Direct Access Self-Defining Parameter

The presence of the Direct Access ID self-defining parameter indicates that the auxiliary device can be accessed directly by using the destination/origin structured field. When multiple auxiliary devices are supported that use a product-defined data stream, separate Product-Defined Data Stream query replies must be provided, each of which has a unique DOID.

Table 1. IBM Product-Defined Direct Access Self-Defining Parameter
Offset Length Content Meaning
0 1 byte X'04' Parameter length
1 1 byte X'01' Direct access ID
2–3 2 bytes DOID Destination/origin ID
The value in these bytes is used in the ID field of the destination/origin structured field to identify the auxiliary device as the destination or origin of the data that follows.