###### tags: `work`

# DLMS/COSEM
## Naming and addressing
- A name identifies a communicating entity.
- An address identifies where that entity can be found.
- Server physical devices may host one or more logical devices (LDs).

### Naming
#### system title
- LDs hosted by the same physical device share the system title.
- shall be ***8 octets long***, shall be unique.
- The 3 leftmost octets should hold the three-letter manufacturer ID
(This is the same as the leading three octets of the Logical Device Name)
- The remaining 5 octets shall ensure uniqueness.
### Addressing
#### Service Access Point (SAP)
- Each DLMS/COSEM client and each server – a COSEM logical device – is bound to a Service Access Point (SAP)

### Application associations

AAs are modelled by COSEM “Association SN / LN” objects that hold the SAPs identifying the
associated partners, the name of the application context, the name of the authentication mechanism,
and the xDLMS context.

The “Association SN / LN” objects also determine a specific set of access rights to COSEM object
attributes and methods and they point to (reference) a “Security setup” object