標準號：BS EN 62056-21-2002
中文標準名稱：電度表.電度表讀數,計價和負載控制的數據交換.直接地方性數據交換
英文標準名稱：Electricity metering - Data exchange for meter reading, tariff and load control - Direct local data exchange
標準類型：N22
發布日期：2002/7/17 12:00:00
實施日期：2002/7/17 12:00:00
中國標準分類號：N22
國際標準分類號：35.240.60;91.140.50
適用范圍：This part of IEC 62056 describes hardware and protocol specifications for local meter data exchange. In such systems, a hand-held unit (HHU) or a unit with equivalent functions is connected to a tariff device or a group of devices. The connection can be permanent or disconnectable using an optical or electrical coupling. An electrical interface is proposed for use with a permanent connection, or when more than one tariff device needs to be read at one site. The optical coupler should be easily disconnectable to enable data collection via an HHU. The protocol permits reading and programming of tariff devices. It is designed to be particularly suitable for the environment of electricity metering, especially as regards electrical isolation and data security. While the protocol is well-defined, its use and application are left to the user. This standard is based on the reference model for communication in open systems. It is enhanced by further elements such as an optical interface, protocol controlled baud rate switchover, data transmission without acknowledgement of receipt. The protocol offers several modes for implementation in the tariff device. The HHU or equivalent unit acts as a master while the tariff device acts as a slave in protocol modes A to D. In protocol mode E, the HHU acts as a client and the tariff device acts as a server. As several systems are in practical use already, particular care was taken to maintain compatibility with existing systems and/or system components and their relevant protocols.