This “OPC UA for Sercos Devices Companion Specification” is mandatory using String as IdentifierType for all Objects / instance NodeIds and any NodeIds, e.g. Numeric, for the ObjectType NodeIds.

The symbolic name of each Node defined in this document is its BrowseName, or, when it is part of another Node, the BrowseName of the other Node, a “.”, and the BrowseName of itself. In this case “part of” means that the whole has a HasProperty or HasComponent Reference to its part. Since all Nodes not being part of another Node have a unique name in this document, the symbolic name is unique.

In this “OPC UA for Sercos Devices companion specification”, the Identifier for each Node starts with one out of the three possible connection / addressing types

  • Topological (defined in Sercos Communication Profile Specification).

The Sercos topology index (topological address) describes the position of a slave (device) in a Sercos network. It uses a daisy chain numeration starting with value 1 at the first slave behind the master.

  • Sercos (defined in Sercos Communication Profile Specification).

The Sercos address is a freely selectable address of a slave (device) in the range between 1 and 511. It has to be unique in the Sercos network.

  • SercosIP (defined in Sercos Internet Protocol Services Specification).

This is the IP address of a Sercos device within an IP network, e.g. Sercos network or “non-Sercos” network.

Each connection type has its own NodeId composition that can be explained as follows. Each of the following examples addresses the variable MinValue from parameter S-0-0001 (SercosParameterType).


Topological,[Sercos Master No.], [Sercos Topological Address]

e.g. Topological,0,1.ParameterSet.”S-0-0001”.MinValue


Sercos,[Sercos Master No.], [Sercos Slave Address]

e.g. Sercos,0,1.ParameterSet.”S-0-0001”.MinValue


SercosIP,[IP Address], [SlaveIndex], [SlaveExtension]

e.g. SercosIP,””,0,0.ParameterSet.”S-0-0001”.MinValue

(The SlaveIndex will be derefered to a SlaveAddress using the IDN S-0-1046. For further information please refer to the Sercos Communication Profile Specification.)

The namespace URI for Sercos Types is “”.

The namespace URI for Sercos Instances is arbitrary, e.g. “http://[]/UA/Sercos/”.