• Supported Platforms
• T640 Routers

• Related Topics
• T640 Chassis Description
• T640 Host Subsystem Description
• Replacing a T640 SCG

Maintaining the T640 SCGs

Purpose

For optimum router performance, verify the condition of the SCGs.

Action

On a regular basis:

• Check the SCG LEDs. For more information, see T640 SONET Clock Generators (SCGs) Description.
• Issue the show chassis environment scg command to display information about the SCGs. The output is similar to the following:
  
  

  user@host> show chassis environment scg

  SCG 0 status:
    State                           Online -  Master clock
    Temperature                  31 degrees C / 87 degrees F
    Power:
      GROUND                      0 mV
      3.3 V                    3310 mV
      5.0 V                    5052 mV
      5.6 V                    5689 mV
      1.8 V bias               1782 mV
      3.3 V bias               3306 mV
      5.0 V bias               4989 mV
      8.0 V bias               8336 mV
    GBUS Revision                40
    FPGA Revision                 1.6
  

  For further description of the output from the commands, see the Junos System Basics and Services Command Reference.