Defined terms of OPC UA specifications, types and their components defined in OPC UA specifications and in this specification are highlighted with italic in this specification.

For the purposes of this document, the terms and definitions given in the OPC UA Specifications OPC 10000-1, OPC 10000-3, OPC 10000-8 and the OPC UA for Devices Companion Specification as well as the following apply.

A Sercos Profile defines the complete behavior of certain functionality and their extensions including all appropriate parameters.

A Sercos Device provides access to the all Sercos Parameters of a device using the defined Sercos Function Groups and Sercos Classes using the Sercos real-time protocol, the S/IP protocol or OPC UA directly.

A Sercos Function Group is a group of different Sercos Parameters which comprise and describe one functionality.

A Sercos Class defines mandatory parameters and mandatory functionality. Usally, the Sercos Class is a sub-set of one ore more Sercos Function Groups. For instance, the class “Drive Velocity” of Function Specific Profile (FSP) Drive represents the velocity operating mode of a drive. All parameters within this class are necessary to implement this functionality and therefore mandatory.

A Sercos Parameter includes the device data structure that can be read or written.

All Sercos Parameters obey a defined notation system as naming rule. The corresponding notation is as follows:

<S/P>-<PS>-<DBN>.<SI>.<SE>

For Example: S-0-1301.0.1

The <S/P> specifies whether the Sercos Parameter is a standardized parameter (S) or a product-specified parameter (P). S-parameters are parameters defined by Sercos International and therefore have the same meaning and functionality for all Sercos devices independent of the manufacturer and product type (for more information see Sercos General Overview and Architecture, part 7).

Parameter Set (<PS>) is the set index of the specific parameter. Sercos specifies currently IDNs with parameter set 0 only.

Data Block Number (<DBN>) is the identification number for the parameter.

Structure Instance (<SI>) specifies the index of a structure (array). This serves to address the structure of the same type within one sub-device. There are 255 instances of the same structure possible in one sub-device.

Structure Element (<SE>) specifies the element within the Structure Instance.

The Sercos Parameters of any device can be identified with its 32-Bit identification number (IDN) in format e.g. S-0-0047.0.0 or S-0-0047 (see Figure 1).

Figure 1 – Sercos 32 Bit IDN structure

The Sercos Profile description markup language is a markup language that contains Sercos defined tags to list all profiles that a Sercos device supports, in the form of a text (XML) file.

DBN Data Block Number

FSP Function Specific Profile

GDP Generic Device Profile

IDN Identification Number (of a Sercos Parameter)

PS Parameter Set

SCP Sercos Communication Profile

SE Structure Element

SI Structure Instance

S/IP Sercos IP

SPDML Sercos Profile Description Language

XML Extensible Markup Language