What is BS EN 62056-53 - Electricity metering using COSEM application layer about ?
COSEM stands for Companion Specification for Energy Metering. It is an interface model for communicating with energy metering equipment, providing a view of the functionality available through the communications interfaces.
BS EN 62056-53 is the 53rd part of the BS EN 62056 series which specifies the COSEM application layer in terms of structure, services and protocols for COSEM clients and servers, and defines how to use the COSEM application layer in various communication profiles.
Who is BS EN 62056-53 - Electricity metering using COSEM application layer for ?
BS EN 62056-53 on electricity metering using COSEM application layer is relevant to: 
- Electricity supply meter manufacturers
- Power distribution and transmission companies
- Utility companies
- Communication media network providers
- Local authorities
- Regulatory bodies
- Quality control and testing personnel
- Engineers
Why should you use BS EN 62056-53 - Electricity metering using COSEM application layer ?
Communication with electricity metering equipment using the COSEM interface object model is based on the client/server paradigm where metering equipment3 plays the server role. In this environment, communication takes place always between a client and a server AP: in other words, the server AP provides remote services to the client AP. These services are provided via exchanging messages (SERVICE.requests/. responses) between the client and the server Aps. The main component of the client and server COSEM application layers is the COSEM ASO, which provides services to the COSEM AP, and uses services provided by the supporting lower layer.
BS EN 62056-53 defines services for establishing and releasing application associations, and data communication services for accessing the methods and attributes of COSEM interface objects, defined in IEC 62056-62, using either logical name (LN) or short name (SN) referencing.
Overall, BS EN 62056-53 can contribute to enhanced operational efficiency, functionality and interoperability of COSEM application layers.
What’s changed since the last update ?
BS EN 62056-53:2007 supersedes BS EN 62056-53:2002. BS EN 62056-53:2007 includes some technical changes with respect to BS EN 62056-53:2002. These include:
- The protocol of the COSEM-RELEASE service has been changed: depending on the communication profile used, these services may rely on the ACSE A_RELEASE services
- The parsing order of the AARQ APDU has been changed
- Handling of repeated application association requests has been simplified
- The Service_Class parameter of the COSEM-OPEN service is now linked to the response allowed field of the xDLMS-Initiate.request APDU
- The Service_Class parameter of COSEM services for data exchange using LN referencing is now linked to bit 6 of the Invoke-Id-And-Priority parameter
- A new, optional EXCEPTION APDU has been introduced. The server may send back this APDU after an erroneous service request
- A general part about using the COSEM application layer in various communication profiles has been added
- The description of using the COSEM Application layer in the 3-layer, connection-oriented, HDLC based communication profile has been amended
- A new, TCP-UDP/IP based communication profile has been defined
