Warning/Status
Message
Description
OVN COLD
This warning message indicates that the 100 MHz
Crystal oven (or the 10 MHz Crystal oven if Option 16 is
installed) has not reached operating temperature.
Normally displayed during a cold start of the sweep
generator. If the message is displayed during normal
operation, it could indicate a malfunction. Run self-test
to verify.
UNLEVELED
Displayed when the RF output goes unleveled.
Normally caused by exceeding the specified leveled-
power rating. Reducing the power level usually clears
the warning message.
If the warning message is displayed only when AM is
selected ON, the modulating signal may be driving the
RF output unleveled. Reducing the modulating signal or
adjusting the power level usually clears the warning.
UNLOCKED
When FM is selected ON, this warning message
appears indicating that the instrument is not phase-
locked during the FM mode of operation.
EXT REF
This status message indicates that an external 10 MHz
signal is being used as the reference signal for the
681XXB.
OFFSET
This status message indicates that a constant (offset)
has been applied to the displayed power level.
SLOPE
This status message indicates that a power slope
correction has been applied to the ALC.
USER 1...5
This status message indicates that a user level flatness
correction power-offset table has been applied to the
ALC.
SS MODE
This status message indicates that the 681XXB has
been placed in a source lock mode for operation with a
360B Vector Network Analyzer.
Table 6-3.
Possible Warning/Status Messages during Normal Operation
OPERATOR
ERROR AND WARNING/
MAINTENANCE
STATUS MESSAGES
681XXB OM
6-9