IEC 62056的本部分从DLMS®/COSEM客户端和服务器的结构、服务和协议方面规定了DLMS®/COSEM应用层，并定义了指定DLMS®/COSEM通信配置文件的规则。 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COSEM接口对象的方法和属性的数据通信服务，这些对象在IEC 62056-6-2:2021中使用逻辑名称（LN）或短名称（SN）引用定义。 附录A（规范性附录）定义了如何在各种通信配置文件中使用COSEM应用层。它规定了如何构建各种通信配置文件，以便使用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的必要元素。 IEC 62056系列的单独部分规定了实际的、特定于媒体的通信配置文件。 附录B（规范性附录）规定了SMS短包装。 附录C（规范性附录）规定了网关协议。 附录D、附录E和附录F（资料性附录）包括APDU的编码示例。 附录G（规范性附录）提供了NSA套件B椭圆曲线和域参数。 附录H（资料性附录）提供了使用P-256签名的最终实体签名证书示例。 附录I（规范性附录）规定了DLMS®/COSEM中关键协议方案的使用。 附录J（资料性附录）提供了在第三方和服务器之间交换受保护xDLMS APDU的示例。 附录K（资料性附录）列出了本版标准中的主要技术变更。

This part of IEC 62056 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. Annex K (informative) lists the main technical changes in this edition of the standard.