What are the intervals for Trends when using StruxureWare Building Operations
Enterprise Server or Automation Server
Questions regarding what the interval in time is for trending
Intervals can be in Days, Hours, Minutes, Seconds, and Milliseconds.
Trend logs can be of different types and used for different purposes. All logs in StruxureWare use circular storage. The interval trend log collects data at a specific time interval. Each logged value is stored as a record in the trend log. Use this trend log when the logging interval is less than 1 hour.
You create interval trend logs using WorkStation or WebStation. In WorkStation, you configure the properties of the interval trend log to meet the specific needs of your site.
The interval trend log does not record the values between the intervals. An interval log checks the monitored value at each interval and records the new value if it differs from the previously recorded value by more than the delta. Delta is the difference between the current variable value and the last log value. To log a variable according to the time interval, use a delta of zero.
You use an extended trend log to transfer records from a trend log. An extended trend log can be connected to a trend log or connected in a series to another extended trend log. Only one extended trend log can be connected to a trend log. You create and configure extended trend logs using WorkStation.
The extended trend log is often saved on a higher server level with more storage capacity than the server of an ordinary trend log. This extra storage capacity enables the server to store more records before it overwrites old ones. The extended trend log can be viewed in a trend log list or a trend chart.
Trend log lists and records can be exported in two different formats:
CSV (Comma separated values) is a standard file format for digital storage of data structured in a table of lists form. The CSV format can be used by Excel and in databases such as SQL.
XML (Extensible Markup Language) is a standard file format for structured data and can be use with a lot of different tools.
One last suggestion is the number of records, depending on how many records you want to store is important. For example: a single one minute interval Trend Log, and for 66 day, that would be 99,792 records. The maximum is 100,000 on an AS, so take this into account when configuring. This is why Extended Trend Logging is important. Check out article 5032 for information on Trends and Extended Trends.