In a digitized production, devices are interconnected with each other. This is achievable with OPC UA, which is currently increasing in popularity. To accommodate different kinds of machinery, Companion Specifications (CSs) for OPC UA are being defined. To achieve connectivity at the installation of machinery equipment, interoperability and correct implementation of the CS interfaces must be guaranteed. Discovering faults as soon as possible can be achieved through testing. For OPC UA and CSs, a testing framework exists, but the test cases are written by hand. This is a drawback for CS standardization groups, that have to put in the effort to develop test cases. In this work, the prerequisites to automatically generate CS test cases are outlined. An approach for automatic test case generation is sketched, that synthesizes test cases based on these prerequisites. In a comparison to existing test cases, the possibilities and limits of autogenerating test cases are discussed.