About stored variables

A Stored variable stores data in any of the supported data types. These items are useful for persisting variable values between code method calls, and between service restarts.

Stored variables have global scope in the project, and can be accessed by any expression field or code items. You can use stored variables as accumulators, counters, variables, or constants.

The value of a stored variable is set by one of two ways:

• The value is typed into the Value property

• Running code is executed

Comparison between stored variables and calculated variables

• Calculated variable items each have their own expression element. This stores and evaluates code script to determine the value of the calculated variable at run time.

• Stored variable items do not store an expression for evaluation, so do not evaluate themselves at run time. Stored variable items commit their samples to Server database, whereas calculated variable items commit their expression, not the resultant value.

  Stored variable	Calculated variable
  Does not store an expression	Stores an expression
  Does not evaluate value at run time	Determines value of the expression at run time
  Commits sample to server database	Commits expression to server database

Related topics

• Add and configure a stored variable

• Stored variable properties

• Add and configure an accumulator variable

• Add and configure a calculated variable