Understanding the Types of Trend Pen Periods

A trend time period is the interval of process values shown on the X-axis of the trend during run time, which consists of a start time, end time, and a duration.

• The StartTime and duration properties are read/write.

• The EndTime property is a read-only value that the system calculates by adding the duration to the start time.

You can configure two types of Trend Pen periods.

• Moving time period

  In a Moving trend period, the start time of a trend period is the current time, and the end time is the duration of the time period from the start time. When the period ends, the next period begins. The start time for the next period is set to the end time of the previous trend period.

• Fixed time period

  In a Fixed trend period, the start time is initially the current time. The start time of a trend period does not change automatically, but can be specified by a script using the StartTime property.

  The end time of a Fixed trend period is set by the duration of the trend from the specified start time of the period.

  End Time = Start Time + Duration

Related Topics

Configuring a Trend Pen