• Supported Platforms
• M40e Routers

• Related Topics
• M40e Packet Forwarding Engine Clock Generators (PCGs) Description
• M40e Packet Forwarding Engine Architecture
• Installing a PCG in an M40e Router
• Replacing a PCG in an M40e Router

Maintaining the M40e PCGs

Purpose

For optimal performance, verify the condition of the Packet Forwarding Engine Clock Generators (PCGs).

Action

The router has two PCGs installed in the slots labeled PCG 0 and PCG 1 on the rear of the chassis, as shown in M40e Chassis Description. To maintain the PCGs, regularly:

• Check the LEDs on the PCG faceplates. The green LED labeled OK lights steadily when the PCG is functioning normally. The blue LED labeled MASTER lights steadily on the master PCG. For more information, see M40e PCG LEDs.
• Issue the CLI show chassis environment pcg command to check the status of the PCGs. As shown in the sample output, the master PCG is designated Online -  Master clock and the standby PCG Online - Standby:
  
  

  user@host> show chassis environment pcg

  PCG 0 status:
    State                           Online -  Master clock
    Temperature                  40 degrees C / 104 degrees F
    Frequency:
     Setting                 125.00 MHz
     Measurement             125.01 MHz
    Power:
      3.3 V                    3274 mV
      5.0 V bias               4974 mV
      8.0 V bias               8183 mV
    BUS Revision                 12
  PCG 1 status:
    State                           Online - Standby
    Temperature                  40 degrees C / 104 degrees F
    Frequency:
     Setting                 125.00 MHz
     Measurement             125.03 MHz
    Power:
      3.3 V                    3267 mV
      5.0 V bias               4993 mV
      8.0 V bias               8190 mV
    BUS Revision                 12

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