CSA Preface
This is the second edition of CSA C900.3, Heat meters - Part 3: Data exchange and interfaces, which is an adoption without modification of the identically titled CEN (European Committee for Standardization) Standard EN 1434-3 (second edition, 2008-10). It supersedes the previous edition published in 2006 as CSA C900.3 (adopted EN 1434-3:1997).
Scope
This European Standard applies to heat meters, that is to instruments intended for measuring the heat which, in a heat-exchange circuit, is absorbed or given up by a liquid called the energy-conveying liquid. The meter indicates heat in legal units.
Electrical safety requirements are not covered by this standard.
Part 3 specifies the data exchange between a meter and a readout device (POINT / POINT communication). For these applications using the optical readout head, the EN 62056-21 protocol is recommended.
For direct or remote local readout of a single or a few meters via a battery driven readout device, the physical layer of EN 13757-6 (local bus) is recommended.
For bigger networks with up to 250 meters, a master unit with AC mains supply according to EN 13757-2 is necessary to control the M-Bus. For these applications the physical and link layer of EN 13757-2 and the application layer of EN 13757-3 is required.
For wireless meter communications, EN 13757-4 describes several alternatives of walk/drive-by readout via a mobile station or by using stationary receivers or a network. Both unidirectionally and bidirectionally transmitting meters are supported by this standard.
