The Device Access module is designed to abstract all physical devices which come from the network. This abstraction allows you to manage all devices the same way via the DA API regardless of the protocol adapter they are using. On the other hand, Device Access has a unified device representation to a lower level of abstraction through the HDM SPI. In other words, Device Access isolates the low-level device representation from the high-level management of these devices. The low-level abstraction is represented in the com.prosyst.mbs.services.hdm.spi package.

The following diagram shows the main components that are contained in the HDM SPI and how they relate to the DA API.