The SML messages are transmitted in several blocks as data telegrams. Each individual SML message and the complete SML frame arechecked with a cyclic block check(CRC-16). The message parts of a data block are prepared according to the Object Identification System( OBIS). They include the useful data such as the active powers, reactive powers, power peaks or other power values. The entire data block starts with the start sequence and ends with the end sequence.
The SML data transmission works with a low data rate between 300 bit/s and 9.6 kbit/s. They can be transmitted in an adjustable repetition sequence. The SML protocol uses the TCP protocol or the connectionless UDP protocol as transport protocol.