Callsign converter
M17 address encoding reference
Character set
M17 uses a 40-character alphabet for its 48-bit (6-byte) addresses:
- Space (value 0, also used for invalid characters)
- A-Z (values 1-26)
- 0-9 (values 27-36)
- Special: hyphen (37), slash (38), dot (39)
Encoding process
- Callsigns encode backwards (last character to first)
- First character is in least significant bits
- Trailing spaces don't affect the encoded value
- Final address is in big endian (network byte order)
Address space
| Address range | Category | Notes |
|---|---|---|
| 0x000000000000 | INVALID | Forbidden |
| 0x000000000001 - 0xEE6B27FFFFFF | Codable | "A" to "........." (~262 trillion) |
| 0xEE6B28000000 - 0xFFFFFFFFFFFE | Uncodable | For application use (~19 trillion) |
| 0xFFFFFFFFFFFF | BROADCAST | Valid only for destination in RF |
Usage examples
Source addresses typically decode to amateur radio callsigns, while destination addresses often represent commands (e.g., ECHO, UNLINK) or reflector modules (e.g., M17-M17 C).