This paper addresses the problem of abstracting from diverse field bus technologies towards a function-related, generic interface. Such an abstraction is required by several applications as Plant Asset Management solutions. The abstraction methodology presented here relies on the usage of device descriptions to grant a generic access to field bus data. For this purpose, data types contained in diverse device description technologies are mapped to a generic type. Furthermore access methods get mapped towards a generic interface. The abstraction is defined based on the functionality of the devices, but leaves devices and communication systems unchanged. The exact methodology is described for EDD and EDS.