IEC 62056 的很有价值的参考文档，包括： DLMS UA 1000-1 ed.8, Blue book, COSEM Identification System and Interface Classes DLMS UA 1000-2 ed.6, Green book, DLMS/COSEM Architecture and Protocols DLMS UA 1001-1 ed.3,Yellow book, DLMS/COSEM Conformance Testing Pro