Configuring Isolated Execution Environments for .NET Modules

Learn how to configure isolated execution environments for specific step types in .NET modules to ensure sensitive or complex operations run independently.

Introduced in TestStand 2026 Q1.

  1. Launch TestStand.
  2. Select View » Types.
  3. Right-click a type and select Properties.
    You can select any step type that supports .NET modules.
  4. Click Advanced » Attributes.
  5. Under Type Attributes, right-click to add an attribute.
  6. Select Insert Attribute » Boolean.
  7. Enter UseSeparateAlc for the attribute name.
  8. Set Value to True.
  9. If you want to use the same assembly load context across multiple step types, configure the first step type as detailed above.
    1. For each additional step type, follow steps 2 through 5.
    2. Select Insert Attribute » String
    3. Enter UseAlcFromStepType for the attribute name.
    4. Set Value to the name of the first step type. For example, if you have StepType1 and StepType2 the value of the UseAlcFromStepType attribute for StepType2 would be StepType1.
  10. Click OK twice to return to the main TestStand window.

By opting into isolated execution environments, you can reduce interference from other .NET-based step types. This feature is particularly useful for workflows involving complex or critical operations.

Note Only TestStand 2026 Q1 and later support the UseSeparateAlc and UseAlcFromStepType attributes. Using step types with these attributes in older versions of TestStand results in no behavioral changes or breakages.