What is BS EN 62056-21 - Direct local data exchange for electricity metering about ?
Meter data exchange can be local or remote. This part of IEC 62056 is restricted to local data exchange.
BS EN 62056 is a European Standard that discusses data exchange for meter reading, tariff and load control.
BS EN 62056-21 is the 21st part of BS EN 62056 series that 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.
Who is BS EN 62056-21 - Direct local data exchange for electricity metering for ?
BS EN 62056-21 on electricity metering for direct local data exchange is relevant to: 
- Electric supply meter, tariff an HHU device manufacturers
- Power distribution and transmission companies
- Personnel involved with meter reading, tariff and load control
- Utilities
- Local authorities
- Regulatory bodies
- Quality control and testing personnel
- Engineers
Why should you use BS EN 62056-21 - Direct local data exchange for electricity metering ?
The connection for electricity metering for direct local data exchange 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 mentioned in BS EN 62056-21 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.
BS EN 62056-21 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 mentioned in BS EN 62056-21 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.
BS EN 62056-21 provides best industry guidance on physical properties, charachter transmission and data transmission protocol. The protocol offers five alternative protocol modes, which can be used by the tariff device: A, B, C, D and E.
Thus, by complying with BS EN 62056-21 guidelines, you can ensure that the HHU play a posiitve role in data collection and transmission for accurate meter reading, tariff and load control.
