Default Header Format Obj.: Difference between revisions
No edit summary |
(add flowgraph) |
||
(One intermediate revision by one other user not shown) | |||
Line 29: | Line 29: | ||
; Payload Bits per Symbol | ; Payload Bits per Symbol | ||
: The number of bits | : The number of bits per symbol used in the payload's modulator. | ||
== Example Flowgraph == | == Example Flowgraph == | ||
[[File:Pkt_3_fg.png|800px]] | |||
== Source Files == | == Source Files == |
Latest revision as of 13:53, 12 November 2021
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 [1] for more info.
Parameters
- 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.
- Threshold
- 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.
Example Flowgraph
Source Files
- C++ files
- TODO
- Header files
- TODO
- Public header files
- TODO
- Block definition
- TODO