The standard specifies 4800 as the speed, but this is no longer common. The most significant bit is always zero. An NMEA sentence consists of a start delimiter, followed by a comma-separated sequence of fields, followed by the character '*' (ASCII 42), the checksum and an end-of-line marker.
The standardized bus speed is 250 bit/s bus speed. Protocol is based on J1939 (ISO11898 and ISO 11783). Physical Layer based on DeviceNet cables and Micro-C and Mini-C connectors.
