DOC06501_Revision
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ATS-6501 Users Guide
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The outputs are not locked to the reference
Over temperature (internal temperature is greater than 65 C)
The internal rubidium clock is unlocked.
If set up for an External Reference:
System is unable to communicate with the 5071A if set up to operate
with the reference_type=hp5071a
10MHz input from the external reference is not detected
Table 3-2 Alarm Indicator
3.1.3 Oscillator Locked (Osc Lock) Indicator
The Oscillator Locked indicator on the ATS 6501 indicates the current status of the
internal or external references. During system start up this light can take up to 10 minutes before
it comes on.
Indicator Status
Off Internal
Reference:
The Internal rubidium reports that it is not functioning properly
The OCXO cannot be steered.
External Reference:
System is unable to communicate with the 5071A if set up to operate
with the reference_type=hp5071a
10MHz input from the external reference is missing
Green
Internal: The rubidium reports that it is functioning properly and the OCXO is
being steered.
External: ATS-6501 is able to communicate with the external reference (if
5071A) and the 10MHz signal from the reference is available on the 10Mhz In
connector.
Red POST
only.
Table 3-3 Oscillator Locked Indicator
3.1.4 GPS Tracking Indicator
The TRACKING GPS light indicates whether the unit is collecting data from enough
GPS satellites to calculate a position and time solution. If the light is green then the GPS data is
being used in steering the frequency reference. If it is not lit and GPS was previously available
then the reference is being steered to the unit’s best estimate of UTC(USNO). This light should
be green during normal operations but may have occasional outages depending on the location of
the GPS antenna and quality of the installation. These outages do not significantly degrade the
timing performance of the system unless they occur for extended periods of time. If this light
remains off for more than six hours then the ALARM light will illuminate to indicate a possible
error. This light will turn RED if the operator manually enters a position and makes an error such
that the GPS receiver is unable to use the data.
Indicator Status
Off
GPS receiver is not tracking at least four GPS satellites
Position coordinates were entered incorrectly (Manual Mode).
External Reference: This indicator will go out when the 10Mhz is lost and will
come back on after the 10Mhz has been restored.
