Testing the TX-SIB Fiber-Optic Array Adapters
Purpose
Test the TX-SIB fiber-optic array adapters using the fiber-optic array loopback connector that is shipped with the TX Matrix router (see Figure 1).
Figure 1: Fiber-Optic Array Loopback Connector and Loopback Adapter

![]() | Caution: Do not connect and disconnect a fiber-optic array cable connector, a loopback connector, or a loopback adapter more frequently than required. These fiber-optic components are rated for a limited number of insertions (approximately 100). |
Action
To test for the five TX-SIB fiber-optic array adapters that connect to a single T640 router:
- Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
- Remove the protective tape covering each of the
five TX-SIB fiber-optic array adapters that connect to the T640 router.
For example, if you are connecting a T640 router with a chassis ID
of 0, remove the tape from each TX-SIB fiber-optic array
adapter labeled LCC0 (top row of adapters). (Fiber-Optic Array Cable Connections between TX-SIBs and T640-SIBs lists the connections between TX-SIBs and T640-SIBs.)

Caution: Do not remove the protective tape covering unused fiber-optic array adapters. The tape prevents dust from entering the adapters.
- Remove the dust cover from the loopback connector
by loosening the two hex screws with a 2.5-mm ball hex driver and
pulling off the cover. Temporarily store the dust cover in a dust-free
resealable plastic bag.

Warning: Do not look directly into a fiber-optic array adapter or a connector at the end of a fiber-optic array cable attached to an adapter. The fiber optics emit laser light that can damage your eyes.
- Starting with TX-SIB-0, align the loopback connector
with the TX-SIB adapter, and carefully press it into the adapter until
it stops. The loopback connector and TX-SIB adapter are keyed to ensure
proper mating.

Note: The optics in a fiber-optic array adapter are spring loaded, so you must continue to apply force to a fiber-optic array cable connector or loopback connector while securing it to a TX-SIB or T640-SIB adapter.
- Using a 2.5-mm ball hex driver, at least 4 in. long, partially tighten the upper and lower hex screws on the loopback connector. Alternate between the upper and lower hex screws until the loopback connector is secured to the adapter.
- Enable the TX-SIB adapter receivers.
user@host> request chassis sib slot slot-number start-receiver interface-number sccThe slot number can be from 0 through 4 and corresponds to the TX-SIB chassis slot. The interface number can be 0 through 3 and corresponds to the TX-SIB adapters labeled LCC0 through LCC3.
- Verify that the RX LED next to the TX-SIB adapter is steadily lit green.
- Disable the TX-SIB adapter receivers.
user@host> request chassis sib slot slot-number stop-receiver interface-number sccThe slot number can be from 0 through 4 and corresponds to the TX-SIB chassis slot. The interface number can be 0 through 3 and corresponds to the TX-SIB adapters labeled LCC0 through LCC3.
- Using a 2.5-mm ball hex driver, at least 4 in. long, partially loosen the upper and lower hex screws on the loopback connector. Alternate between the upper and lower hex screws until the loopback connector is removed from the adapter.
- Repeat Step 4 through Step 9 for TX-SIB-1 through TX-SIB-4. If the RX LED next to each of the five TX-SIB adapters was steadily lit green, proceed to Step 11.
- Remove a dust cover from the dust-free resealable plastic bag, and reinstall it on the loopback connector. Align the dust cover with the loopback connector, and carefully press them together until they stop. The cover and the loopback connector are keyed to ensure proper mating.
- Secure the dust cover by tightening the hex screws, and then store the loopback connector in the dust-free resealable plastic bag.
