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Legacy data modeling
This resource is part of the asset-centric data model.
  • New projects: We recommend using the data modeling service for greater flexibility and performance.
  • Existing projects: This resource remains fully supported for maintaining legacy applications.
Events store complex information that happens over a period. Events have a start time and an end time and can be related to multiple assets. For example, the Events API includes alarms, process data, and logs. The startTime and endTime for the event’s period are represented in Unix Epoch time in milliseconds. CDF doesn’t support fractional milliseconds and doesn’t count leap seconds. You can specify both the start and end times in the future, but the end timestamp must be greater than or equal to the start timestamp for the input to be valid. To describe and classify events, you can add arbitrary string values for description, metadata, type, and subtype. All event information is stored in string format when you store it in metadata.
Use the Data Modeling service to store manually generated, schedulable activities with low volumes, such as maintenance schedules, work orders, or other appointment-type activities.
Events and time series data are high-volume data types that can record data in microsecond resolutions. Avoid using events as a time series store, especially when the data flow is from a single instance of sensors (temperature, pressure, voltage), simulators, or state machines (on, off, disconnected). The Time Series API provides very low latency read and write performance and specialized filters and aggregations designed to analyze time series data.

What you can do

  • Create events with metadata, time ranges, and asset links.
  • Search for events by description, metadata, or time range.
  • Filter events using advanced criteria.
  • Aggregate event data for analytics and reporting.
  • Update event properties and asset associations.
  • Delete events that are no longer needed.

Rate and concurrency limits

For Events rate and concurrency limits, see API rate limits.
Last modified on April 23, 2026