### 3 Terms, definitions, and abbreviations

### 3.3 OPC UA for Sercos Information model terms

## 3.3.5 Sercos Parameter (32-Bit IDN)

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**