Blocks
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NcBlock
is a container class for other classes or blocks.
The top most block in a device model is called a root block
and MUST always have an oId of 1
and a role of root
.
All device implementations MUST have a root block
in their device model.
The control class model for NcBlock is listed in the Framework.
A object’s role path is a sequence of role values starting with the root block’s role, continuing with any containing blocks and ending with the object’s role.
An object in a hierarchy of nested blocks MUST be uniquely identified by its role path which MUST be persisted across device reboots.
Device model discovery
Blocks enable device model discovery by offering the descriptors of their contained members in the members
property which holds a collection of type NcBlockMemberDescriptor.
Search methods
Blocks are searchable by calling any of the following methods:
- FindMembersByPath - retrieve descriptors for members filtered using a relative role path sequence of roles. The relative path to search for MUST not include the role of the block targeted by oid
- FindMembersByRole - retrieve descriptors for members filtered by the role property
- FindMembersByClassId - retrieve descriptors for members filtered by a given class id