42
Programming
T801-4 Installation and Operation Manual
© Tait Electronics Limited September 2007
3.4
Viewing the Data Log
The Data Log screen displays the last 10 control measurements which
resulted in the master oscillator control voltage being updated. To open the
Data Log, click
Log
on the monitoring screen.
The correction algorithm adjusts the DAC according to the
Error
. When
the error is less than 1, the
Test Period
is extended to a maximum of 30
seconds. The best indication is 1 error (cycle) in 30 seconds (the master
oscillator runs at just over 107MHz).
The information available on this screen is explained in the following
paragraphs.
Time
The time when the event took place. Note that the time displayed in this
field is based on the computer’s clock, not UTC.
SV
The number of Space Vehicles (satellites) in use at the time of the event
(refer to
“Viewing the GPS Status” on page 44
).
Test Period
The length of the count period, displayed in seconds.
Error
The difference between the master oscillator count and the count expected
over the test period. The system does not measure fractions of a second, so
this figure is rounded up to the nearest whole second. An error of 1
indicates that the actual difference is between 0 and 1, an error of 2 indicates
that the actual difference is between 1 and 2, etc.
