3 EPC-Specific Content and Structure

An EPC file (or Energistics package) is an OPC file; this means first and foremost that any standard OPC reader or library should be able to read an EPC file. This chapter explains the EPC-specific differences that developers must address when implementing EPC.

IMPORTANT! IT professionals implementing EPC must use either OPC libraries or the OPC specification for the majority of their coding. Use this EPC specification to implement the EPC adaptations, which are explained in this chapter.

Figure 3-1 shows an example EPC file.

Figure 3-1 An example EPC file. The basic package structure is consistent with OPC; that is; the root folder must contain at least the _rels folder and the [Content_Types].xml document. An EPC file must include core properties, which may be stored in a docProps folder. This example includes the data being exchanged in folders labeled resqml and witsml. All of these parts are described below.