Identification
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NCA defines the following framework identifiers (a “framework” identifier is an identifier that is used by the basic NCA framework, irrespective of application).
Identifiers
Class ID
Uniquely identifies a class. Stored in property NcObject.classId
| Datatype | Scope | Lifespan |
|---|---|---|
| NcClassId | NCA control model | Permanent |
Further information provided in Appendix A.
Object ID
Compact read-only handle that uniquely identifies an object within its device. Stored in property NcObject.oid.
| Datatype | Scope | Lifespan |
|---|---|---|
| NcOid | Device | Constant until reboot |
Element ID
Static identifier of a property, method, or event of a control class.
| Datatype | Scope | Lifespan |
|---|---|---|
| NcElementId | Class | Permanent |
Role
Static, read-only text property that names an object within the block to which it belongs. Unique within the block. Stored in property NcObject.role.
| Datatype | Scope | Lifespan |
|---|---|---|
| NcString | Block | Permanent |
Role path
Uniquely identifies the location of an object within a device model. Sequence of strings, consisting of the role values of all the object’s containing blocks, starting from the root block and ending with the object’s own role value.
Role paths are enabled by the existence of blocks in the device model.
| Datatype | Scope | Lifespan |
|---|---|---|
| NcRolePath | Device | Permanent |
User label
Read/write string that users can set to identify an object’s operational purpose in a particular application context. Analogous to the texts written on mixing console scribble strips, labels, and bits of paper tape affixed to equipment in use. Stored in property NcObject.userLabel.
| Datatype | Scope | Lifespan |
|---|---|---|
| NcString | n/a | Permanent |
Product UUID
UUID that uniquely identifies the particular product that constitutes the Device. Stored in field uuid of datatype NcProduct. In turn, product descriptor for a Device is stored in property NcDeviceManager.product.
| Datatype | Scope | Lifespan |
|---|---|---|
| NcUuid | Manufacturer portfolio | Permanent |
NCA-NMOS identity mapping
NCA’s Touchpoint feature allows applications to attach a list of touchpoints to any control object. A touchpoint is a defined relation between an entity in NCA and an entity in a different namespace. Stored in property NcObject.touchpoints.
| Datatype | Scope | Lifespan |
|---|---|---|
| NcTouchpoint | Referred namespace | Permanent |
NCA discoverability in IS-04
Compliant NCA protocols are advertised through existing IS-04 practices inside the controls array of an NMOS Device.