Alarms, Events, and Trends

The Alarm and Trend tasks are used to log historical data, and the Alarm/Event and Trend Control objects are used to display historical data on a project screen.

These two features are normally used together, but they do not need to be; project data may be logged without being displayed during runtime, and the data displayed during runtime may be taken from outside the project.

  • Alarm worksheet
    The Alarms folder enables you to configure alarm groups and tags related to each group. The Alarm worksheet defines the alarm messages generated by the project. The primary purpose of an alarm is to inform the operator of any problems or abnormal condition during the process so he can take corrective action(s).
  • About events and event logging
    This section describes IWS‘s logging and event-retrieval features. An event can be any tag change, generating reports or recipes, opening and closing screens, logging onto and logging off the security system, and so forth. IWS saves all of these events in a log file, which can then be retrieved by the Alarm/Event Control object.
  • Alarm/Event Control object
    Use the Alarm/Event Control tool to add an Alarm or Event Control object to a project screen.
  • Trend worksheet
    The Trend folder enables you to configure history groups that store trend curves. You can use the Trend worksheet to declare which tags must have their values stored on disk, and to create history files for trend graphs. The project stores the samples in a binary history file (*.hst), and shows both history and on-line samples in a screen trend graph.
  • Trend Control object
    The Trend Control object displays data points (values) from different data sources in a graphic format.
  • Grid object
    The Grid object allows you to read/write data in a tabular format from the data source configured in the object.
InduSoft Web Studio -Technical Reference

Alarms, Events, and Trends