Trend Recorder; Retrieving Trend Records; Comtrade Format - Novatech Bitronics M87X Series Manual

5.4.3 Trend Recorder

The M87x stores the values of a user-configurable set of up to 230 parameters every log
interval. The default setting of this interval is 0 minutes, which disables the Trend
Recorder. This interval can be changed from 1 to 720 minutes (12 hrs.) in 1-minute
increments. Once the log file has reached its maximum length, it will wrap around to the
beginning and overwrite the oldest entries in the file. The log file is stored in non-volatile
memory, allowing for retrieval of a complete log file even after power has been cycled to
the instrument.
The user may select between recording the instantaneous values only, or storing the
minimum, maximum, and average values recorded during the previous interval.
recorded values are based on measurements that are updated every cycle.
Trend Recording is always started at the closest time that is an integral multiple of the log
interval.
Example:
If the trend interval is set to 15 minutes and the M87x system clock time is 9:18, the first
entry will occur at 9:30. Subsequent entries will be made at 15-minute intervals. If the
trend interval is changed to 5 minutes at 9:37, the next entry will occur at 9:40.
Subsequent entries will occur at 5-minute intervals.
For intervals less than 60 minutes, it is recommended that the trend interval be set to a
number that will evenly divide 60 minutes. If the interval is greater than 60 minutes, it
should evenly divide 24 hours.
Recommended intervals:
1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30 minutes
1, 2, 3, 4, 6, 8, 12 hours
NOTE: If the System Clock setting (Section 3.1.3) is to be changed backwards, it is
recommended that all trend recorder files be retrieved, the time changed, and the
trend recorder file be deleted. If this is not done, the file will effectively contain a
section that shows time going backwards! This will cause problems with the
Comtrade file format.
5.4.3a Retrieving Trend Records
The trend file is stored on the unit in a proprietary data format. BiView or the Retriever
program (supplied on the Utilities CD) is required to download & convert the raw trend file
stored on the unit into an industry standard Comtrade file. When downloading the raw file
via BiView or Retriever, the trend file on the unit will automatically be deleted; however
both programs will preserve a copy of the raw trend file on the PC and append the new
data every time the trend file is downloaded.

5.4.4 Comtrade Format

Waveform and Disturbance Records are available in Comtrade file format (C37.111-1999)
and Trend Records can be converted into this format when retrieved using BiView or
ML0021 August 15, 2018
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