118                                    Keysight X-Series Signal Generators Error Messages
Error Messages
List of Error Messages
508 Synthesizer Unlocked; Sum Loop (over).
            The synthesizer is unlocked. Service may be needed.
508 Synthesizer Unlocked; Sum Loop (under).
            The synthesizer is unlocked. Service may be needed.
512 Reference unlocked; There is a problem with the external reference
     settings or connections. If reference is internal check Ref Oscillator
     Tune.
            The instrument's reference is unlocked. If an external reference is 
            connected, check its frequency and power and its physical
            connection. Also make sure that the external reference frequency
            specified in the instrument setup is correct. If this error occurs
            when an external reference is not being used, the instrument may
            require service.
514 Reference Oven cold; The reference oven is not at the required
     operating temperature. This  is normal if the instrument has been
     powered down for a while. If the  error persists, the instrument may
     require service.
515 Reference Missing; Reference board: 10Mhz reference signal bad or
     missing
            The instrument's reference is unlocked. If an external reference is 
            connected, check the frequency and power. It is possible for this
            to occur during a poor connection/disconnection of an external
            reference. If this error reoccurs when no external reference is
            connected, the instrument may require service.