early failure.

Figure 3. Small Form-factor Pluggable (SFP) Fiber Optic Transceiver

Item Description
1 Formerica SFP with Tx and Rx arrows on label
2 Applied Optoelectronics SFP with Tx and Rx arrows on bail

Bend Radius of Fiber Optic Cable

Avoid twisting, squeezing, pinching, or bending the fiber optic cable beyond the specification for fiber optic cable. Sometimes damage does not manifest itself until much later. Even minor damage (not visible damage) can result in dB signal loss due to scattering and refraction of the light through the cable. Fiber optic cable needs a clear path for transmission of high speed data. See DOC1465935 in the online documentation library for the maximum bending radii of both riser/plenum cables and simplex/duplex fiber optic cables.

  • Avoid letting the fiber optics hang, causing a sharp bend in the cable.

  • Avoid letting anything compress the cable, causing kinks, such as routing the cable under ATE equipment or placing the cable in a position to be pinched or stepped on.

Cleaning Fiber Optic Cables, Connectors, and SFP Optical Transceiver

Procedure

    Notice Image
    • caution
    • Possible Component Damage!
    • Dust and body oil can contaminate both the ends of the fiber optic cable and the connections on the SFP optical transceiver.
    • Keep the inspection and rework area as clean as possible at all times to avoid risk of recontamination. Use an alcohol wipe to clean your hands before you begin work. The figure below shows dust and oil contamination (left) versus a clean fiber optic signal (right).

    Notice Image
    • caution
    • Possible Component Damage!
    • Improper chemicals and cleaning materials can damage the fiber optic cable, connectors, and SFP optical transceiver.
    • Use the chemicals and cleaning implements specified in the Consumables section of this document.
    Notice Image
    • notice
    • Training GEHC-IMG-MR2230920_CURR is required for all those who contact with the fiber optic transceivers.
  1. Confirm that all power has been removed from the unit or subsystem where you will be working. If necessary, perform lockout/tagout (LOTO) on any systems in the area.
  2. Handle the fiber optic cable in a clean, dust-free environment. Confirm that your hands are free from dirt and oil.

    To avoid recontamination or damage to the optical coating on the fiber optic cable, observe the following best practices:

    • Do not scrub the fiber optic cable with the wipe or clean the same surface more than once.

    • Never blow on the fiber optic cable end.

    • Never use material not specifically manufactured for optical cleaning, such as a tissue or shirt tail, because these fibers scratch and transfer impurities.

    • Never reuse a wipe or swab, because it could transfer dirt or oil from one connector to another.

    • Avoid contamination of clean materials by keeping lint-free non-woven fabric and cleaning swabs in a clean, sealed container.

  3. Remove the protective cap (if present) from the end of the fiber optic cable.
  4. Follow the cleaning instructions in the Fluke Fiber Optic Cleaning Kit. You can clean the SFP and fiber in place as shown. Use the cube and solvent pen to clean an ST bayonet connector.

    Figure 4. Cleaning a SFP in Place

    note:

    The MPO-MTP cleaner is not used in any MR procedures. It is used with PET/MR.

  5. If the transceiver, connector, or cable is not to be immediately deployed, recap with the protection cap.

ST Bayonet Connector

The ST bayonet connector is used on the 80 MHz clock (BNC).

Connect Fiber Optic Cable to ST Bayonet Connector

Procedure

  1. Remove the protective cap on the ST bayonet connector (if present) (seeFigure 1).
  2. Clean the end of the fiber optic cable and the ferrule of the ST bayonet connector using the cube and the solvent pen per instructions on the laminated card in the Fluke Fiber Optic Cleaning kit..
  3. Align the slot on the inner sleeve of the connector with the alignment pin above the ferrule on the cable.
  4. Gently push the cable into the connector. Do not force.
  5. Turn the connector clockwise until it locks into place.

Extract Fiber Optic Cable from ST Bayonet Connector

Procedure

  1. Gently push the cable into the connector and twist the connector counterclockwise until it unlocks. Do not force.
  2. Gently remove the cable from the bayonet ferrule.
  3. Insert the protective cap on the connector if the connector is to be left unattended for any length of time.

LC Connector and SFP Transceiver

Connect LC Connector to SFP Transceiver

Procedure

  1. Remove the protective caps on the LC connectors (see Figure 2).
  2. Remove the protective plug from the SFP transceiver.
  3. Clean the LC connector and SFP transceiver (see Cleaning Fiber Optic Cables, Connectors, and SFP Optical Transceiver).
  4. Insert the LC into the SFP until it contacts the bottom of the SFP.
    1. Grasp the upper exposed plastic LC housing (not rubber boots on fiber cables) and press down to begin seating the LC into the SFP.

      Figure 5. LC Connector and SFP Transceiver

      Item Description
      1 SFP transceiver
      2 LC connector
      3 LC connector
    2. Use your finger nail to press the black clip to finish seating the LC connectors into the SFPx`.

      Figure 6. Pressing Black Clip to Lock LC Connector in SFP

  5. Confirm that the LC connector is locked in place by gently attempting to pull it out.

Remove LC Connector from SFP Transceiver

Procedure

  1. While holding down the locking mechanism on the LC connector, gently pull out the LC connector from the SFP transceiver.
  2. Insert the protective cap on the connector, if the connector is to be left unattended for any length of time.
  3. Insert the protective plug on the SFP transceiver, if it is to be left unattended for any length of time.

Confirm Good Connections

Procedure

  1. (For ICE) Observe the LEDs on the ICE.

    Figure 7. LEDs on ICE

    Table 4 LEDs on ICE
    Mnemonic Functional Description
    Green DVMR/AXIS2G LEDs LED On: Corresponding link is up

    LED Off: Corresponding link is down
    Red DVMR/AXIS2G LEDs LED On: Corresponding SFP is either missing or has reported a fault and should be replaced. SFP is a FRU.

    LED Off: Corresponding SFP is present and not reporting a fault.
  2. (For IRF3 board) Observe the LEDs on the IRF3 board. Figure 8 shows J14, J13, J12 and J11 lit. The LEDs are bright green. If the LED is a dim green, the connection is not ON.

    In the illustration below, the LED for J10 is dim, indicating J10 is down. It is not completely dark because the light bleeds from the other LEDs.

    The REF OK LED at the bottom of the board is lit, indicating that there is a good signal for the 80 MHz reference clock coming from the exciter.

    Figure 8. LEDs on IRF3 Board

  3. (For IXG board) Observe the LEDs on the IXG board. Figure 9 shows four active links and one unused link. None of the fault LEDs are lit.

    The REF OK LED at the bottom of the board is lit, indicating that there is a good signal for the 80 MHz reference clock coming from the exciter.

    Figure 9. LEDs on IXG Board

  4. (For SFP transceiver) A common reason for SFP transceiver failure is a static discharge event. Voltages as low as 400 V have been known to damage the SFP transceiver. Fouled optics are another common reason. Follow the cleaning procedures in Cleaning Fiber Optic Cables, Connectors, and SFP Optical Transceiver to avoid contamination of the cable ends and the SFP transceiver.

Finalization

Finalization

No finalization steps.