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• Postfault Time (ms)*
This setting determines the period of Post-Fault data that the DFR will record after the trigger event
clears, or after the Fault Limit period has elapsed. This entry is in milliseconds. Transient record
Post-Fault can be set to a maximum of 10000. The default entry automatically assigned to this field
is 100.
• Long Term Prefault Time (sec)*
This setting determines the period of prefault data that the DDR will record prior to the trigger
event. This entry is in seconds.
• Long Term Postfault Time (sec)*
This setting determines the period of Post-Fault data that the DFR will record after the trigger event
clears, or after the Fault Limit period has elapsed. This entry is in seconds.
Note: The sum of Long Term Prefault and Long Term Postfault time is limited to 300 seconds.
The total length of a Long Term (DDR) record is equal to (Pre-Fault period) + (Post-Fault
period).
• Trigger Limit (ms)*
This setting determines the time limit of any record. Transient Fault-Limit may be set for any value
up to a maximum of 10000. This entry is in milliseconds.
Note: The total length of a fault record is equal to (Pre-Fault period) + (Fault period) + Post-Fault
period). If an analog or digital trigger should re-occur during the Post-Fault period, the fault
record will be extended to contain the entire event in a single COMTRADE data file.
If a repeat fault occurs after the Post-fault + Pre-fault time period of the initial fault, it is
recorded in a separate data file. If a repeat fault occurs before the Postfault + Prefault time
period of the initial fault, the initial data file is extended.
The maximum length of a Fault Record in a re-trigger situation is 10 seconds.
• Trigger Chatter Filter
The filter employed uses two parameters to determine when a trigger should be automatically
disabled—total triggers and trigger repetition rate. The filter can be customized for each analog and
digital trigger.
The Chatter Limit parameter is a value which determines when a trigger will be disabled. The
Chatter Rate parameter is a value which determines an acceptable number of triggers per second.
The value for these two entries can be a whole or decimal number. These values can be modified
for each discrete analog and digital trigger on the Measurements and Events pages (see Sections
3.1.4 and 3.1.5).
The filter works by accumulating the number of triggers that have occurred and then reducing this
value by the Chatter Rate parameter each second. If the volume of triggers reaches the set Chatter
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