14.5.3
Absolute time of day synchronization
The relevancy of this synchronization is a pure user application requirement.
GEN series systems are synchronized to the controlling PC when Perception
makes the first connection to the mainframe. If the PC is connected to the
internet or an intranet, the NTP process running within the operating system
allows the GEN series mainframe to synchronize to approximately one second
to the absolute time of day.
In most cases, this time indication meets the generic requirements to trace the
time of day that the recording was made.
HINT/TIP
GEN series systems store this time inside the PNRF file and set the file date/
time to this same time as well. However, copying files from one storage medium
to the next, such as during archiving, might change the file date and time listed.
Perception software only uses the date/time stored inside the PNRF recording
file. This information is never affected by the adjustment that might occur while
transferring the datafile.
If GEN series recorded data needs to be correlated to other (GEN series)
systems that are not directly synchronized to the same time source, a more
accurate absolute time of day is required to enable data correlation at a later
point in time.
HINT/TIP
Whenever a GEN series recording is made using any of the available
synchronization methods, the need for absolute time of day synchronization is
not required to get a correct signal phase match.
A typical use of absolute time of day synchronization would be two GEN series
systems, each at different locations that cannot be connected by wires. Using
GPS absolute time synchronization would allow recorded data to be compared,
even if these two systems were not connected.
GEN3i
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