Maintaining the PCGs

The router has two Packet Forwarding Engine Clock Generators (PCGs) installed in the slots labeled PCG 0 and PCG 1 on the rear of the chassis, as shown in Figure 3. To maintain the PCGs, perform the following procedures 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 PCG Components.
• 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 Internet Software Operational Mode Command Reference: Protocols, Class of Service, Chassis, and Management.