Expression Engine Overview

The Expression Engine is a tool contained in many components in GENESIS. It provides a standardized syntax for creating logical expressions and enables data processing and transformation. You can define your own custom calculations and expressions to support your objectives in data visualization, monitoring, and analysis.

The Expression Engine is designed to have a core set of common functions for mathematical, logical, string, array, and time-based operations that can be used across a wide range of applications. Some GENESIS components that use the expression engine also include additional specialized functions related to the component. They may accept input in the form of subscriptions to other data points and may use the available functions to define the output value.

The Expression Engine extends the data browsing capability of many GENESIS components, and depending on the application, may be used to directly evaluate a value, to define the tag name of a point to browse, or to configure mapping data into a dataset. Some of the prominent components that use expressions are:

• GraphWorX Configurations - Most configurable aspects of GraphWorX where you can access a data browser, you will be able to configure an expression.
• Asset Properties - Expressions are a valid input type for the real-time data source of an Asset Property.
• Asset Fault Definitions - The triggering condition of a fault is defined with an expression that may resolve to TRUE or FALSE indicating the fault state.
• Alarm Type Expressions - Alarm Types have expressions that define how and when the alarm state should be active.
• Data Historian Calculated Tags - The expression defined in a calculated tag defines the resulting value that is stored for this tag.
• Bridging Activity Blocks - Conditional blocks in Bridging use expressions to determine the branch to follow in the workflow, and data input and output activities can use expressions in the definition of tag names.