The PROFINET Encoder Information Model aims to offer Clients Objects and Services based on the Encoder Profile as defined in [ENCP]. The Information Model defined in this specification can also be seen as an extension of the OPC UA for RIO Information Model as defined in [OPC RIO].

OPC UA for PROFINET Encoder consists of all Objects and types provided by an OPC UA Server allowing OPC UA Clients to access data and services of Encoder Objects. As specified in [OPC RIO], the Information Model is divided into a PROFINET aspect and a functional aspect. The PROFINET aspect offers detailed Telegram information (See [OPC RIO]), the functional aspect provides an Information Model for Encoder Objects by providing EncoderChannelType Objects. The Signal Objects (See [OPC RIO]) in the PROFINET aspect are connected with components of the Encoder Objects in the functional aspect by dedicated 0:RepresentsSameEntityAs References.

The EncoderChannelType serves as the root container for modelling of Encoder Objects. The functional aspect with PROFINET Encoder contains as many EncoderChannelType Objects as needed to represent the Encoder Objects of the P-Device. The components of the EncoderChannelType are separated into five different sub-aspects as shown in Figure 9.


Figure 9 – EncoderChannelType Organization

The “Signals” sub-aspect contains the Variables representing the Signal as transmitted in the PROFINET Telegram as Value.

In contrast, the “Measurement/Actual Values” sub-aspect is mainly consisting of Variables which contain the measurement values like position and velocity encoded as numeric data types. If containing information of the same Signal, Variables of these two sub-aspects may also be connected using the 0:RepresentsSameEntityAs Reference type.

The “Configuration” sub-aspect contains Objects holding configuration settings of the Encoder Object. There are also Methods available allowing Clients changing certain settings (See chapters 7.6, 7.7 and 7.8).

The “Sensor & Probes” sub-aspect gives access to sensor and probe data of the Encoder Object by providing the “Sensor” and “Probe” Objects. These Objects offer Variables, Methods, and Events for detailed control and information (See chapters 7.2 and 7.3).

The “Diagnosis” sub-aspect gives Clients access to the content of the Encoder Object’s fault buffer. The Logbook ObjectType provides information about present and transient error conditions (See chapter 7.5). The “Diagnosis” sub-aspect also provides the EncoderDiagnosisEventType offering fault and warning information information.