Default Header Format Obj.
Default header formatter for PDU formatting. Used to handle the default packet header.
See the parent class header_format_base for details of how these classes operate.
The default header created in this base class consists of an access code and the packet length. The length is encoded as a 16-bit value repeated twice:
| access code | hdr | payload |
Where the access code is <= 64 bits and hdr is:
| 0 -- 15 | 16 -- 31 | | pkt len | pkt len |
The access code and header are formatted for network byte order.
This header generator does not calculate or append a CRC to the packet. Use the CRC32 Async block for that before adding the header. The header's length will then measure the payload plus the CRC length (4 bytes for a CRC32).
The default header parser produces a PMT dictionary that contains the following keys. All formatter blocks MUST produce these two values in any dictionary.
See  for more info.
- Access Code
- An access code that is used to find and synchronize the start of a packet. Used in the parser and in other blocks like a corr_est block that helps trigger the receiver. Can be up to 64-bits long.
- How many bits can be wrong in the access code and still count as correct.
- Payload Bits per Symbol
- The number of bits per symbol used in the payload's modulator.
- C++ files
- Header files
- Public header files
- Block definition