Nortel Networks NN43001-301 User Manual

Page 174

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Clock Controller description and installation

Note 2: ERR20 messages can be generated. These can
usually be ignored. However, excessive clock switching should
be avoided, especially when counters are near the maintenance
or out-of-service thresholds. Excessive switching could
generate threshold-exceeded messages or cause the PRI to
be automatically disabled. Check the counters in LD 60. If
necessary, reset the counters using the RCNT command.

a. Set the old card’s faceplate ENL/DIS switch to DIS.

b. Disconnect the cables from the old clock controller card and

remove it from the shelf.

Install the new clock controller in the selected slot.

Run and connect the cables

a. Connect the primary reference to J2.

b. Connect the secondary reference to J, if available.

c. Connect the cable from J3 on each controller card to the junctor

group connector.

Set the faceplate ENL/DIS switch to ENL.

Execute the ENL CC X command in LD 60. The faceplate LED
should go to the OFF state.

Set the error detection thresholds and clock synchronization controls
in LD 73. (Optional if replacing card; required with new installation.)

Track on a primary or secondary reference clock, use LD 60. The
command follows:

TRCK

PCK

(for primary)

SCLK

(for secondary)

FRUN

(for free-run)

Issue the status check command, SSCK.

(Optional) Wait two minutes before activating the newly installed
clock controller with the LD 60 SWCK command.

Note: This allows a smooth transition of the clock controller
upgrade.

Repeat for the second clock controller, if necessary.

—End—

Nortel Communication Server 1000

ISDN Primary Rate Interface Installation and Commissioning

NN43001-301

02.03

Standard

Release 5.5

7 December 2007