Important!

If the 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 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 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 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 circuit pack to be replaced is not the active circuit pack for timing.

Important!

If the 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 circuit pack to be replaced.

From the System View select Reports → Status Lists → Pack. Click Shelf and Select. Observe the value of the Switch State parameter to determine if the circuit pack to be replaced is active for transmission. Click Close.

Important!

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

If the circuit pack to be replaced is not the active circuit pack for transmission, proceed to Step 6 .

To perform an optional manual transmission switch, select Fault → Protection Switch. Click on 2F BLSR main-1-1 and Select. Select the required Direction for the circuit pack to be replaced (West for slot M1 or East for slot M2) and Manual to Protection, Ring Switch Type, and click Apply.

Result:

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

The ABN LED is lighted on the SYSCTL circuit pack faceplate and the Alarm List shows the Protection Switch, OC48 Port, Manual Switch, MSR, 2F condition (Not Alarmed).

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

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

End of steps