IEC 62056-5-3:20 23规定了DLMS？/COSEM应用层在DLM的结构、服务和协议方面？/COSEM客户端和服务器，并定义规则来指定DLM？/COSEM通信配置文件。 它定义了用于建立和发布应用程序关联的服务，以及用于访问IEC 62056-6-2:20 21中使用逻辑名称（LN）或简称（SN）引用定义的COSEM接口对象的方法和属性的数据通信服务。 附录A（规范性）定义了如何在各种通信配置文件中使用COSEM应用层。它指定了如何构建各种通信配置文件以使用COSEM接口模型与计量设备交换数据，以及在每个通信配置文件中指定哪些必要元素。IEC 62056系列的单独部分中规定了实际的、特定于媒体的通信配置文件。 附录B（规范性）规定了SMS短包装。 附录C（规范性）规定了网关协议。 附录D、附录E和附录F（资料性）包括APDU的编码示例。 附录G（规范性）提供了NSA Suite B椭圆曲线和域参数。 附录H（资料性）提供了一个使用P-256签名的P-256的终端实体签名证书的示例。 附录I（规范性）规定了DLMS中密钥协议方案的使用？/. 附录J（资料性）提供了在第三方和服务器之间交换受保护的xDLMS APDU的示例。 这第四版取消并取代了2017年出版的第三版。本版构成技术修订版。 附录K（资料性）列出了与上一版相关的重大技术变更。

IEC 62056-5-3:2023 specifies the DLMS？/COSEM application layer in terms of structure, services and protocols for DLMS？/COSEM clients and servers, and defines rules to specify the DLMS？/COSEM communication profiles.
It 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 62056-6-2:2021 using either logical name (LN) or short name (SN) referencing.
Annex A (normative) defines how to use the COSEM application layer in various communication profiles. It specifies how various communication profiles can be constructed for exchanging data with metering equipment using the COSEM interface model, and what are the necessary elements to specify in each communication profile. The actual, media-specific communication profiles are specified in separate parts of the IEC 62056 series.
Annex B (normative) specifies the SMS short wrapper.
Annex C (normative) specifies the gateway protocol.
Annex D, Annex E and Annex F (informative) include encoding examples for APDUs.
Annex G (normative) provides NSA Suite B elliptic curves and domain parameters.
Annex H (informative) provides an example of an End entity signature certificate using P-256 signed with P-256.
Annex I (normative) specifies the use of key agreement schemes in DLMS？/COSEM.
Annex J (informative) provides examples of exchanging protected xDLMS APDUs between a third party and a server.
This fourth edition cancels and replaces the third edition published in 2017. This edition constitutes a technical revision.
The significant technical changes with respect to the previous edition are listed in Annex K (Informative).