Monitoring the SCGs

You monitor the SONET Clock Generators (SCGs) that provide a clock signal for the SONET/SDH interfaces on the T320 router and the T640 routing node. The SCGs select a clock signal from any Flexible PIC Concentrator (FPC). (See Table 75.)

Table 75: Checklist for Monitoring the SCG

Monitor SCG Tasks	Command or Action
Understanding the SCG
Monitoring the SCG Status
Monitor the SCG Environmental Status	show chassis environment show chassis environment scg
Display the SCG LED States at the Command Line	show chassis craft-interface
Look at the SCG LEDs on the Faceplate
Determining SCG Mastership
Display the SCG Master from the Craft Interface Output	show chassis craft-interface
Look at the SCG LEDs on the Faceplate
Displaying SCG Alarms
Display Current SCG Alarms	show chassis alarms
Display SCG Error Messages in the System Log File	show log messages
Display SCG Error Messages in the Chassis Daemon Log File	show log chassisd
Verifying SCG Failure
Check the SCG Connection	Make sure the SCG is properly seated in the midplane. Make sure none of the SCG pins are bent. Check the thumbscrew on the right side of the SCG.
Perform an SCG Swap Test	Take the SCG offline. Replace the SCG with one that you know works. Bring the SCG online. Check the SCG status.
Getting SCG Hardware Information
Display the SCG Hardware Information	show chassis hardware
Locate the SCG Serial Number ID Label	Look on the top of the SCG, close to the midplane connector.
Returning the SCG	See Return the Failed Component, or follow the procedure in the appropriate router hardware guide.