8.2 OPAQUE NodeIds ToC Previous Next

8.2.2 NodeIds for single instances ToC Previous Next

To access POWERLINK Objects on a Server, which represents only one POWERLINK Object Dictionary the size of the NodeId is 4 byte and the format is defined in shown in Table 48.

Table 48 – NodeIds for single instances

Byte Description
0 LSB of the objects POWERLINK Index
1 HSB of the objects POWERLINK Index
2 POWERLINK Sub-Index
3 DataTypeId

Byte 0, 1 and 2 are the values of the POWERLINK addressing scheme Index / Sub-Index. If the POWERLINK Object requested by Index/Sub-Index is not existing the server shall signal this case with the StatusCode Bad_NodeIdUnknown.

With byte 3 the client specifies the expected DataType of the response data by using the built-in types defined in OPC 10000-6. Allowed values are 1 to 12, as well as 15. If byte 3 is set to 12 or 15 (String or ByteString) the server shall respond with the same length like the POWERLINK Object. Otherwise, if the bit-length of the referenced POWERLINK Object is different to the bit-length of the requested DataType, the Server shall signal this case with the StatusCode Bad_NodeIdInvalid.

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