Important!

If the OLIU circuit pack to be replaced is the active circuit pack for timing and the circuit pack is removed, the system performs an automatic protection switch and subsequent transmission hits (less than 60 ms) will occur. If desired, perform this step to determine the timing state of the OLIU circuit pack to be replaced.

Select View → Timing/Sync. Observe the value of the Active Circuit Pack parameter to determine the active circuit pack for timing. Click Close.

Important!

If the OLIU circuit pack to be replaced is the active circuit pack for timing, an optional manual timing switch can be performed before replacing the circuit pack. Transmission hits (less than 60 ms) will occur for each separate protection switch.

If the OLIU circuit pack to be replaced is not the active circuit pack for timing, proceed to Step 4.

To perform an optional manual timing switch, select Fault → Timing/Sync Protection Switch → Main Circuit Pack Timing Switch. Select the Manual Switch Command and click OK.

Result:

A dialog box appears asking you to confirm executing this command. Click Yes.

If required, repeat Step 1 to verify that the OLIU circuit pack to be replaced is not the active circuit pack for timing.

Important!

If the OLIU circuit pack to be replaced is the active circuit pack for transmission and the circuit pack is removed, the system performs an automatic protection switch and subsequent transmission hits (less than 60 ms) will occur. If desired, perform this step to determine the transmission state of the OLIU circuit pack to be replaced.

Select View → Protection to access the required protection group (according to the work instructions) and determine if the OLIU circuit pack to be replaced is active for transmission. Record the active paths supported by the OLIU circuit pack to be replaced. Click Close.

Important!

If the OLIU circuit pack to be replaced is active for transmission, optional manual switches can be performed before replacing the circuit pack. In UPSRs, each path supported by the OLIU circuit pack to be replaced must be switched separately. Transmission hits (less than 60 ms) will occur for each separate protection switch.

If the OLIU circuit pack to be replaced is not active for transmission, proceed to Step 7.

To perform an optional manual transmission switch, select Fault → Protection Switch.

Result:

A dialog box appears asking you to confirm executing this command. Click Yes.

The ABN LED is lighted on the SYSCTL circuit pack faceplate.

If a UPSR or 1+1 protection group, the system reports a manual switch condition for the affected line/path.

If required, repeat Step 4 to verify that the OLIU circuit pack to be replaced is not the active circuit pack for transmission.

Important!

Perform this step to determine if the LNW111/LNW112/LNW39/LNW391 circuit pack to be replaced is active for transmission.

The LNW111/LNW112/LNW39/LNW391 circuit packs fit in the same physical half-size slots; however, the DS1 ports are reported in virtual slots fn-a-(1,2), and the DS3 ports are reported in virtual slots fn-b-(1,2).

From the System View select View → Protection. Click on the required 1+1 Equip protection group and Select. Observe the value of the Active Unit parameter to determine the active circuit pack for transmission. Click Close.

Important!

If the LNW111/LNW112/LNW39/LNW391 circuit pack to be replaced is active for transmission, an optional manual switch can be performed before replacing the circuit pack.

To perform an optional manual transmission switch, select Fault → Protection Switch. Click on the required 1+1 Equip protection group and Select. Select the Normal Switch Type and click Apply.

Result:

A dialog box appears asking you to confirm executing this command. Click Yes. Then click Close.

STOP! To complete the upgrade, return to the procedure that directed you to perform this procedure.

End of steps