The Encoder Model is derived from the PROFIdrive Drive Model as defined in [PDP]. The Encoder Profile defined in [ENCP] used as basis for this specification defines that a P-Device contains exactly one or multiple Encoder Units containing exactly one or multiple Encoder Objects (See Figure 1).


Figure 1 – General Encoder Unit model ([ENCP] chapter 5.2.3)

The main functions of a PROFINET Encoder are defined by the Encoder Object (EO). The general architecture of an Encoder Object is shown in Figure 2.


Figure 2 – General Encoder Object architecture ([ENCP] chapter 5.2.3)

As defined in [ENCP], the EO shall have the following minimum functionality:

  • Parameters
  • Measuring task
  • IO Data (setpoint values, actual values)
  • Support for diagnosis mechanism
  • Clock synchronous operation
  • Fault buffer

The OPC UA for PROFINET Encoder Information Model provides access to parameters, IO Data, diagnosis, and fault buffer information.

The communication channels available between the P-Device and other Devices are shown in Figure 3.


Figure 3 – Overview about available Communication Services

The Encoder Profile defined in [ENCP] allows two communication interfaces for Encoder devices: PROFIBUS or PROFINET. This specification applies to Encoder devices using different communication protocols also. PROFINET specific parts of the Information Model are optional.