Direct Replacement: Can be used in place of an earlier product without any user modification or adjustment. Form, fit, and function are backward-compatible, and no additional tools, configuration or application changes, or software or product updates are required to the product or any system-related products. Often referred to as a “drop-in replacement,” a direct replacement product does not noticeably affect system functionality.
Functional Replacement: Can be used in place of an earlier product with minimal changes to an existing application. Form, fit, or function remain backward-compatible, but include alterations that may require software or firmware updates, configuration changes, or minor mounting and electrical modifications. The new product/family may have features or functions to provide increased capability, but whose usage is optional. A functional replacement does not noticeably affect system functionality.
Engineering Replacement: Can be used to migrate an earlier product, but requires engineering changes to existing applications. Form, fit, or function have changed and are NOT backward-compatible, requiring engineering effort that may include additional software/hardware tools and products or architectural modifications. Services to support these replacements may be available from Rockwell Automation or our partners.