Tektronix SPG8000 Technical Reference page 175

SPG8000 Technical Reference
Tmp Wtd: Displays the number of temperature weighted hours that the
selected supply has been in operation versus a limit of 131,400 hours. OK is
displayed as the status when number of temperature weighted hours is within
the operating limit; WARN is displayed when the number of hours exceeds
the limit. For critical applications, you may want to replace the power supply
periodically to prevent down time.
The instrument uses a log to track the number of hours that a Power Supply
module has been powering the instrument. The expected life of a Power
Supply module varies with the temperature and load. For a fully-loaded
instrument in a 25 °C room, the power supply is specified to last at least 15
years (131,400 hours). For a lightly loaded instrument with only one or two
modules running a 25 °C, the power supply should last 20 years (175,000
hours).
At the maximum room temperature, the expected life of the power supply is
significantly less. For example, for a fully loaded instrument operating at 50
°C room temperature, the expected life of the power supply is 5 years (43,800
hours). The temperature-weighted hours (TWH) accounts for variations in the
operating environment and displays a number normalized to 25 °C operation.
Therefore, if the TWH is near the 131,400 recommended limit, then you
should consider replacing the supply.
+12.0V: Displays the status of the +12 V supply. OK is displayed as the
status when the voltage is within the operating range; WARN is displayed
when the voltage is out of range.
Mfg Date: Displays the manufacturing date of the selected supply. The
readout includes the time (HH:MM:SS) and the date (day, month, year).
GPS PHS DET RAMPS. This diagnostic monitors voltage ramps used in the GPS
phase detector (Option GPS only). Use the left (◄) or right (►) arrow button
to view all of the voltage information. OK is displayed as the status when a
voltage is within the nominal range; WARN is displayed when a voltage is out
of range. If these voltage ramps are outside the nominal range, it means that the
instrument should be serviced.
GPS ADC BUS. This diagnostic displays the condition of the Genlock input
circuit (Option GPS only):
NOTE.
If no input is applied to the Genlock input circuit, then the ADC bits will
be moving and so may appear stuck. This is not an indication of a problem.
Stuck: A 12-bit display showing the bits stuck high (H), low (L), or OK (-).
Short: A 12-bit display showing any shorted adjacent lines (SS) (-).
SYSTEM button menu
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