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Creating Expressions

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Overview

Expressions can be created or modified by utilizing the Expression Builder which is available under DataXchange → Expressions → Create Expressions on the ribbon bar.

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Creating Expressions

An expression can be built by typing in the Expression text area or by using the ribbon bar to select Variables and the Operators.

The variables and constants for each type of communication can be accessed using the appropriate button in the Variables section in the ribbon bar. Search boxes are available to find the desired variable, and the cursor can be held over the variable name to show the toggled syntax assisting in finding the appropriate variable and creating the expression.

The Validate button verifies that all parenthesis are in the correct location. If there is an error with placement, a notification will pop up advising the needed corrections. If the expression is written in the correct format, a notification will pop up indicating that the expression has validated properly.

There are a variety of expression examples that can be within this help file. Additionally, more information on the structure can be found here.

Modifying expressions

Existing expressions can be customized using the Modify button. Highlight an existing expression and click Modify to adjust the values. Once complete select enter, and your new expression will appear within the expression group tree. Modification of an expression will create a new version. See below for more detail.

Existing expressions can be copied with the Copy button. This is recommended in most cases when changes are needed to an expression that is already assigned to equipment.

Expression Groups

Expressions can be optionally placed in Expression Groups to help organize the expressions when modifying or assigning them to machines.

Locating Expressions

When an Expression Group is highlighted the list of expressions will be filtered to only show expressions within the selected group. In addition, the text boxes and drop downs above the lists can be used to filter the content of the lists. In the expression list a green icon with a check will appear next to each expression that is currently assigned to one or more equipment.  

Where Used: This button shows which equipment a highlighted expression is assigned to. Another option is to highlight the equipment and a green check box icon will appear next to all expressions that are currently assigned to the selected equipment. Likewise, when an expression row is selected in the list the “Where Used” button will be enabled. When selected this will pop up a list of equipment that uses the selected expression. 

Versions

The version number (bottom right by the blue arrows) will be an number representing the amount of history records for the selected expression. The arrow buttons will navigate through previous versions which cannot be modified or removed, only copied to a new expression. The date will represent the date of the expression was modified. NOTE: Historical expressions cannot be removed or modified.

Data Listener

The data listener pull down allows you to apply listeners to expressions when needed. More information can be found here.

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