User's Manual

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Set Date: Displays the current date. The year, month and day can be set using the drop-
down selection boxes.
Time Zone: See Section
1149H8.3.11.7.
Daylight Saving: See Section
1150H8.3.11.7.
8.3.12 Diagnostics
To further enhance the diagnostic capabilities of the PTP 600 Series, the storage of link
performance histograms has been extended to 31. To optimize RAM (volatile memory) usage
a cascading histogram approach has been adopted. The root histogram is identical to the
histograms in 58100 that is data is stored for one hour at a resolution of one second. In 58100
the histograms were simple cyclic buffers which never stored more that the last one hour of
data. The new cascading histogram approach daisy chains multiple histograms together.
When the first histogram fills up the overflow from the first is used as an input to the next
histogram in line. To optimize memory utilization a statistical analysis is performed on the
overflow to reduce the amount of data to be stored. In the case of the PTP 600 Series the
cascading histograms are defined as:
• Histogram 1: 1 hour at a resolution of 1 second
• Histogram 2: 24 hours at a resolution of 1 minute
• Histogram 3: 30 Days at a resolution of 1 hour
For example, when histogram 1 fills up and starts to overflow the first minute of overflow is
analyzed and the maximum, minimum and mean over that minute are computed and inserted
into histogram 2. When histogram 2 fills up and starts to overflow the first hour of overflow is
analyzed and the maximum, minimum and mean over that hour is computed and inserted into
histogram 3. When histogram 3 starts to overflow, the overflow data is simply discarded.