3Com DUA3700-0BAA04 manual Damaged Transceiver Due to Excessive Insertion Force

E-4APPENDIX E: CABLING REQUIREMENTS

Damaged Transceiver Due to Excessive Insertion Force

The ATM specification for insertion force on the connector into an ATM SC receptacle is 3.5 lbs. However, it is possible to exert up to 30 lbs. of insertion force on the transceiver if you are too forceful while inserting the SC connector into the receptacle. This can cause failure of the transceiver's mechanical joints, permanently damaging the part and disabling the port.

When inserting connectors into the ATM ports, gently insert the SC connector into the receptacle until you hear the connector click into place. Use only enough force to engage the connector in the receptacle - no more than 3.5 lbs. This will avoid damage to the transceiver.

Multi-mode Fiber The MMF-PMD standards define the requirements for an ATM cable plant Standards to support an interstation distance of up to 2 kilometers (1.25 miles) of

multi-mode fiber. The cable plant includes all fiber optic components between any two communicating ATM devices and their associated “station-to-network” connectors at each end.

To determine whether the cable plant complies with the MMF-PMD standard, do the following:

1Compare the specifications of the fiber you are using to standard specifications, as described in Table E-1 and Table E-2.

2If unlike fibers are mated in the cable plant, calculate insertion losses to see whether they exceed the maximum attenuation value allowed for a link, as described in Table E-3 and Table E-4.

3Verify that the fiber's modal bandwidth is within an acceptable range for the length of the link, as described on page E-7.

The following sections describe each of these steps and give examples.

Comparing Fiber to Specifications

Compare the specifications of the fiber you are using to those in the following tables. If the fiber does not meet the specifications, use a different fiber or contact 3Com's Technical Support.

The fiber you use must meet the specifications listed in Table E-1, which describes the standard set forth in MMF-PMD. Table E-2 describes 62.5/125 cable, commonly sold as “ATM Spec,” which meets all the requirements of the MMF-PMD standard.